U-boat Archive - U-172 - Interrogation Report


	Copy No 47 of 47.
	S E C R E T
	Op-16-Z

	NAVY DEPARTMENT
	CHIEF OF NAVAL OPERTIONS
	WASHINGTON




	Final Report - G/Serial 29

	REPORT ON THE
	INTERROGATION OF SURVIVORS FROM U-172
	SUNK 13 DECEMBER 1943


	BAD
	BuOrd
	BuShips
	BuShips (Code 515)
	BuShips (Code 815)
	Cominch (F-21)
	Cominch (FX-40)
	Cominch (FX-43)
	Comnaveu
	DNI (Ottawa)
	G-2 (Col. Jones)
	Op-16-1 via Op-16-1-F
	Op-16-FA-4
	Op-16-P
	Op-16-W
	Op-16-1-V
	Op-20-G
	Op-30
	SONRD
	C.O., Naval Unit, Tracy, Calif.
	Lt. S. R. Hatton (CSDIC, AFHQ)
	Lt. (j.g.) R. J. Mullen (4th Fleet)
	Lt. Cdr. V. R. Taylor
	Lt. (j.g.) B. Tweedy (CSDIC, AFHQ)

	7 April 1944

	S E C R E T

S E C R E T

TABLE OF CONTENTS

			Page
CHAPTER	I.	INTRODUCTION	1

	II.	DETAILS OF U-172	2

	III.	TRPEDOES	11

	IV.	ARMAMENT	37

	V.	CREW OF U-172	41

	VI.	EARLY HISTORY OF U-172	44

	VII.	FIRST PATROL OF U-172	46

	VIII.	SECOND PATROL OF U-172	47

	IX.	THIRD PATROL OF U-172	52

	X.	FOURTH PATROL OF U-172	60

	XI.	FIFTH PATROL OF U-172	66

	XII.	SIXTH PATROL OF U-172	73

	XIII.	SINKING OF U-172	80

	XIV.	OTHER U-BOATS	89

	XV.	BASES	104

	XVI.	GENERAL REMARKS ON U-BOATS	111

	XVII.	SUBMERSIBLE SPEED BOATS	120

	XVIII.	GERMAN DESTROYERS	123

	XIX.	MISCELANEOUS	126

ANNEX		CREW LIST OF U-172 AND U.S. EQUIVALENTS OF GERMAN NAVAL RANKS

S E C R E T

LIST OF ILLUSTRATIONS

		Facing Page
Plate A	Plan of Superstructure of U-172		4

Plate 1	Listening Room on U-172		6

Plate 2	"Main" Short Wave Reciever		8

Plate 3	Multi-Unit Hydrophone Gear		10

Plate 4	T-5. German Acoustic Torpedo		22

Plate 5	Pistols (Pi-2) and (Pi-3)		34

Plate 6	Track Chart of 2nd Patrol		50

Plate 7	Track Chart of 3rd Patrol		58

Plate 8	Track Chart of 4th Patrol		64

Plate 9	Track Chart of 5th Patrol		70

Plate 10	Track Chart of 6th Patrol		78

Plate 11	Sketches of Walterboot		120

S E C R E T



S E C R E T

CHAPTER I. INTRODUCTION

U-172, a 750-ton U-boat commanded by Oberleutnant z. S.* Hermann Hoffman, was sunk 1221 Z, 13 December 1943 in 26⁰19’ N., 29⁰58’ N. by escorts of U.S.S. BOUGE and aircraft from BOUGE after a 27-hour action. She was on her sixth patrol.

Forty-six men – 4 officers, 14 petty officers, and 28 men of the crew of 59 were rescued by BOUGE’s escorts. They were landed in the UNITED STATES 29 December 1943. The following report is based upon the interrogation of these survivors and should be treated with the reserve due claims and statements made by prisoners of war who are security conscious and, for the most part, anxious to keep their opponents in the dark.

The interesting aspects of this report consist in the successful career of U-172, up to her last patrol, and the constant misfortune which pursued her after her original commander left her.

* For U.S.N. equivalents of German Navy Ranks, see Annex.













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CHAPTER II. DETAILS OF U-172

Although U-172 was a standard 750-ton U-boat, its principal details are enumerated below:

TONNAGE

750 tons.

TYPE

IX C.

BUILDING YARD

Deschimag, Bremen; yard number 1012.

FLOTILLA

10th, at Lorient.

F.P.N.

M-29596.

CALL LETTERS

U.H.D.

INSIGNIA

Figure of Neptune, clad in white, trident in one hand, drinking horn in other. Also flotilla insignia: U-boat within a cross.

PATRON

Dr. Goebbles.

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CONSTRUCTION

Fully welded pressure hull. Pressure hull plating 20-25 mm. thickness. Four pressure-proof bulkheads; one each fore and aft of Control Room, one aft of Bow Compartment and one forward of Stern Compartment. Five hatches: Conning Tower, Bow Compartment, Galley, Engine Room, Stern Compartment. Spacing between pressure hull and upper deck 50/60 cm. at exhaust pipe valve. Two usual periscopes. Bridge fairing was not armored and was shot through by aircraft fire at sinking. Three waterproof bulkheads: Forward and aft of Galley and between Diesel and Electric Motor Room.

DIVING

Extreme depth: Stated to have been 280 meters, but also stated capable of even greater depths.

Time: 14 meters in 30 seconds, 20 meters in 40 seconds.

MODIFIED BRIDGE STRUCTURE

A. Gun Platforms: Two, second being on same level as after part of Bridge.

B. “Air Raid Shelter”: An armored shelter of plate about 15 mm. thick, 1.5 meters high was built into the inboard bridge fairing on the starboard side just forward of the main induction. It accommodated 3 men and afforded good protection from M.G. fire at angle usual from aircraft. A smaller “shelter” for the C.O. was built into the bridge fairing on the port side. (5 and 6 on Plate A.)

C. The section of the Bridge forward of the periscope mounts was lowered 10 cm. to permit the twin 20 mm. guns to fire forward. (See X on Plate A.)

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ARMAMENT

1 – 105-mm. gun on forward deck.

1 – quadruple mount AA gun on Platform II, fitted with two armored shields.

2 – twin mount AA guns on Platform I.

4 – bow torpedo tubes.

2 – stern tubes.

S.B.T

Fitted, at after head.

PROPULSION

Two M.A.N. Diesels, 9 cylinder, 4 cycle, single acting. 2200 H.P. each with supercharging, bore 40 cm., stroke 46 cm. “KAPSEL” (position displacement) superchargers. Hand exhaust line valve grinding. M.A.N. (Sandner type) vibration dampers. Vee type 2-cylinder cooling water pumps driven from eccentric on crankshaft. Main clutches: Pneumatically actuated cone friction type.

Engine speeds:

Telegraph Speed	R.P.M.

K.F. (dead slow)	170

L.F. (slow)	240

H.F. (slow)	300

2 x H.F. (3/5)	390

G.F. (3/4)	415

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Telegraph Speed	R.P.M.

2 x G.F. (4/5)	445

A/K (full)	470

U-172 never used Diesels in tandem with motors/generators on the surface.

Two Siemens 500 H.P. motors/generators, 210 R.P.M. at A.K. (full speed).

BATTERIES

Hagen batteries, lead-acid type, 13,000 ampere hours capacity, inner rubber lining.

CONTROLS

Push button remote rudder and plane controls. Emergency hand gear for both.

AIR SUPPLY

Eight groups of flasks, 215 kg. per sq. cm. pressure.

PUMPS

Two usual ballast pumps (1 main and 1 auxiliary) in Control Room. One auxiliary pump in Bow Compartment. One auxiliary pump in Stern Compartment.

FUEL SUPPLY

230 to 240 cu. meters of 85 specific gravity Diesel oil.

RADIO ROOM

See Plate 1.

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S E C R E T

RADAR

Usual U-boat type with mattress aerial. Wavelength 80 cms. On back of mattress aerial were 2 figures of eight which could be used in place of the drum-shaped dipole-type aerial to get a bearing with the “Wanz” G.S.R. (See Op-16-Z Final Report G/28 for description of Radar set.)

R.D.B.

Fitted.

G.S.R.

1. Wanz-G2. This is a new and improved type of Wanz covering a wave band from 1.30 m. to 1.80 m. It is similar in all respects the Wanz-G1 except that it did not radiate. This set could be plugged in either to the drum-shaped dipole-type aerial or to the figure-8 array on the back of the Radar mattress.

2. Naxos. This was the small apparatus described in Op-16-Z Final Report G/28, which operated through the low frequency stage of the Radione to a loudspeaker. It was stated that within the Naxos itself there was an intermediate stage and an amplifier. The high frequency stage of the Radione is closed off. The prisoner believes that the frequency tuning takes place in the antenna itself, which consisted of a wooden rod about three feet long at the top of which was a metal container inside which, the prisoner believed, there was a condenser and possibly a coil. Projecting from this container at an angle of 45⁰ to the horizontal was a small

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copper tube on top of which was a bakelite screw. The prisoner had been warned under no conditions to turn this screw, as doing so would alter the frequency. This aerial had to be unshipped whenever the boat submerged. One spare was kept. The Naxos operated on a wavelength of 10 cm. only. The cable connecting the Naxos G.S.R. to its aerial contains a single thin lead. Part of this lead projects from the cable and is wound around a screw at the back of the Naxos.

3. Borkum. This was another very small box, similar in outward appearance to the Naxos, which covered a wavelength from 3 cm. to 3 m. It was connected to the drum-shaped dipole-type aerial. It was stated that the Borkum contained a detector, two condensers and one coil. It was plugged into the Naxos and signals received were, therefore, heard through the Radione on the loudspeaker. The connection between the Borkum and Naxos G.S.R. is by a single phase plug. When a signal was heard on the loud-speaker the operator would disconnect the Borkum from the aerial. If the signal was then still heard this was an indication that the transmission was on the 10 cm. wavelength for which the Naxos is tuned. Any transmissions heard on the Borkum and the Naxos G.S.R. were always intermittent, never continuous. It was claimed that neither the Borkum nor the Naxos gave off any radiation whatsoever.

4. Reserves. In addition to the Borkum G.S.R. fitted on U-172, five additional Borkum sets were carried for delivery to other boats. One of these was given to Burghagen when he supplied

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them on her last patrol.

RADIO EQUIPMENT

U-172 was fitted with the usual 200 Watt short wave transmitter for wavelengths from 20 to 80 meters and a 150 Watt long wave transmitter for wavelengths from 250 to 1500 meters, as well as a 40 Watt emergency short wave transmitter, by Lorenz.

A “Main” short wave receiver by Telefunken was fitted prior to the last patrol. The dials were graduated in kilocycles. (See Plate 2.) This set was fitted with 14 RV 12 P 2000 tubes and a fifteenth, larger, tube which has not been identified. This receiver was said to be most satisfactory and to be entirely free from radiation. An all-wave receiver by Telefunken, usual type.

The usual type of D/F gear (G/Serial 28), known as a “Heereslangwellenpeiler”. It was fitted for frequencies from 15 to 2500 kilocycles.

A broadcast receiver, type “Elak” 10/12. This had been disconnected and its use was forbidden on the last patrol because of the danger of radiation. A 40 Watt broadcast amplifier, for the various loud-speakers throughout the boat. This was used in connection with the record player in the listening room.

U.K. GEAR

U-172 was fitted with V/H/F (U.K.) gear just before leaving on her final patrol. A special converter for this gear was also fitted. She had, of course, been fitted with this gear during her

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trials, but this first equipment had been removed during the final refit, as is customary for U-boats proceeding on patrol. The V/H/F gear fitted for the last patrol was, however, different from the usual type, in that it was fitted with a standard telephone receiver and transmitter, identical with those in use on city telephone. None of the prisoners could give any explanation for the presence of this gear on board, its use on patrol being notoriously dangerous. It had never been used.

UNDERWATER TELEGRAPH

Fitted.

AIRCRAFT WARNING SYSTEM

A place for it was built in, but the instrument itself never was brought aboard; the assumption was that there was never one available.

ROTARY CONVERTERS

1 – 6 K.V.A. for transmitters.

1 – 1½ K.V.A. for depth sounding gear.

1 – 0.3 K.V.A. for U/T.

1 – special converter for the V/H/F mentioned above.

HYDROPHONES

G.H.G. (multi-unit hydrophones). “Atlas” type; not well thought of on U-172 (see Plate 3).

K.D.B. Useless on last patrol but left on after final overhaul at Kapitänleutnant Emmerman’s request.

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ECHOLOT

Fitted, “Atlas” type.

GYROS

Anschütz, Kiel. One master and five repeaters. One each in Conning Tower, Stern Compartment, Control, Listening Room, and on Bridge in water-tight container.

RUBBER BOATS (Schlauchboote)

U-172 carried five Schlauchboote:

One 3-meter raft (Originally for outboard motor) in pressure proof container forward.

One in Upper Deck stowage (Marx life-raft).

One in Upper Deck Head (port Conning Tower fairing).

One 4-meter raft in dinghy stowage (foremost part of water-tight stern).

One 3-meter raft in dinghy stowage.

Thirty one-man rubber life-rafts were carried inboard.

LIGHT BULBS

Before her last cruise U-172 was equipped with new electric bulbs that were designed to withstand all depth charging.

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CHAPTER III. TORPEDOES

TERMINOLOGY

Torpedo-room personnel on U-172 referred to torpedoes and pistols with the following designations:

T-1: Air-driven torpedo. Ato. G7a

T-2: Electric torpedo. Eto. G7e.

T-3: Electric torpedo with combination magnetic and impact firing. Eto. With MZ/AZ

T-4: Acoustic torpedo. Known only to the petty officer in charge. Never carried by U-172.

T-5: Newer acoustic torpedo. Two carried by U-172 on her last patrol.

FAT-1: Air-driven convoy torpedo with “Curly” course.

FAT-2: Electric convoy torpedo with “Curly” and circle settings (Note: Details given below).

AZ-Pistole: Pistol with impact firing for use in T-1 and T-2. Four-wiskered.

MZ/AZ-Pistole: Pistol with combination impact and magnetic firing (the latter at option). Two types: One for T-1, one for T-3. Four-wiskered.

Pi-4: Top-insertion pistol for use in T-5.

The petty officer was the only one who used the following designations for pistols:

Pi-1: Same as above. For T-1 and T-2.

Pi-2: MZ/AZ for T-3 (electric torpedo) only.

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Pi-3: MZ/AZ with dry cells attached for use in T-1 (air torpedo) only.

Pi-4: Inertia type used in T-4 and T-5.

An officer contributed further the information that Pi-4 has combination inertia and magnetic firing.

TORPEDO DETAILS OF FIRST FOUR PATROLS OF U-172

On her first, second, third, and fourth patrols, U-172 carried 23 torpedoes, stowed as follows:

4 in tubes in Bow Compartment.

2 on floor plates in Bow Compartment.

4 under floor plates in Bow Compartment.

2 in tubes in Stern Compartment.

3 on floor plates in Stern Compartment.

8 in Upper Deck Containers.

The 15 torpedoes carried in the boat were T-2 (electric). The eight carried in Upper Deck containers were T-1 (air torpedoes).

All were provided with impact firing pistols (AZ-Pistolen). On these four patrols, torpedoes were expended as follows:

1st – none
2nd – 22
3rd – 23
4th – 22

Although supplied at sea several times during these patrols, U-172 never took over torpedoes from other U-boats. On the second, third, and fourth patrols, all eight of the air torpedoes

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carried in the Upper Deck containers were lowered into the boat while at sea.

TORPEDO DETAILS OF THE FIFTH PATROL OF U-172

On her fifth patrol, U-172 carried two, or possibly three, torpedoes fewer than on previous patrols. Instead of eight in Upper Deck containers, only six were stowed there. These were all air torpedoes (T-1). There may also have been only nine torpedoes in the Bow Compartment instead of the usual ten. (O.N.I. Note: There was available for interrogation only one torpedo specialist who made this patrol. As his station had been moved to the Stern Compartment for this patrol, his memory was not clear as to what had been carried in the forward compartment.) Otherwise, torpedo storage was normal. All torpedoes in the boat were electric (T-2 and T-3). No FATs (convoy torpedoes) were carried.

On this patrol U-172 was for the first time provided with combination impact and magnetic firing pistols (MZ/AZ-Pistolen), some (less than half) of the electric torpedoes being T-3. There were no MZ/AZ pistols in reserve; three extra AZ pistols were carried.

It was stated that Emmermann gave instructions that the magnetic firing in all MZ/AZ pistols be switched off. It was felt by prisoners that, having been so successful in the past with only impact firing, he did not care to take chances with this innovation. At any rate, Emmermann never fired any torpedoes with MZ setting.

Although U-172 was supplied twice on this patrol, no torpedoes were taken over from another U-boat. The air torpedoes in

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Upper Deck containers were brought into the boat while at sea, all six in one transfer.

U-172 returned to base with five torpedoes remaining, having thus shot a total of 16 (or possibly 15) torpedoes.

TORPEDO DETAILS OF THE SIXTH AND LAST PATROL OF U-172

U-172 sailed from Lorient with five torpedoes less than the number she had carried on her first four cruises. These are accounted for as follows:

Only six in Upper Deck containers.

None in stern tubes.

Only two on floor plates in Stern Compartment. 20-mm. ammunition was stored on the floor in the place usually occupied by a third torpedo.

The stern tubes were left empty to receive two acoustic torpedoes (T-5) which could not be supplied at Lorient and had to be picked up at St. Nazaire.

On leaving St. Nazaire, U-172 had 20 torpedoes on board, stowed as follows:

In Bow Compartment:

Tube 1: T-3

Tube 2: T-3

Tube 3: T-1 FAT-1

Tube 4: T-3

Under floor plates: One T-1 FAT-1 and three T-3s



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On floor plates: Two T-3s

In Stern Compartment:

Tube 5: T-5

Tube 6: T-5

On floor plates: Two T-3 FAT-2

In Upper Deck containers:

Six air torpedoes

The FAT-2s were fitted with MZ/AZ pistols, the T-5s with Pi-4. Two reserve MZ/AZ pistols were carried in the Stern Compartment. The T-3s were fitted with MZ/AZ pistols (Pi-2) and the FAT-1s with MZ/AZ pistols (Pi-3).

When U-172 had safely passed the Biscay area, the T-5 in tube 5 was unloaded and one of the FAT-2s was put in its place.

Only one torpedo was fired during U-172’s final patrol. This was the T-5 in tube 6. It was fired from the surface at a destroyer, firing angle 180 degrees (i.e., straight out from stern tube), depth setting 4 meters, range somewhat under 4000 meters. The torpedo failed to hit. The torpedo petty officer explained this failure as being the result of some damage to the acoustic mechanism sustained during the depth-charge just previous. He blamed the Captain for an error in judgment, stating that the acoustic torpedo should not have been presumed to be undamaged. He added that, if the FAT-2 in tube 5 had been fired instead, the destroyer would, in his opinion, definitely have been sunk (See also Chapter XIII).

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ACOUSTIC TORPEDO (T-5) CARRIED BY U-172

The torpedo petty officer received some instruction in both types of German acoustic torpedo, namely T-4 and T-5. (O.N.I. Note: A description of T-4 is given on OP-16-Z Final Report G/Serial 27 on U-664, pages 26-48). As part of the regular course for torpedo petty officers, given in Flensburg, he was taught what he needed to know in order properly to service T-4. He was shown no models, plans, or track charts, and did not take part in a “Spatz” test.

He received his instruction in T-5 about 9 November 1943 at the 10th flotilla base, Lorient. This consisted of a lecture lasting about three hours. His teacher was a torpedoman regularly attached to the flotilla. The prisoner was shown a longitudinal section of T-5 (reproduced from memory on Plate 4, marked A) and a track chart (marked E on Plate 4). He was also present at the “Spatz” test made on the two torpedoes taken aboard U-172. This test was made at St. Nazaire about 20 November 1943. (Details are given below.)

The following is a summary of this petty officer’s statement on T-5:

T-5 is simply an improved version of T-4, principal differences being increased speed and improved steering mechanism. It is electrically propelled and has a speed of 24½ knots constant. It has the same dimensions as T-4, length overall being equal to the length of the ordinary electric torpedo with pistol fitted.

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T-5 has two two-bladed propellers with provision for silent operation. A special oil, said to be heavier than water, is used. A reserve supply of this oil is carried on board to keep torpedo oil chamber full.

Depth settings are 0 to 12 meters. Depth is not acoustically controlled. T-5 uses the same pistol as T-4, i.e., Pi-4 (further discussion below, in connection with Plate 4).

The torpedo has no temperature limitations nor any self-destroying device. The torpedo will sink when exhausted . It is ejected from the tube in the same manner as any ordinary torpedo.

T-5 has the following settings:

SS - acoustic gear cut out. Torpedo will operate like an ordinary electric torpedo.

WS - said to be used against an escort vessel approaching the U-boat.

NS - said to be used against a target not on course approaching the U-boat.

L/O - setting for charging.

The impeller has three blades of hard rubber.

T-5 has one battery with 34 cells. Normal voltage is 75-80. The battery is like the normal battery of the German electric torpedo, simply having additional cells and being, therefore, somewhat longer.

Loading procedure is as follows:

The torpedo arrives with a protecting hood or cover which is not removed until the torpedo is

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actually ready to go into the tube. The hood is held on by an arrangement of springs and clasps. When the torpedo has been safely lowered into the boat and is ready to be loaded into the tube, the pistol is inserted. Then the G-switch is turned from L/O to SS. The prisoner believed this to be a safety measure, but could give no adequate explanation of the nature of protection thus afforded. The torpedo is put into the tube, then the key is again inserted, through the tube, and setting WS is made. Depth is then set to 4 meters. This latter, the prisoner states, is at the discretion of the Captain, who in the case of U-172 set for 4 meters.

When the torpedo has left the tube and is heading for the target, its behavior is as follows, as nearly as the prisoner was able to describe it:

Two solenoids, one starboard and one port, are situated aft over the gyro. When one of the solenoids is activated, the jet pipe is moved to one side, as in T-4, directing the air into one side of the air steering mechanism. By this means the rudder is immediately (No delay mechanism) forced hard over (by air, not directly by magnetic action) to starboard or port. The heading of the torpedo is heading directly for the area of most concentrated sound, whereupon the rudder returns to mid-

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position. The alternation between mid-position and hard-over position was described as taking place constantly and continuously from the time that the acoustic apparatus first picks up sound. This results in an oscillating motion of the rudder. The prisoner was unable to explain the exact mechanical and electrical activity involved here, as it was explained to him only in general terms.

The torpedo moves onward to the center of noise. It comes to the propellers of the target, or to their immediate vicinity, passes under the propellers (having been set sufficiently deep to do this), then turns with rudder hard over and strikes the side of the ship (O.N.I. Note: Other sources (see below) indicate that the torpedo does not strike the ship, but detonates magnetically under it).

The torpedo responds to any and all noises, the prisoner specifically mentioning propeller noises, engine noises, accidental noises produced on board, etc.

Rudder-throw is always hard over, 12 to 12.5 degrees to port or starboard.

The torpedo is fired on a collision course like any ordinary torpedo. It can be angled in normal fashion.

The prisoner had no factual knowledge on the effect of noisemakers on this torpedo. When hypothetical cases were presented

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to him, he described what he thought must happen in accordance with the characteristics of the torpedo. A series of noisemakers, he said, would conceivably lead the torpedo eventually to the ship, unless the ship stopped its engines and all noises were stopped. In the diagram below, for example, the torpedo would be attracted by noise a, head for it, turn when just past it; at b it would strike nothing, but hear c, turn again, hit nothing at d but near e, turn and strike the ship at f. The prisoner also admitted the possibility that the noisemakers might be so placed as to cause the torpedo to double back and exhaust itself describing figure 8’s.



A noisemaker making only intermittent noises would, he thought, be effective in luring the torpedo back after it had passed on, providing that the sound of the noisemaker was louder than any other sound in the vicinity.

Each T-5 carried by U-172 was tested twice with the “Spatz” box, once on setting NS and once on setting WS. This operation was carried out on land at St. Nazaire. The whole operation took only a very few minutes. The “Spatz” box produced supersonic noises. Each test started with the box at zero degrees (i.e., directly in front of the nose of the torpedo). The box was then moved to 90 degrees right, then back to zero, to 90 degrees left, and back to zero. The rudder was thrown hard right at the moment the box left the zero degree position. It remained hard right as the box was

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moved to 90 degrees right and back approaching zero. When the box arrived again at zero degrees position, the rudder snapped back at once to mid-position. Then the box was moved left, the same sequence of events (left instead of right) resulting. The rudder went to amidships position at the moment a pause was made at zero degrees position in front of the nose. Such a pause was always made at this position.

At the conclusion of this test, the prisoner made a few experiments of his own. A snap of the fingers or the lighting of a cigarette-lighter caused rudder to go hard over on the side on which the noise occurred. The rudder returned immediately to mid-position if no further noise was made.

Although only two T-5’s were carried on U-172, both in stern tubes (tubes 5 and 6), two of the bow tubes (1 and 3) in addition could have T-5s if desired. The prisoner explained that two extra holes have to be bored in the setting shaft, as the lever is harder to turn than is the case for making ordinary speed settings for air torpedoes. This had been done to both stern tubes and two of the tubes in the Bow Compartment.

Forty meters is considered a safe depth for a U-boat to dive to after firing a T-5 or after receiving warning that another U-boat in the vicinity has fired a T-5. U-boats always submerge after firing a T-5, and a T-5 warning is supposed to be signaled if other U-boats are in the vicinity. U-172, after firing T-5, went much deeper than 40 meters and did not give a T-5 warning.

T-5 begins to circle when, having been drawn toward a

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noise, the sounds are removed. In the prisoner’s own words: “When the destroyer is moving away at a speed too great for the torpedo to overtake it, and the torpedo gets outside of the radius of sound, the torpedo will begin to circle.” (O.N.I. Note: This is true only when the torpedo is on WS setting.)

The only prescribed depth setting the prisoner can remember from his lecture is as follows: When T-5 is used in an attack on an aircraft carrier, the depth setting should be 10 meters.

EXPLAINATIONS AND NOTES FOR PLATE 4

A shows a longitudinal section of T-5 with nose like that used on T-4. (Note: This is NOT the type nose on T-5s carried by U-172.) The liquid was described as being “glycerin or something similar.” This longitudinal section is the prisoner’s reconstruction of the section shown him in Lorient. It will be noted that the prisoner was shown no details of wiring, nor was the purpose of the rectangles marked “possibly transformers” explained to him. (O.N.I. Note: These “transformers” were on several occasions stated by the prisoner to look “like condensers”. He had not used the term “transformer” previous to putting it on the drawing.)

B shows the warhead of the T-5 carried by U-172. A T-5 with either type of nose is delivered to the U-boat with the metal protective hood attached as explained above.

B 1 shows a protective covering of wood, held in place by two screws fitting into the holes B 3. When the torpedo is

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about to be loaded into the tube, this wooden covering is removed. The two holes remain open and must be kept clear of any accumulation of dirt or grease. As the torpedo, after being fired, moves through the water, seawater enters through the holes and, the prisoner was told, combines with some chemical inside to produce the glycerin-like fluid mentioned above.

The prisoner does not know the purpose of the “bright metal parts” marked B 2. They are unpainted and are flush with the rest of the surrounding surface, which is painted gray. Their dimensions are as follows.

15 mm. width of each

65-70 mm. length of each

15 mm. space between (in each case)

150 mm. diameter of nose

75 mm. distance from inside of one outer “part” to inside of the other outer “part”.

(O.N.I. Note: These are believed to be microphones. See below.)

The tail piece has a winding of wire covered with asphalt (at C). This is visible, but on newer types is believed to have been put inside. The only explanation given the prisoner of the purpose of this was that “if the target produces a positive field, the torpedo will take a negative field, and vice versa, through the action of this winding”.

The rudder of T-5 is one and a half times the size of the rudder of an ordinary electric torpedo. Estimated dimensions:

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19 cm. long, 3 cm. wide, 4 mm. thick. The rudder is painted red.

D shows as much of the pistol as the prisoner has actually seen, and as nearly as possible to scale.

The pistol has a safety device to prevent any possibility of a hot runner. The safety pin holds the impeller and prevents it from turning until the torpedo leaves the tube. Immediately above D, in SECTION A”, a small safety lever will be seen. When the torpedo has left the tube, water pressure will force this lever back. This will cause the safety mechanism in D to be fed with a current of 4 volts. This causes the safety pin to drop back and release the impeller, which water pressure causes to turn. As the impeller turns, the primer is gradually lowered to a point close to the firing pins. The pistol is then armed. This occurs in the time it takes the torpedo to run 150 meters.

E is a reproduction of the track chart shown to the prisoner in Lorient. He admits that there is no real difference of behavior apparent here and does not himself completely understand what the chart is meant to show.

FURTHER DETAILS ON T-5

An officer prisoner was able to add certain facts which were unknown to the petty officer. His statements are as follows:

The range of the T-5 is guaranteed by the manufacturer up to 5400 meters. It is claimed that on trials T-5s have run up to 11,000 meters.

T-5 is always fired on a calculated collision course.

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The best bearings are 0 to 10 degrees and 170 to 180 degrees.

The pistol is armed after a run of 500 meters. The acoustic mechanism becomes receptive to sound after a run of 500 meters. The acoustic mechanism is switched on by a device which is actuated after the driving shaft of the propeller has performed the required number of revolutions to propel the torpedo 500 meters.

The prisoner could give no definite answer to the question of how far from the target the acoustic mechanism can hear. He stated that on trials, in one instance, he had seen the torpedo turn toward the noise of the propellers of the target ship at a distance of approximately 1000 meters.

There are no prescribed depth settings for given targets. The prisoner stated, however, that for a destroyer he would set a T-5 at 4 meters; for a CVE, at 6 to 7 meters; and for a loaded merchantman of 7000 to 8000 tons, at 8 meters. Obviously a depth setting would depend on the draft of the target.

The pistol has combination inertia and magnetic firing, and is guaranteed by the manufacturer to explode at a depth of as much as 6 meters under the keel of the target.

Tactics to avoid being hit by one’s own torpedo are to crash dive immediately after firing to a depth not less than 30 meters. The maximum delay compatible with safety for such a crash dive would be 30 seconds, but it is customary to dive immediately. If a U-boat were unable to dive after firing a T-5, she would proceed on opposite course on both Diesels, starting with 2 minutes

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at slowest speed and gradually increasing speed every 2 minutes until full speed had been attained after 12 minutes. He stated that these tactics had been tested at the trials and found satisfactory.

If other U-boats are in the vicinity, but only if they are within the possible line of fire, the short signal used for FAT-warning, with the true bearing of the shot to be fired, is sent. The other U-boat would then either stop, get out of the way, or dive to a safe depth, which he stated to be 35 or 40 meters.

The trials which the prisoner attended took place at Gotenhafen in the first week of November, 1943. The U-boat used was U-534, commanded by Kapitänleutnant Herbert Nollau. The target ship was T-26, a new torpedo boat with one funnel, built at Elbing, 600 tons, maximum speed 34 to 38 knots, draft 2½ meters. The observers, including the prisoner, were aboard the torpedo boat and the torpedoes were fitted with a light in the head. Speeds of the target ship were 13, 16, and 18 knots. Five or six torpedoes were shot on each trial, bearing 0, 10, 170, and 180 degrees; distance from the target was 3000 to 4000 meters. One torpedo was shot at 1500 meters. Depth setting on the trials was 5 to 6 meters. No noisemakers were used and the observers were told that these had been tested and found to be useless. The prisoner was also told that stopping the target ship would not prevent the torpedo from finding it since, in the case of an NS setting (see below), the torpedo would continue in the direction of the original gyro setting

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and would then eventually pick up the noise of ventilators and other auxiliary machinery. In the case of a WS setting (see below), it would begin to circle with the same eventual result. The diameter of the circle on WS setting was said to be approximately 90 meters. The prisoner was told that the only escape from a T-5 was an instant increase to a speed sufficient to get away from the torpedo. Whereas the torpedo has an actual speed of 24½ knots, the prisoner estimated its rate of advance at 16 to 18 knots because of its “snaking” course (see below).

The purpose of the winding on the afterbody (now put inside the torpedo, not outside as formerly and as shown in drawing) is to create a magnetic field. The prisoner was positive that this would counteract any degaussing devices. In fact, he stated that any demagnetizing countermeasure would be useless since no two torpedoes had the same number of windings. The prisoner was asked whether a noisemaker of sufficient size and at sufficient depth would be able to explode the torpedo. He was positive that it would not, because the impact would be insufficient to detonate the inertial pistol and the magnetic field would be insufficient to detonate the pistol magnetically. He stated in this connection that the inertia firing of the pistol was not guaranteed by the manufacturer, whereas the magnetic firing was guaranteed to 6 meters below the keel of the target.

In view of the present scarcity of T-5s, U-boats are instructed to use them only against destroyers as a defensive weapon.

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The nose as shown at B in Plate 4 was stated to be the newer type.

NS setting was stated to be “NACHSCHUSS”. This setting is used for firing at a target moving away from the U-boat. If the torpedo loses acoustic contact while on NS setting, it returns to the original gyro course. It continues under gyro control until the torpedo is exhausted or picks up new sounds.

WS was stated to mean “WIDERSCHUSS’. This setting is used against an approaching target. A T-5 with this setting which loses acoustic contact will circle in the direction in which it last heard sound until it picks up another sound or becomes exhausted. A relay keeps the rudder hard over in the direction in which the sound was last heard.

T-5 can hear in an arc of 45 degrees to each side of a point directly in front of the nose.

T-5 has a rudder somewhat larger than other torpedoes which run at higher speeds. The rudder is constantly in motion and does not check itself but always reacts to that side from which it hears a sound.

The prisoner could give no definite information as to the acoustic range on ships at various speeds since, of course, this depends on many factors such as speed of target, size of propeller, etc. He believes, however, that a T-5 would hear a destroyer proceeding at 15 knots at a range between 1000 and 1500 meters; other ships and other speeds in proportion. Furthermore, with new type nose which admits seawater, the sensitivity

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would be affected by such factors as temperature and density of the water.

The “Bright metal parts” at B on Plate 4 are of “Vibrating metal” which covers microphones. There are four of these, as shown. The visible dimensions of these microphones are 50 mm. long by 15 mm. wide. The distance between each pair is 15 mm. in all cases. The diameter of the nose is 150 mm. Everything forward of the first vertical line shown in the drawing is of bronze, painted gray.

The prisoner believes that the winding on the afterbody is constantly fed with current. This has some connection with the magnetic firing mechanism in the pistol. The whole torpedo is not magnetized by this winding, he thinks.

The magnetic firing of the torpedo is situated in the small square inside the pendulum (see D on Plate 4).

When asked if he could mention anything in Plate 4 that was incorrect, the prisoner stated that the winding is too far aft (it should be over the gyro) and that the tail should be longer (the seam should, therefore, be somewhat forward of where it is indicated). The lower part of the rudder is also smaller than the upper part.

The prisoner believes that no cotton-wool or other stuffing is used to absorb excess noise (as has been suggested by other sources).

The lane made by T-5’s wriggling progress through the water

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was stated to be about 40 meters wide:


However, as the torpedo gets nearer to the center of the noise, the curves flatten out, with corresponding lessening of the width of the lane:


On reaching the immediate vicinity of the noise source, the torpedo will turn sharply and explode beneath the ship, somewhere within the after third of the ship.

The torpedo’s actual rate of progress through the water is 16 to 18 knots. As the torpedo gets nearer to the center of noise, however, the curves flatten out (as above) with corresponding increase in actual rate of forward movement.

T-5 can hear within an arc of 90 degrees, i.e., 45 degrees on each side of the nose. In spite of the torpedo’s wriggling course, it rarely happens that the torpedo is thrown so far over as to lose acoustic contact on the side nearest the noise source.

The prisoner confirmed that the rudder has only three positions, hard over right, hard over left, and amidships position (no intermediate positions).

A 500-tonner operating in the North Atlantic would normally be equipped with 4 T-5s, a 750-tonner would carry 4 to 6. As more T-5s become available it is the intention to equip U-boats

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almost exclusively with this type. The prisoner thought that by April 1944 sufficient T-5s would be available.

Future developments which may be expected are as follows: Progress is being made toward obtaining higher speeds. One of the main disadvantages that the Germans are trying to overcome is that the rudder throw is too hard. This tends to reduce the rate of advance, causes the torpedo to use up its running time in excessive curves and may even through it so far out that it loses the sound of the target and fails to pick it up again. It is also the opinion of the prisoner that the size of the arc through which the torpedo can hear will be increased.

CONVOY TORPEDOES (FAT-1 and FAT-2)

The torpedo petty officer, while taking the regular course of training at Flensburg from 29 March to 28 June 1943 was told the following facts about convoy torpedoes:

FAT-1 – Air-propelled, always. Has three speeds (30, 40, and 44 knots), but is shot with only 30 and 40 knots—and practically always with 30 knots. Initial straight run settings from 1 to 150 hektometers (0.1 to 15 kilometers). Depth settings 0 to 12 meters. Two propellers with either 4 or 6 blades. Arming distance, 150 meters. Rudder throw is 13.5 to 14 degrees port and starboard. Rudder always hard over on all turns. Uses impact pistol (Pi-1) or combined impact-magnetic pistol specially constructed for air torpedoes. Courses designated:

Schleife rechts lang (long leg to right)

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Schleife links lang (long leg to left)

Schleife rechts kurtz (short leg to right)

Schleife links kurtz (short leg to left)

The prisoner does not know the length of the legs for any of these settings, but states that with any given setting the length of leg is constant. The torpedo always advances on its “Curly” course at an angle of 90 degrees to the initial straight run. (O.N.I. Note: The officer prisoner stated that the long legs are 150 m., the short legs 80 to 90 m. Diameter of turning semicircle 90 meters.)

FAT-2 – Electrically propelled, always. Has a range of 5000 meters at 30 knots. Initial straight run settings from 1 to 150 hektometers, i.e., the same dials and setting gear are used as in FAT-1. The FAT-2 will not, of course, run farther than its endurance limit of 5000 meters (50 hektometers). Depth settings 0 to 12 meters. Two two-bladed propellers. Arming distance 150 meters. Uses combined impact-magnetic pistol (Pi-2). Course designations same as in FAT-1, but the actual course of the torpedo differs as noted:

Schleife rechts lang gives long leg to right.

Schleife links lang gives CIRCLE TO LEFT with rudder hard over.

Schleife rechts kurtz gives short leg to right

Schleife links kurtz gives CIRCLE TO LEFT with rudder hard over.

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(O.N.I. Note: Reports from other sources indicate that Schleife links lang gives long leg left (NOT circle) and that Schleife rechts kurtz gives circle LEFT (NOT short leg to the right). In other words, other prisoners have stated that it is the SHORT settings which cause circles. This prisoner insists that it is the LEFT settings which cause circles. In any case, there are two “Curly” settings and two circle settings. THE CIRCLE IS ALWAYS TO THE LEFT and has the same diameter with either of the two possible circle settings.)

The circle is always with rudder hard over. Rudder-throw is 12 to 12.5 degrees. When on circle setting the torpedo begins to circle at the end of the pre-set initial straight run. The circle remains on the same spot. The torpedo continues to circle until exhausted.

FAT-2 can be used against a ship proceeding alone, or against an escort vessel. Its maximum run is considered insufficient for use against a convoy. For this purpose a FAT-1 would be used.

The torpedo at rest in the tube is on setting Schleife rechts lang (long leg to right), 150 hektometers initial straight run.

GERMAN TORPEDO PISTOLS. NOTES FOR PLATE 5

Plate 5 was made by the same prisoner who furnished the above information on FATs.

A shows the pistol (Pi-3) with combination impact and

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magnetic firing (the latter at option) for use in air torpedoes (T-1).

The current for magnetic firing is supplied by 5 or 6 dry cells attached to the rest of the pistol. It was stated that this pistol is delivered on board the U-boat with the dry cells attached, never separate. The war head of the T-1 has been modified to the extent of increasing the depth of the pistol insert so as to accommodate the added length represented by the dry cells.

B shows the pistol (Pi-2) with combination impact and magnetic firing (the latter at option) for use in electric torpedoes (T-3 only).

The current for magnetic firing is supplied from the battery via the contact shown. It will be noted that this pistol is the same length as Pi-3 (at A) minus the dry cells.

In both pistols, magnetic firing may be cut out by using a setting-spindle in one of the holes at P. (Another of the holes is used for testing. Purpose of the other two holes is unknown.)

Both pistols are four whiskered.

MISCELLANEOUS TORPEDO DATA APPLYING TO U-172

1. As nearly as prisoners could remember, U-172 had four hot runners in all her six patrols. The first occurred on the second patrol during the attack on SANTA RITA. On this occasion, an air torpedo in tube 4 (Bow Compartment) failed to leave the tube. It was belatedly ejected by means of additional air pressure. Two hot runners were experienced on the third patrol, one in tube 2 and

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one in tube 4. The fourth hot runner was on the last patrol not long before the sinking. Prisoners stated that somehow sea water got into the battery of the electric torpedo in tube 2. It was impossible to eject the torpedo from the tube because of damage sustained in depth charge attack. Pressure in the tube rose rapidly, and it was necessary to vent the gasses inboard. When the U-boat finally surfaced again, pressure in tube 2 was 10 kilos.

2. At the time of the sinking an unusual procedure was necessitated by the fact that it was found that there was not enough air in the bottles to bring the U-boat to the surface. Air was bled into the bottles from the air chamber of the air torpedo (FAT-1) in the bilge. This provided just enough air to enable the boat to surface.

3. Pressures for ejecting torpedoes on U-172 were stated to be 11 atmospheres from the surface, and 17 atmospheres from periscope depth.

4. After U-172’s fourth patrol, an angle-of-impact switch was built into the torpedo data computer. This was stated to help in the elimination of errors in firing. (For details of this switch, see Op-16-Z Final Report G/Serial 28 on U-841, page 24.)

GENERAL REMARKS ON TORPEDOES

1. Torpedo-room personnel spoke of having heard that there are U-boats now operating which are fitted with steel torpedo tubes. One rating had seen in December 1942 at St. Nazaire a 500-tonner in which the stern tube was of steel.

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2. One prisoner stated that T-3 identification markings are as follows: Either a green cross or two green strokes painted on the afterbody of the torpedo.

3. Torpedo-room personnel knew nothing of Radar-controlled or Radio-controlled firing of torpedoes from U-boats, but considered both “not impossible”.

4. The torpedo petty officer mentioned having heard of experiments being made in Lake Constance with torpedoes capable of greatly increased speed (55-60 knots). He added that it was planned to continue the torpedo series as far as T-10. Another prisoner mentioned that T-6 and T-7 are now being perfected.

5. It was stated that German electric torpedoes are guaranteed by the manufacturer for 120 days, provided that they are regularly recharged every three days as prescribed.

6. It was stated that torpedoes with the new gear permitting depth-settings to 15 meters are not yet operational. The present settings for all torpedoes are 0 to 12 meters.

7. Cover names:

Falke (Falcon) – T-4

Zaunköning (Wren) – T-5

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CHAPTER IV. ARMAMENT

ARMAMENT OF U-172 ON HER VARIOUS PATROLS

First Patrol - One 105-mm. forward of Conning Tower.
One 20-mm. on Platform abaft the Bridge.
37-mm. (old type) aft.

Second and Third Patrols - Same as first patrol.

Fourth Patrol - One 105-mm. forward of the Conning Tower.
Two 20-mm. on Platform abaft the Bridge.
Machine guns on the Bridge.
37-mm. (old type) aft.

Fifth Patrol - Same as fourth patrol.

Sixth Patrol - One 105-mm. forward of Conning Tower.
Two twin 20-mm. on Platform I.
One quadruple 20-mm. on Platform II.
Two twin MG 81 and two MG 34 on Bridge.

DETAILS OF VARIOUS GUNS, AMMUNITION, AND STOWAGE

105 mm. – On U-172’s last patrol, 90 rounds of 105-mm. ammunition were carried, of which 36 rounds were stored in containers on upper deck. Only one kind of ammunition for this gun was carried. It was called Zonenmunition, consisting of H.E./A.A. shells. The projectiles had red marking. The fuze was not set in advance, but would have been set as the projectiles were about to be used. Ready-use locker was abaft the gun. The cover of the locker was

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hinged at the sides and opened in the middle. It held four rows of nine shells each in steel containers. U-172 never fired any of this new 105 mm. ammunition.

This ammunition has a pointed head. The shell is said to have a muzzle velocity of 1,200 meters per second as against 900 meters for the old type. The explosive power of the shell is said to be 8 times that of the old kind. The point of the shell is made of lead and its effect on the type of armor plate in use on Wellingtons and Liberators is said to be amazing. The prisoner who gave this information had seen tests carried out on the captured wrecks of Wellingtons and Liberators at 2,000 meters. The ammunition is distinguished by the death’s head painted on the shell. The very powerful explosive, which is a liquid glycerin derivative (he is not quite certain on its being a liquid), is a new invention of the I.G. Farben at Cheminitz.

Although the 105-mm. gun could be used as an A.A. gun, elevation was stated to be not over 65 degrees. The gun had to be depressed after each shot for loading.

On patrols other than the last, armor-piercing projectiles with time fuze and impact detonation were provided, as were also incendiary shells with impact detonation. On the third patrol this ammunition was used in the 105-mm. gun against two aircraft which were attempting to attack. (The planes were successfully driven off by combined fire from all of U-172’s deck guns.)

20-mm. twin mounts. – The twin 20-mm. guns could fire over the bridge forward at a minimum elevation of about 20 degrees. There

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were no armored shields for these guns.

The magazine inserts for the twin mounts were so arranged that only one man was necessary for loading the two guns. The gun on the left received the magazine from above, the other from the right side.

20-mm. quadruple mount. – The quadruple mount is “toed” in so that the fire concentrates at 2,000 meters. This cannot be regulated on board but is determined in the construction of the gun. Fire is opened at 2,000 meters. Ammunition is self-destroying at 2,500 meters.

Prisoners stated that the newest type of 20-mm. quadruple mount is a new Hanomag gun capable of being elevated and trained by one man. This type was not carried aboard U-172.

Armored shields for U-172’s 20-mm. quadruple mounts were of a thickness varying from a minimum of 8 mm. to a maximum of 16 to 18 mm.

U-172 carried 80,000 rounds of 20-mm. ammunition. Extra stowage space was provided by the omission of one of the torpedoes usually carried in the Stern Compartment. In its place 20-mm. ammunition was stored.

Clips for the 20-mm. guns could be rapidly and efficiently loaded by a “magazine filling machine”. This apparatus, which first began to be supplied to U-boats in the summer of 1943, can be used only for 20-mm. ammunition. It is a simple mechanical device. Shells are fed in the top, a lever is moved back and forth, and the magazine is filled very quickly. U-172 carried two of these. Loading sequence

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was one H.E. with tracer and one A.P. with tracer, alternately.

H.E. shells were blunt-nosed and had yellow marking with red stripe. A.P. shells had pointed nose, blue markings. Both types had tracer. No other 20-mm. ammunition was carried. Ready use ammunition containers on Platform I and II were all round with screw tops.

MISCELLANEOUS

Six of U-172’s crew were sent to Mimizan during the interval between the fifth and sixth patrols to take a week’s course in anti-aircraft gunnery. They had instruction in 20-mm. and M.G. 81. Each man stripped down and reassembled both types of gun at least once, and each had practice shooting at a towed sleeve. They were told that in actual combat they should shoot at the motors of attacking aircraft.

During the overhaul period before the final patrol, yard authorities took it upon themselves to remove the 105-mm. gun and mount in its place an old type 37-mm. gun. As Emmermann had left the boat and Hoffmann had not yet taken over, the executive officer, Oberleutnant Coreth, was in charge. He objected so strenuously to the procedure that the 105-mm. was replaced.

Prisoners stated further that if U-172 had returned safely from her sixth patrol she would have received a 37-mm. gun of the new type. This would have been mounted on Platform II in place of the quadruple 20-mm.

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CHAPTER V. CREW OF U-172

OFFICERS

(A list of the officers on each patrol is given in the pertinent chapter.)

The captain of U-172 on her last patrol was Oberleutnant z. S. Herman Hoffmann who, as Executive Officer on Patrols 4 and 5, was a Leutnant z. S. and as Second Watch Officer on the first 3 patrols, was an Oberfähnrich. The former, original Captain, Kapitänleutnant Carl Emmermann considered him a good Watch Officer and Executive, but once said that he could never make a ships captain. It would appear that Emmermann’s estimate was correct. Hoffmann was thoroughly disliked by his officers and crew. He was not skillful in handling either boat or men. There was not a single voice in his support among the prisoners from his command, although a few of the toughest declined any comment.

Oberleutnant Maximilian Coreth, the Executive Officer, who joined U-172 between the fifth and the last, is a member of a titled Austrian family. He joined the German Navy directly after the Germans took over his country in 1938. Part of his duties at Lorient before joining U-172 seem to have been connected with the salvaging of the U-boat which struck a mine in Lorient and broke in two (O.N.I. Note: This was U-526 under Kapitänleutnant Möglich). Coreth was not held in high esteem by the crew.

Leutnant z. S. Friedrich Wilhelm Heitz was the Second

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Watch Officer. He joined U-172 in St. Nazaire to replace Leutnant z. S. Heinz Rietdorf who had come aboard in Lorient but proved to be totally inept. The latter was said to have been sent to the Training Flotilla in Pillau. Heitz was not much better than his predecessor and was not at all popular on board.

The Engineer Officer, Leutnant (Ing.) Alfred Loeffler was a promotion from the Engine Room force and the only well-liked and respected officer on board.

Little could be ascertained about the Medical Officer on board. His family name was Vole, his rank was Oberassistenzarzt. He was acceptable to most of the personnel, but not especially well-liked.

The Naval Correspondent was a gunnery specialist, stated by one man to be a Coast Artillery Officer. He was said to be able to talk French and English. It was also claimed that he trained the gun crews and had the rating of Gunner’s Mate 3c.

The crew was a composite group. The warrant officers and C.P.O.s were hard, tight-lipped old hands, some of them enthusiastically and thoroughly convinced Nazis. Several were abysmally stupid with no apparent ability in their own specialty. Others were extraordinarily fine types.

Security consciousness on the part of the lower petty officers and enlisted men was much less marked. Many were new hands at U-boat work, others were raw recruits, and several had been broken to Apprentice Seaman for various offenses.

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A note-book, a list of sinkings and the active, positive cooperation of a few prisoners eventually enabled the compilation of this report. The morale of the boat on this last patrol was anything but desirable.
















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CHAPTER VI. EARLY HISTORY OF U-172

It is not known when U-172 was laid down. She was launched before mid-September 1941. Among the survivors were several men who arrived in Bremen at this time to stand by the U-boat during the final phases of construction; U-172 was already in the water when they came to the Deschimag yard (at the latest, before 4 October 1941).

The commissioning is believed to have taken place 5 November 1941.

Leaving Bremen in mid-November, she proceeded through the Kaiser Wilhelm Canal to Kiel, where the customary U.A.K. (U-boats Acceptance Command) tests were conducted in a period of 10 days. Upon leaving Kiel, U-172 was assigned for the duration of her trials to the 4th Flotilla based at Stettin.

U-172’s trials were run off without incident. She shared the experience of all U-boats working up in the Baltic in the winter of 1941-1942 by being frozen in for 3 months.

The exact sequence of trials has not been determined, but appears to have been normal, with listening trials carried out at Rönne, torpedo firing off Gotenhafen, gunnery at Memel, “Agrufront” at Hela, and tactical exercises in the vicinity of the Bay of Danzig. U-172 put into Stettin in early January for overhaul at the Oderwerke yards.

Her trials had been completed in something less than 2 months. The U-boat remained frozen in during and after overhaul,

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not leaving Stettin for Kiel until early April. She remained in Kiel about a week, taking on board provisions, fuel and torpedoes preparatory to her first war patrol.














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CHAPTER VII. FIRST PATROL OF U-172

U-172 left Kiel toward the end of April, 1942 on her first patrol, stopped overnight at Kristiansand, and proceeded into the Atlantic. Off the northern coast of Ireland she was attacked by a twin-motored aircraft and sustained minor damage which curtailed what had been planned as a war cruise of normal duration. It was deemed advisable to put into Lorient for repairs, and U-172 reached her Atlantic base about 10 May 1942 after two weeks at sea. No attacks on shipping had been made. 23 torpedoes, air and electric, had been taken aboard. The following officers made the first patrol:

Captain:	Kapitänleutnant Carl Emmermann

Executive Officer:	Oberleutnant z. S. Heinz-Günther Scholz

Second Watch Off:	Oberfähnrich Hermann Hoffmann

Engineer Officer:	Oberleutnant (Ing.) Lothar Dick

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CHAPTER VIII. SECOND PATROL OF U-172

(See Plate 6 for Track Chart of this Patrol)

Sometime after 20 May 1942, U-172 set out alone from Lorient on her second patrol which was said to have lasted about 10 weeks. This cruise was called the “Caribbean Patrol” by the crew and was quite successful. The trip across the Biscay was uneventful, and at no time on the patrol was U-172 attacked.

The officers on this patrol were:

Captain:	Kapitänleutnant Carl Emmermann

Executive Officer:	Oberleutnant z. S. Heinz-Günther Scholz

Second Watch Off:	Oberfähnrich Hermann Hoffmann

Engineer Officer:	Oberleutnant (Ing.) Lothar Dick

ATHEL KNIGHT

The first score to U-172’s credit was the British tanker ATHEL KNIGHT of 8940 tons. This vessel was torpedoed 26 May 1942 (O.N.I. Note: She went down in approximate position 28 N. – 46 W.).

UNKNOWN SINKING

Nine days later, 4 June, Kapitänleutnant Emmermann claimed the sinking of a 5000-ton freighter which he identified neither by name, type, nor nationality. (O.N.I. Note: No sinking is listed in the area in which U-172 might reasonably be expected to have been on that day.) This is the first of several questionable claims by the high-scoring Emmermann.

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DELPHINA

5 June 1942 saw the sinking of the American freighter DELPHINA (O.N.I. Note: DELPHINA sank in 20⁰.20’ N. – 67⁰.07 W.) Emmermann claimed 3500 tons for this ship which is registered at 3480 tons.

SICILIEN

Two or three days later, U-172 torpedoed and sank SICILIEN and claimed 1650 tons for her record. (O.N.I. Note: SICILIEN, an U.S. Army Transport of 1653 tons was sunk about 2200 R, June 1942 off San Juan, P.R. (the U-boat listed this action as of 8 June because of the time differential).

LEBORE

The American freighter LEBORE was U-172’s next prey. She was successfully attacked and sunk 14 June and a claim of 8243 tons was added to the U-boat’s credit. (O.N.I. Note: LEBORE sank in 12⁰53’ N. – 80⁰40’ W.; she is listed as 8289 tons.)

BENNESTVET

The next day U-172 sank the Norwegian freighter BENNESTVET and Kapitänleutnant Emmermann added 2438 tons to his score. (O.N.I. Note: This sinking occurred in 10⁰47’ N. – 82⁰12’ W.)

MOTOR REX

Two to three days later U-172 claimed a sinking of 3,500 tons. She listed the vessel as MOTOR-REU of American registry. (O.N.I. Note: It appears to refer to the British tanker M/T

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MOTORREX, 1958 tons, set afire and left sinking late 17 June 1942 after being shelled by 2 U-boats. Again, the difference between German time and local time accounts for the difference in dates.)

ONE SCHOONER

Another victory for Kapitänleutnant Emmermann was registered 23 June with the sinking of a sailing vessel which he identified as American, named BOLIVE (also BOLIN in a crew member’s note-book). For this action he claimed 50 tons. (O.N.I. Note: On that day the schooner RESOLUTE, 35 tons, of Colombian registry was sunk in 13⁰30’ N. – 80⁰55’ W. This would seem to be the vessel in question.)

SANTA RITA

After the above exploit, U-172 started on her return to Lorient. She left the Caribbean and was about a quarter of the way back when she torpedoed the American passenger-freighter SANTA RITA 9 July 1942. The U-boat had two torpedoes left, one of which was said to be damaged; the other stopped SANTA RITA and caused her to be abandoned. It seems that the gun crew left the ship before the Captain ordered her to be abandoned. When SANTA RITA was deserted, Kapitänleutnant Emmermann ordered his second Watch Officer (Oberfähnrich z. S. Hermann Hoffmann) and four enlisted men to board her and set scuttling charges, after searching her and removing whatever might be of use to the Germans. Sundry valuables are reported to have been taken off, but the prize that made the

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whole cruise worthwhile was a chart of the mine defenses off Capetown, South Africa.

Emmermann then ordered the Master of SANTA RITA aboard the U-boat and proceeded homewards with him as prisoner. The latter was well treated, given considerable freedom aboard the U-boat and quizzed thoroughly about the Capetown situation. Unfortunately his security indoctrination had been unsuccessful, for he proved, according to reports from the crew of U-172, to be most “cooperative” with and extremely helpful to his captors, thus laying the ground work for the success of their next patrol.

SANTA RITA sank as the scuttling charges did their work, and U-172 claimed 8400 tons more to her credit. (O.N.I. Note: SANTA RITA is listed as 8379 tons, and was reported by survivors as being sunk about 1730 Z in 26⁰11’ N. – 55⁰40’ W. by shell fire after having been torpedoed about 3½ hours earlier. They also reported that confidential codes had been duly jettisoned, but that gun crew’s documents probably remained aboard. This would not account for the chart of the Capetown minefields. A most serious breach of security occurred here and in the talking of the ship’s master.)

END OF PATROL

The rest of U-172’s return to Lorient was apparently without noteworthy incident. She was said to have arrived around the beginning of August. On this patrol, she was not supplied, and claimed not to have met any other U-boats. This statement

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does not match the story of the survivors of MOTORREX.

The total tonnage sunk was claimed to be 41,720 tons; the total listed amounts only to 35,172 tons. This makes an overclaim of some 6,500 tons to Emmermann’s discredit.
















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CHAPTER IX. THIRD PATROL OF U-172

(See Plate 7 for Track Chart of this Patrol)

After a brief layover, U-172 sailed from Lorient on the day of the now famous Dieppe Raid (19 August 1942). Her officers on this patrol, called the Africa or Capetown Patrol by the crew, were:

Captain:	Kapitänleutnant Carl Emmermann

Executive Officer:	Oberleutnant z. S. Heinz-Günther Scholz

Second Watch Officer:	Oberfähnrich Hermann Hoffmann

Engineer Officer:	Oberleutnant (Ing.) Lothar Dick

ARMADA

This patrol lasted over 18 weeks, during which time the U-boat was supplied twice. She was accompanied by several other U-boats which were reported to include:

U-Witte (O.N.I. Note: Kapitänleutnant Helmut Witte is believed to command U-159.)

U-Merten (O.N.I. Note: U-68, claimed 60,000 tons on Capetown Patrol at this time.)

U-Ibbeken (O.N.I. Note: U-178 was in South Atlantic at this time, returning from Indian Ocean Patrol.)

U-Mohr (O.N.I. Note: U-124 C.O. Kapitänleutnant Johann Mohr.)

U-Hartenstein. (O.N.I. Note: U-156, C.O. Korvettenkapitän Werner Hartenstein.)

This expedition was planned as a result of the capture

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of charts and the acquisition of intelligence of and about Capetown defenses and shipping. The little armada was highly successful, and U-172 played no small role in the operation. It is interesting to note that there was no evidence forthcoming that these U-boats acted in the concerted manner usual to a group or "Wolf Pack" formation. On her return voyage, U-172 conducted an apparently independent operation with continued success.

There is no evidence of any attacks by or on this group of U-boats en route to their objective.

ACCIDENT

Mechanikermaat Fleischmann, in charge of the Bugraum on this and the preceding patrol, was accidentally shot in the knee by Oberbootsmannsmaat Schmidt who was cleaning a machine gun which he “didn’t know” was loaded. Fleischmann was put aboard U-Wilamowitz-Möllendorf when U-172 was supplied by her, and Obermechanikermaat Trompelt was put aboard U-172 by the supply boat in his place.

FIRST SUPPLYING

Reports on the first supplying which U-172 received on this patrol were vague, but they agreed on these points: That it occurred somewhere south of the Azores, probably not much below the Equator; that several U-boats were present at that time; and that U-Wilamowitz-Möllendorf was the supply boat. (O.N.I. Note: This meeting between U-172 and U-459 (Wilamowitz-Mölendorf’s

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boat is not mentioned in the Final Report on U-459, British C.B. 04051(79) ).

CAPETOWN OPERATIONS

The U-boat armada proceeded from the rendezvous with the supply boat to Capetown which was reached about 4 or 5 October 1942.

It was said by some prisoners of not too great reliability that U-172 entered the harbor of Capetown and lay submerged there a couple of days until orders to attack were received. This story was denied by equally unreliable men. Be this as it may, U-172 claims sinking which are recorded as off Capetown, but not in the harbor proper.

From Allied records it is apparent that the other U-boats with U-172 at that time were also successful, but details are lacking.

CHICKASAW CITY

The first success for U-172 on this South African venture was the torpedoing and sinking of CHICKASAW CITY, 7 October 1942, (O.N.I. Note: This sinking was once attributed to U-Hartenstein). Kapitänleutnant Emmermann identified the ship as an American Freighter of 6,196 tons, which was correct in both instances. (O.N.I. Note: S.S. CHICKASAW CITY sank in 34⁰05’ S. – 17⁰E., about 3 minutes after being hit by two torpedoes.)

FIRETHORN

Less than four hours later the same day, U-172 torpedoed and sank FIRETHORN which was identified as an American freighter of

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6,000 tons. (O.N.I. Note: M.S. FIRETHORN was struck by 2 torpedoes from opposite sides and sank at once approximately 60 miles N.W. of Capetown. She was of Panamanian registry and listed as 4,700 tons.

UNIDENTIFIED SINKING

The next day, U-172 claimed the sinking of a 3,500-ton freighter whose name and nationality were not identified. (O.N.I. Note: There were two ships sunk in the Capetown area which are close to the tonnage claimed: PANTRLIS of 3,845 tons, sunk in 34⁰20’ S. – 17⁰50’ E., and KOUMANDOUROS of 3,598 tons, sunk in 34⁰21’ S. – 18⁰30’ E. Both these vessels were Greek.)

ORCADES

The greatest single tonnage gain to Emmermann’s credit was made 10 October 1942 when U-172 attacked and sank the British transport ORCADES. Seven torpedoes were expended. One story was that the U-boat came upon ORCADES at dawn through a curtain of fog. She dived and fired torpedoes which struck the ship which kept on her course, however, U-172 surfaced and ran ahead of her quarry. Again she dived and fired two torpedoes. These struck ORCADES but she could still proceed. The U-boat then followed on the surface and fired a spread of three, two of which were hits. This final blow sank ORCADES and enabled Kapitänleutnant Emmermann to report 23,456 tons more to his mounting score.

At that moment a plane appeared and dropped depth charges. U-172 is said to have made off on the surface in a zigzag course.

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(O.N.I. Note: ORCADES sank in 35⁰51’ S. – 14⁰40’ E. The tonnage claim and identification were correct.) Kapitänleutnant Emmermann now continued toward the middle of the South Atlantic at a slow speed.

ALDINGTON COURT

On the last day of October, ALDINGTON COURT was torpedoed and sunk. She was listed as a British freighter of 4,891 tons. (O.N.I. Note: M/V ALDINGTON COURT of British registry, 4,891 tons, was hit by 2 torpedoes 31 October 1942 at 2045 Z and sank in 10 minutes.

LLANDILO

Three days later, 2 November 1942, the British freighter LLANDILO, 4,966 tons, was struck by one torpedo from U-172 and sank. (O.N.I. Note: S.S. LLANDILO was hit in 27⁰03’ S. – 02⁰59’ W. at 2047 Z and sank in about half an hour.

BEN LOMOND

Continuing in a northwesterly direction, U-172 passed the bulge of Brazil and found her next victim, BEN LOMOND, which she sank 23 November 1942. This ship was listed by Kapitänleutnant Emmermann as a British freighter of 6,650 tons. (O.N.I. Note: BEN LOMOND, 6,630 tons, sank in 00⁰30’ N. – 38⁰45’ W.)

KNIGHT’S CROSS

Sometime between 23 November and 28 November 1942 (according to U-172’s list of sinkings and the claimed tonnage for

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which the award was made), Kapitänleutnant Emmermann was awarded the Knight’s Cross of the Iron Cross. (O.N.I. Note: The Hamburger Fremdenblatt of 2 December 1942 announced the award as of 30 November, but by that date Emmermann’s tonnage score had been increased by over 5,000 tons, which fact points to an earlier date.) The tonnage claimed was a total of 97,380 tons. (O.N.I. Note: According to Allied listings of sinkings and Lloyd’s Registry, the total ascribable to U-172 was 89,711 tons. This makes it appear that Kapitänleutnant Emmermann was given his K.C.I.C. on an overclaim of more than 7,600 tons.

ALASKAN

On 28 November, U-172 torpedoed the 5,364-ton American freighter ALASKAN. As the ship did not go down, the U-boat surfaced and sank her with shell fire from the 105 mm. gun. One of the gunners claimed that they fired 168 rounds, of which138 were hits. (O.N.I. Note: S.S. ALASKAN was struck by two torpedoes at 0650 Z, 28 November 1942 in 03⁰58’ N. – 28⁰19’ W. She sank at 0745 Z. Survivors variously report shelling, after they had abandoned ship, with 40 rounds – 30 hits, 10 misses, and with 60 rounds – 35 to 40 hits, 25 to 20 misses.)

SECOND SUPPLYING

The next incident of note on the homeward voyage was when U-172 was supplied by an unidentified U-boat, said by an unreliable prisoner to have been a Supply U-boat, also reported to have been U-461 (C.O. Stiebler). It was further claimed there were six or

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seven 500-ton U-boats and some 750-ton U-boats present. It would seem that this rendezvous must have occurred before 2 December, since on that date a sinking was claimed and several sources stated that their last attack was made after the second supplying. The position of this rendezvous was not stated, but seems to have been “near” the Equator, apparently north of it. (O.N.I. Note: O.N.I. 250-G/Serial 13 reports what must have been this meeting as about the middle of December 1942. This date would have been too late to have enabled U-172 to reach Lorient 27 December 1942, unless the rendezvous occurred much nearer the Azores and after the purported sinking of 2 December.)

UNKNOWN SINKING

Kapitänleutnant Emmermann’s list of sinkings does not identify his last claimed sinking on this patrol beyond “Tanker 6,000 Brt.” He dated this action 2 December 1942. In the crew member’s note book there is a torpedoing entered as of that date and tonnage and as “in convoy”. Some prisoners also mentioned such a convoy attack after the second supplying, so that it would seem that the crew were definitely of the impression that they had participated in an action on that date. (O.N.I. Note: There is no sinking, torpedoing, or vessel missing listed in Allied files as of that date, which would reasonably be assigned to U-172 either by reason of probable position or by the tonnage claimed.) It was also said that the last torpedoes were used in this attack, and that there was one depth charge dropped which U-172 seemed to think

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was for her, although no damage was done by it.

PLANE ATTACK

Subsequent to the purported sinking of 2 December, U-172 was attacked by planes (probably two) that were variously identified as Sunderland and as Halifax type planes. Some bombs were dropped, but no damage resulted, and the planes were driven off. This attack was not located except as “off the coast of Africa” and by the suggestion that the planes, being land planes, might have been based on Casablanca or Dakar.

RETURN TO LORIENT

The rest of the cruise home was apparently routine. U-172 arrived at Lorient 27 December 1942 from a long successful patrol, undamaged, without torpedoes, but with a score of 67,023 tons claimed sunk which was within 7,000 tons of the Allied count.












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CHAPTER X. FOURTH PATROL OF U-172

(See Plate 8 for Track Chart of this Patrol)

The “Atlantic Patrol” of U-172 commenced with her departure from Lorient 21 February 1943, after 8 weeks’ layover during which no unusual repairs occurred and no new construction was added. This patrol lasted 56 days and was quite successful. The officers on this patrol were:

Captain:	Kapitänleutnant Carl Emmermann

Executive Officer:	Oberfähnrich Hermann Hoffmann

Second Watch Officer:	Oberleutnant z. S. Klaus Hackländer

Engineer Officer:	Oberleutnant (Ing.) Lothar Dick

EMERGENCY REPAIR

When out about a week, U-172 met U-Staats (O.N.I. Note: U-508 is commanded by Kapitänleutnant George Staats of the 1935 term; Executive Officer: Kapitänleutnant Erich Mäder, 1936 naval term; Engineer Officer: Kapitänleutnant (Ing.) Gerhard Reuter, 1936 term. U-508 has been reported sunk and later as being heavily damaged and in Lorient for repairs.) She had been severely damaged by an aircraft attack in crossing the Biscay and was said to be incapable of diving, having four holes in her pressure hull. One Diesel was also said to be out of order. The 2 boats proceeded together in a westwardly direction to clear the danger zone and at the same time effect repairs on U-508. Oxy-acetylene welding equipment was put aboard the damaged U-boat which made herself clear for

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diving in about two days of ceaseless work.

U-172 then topped off with oil from U-Staats. The latter put about and headed for Lorient where extensive repairs were commenced.

MUNITIONS SHIP

Kapitänleutnant Emmermann then headed northwards until 4 March 1943 when he sank an unidentified munitions ship and claimed 9,000 tons to his credit. (O.N.I. Note: It seems most likely that this vessel was the M/V CALIFORNIA STAR 8,300 tons, of British nationality, sunk 4 March 1943 in 42⁰32’ N. – 37⁰44’W.) U-172 was so close to this ship that the shock of her exploding was like that of a close depth charge.

THORSTRAND

Two days later, U-172 sank THORSTRAND, a Norwegian freighter, and added 3,041 tons to his score. (O.N.I. Note: THORSTRAND was torpedoed 2005 Z and sank at 2230 Z, 6 March 1943. The nationality and tonnage were correctly listed by Kapitänleutnant Emmermann.)

“GRUPPE UNVERZAGT”

Some time after sinking THORSTRAND, U-172 received orders to join “Gruppe Unverzagt” in its attack on an eastbound convoy then in that vicinity. It was said that there were 5 U-boats in this group. (O.N.I. Note: This group has already been listed as attacking Convoy UGS-6.) Concerning this group it was stated that:

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“Henke hat Sichenung gestanden”. This was explained as signifying that U-Henke was the contact keeper for “Unverzagt”.

KEYSTONE

U-172 listed the sinking of a 5,565-ton freighter which Emmermann identified as an American ship named SAGE BRUSH. (O.N.I. Note: No vessel by that name was sunk in those waters on that date but KEYSTONE, of that tonnage, was torpedoed and sunk 13 March 1943 in 37⁰59’ N – 37⁰40’ W. She was a straggler from Convoy UGS-6 and is presumably the ship claimed by Kapitänleutnant Emmermann.)

FIVE CLAIMED

Three days later, U-172 had maneuvered herself ahead of the convoy and submerged. After the destroyer screen had passed over her, she came up to periscope depth in the midst of the convoy and fired all six tubes in rapid succession. Kapitänleutnant Emmermann announced four ships hit and claimed to have sunk BENJAMIN HARRISON, which he identified as an American transport of 10,000 tons, and three other transports of unknown name and nationality, which he estimated as of 8,000, 6,800 and 6,000 tons respectively. (O.N.I. Note: The facts are: BENJAMIN HARRISON was hit and crippled by one torpedo. She had to be sunk by an escorting destroyer. No other member of this convoy was hit on this date, 16 March 1943, which makes Emmermann’s claims a matter of wishful thinking.) This attack was followed by a counter-attack and U-172 dived to safety. Some depth charges were dropped, but no damage to U-172 resulted.

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The next day Emmermann surfaced amid debris from a sunken ship. Several life boats were stripped of pumps, provisions, clothing, etc. and some crates were fished out of the water. One claim was that one or two crates were pulled on the U-boat’s deck. Examination showed the crates contained aircraft bombs of an unspecified type. The irony was not enjoyed and the crates were hastily pushed overboard again. It was stated that the flotsam did not identify the vessel from which it came.

THREE MEETINGS

Shortly thereafter U-172 received a signal from B.D.U.: “Emmermann remain at position achieved: commence return trip after delivering oil”. U-Neitzel arrived and received oil from U-Emmermann. (O.N.I. Note: Fregattenkapitän Karl Neitzel was C.O. of U-510.) When Neitzel came aboard U-172 at this meeting, the cook of U-172 baked a cake with a large Knight’s Cross of the Iron Cross on it in icing in honor of his recent award. It was stated that Oberleutnant Eick later took over Neitzel’s boat.

About this time, U-172 also met U-Whitte (O.N.I. Note: Believed to be U-159) from whom she received Leutnant (Ing.) Hauser to relieve Oberleutnant (Ing.) Dick who was suffering from a stomach disorder. (O.N.I. Note: Leutnant (Ing.) Josef Hauser of the 1939 October term.) Dick stayed aboard U-172 for the return trip, but was inactive. Leutnant (Ing.) Hauser has since been promoted to Oberleutnant (Ing.).

It was also said that U-Keller was met, and a sick

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48-year old Engineer Officer was taken aboard for the trip back. There were thus 3 Engineer Officers during the last 2 or 3 weeks of this patrol, 2 of whom were invalided.

CLAIM 26

On the list of sinkings mentioned above, the twenty-sixth is entered as: 16.3.1943 Transport name? Nationality? 7,000 Brt. Interrogation and the crew member’s note-book showed the above date was a typographical error and that the correct date of the last action on this patrol was 29 March. (O.N.I. Note: The British freighters EMPIRE WHALE, 6159 tons, and UMARIA, 6,852 tons, were sunk 29 March 1943 in convoy in approximate position 46⁰44’ N. – 16⁰38’ W. Either is likely to have been the one claimed.

RETURN TO LORIENT

U-172 arrived at Lorient 17 April 1943 after repulsing an aircraft attack with her 105-mm. and 37-mm. guns. Although the 105-mm. was not an A/A gun, it was used successfully in this action, and the U-boat was able to dive to safety.

Torpedoes were twice brought down from the upper deck containers, once the “Unverzagt” action and once afterwards. Upon arrival at the base, there was but one torpedo left aboard. None were supplied them on this patrol. It was reported that “Foxers” were heard on this patrol for the first time.

There were confirmed statements of difficulty with the fresh water distillation unit which produced much below its capacity. Water was rationed sharply until the unit was repaired at sea.

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Due to the extravagant claims of the action of 16 March, Kapitänleutnant Emmermann’s score for his fourth patrol were exaggerated by 24 – 25,000 tons.


















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CHAPTER XI. FIFTH PATROL OF U-172

(See Plate 9 for Track Chart of this Patrol)

U-172 spent 6 weeks in Lorient between her fourth and fifth patrols. Some of her deck torpedo containers were removed, and she, therefore, sailed with fewer torpedoes than previously (See Chapter IV). Ammunition with time fuze was carried on this patrol for the 105-mm. gun. The officers on this patrol were:

Captain:	Kapitänleutnant Carl Emmermann

Executive Officer:	Oberfähnrich Hermann Hoffmann

Second Watch Officer:	Oberleutnant z. S. Klaus Hackländer

Engineer Officer:	Oberleutnant (Ing.) Frohwein

Press Correspondent:	Helmut Brendt

(O.N.I. Note: Men who had known him on board said the Engineer Officer’s name was Frohwein; however, the G.N.L. lists only an Oberleutnant (Ing.) Frowein.)

DEPARTURE

Saturday, 29 May 1943, saw the departure of U-172 from Lorient on her so-called “Rio Patrol”. At a point about 2 hours run from the base, she joined U-Lange who had left 2 hours earlier and waited there. Two hours later, they were joined by U-Staats and the three set out to cross the Biscay. They were escorted by a mine destructor vessel for a while.

When only a few hours out, Mechanikergefreiter Egon Bender, was taking the battery cover plate off a torpedo in preparation to

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servicing the battery. The plate slipped and caused a short circuit which resulted in extensive burns on the boy’s arms and face. He was returned to Lorient on the accompanying vessel and was hospitalized for about 2 weeks. He rejoined U-172 on her next cruise.

The Bay of Biscay was crossed submerged except for a few hours at night when the batteries were charged.

Soon after leaving a signal was received, ordering U-172 to stop using her G.S.R. for the rest of the patrol.

SUPPLY PLANS

Early in June, U-172 was notified that she would be supplied by U-Czygan. (O.N.I. Note: Korvettenkapitän Werner Czygan commanded the 1,600-ton combination minelayer and supply U-boat U-118, sunk 12 June 1943 in approximate position 30⁰14’ N. – 34⁰ W. See Op-16-Z Final Report G/Serial 15, on U-118.) U-172 arrived at the rendezvous and dived as an aircraft was spotted. While submerged, explosions indicating a heavy attack were heard. Upon resurfacing U-118 was not to be found. A message was sent to Commander-in-Chief U-boats: “Czygan not met. Bombs heard. Probably sunk.” Emmermann was then ordered to search for Czygan until the following evening and to send a signal with the single word “No”, if he was not found. The latter turned out to be the case and the signal was sent.

SUPPLYING BY U-LANGE

There seems to have been no further untoward event on

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the outward cruise. U-172 was supplied somewhere below the Azores and above the Bulge of Brazil (off which she later had her first success on this patrol) by U-Lange with whom she had left Lorient. This was claimed to have been a 750-ton U-boat. U-172 took on a torpedo rating to replace the one injured on the first day out.

VERNON CITY

Kapitänleutnant Emmermann listed the sinking of a British freighter of 4,952 tons, 28 June 1943. He identified this ship as CORNISH CITY. (O.N.I. Note: CORNISH CITY was sunk a month later off the S.E. corner of Madagascar. It would seem U-172’s sinking was VERNON CITY which went down in 04⁰30’ S. – 27⁰20’ W., 28 June 1943, she was of the same tonnage as CORNISH CITY.)

OAK LEAVES

With the above sinking, Kapitänleutnant Emmermann’s claims reached a grand total of 169,102 tons. On the basis of this tonnage sunk, he was awarded the Oak Leaves to the Knight’s Cross of the Iron Cross. (O.N.I. Note: By Allied tally, his score at that time was some 38,000 tons less.)

AFRICAN STAR

U-172 continued her way down the coast of Brazil until a little below Rio de Janeiro. There, 12 July, she sank AFRICAN STAR which she correctly identified as an American freighter, but for which she claimed 8,200 tons. (O.N.I. Note: AFRICAN STAR, 6,507

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tons, was hit by 2 torpedoes, 0500 Z and 0515 Z respectively, 12 July 1943 in 25⁰46’ S – 40⁰35’ W. She sank immediately after the second torpedo hit. This sinking appears to have occurred at the southernmost point of U-172’s fifth patrol; what follows may be considered as incidents on the return trip.)

HARMONIC

The list of claimed sinkings ends with the above ship, but the crew member’s note-book lists HARMONIC as U-172’s next sinking.

This ship, identified as British and of 4,558 tons, was sunk 15 July 1943. (O.N.I. Note: Identification is correct; position was 20⁰ S. – 30⁰ W. HARMONIC sank 1842 Z, two mines after second torpedo hit. The first struck her at 1820 Z.)

FORT CHILCOTIN

Heading north from the sinking of HARMONIC, U-172 claimed, 24 July 1943, another British vessel which she rated at 6,000 tons. This was Kapitänleutnant Emmermann last sinking. (O.N.I. Note: FORT CHILCOTIN, British, 7,133 tons, was sunk 24 July 1943 in 15⁰03’ S. – 32⁰35’ W. This was probably the ship referred to in the crew member’s note-book.)

U-604 and U-185

(O.N.I. Note: For another view of this episode, see Op-16-Z Final Report G/Serial 26.)

From the sinking of 24 July, U-172 apparently continued

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to cruise off the Brazilian coast towards the Line Some time between then and 11 August, she received a signal to stand by U-Holtring. When she came up, in the general area of 5⁰ S. – 20⁰ W., U-Maus was already with U-Holtring (O.N.I. Note: U-Holtring was U-604; U-Maus was U-185.).

When an aircraft attacked the group, U-172’s Bridge was strafed and several of the crew were wounded. One man was killed and went overboard. Since her A/A guns were out of order, she dived and thus got into disrepute with the others for deserting them. In submerging, she found her rudder jammed to port and ran in a circle until it was freed by use of the hand steering gear. Some instruments were said to have been broken by the bombs that were dropped. Some batteries of #1 section were also damaged. After about a day under water, U-172 got part of a U/T signal from U-185: “AUFTAUCHEN ---U------S”. It was not known what this meant, so U-172 surfaced and called the Commander-in-Chief U-boats who told her that Maus had shot down a plane, and ordered her to meet him at a given time and place. This order was carried out, and U-172 took over about half the survivors of U-604, including the Engineer Officer and the Press Correspondent. She then headed back for Lorient.

During the submerged period and until after she left U-185, U-172’s compass was out of order; this was eventually corrected, however, before she lost contact with U-185.

SUPPLYING BY U-KUPPISCH

On or about 28 August 1943, U-172 met U-Kuppisch on her

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way to Japan (O.N.I. Note: Kapitänleutnant Herbert Kuppisch commanded U-847, a 1,200-ton U-boat, which has been believed sunk sometime early in the autumn of 1943.). Some 30 tons of fuel oil were taken on by U-172. Somewhat later on Commander-in-Chief U-boats was heard calling U-Kuppisch repeatedly to report her position. As Kuppisch was never heard to reply, it was generally believed on U-172 that his boat was lost.

SICKNESS ABOARD

On the return trip, about half the men on board became sick with what seems to have been an intestinal disorder accompanied by a high fever. This did not last long, but caused great distress and disabled its victims while it lasted. One man, Matrosenobergefreiter Christiani, became delirious, jumped out of his bunk, got a large knife from the Galley, and, running around stark naked, slashed the Engineer Officer on the forearm, shouting, “There, I hope that will teach you to stop loafing!”

UNIDENTIFIED U-BOAT

When somewhere “off Gibraltar” (Which leads to the presumption that Kapitänleutnant Emmermann chose a course east of the Azores) one night, a fix was obtained upon an object and soon a silhouette was seen. Torpedo tubes were made ready and were on the point of being fired, when the shape was recognized as that of a large German U-boat. The recognition signal was flashed several times. When a reply was made, it was incorrect, an M or N being for the other. However, it was concluded that this U-boat must be

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U-Lüth. (O.N.I. Note: Korvettenkapitän Wolfgang Lüth was commander of U-181. She is a 1,200-ton U-boat. Korvettenkapitän Lüth is reported to have been relieved by Fregattenkapitän Freiwald and given a shore assignment.) The mysterious U-boat then suddenly cut across U-172’s bows and raced off into the darkness.

“PIENING WEG”

From the strange nocturnal meeting “off Gibraltar” Emmermann proceeded toward the northwest coast of Spain where, off Vigo, the course established by the U-boat Commander Piening was entered. (O.N.I. Note: Kapitänleutnant Adof Piening, Commanding Officer of U-155, of the Second Flotilla at Lorient.) This run was made submerged by day with constant soundings being made and on the surface at night.

END OF PATROL

Tuesday, 7 September 1943, marked the return of U-172 to her base after a patrol which lasted 102 days. Of a number of U-boats off the coast of South America at that time, variously stated to be 7 or 9, U-Emmermann was the only one to return safely. She had five torpedoes left. Her fresh water distilling unit was limited in its production capacity most of the patrol.

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CHAPTER XII. SIXTH AND LAST PATROL OF U-172

(See Plate 10 for Track Chart of this Patrol)

A long layover occurred between U-172’s fifth and sixth patrols. During this time extensive repairs and alterations were made both on the boat and in the personnel. New batteries, which had to come from Germany, were installed; a second Platform was built on; the 2 single 20-mm. guns were replaced by 2 twin 20-mm. guns; and a quadruple 20-mm. gun was added. (See Chapter IV.)

Kapitänleutnant Carl Emmermann was relieved of the command of the U-boat, and Oberleutnant z. S. Hermann Hoffmann, his Executive Officer, was put in his place. The officers on this patrol were:

Captain:	Oberleutnant z. S. Hermann Hoffmann

Executive Officer:	Oberleutnant z. S. Maximilian Coreth

Second Watch Officer:	Leutnant z. S. Heinz Rietdorf
	Leutnant z. S. Friedrich Wilhelm Heitz

Engineer Officer:	Leutnant (Ing.) Alfred Loeffler

Medical Officer:	Oberassistenzarzt Vole

(See Chapter V for details on these personalities.) The Press Correspondent was replaced, former complement increased by 7 men: A Medical Officer, and 6 seamen to man the extra A/A guns.

This patrol was expected to be unusually long, since an extraordinary supply of provisions was aboard. It was rumored that the Indian Ocean, the Persian Gulf, and ultimately Japan would be the goals. Singapore was also mentioned as the oriental base.

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Supplies were thought to be for 5 or 6 months. Tropical clothing was aboard and also a supply of steel helmets for the use of the Bridge Watch. They were not used, however.

DEPARTURE

Saturday, 13 November 1943, was the sailing date for U-172’s sixth patrol. This patrol was an unlucky one from almost every angle, ending with the loss of the boat and 11 men.

When the start was made, U-172 hit a rock in the harbor, but no damage was noticed, and she continued towards the open sea. There it became evident that the weather was too bad for the escort vessel, and the U-boat had to turn back. It was discovered, after she had docked again, that the guard to one of the hydroplanes had been damaged by the collision with the rock. This was rewelded.

U-172 put out again 16 November and made St. Nazaire 19 November. When she reached the 200-meter line, she dived and found the Diesel exhaust valves leaking and a leak in the Head. Sabotage was suggested. She then proceeded to St. Nazaire under escort the entire distance.

ST. NAZAIRE LAYOVER

In attempting to enter the assigned pen in the U-boat shelter, Oberleutnant z. S. Hoffmann handled his boat so badly that Kapitänleutnant Emmermann, who, as Chief of the Sixth Flotilla at St. Nazaire, had come to welcome his old boat, had to direct him by hand signal from shore in order to prevent an accident.

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While lying over for the 2 new type torpedoes and for repairs, Leutnant z. S. Heinz Rietdorf, the Second Watch Officer, was relieved and Leutnant z. S. Friedrich Wilhelm Heitz was assigned in his place (See Chapter V).

On Saturday, 20 November 1943, as U-172 was moving out of her pen for practice with her quadruple 20-mm., she hit the wall of the pen and tore open her number 7 fuel tank. This was hastily repaired by welding a plate over the hole, but the job was badly done and an Obermaschinist objected to it officially. The Engineer Officer was called in and over-ruled him, and the patch-work stood. This was about the first part of the boat to let go when the final attack hit them.

DEPARTURE FROM ST. NAZAIRE

Finally, 22 November 1943, U-172 sailed out from St. Nazaire and headed for the South Atlantic between the Azores and Portugal. Her orders were sealed and speculation on them took the crew farther than their boat did. The fact that the day of the sailing was a Monday, caused everyone to be nervous and even sure of bad luck. The first example of this “bad luck” was in the fact that the air vents on several diving tanks were found “closed, secured, and set for hand operation”. This condition had lasted from her sailing until 4 hours after the escort vessel had turned back. A dive in that period would have been very delayed.

The Bay of Biscay was crossed submerged by day and on the surface at night for only a few hours to charge the batteries and

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air the boat.

FURTHER MISFORTUNE

Upon submerging, it was discovered that the Diesel exhaust valve still leaked. It was repaired, but not made completely tight.

During an attempted crash dive upon picking up a Radar beam from an aircraft on the G.S.R., it was found that the Conning Tower Hatch would not close. The Control Room Hatch was secured and the boat surfaced. When the water in the Conning Tower was pumped out, the Captain’s cap was found in the Conning Tower Hatch.

Once when emerging from a routine dive an inexperienced fireman opened the Diesel exhaust valves too late after the starboard engine had been started, and the fumes from the engines backed into the room, asphyxiating several men. Others put on their diving lungs for gas masks. The Diesel was stopped; the casualties dragged out of the Engine Room; the valves opened, motors started, gasses pulled out of the room, and the boat proceeded. Artificial respiration in fresh air brought the gassed men around.

Before leaving the Biscay, a stupid radioman nearly brought disaster to U-172. He was manning the G.S.R. and at the end of his watch he incidentally mentioned to his relief that he thought that he had perhaps heard something just previous to being relieved. At that instant a plane was overhead and dropped six bombs. The Bridge Watch heard the aircraft, believed to have been a Liberator, but she

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had already sighted U-172 and turned her spotlights on the U-boat. She strafed the boat with her machine guns and released six bombs which hit the water dead ahead. One magazine was claimed to have been fired from one barrel of a twin 20-mm. gun. As soon as the aircraft had passed, Oberleutnant z. S. Hoffmann took the U-boat down for more than an hour. No significant damage to U-172 occurred. This attack was said to have taken place 3 December 1943.

It was reported that the starboard tail shaft vibrated on this patrol and was quite noisy at higher rates of speed.

PATROL LINE

Upon leaving the Bay of Biscay, or shortly thereafter, U-172 altered her course a little to the southeast in order to avoid a patrol line of 13 or 14 U-boats, which extended in a more or less north-south line between the eighteenth and twentieth meridians west and some distance above and below the forty-fifth parallel. One of the U-boats in this group was U-Reese, another was U-Henke (O.N.I. Note: U-515). This patrol line was said to be set up to intercept a convoy from Gibraltar to the United Kingdom.

ESCAPE FROM DESTROYERS

Four or five days before the sinking, and about 200 miles south of the Azores, U-172 was on the surface at night when 2 destroyers were sighted. It was also stated that the G.S.R. showed she was being searched for. She dived at once and stayed down with the electric motors off. In this way, the destroyers were eluded.

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RENDEZVOUS WITH U-BURGHAGEN

Somewhere near the thirtieth parallel north and east of the thirtieth meridian in the evening of 10 December 1943, U-172 met the supply U-boat commanded by Korvettenkapitän Burghagen and stayed with it for 5 or 6 hours. She topped off with 25 or 30 cubic meters of fuel oil, bringing her total supply to 230 cubic meters. Some provisions were also taken on to bring her stores up to 20 weeks supply. It was not expected that U-172 would be supplied again on this patrol. Mail from U-172 was put aboard Burghagen’s boat, and Oberleutnant (Ing.) Frohwein, who had come out with the new Engineer Officer of U-172 to “break him in” to his new assignment, left his old boat for the return to shore. He complained of being hampered and restricted in his duties by the knife wound he received on the previous patrol. One of the 5 extra Borkum units which they carried for supplying purposes was turned over to U-Burghagen.

BEGINNING OF THE END

It was the policy of Oberleutnant z. S. Hoffmann to run submerged except for 2 to 5 hours at night when the batteries were charged and the boat ventilated. Occasional surfacings were made at set intervals for picking up broadcasts, testing their radar, or even transmitting a necessary message. This cautious policy made slow progress inevitable and the Bootsmaat was very critical of it. On the other hand, the Obersteuermann did not approve the change from this policy after the meeting with U-Burghagen, which

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had them proceed on the surface day and night. The Obersteuermann wanted to run submerged until the Equator, the Captain apparently thought it time to make better speed.

On the morning of 12 December 1943, about sunrise, U-172 had surfaced and tested her radar. The Oberfunkmaat thinks that these beams may have been picked up by the aircraft which subsequently spotted them. The sighting by an aircraft occurred at 0930 Z. One magazine was fired from the quadruple 20-mm. gun and at least one of the twin 20-mm. guns on Platform I was used. Then U-172 dived to about 180 meters.














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CHAPTER XIII. SINKING OF U-172

IN HIDING

When the aircraft sighted U-172 at 0930 Z, it had come out of cloud coverage at about 1500 feet. It ran in close to the surfaced U-boat, and then turned away. Crew members who were topside at that time thought they heard a second plane in the clouds. No bombs or depth charges were dropped, and the U-boat proceeded dead ahead under water until after mid-day.

INVOLUNTARY SURFACING

Some 2 hours after submerging, propeller noises were picked up and Oberleutnant z. S. Hoffmann ordered the boat to periscope depth. When approaching the desired depth, the U-boat suddenly shot to the surface. The Captain was at the periscope but saw no craft anywhere. The boat was taken down again at once.

FIRST ATTACK

At about 1230 Z, it was generally agreed by several prisoners, a strong accurate attack with depth charges commenced. The subsequent events are confused as to time and detail, but the consensus of claims was that a great many depth charges (from 100 to 240 were claimed) were dropped in the course of that afternoon and evening.

Considerable damage was done by the opening attack. Depth gauges were broken; the leaky exhaust valves were made worse; the bilges were flooded, possibly from damage to a trim tank; drinking

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water became mixed with sea water; the bilge pumps were out of order; the fuel oil tank, damaged in St. Nazaire and inadequately repaired there, was opened up and all the oil lost, leaving a tell-tail slick; and the lights went out.

TACTICS

Oberleutnant z. S. Hoffmann tried to keep his boat at a depth between 180 and 200 meters, but once went to about 240 meters. It was claimed that U-172 went down as far as 260 or 270 meters at one time during this action.

Some prisoners denied that evasion tactics were used, others stated that Hoffmann frequently backed his boat into her wake or turned her hard to port or starboard into the are of disturbance made by depth charges which had just exploded. It was stated by an officer prisoner that running in reverse was merely to bring the boat into better trim and that steering into the are of disturbance produced by the detonation of a depth charge was impracticable on two counts: First, they had no D.C.P., and second, there were so many detonations in all directions that one could never be certain just where an area of disturbance would be.

NOISE MAKERS

Frequent mention was made of hearing a humming or buzzing noise, which prisoners attributed to contrivances dragged astern the destroyers. The effect seemed to make the use of the listening gear almost futile. The presence of a destroyer could not be

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ascertained until it was directly overhead.

BATTERY CHARGING

At around midnight the air and battery situation demanded relief. It was, therefore, decided to surface the boat and make a run for it, if only to recharge the batteries and replenish the air supply. The port Diesel was out of order, due to loss of lubricating oil, but U-172 proceeded on the starboard Diesel until forced down again. She had a marked list.

The silhouette of a destroyer about 2,000 yards away was sighted at once, and U-172 attempted to make off out of the moon. She was apparently spotted, since star shells were released and the destroyer maneuvered her into the moonlight and commenced shelling her in earnest. After about a half an hour spent in futile attempts at escape on the surface, U-172 again submerged in spite of low batteries and air pressure supply.

TORPEDO TRY

Just before diving, about 0030 Z, 13 December 1943 Hoffmann tried to torpedo the pursuing destroyer. An acoustic torpedo (T-5) in tube No. 6 was readied and fired. This happened at the wrong moment and was ineffectual. The blame was variously placed; on the Captain, who repeated the command “Ready”; on the seaman receiving the command, who was inexperienced and acted too hastily; on the T.D.C., which had been damaged by the extensive depth charges; and on the possibility of damage to the acoustic gear on the torpedo itself. Whatever the cause, it was a miss; some prisoners even

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claimed they heard the torpedo detonate harmlessly.

SECOND ATTACK

The rest of the night seems to have passed quietly, but daylight brought renewed depth charging in the course of which U-172 was said to have gone to 260 meters. Trim was attempted by shifting the crew and fuzes were constantly blowing out.

The damage done by the first series of attacks was materially increased during the morning of 13 December. The outboard torpedo tube doors would not open, and at least one torpedo started to run in the tube. Toward 1200 Z, the Captain called a conference of his officers and the top ranking petty officers. It was agreed that the boat could not possibly make the trip home, that the air supply which was down to 30 kg., and the battery condition made it necessary to surface or lose all hands as well as the boat.

ABANDON SHIP

Preparations were made to surface. The boat ascended to about 80 meters under power. Air was bled from torpedoes to Air Flask Group No. 8. The crew were indoctrinated in security matters, life jackets and/or diving lungs were put on. The tanks were then blown and the boat shot to the surface.

The crew left by the Bow, the Conning Tower and the Galley Hatches. Reports differed as to guns manned, but seemed to agree that the Captain shot at the destroyers with an M.G. 81. He claimed to have caused a few casualties with his fire. The destroyers

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returned the fire and killed the only men lost by U-172. All hands had gotten out, but only 46 were saved.

The destroyers made some direct hits on the U-boat. It was claimed that the armor plated Bridge was not pierced, but the Hydrogen Bottles for inflating the R.D.B. were set afire by shell fire. She went down with her hatches open and her motors/generators going at full speed. It was repeatedly stated that U-172 was not scuttled.

(The following version of the sinking of U-172 was prepared by an officer prisoner and presents a one man view. It should be treated with some reserve.)

On 12 December 1943 about 10.20 (German Time) an aircraft of undetermined type was sighted to starboard while on course 180⁰. It was seen at a distance of about 4-5,000 meters and quite high. Inside the boat the command “Man the A.A. guns!” was given. The aircraft flew past the boat at a considerable altitude. As the aircraft neared, fire was opened from the twin mounts and M.G. 81’s. The Watch Officer now sighted a second aircraft and recognized them as single motored. When, after fire had been opened, the aircraft continued their course, the Captain gave the order to dive. The boat submerged about 10.30 (G.T.) to 80 meters. The Captain believed he had identified the aircraft as seaplanes. About 1100 hours propeller noises were heard on the hydrophones. The Captain ordered the Engineer Officer to go to periscope depth. In spite of the good weather (about sea force 3, and medium ground swell) the boat could not be controlled and shot

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to the surface. The Captain, who was at the periscope, gave orders to go to 80 meters in order to regain control of the boat; he had seen nothing through the periscope. Just why the boat had shot up from periscope depth could not be discovered; since their departure it had shown peculiarities of trim and displacement. It was the assumption of the Captain that the propeller noises heard were of a convoy from the African Coast. He set course towards these noises. After a while, however, the Captain felt the search not to be safe, since the propeller noises constantly changed course. So the U-boat went to 160 meters depth at slow speed and again took up course 180⁰. Towards 1300 hours, the first series of depth charges detonated. These were not well placed. This first series was followed every 8 or 10 minutes, by others, which were better placed each time. Now the situation was clear! The boat, meanwhile, had gone to 190 meters and now changed course according to the propeller noises. After several depth charge patterns, the upper deck containers burst and the boat became heavier. In spite of immediate correction of displacement, the boat continued to become heavier. The Engineer Officer presumed a loss of oil. Soon the constant increase in displacement could no longer be equalized by the bilge pump. Tank 5 had to be blown and an attempt was made to maintain the prescribed depth by partially blowing the tanks. Also both compasses were no longer operating so that it was impossible to control their course. Drinking water had also become unusable through the entrance of seawater. It was the intention of

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the Captain to surface by night, after the depth charging had let up, in spite of the full moon and calm weather, and to try to escape on the surface. This was the sole possibility. About midnight the boat surfaced. It had a strong list to port. On the bridge were the Captain, his Executive Officer, the Boatswain, a mate and a rating. On first inspection of the horizon no shadow was to be seen. The boat, tried during the blowing, to make off out of the moon. After a short time, the Boatswain reported “Shadow off the port quarter”. Since the shadow was broad and did not get underway it was assumed that their U-boat had not been noticed. At first the Captain wanted to get away by using the motors/generators, but then decided to use the Diesels. One Diesel, however, was not usable on account of loss of lubricating oil, so the boat ran full speed on one Diesel in the aforementioned direction. The Executive Officer kept his eye on the shadow and soon determined that it was moving. It remained broad, however, and did not head toward the boat. Soon, however, the destroyer did turn toward the U-boat and tried to force her to the moonlit side, which maneuver was successful. It was impossible to keep any sort of exact course for the U-boat since no compass was usable. The Captain now ordered an Aphrodite (anti-radar balloon) sent out (which was useless since the boat had already been sighted). The destroyer was gaining fast since the U-boat still had only one Diesel working. It was hopeless to try to escape on the surface. The Captain ordered a T-5 to be shot and to submerge again. It was impossible to fire a T-5 using the T.D.C., because the T.D.C. was out of order. Aim had to be taken by changing

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the course of the U-boat. Meanwhile the destroyer began firing with light guns. The shots fell short. After a few rounds the destroyer began to turn somewhat, or so it appeared from the U-boat. The destroyer was now about 3,000 meters distant and began shooting with high explosive shells which overshot (about 200 meters over the starboard side). Then the T-5 was discharged and the boat submerged. The miss of the T-5 was blamed on board on the failure of the listening device of the torpedo, caused by previous shock. During the short surface run the air had been brought up to 60-70 kg/cm². There were only a few depth charge attacks until the morning (13 December). But then the regular patterns started again. It was again necessary to blow diving tank No. 5 in order to maintain trim, which required a lot of air. Therefore, the air supply had to be increased to about 80(?) kg. From an air torpedo in the Bow Compartment. Meanwhile the boat continued to get heavier and could only be held in trim at half speed. It was running at a depth of 180 – 200 meters by the depth gauge, which indicated an actual depth of about 220 – 230 meters, since the depth gauge registered less on account of the overpressure in the boat. After further depth charging the bilge pumps went out of order, but there was a possibility of fixing them. From the constant shocks the torpedoes in forward tubes II and IV began to run. In order to adjust this situation it would have been necessary to go to 80 meters and send out the torpedoes. But this too was impossible because of the increasing accuracy of the depth charges. At about 1700 (German Time) the boat had become

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so heavy that depth could only be maintained by going at “3/4 speed”. Added to that the negative buoyancy tanks flooded. This added 10 tons of weight. The air had dropped to 47 kg/cm² and the possibility of further pumping was gone, since the pumps could not be repaired. These were only the most important items of damage and the chief reasons which compelled the Captain to consider giving up the boat. After conferring with the Engineer Officer, the other officers and the Division Warrant Officer, it was agreed that under the overwhelming circumstances the boat would have to be abandoned. Above all, the depth charges were constantly hitting closer, and the patterns became more and more frequent. The Captain gave the order to don life jackets and the diving lungs. The boat was taken to 50 meters from which depth the tanks were blown and they shot to the surface. Just before the Captain opened the hatch he gave the order “All hands out of the boat!” The time was about 1820 (German Time).












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CHAPTER XIV. OTHER U-BOATS

(Statements in parentheses have been added by O.N.I.)

U-66

	A prisoner stated that U-66 was attacked near the Azores in August 1943. Kapitänleutnant Markworth was wounded, and a general overhaul of the boat was required. Oberleutnant Gerhard Seehausen took over U-66 from Markworth. U-66 had arrived at Lorient in September 1943 and was still there when U-172 left 13 November 1943.

U-68

	It was stated that Korvettenkapitän Mertin’s U-boat (known to have been U-68) left Lorient with U-172 and U-Hartenstein (U-156) 19 August 1942 and operated off Capetown with U-172 and U-Witte (believed to be U-159). U-Mertin returned to Lorient shortly before Christmas 1942. (O.N.I. Note: Mertin was last reported an instructor in the Baltic, spring 1943.

U-103

	U-103 was said to be commanded by Kapitänleutnant Gustav Adolf Janssen. Her insignia was described as the device of the 2nd Flotilla, a gray U-boat with a streak of lightening (Siegrune) crossing it vertically. U-103 on her return to port was supplied by U-Burghagen early in December 1943.

U-105

	The insignia of U-105 was described as a star. (O.N.I. Note: The insignia of U-105 was previously described as a swordfish.)

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U-106

	A prisoner who formerly served in U-106 said that her former Engineer Officer, Kapitänleutnant (Ing.) Herbert Panknin has recently received the Knight’s Cross of the Iron Cross. The present Engineer Officer was said to be a Volksoffizier or lower deck promotion. U-106 was sunk after a prisoner was transferred from her. In August 1942 Kapitänleutnant Hermann Rasch, then C.O., was wounded and the Executive Officer killed. There was no further loss of life. (O.N.I. Note: According to previous information a coxswain and 2 enlisted men were also killed.) Rasch made one more patrol. In all he sank over 80,000 tons. U-106 was attacked fairly often but never had serious damage. Rasch’s greatest success was a convoy attack off Greenland late 1941. All patrols between March 1941 and December 1942 were in the North Atlantic.

U-107

	It was stated that U-107 left Lorient about the same time as U-172, i.e., 13 November 1943. (O.N.I. Note: U-107 is believed to be commanded by Kapitänleutnant Gelhaus.)

U-118

	U-Czygan (known to have been U-118) was reported to have been ordered to supply U-172 early in June 1943 but failed to keep the rendezvous. (O.N.I. Note: U-118 was sunk 12 June 1943 in approximate position 30⁰14'’N. -–34⁰W. See Oop-16-Z Final Report G/Serial 15.)

U-124

	It was reported that U-Mohr (known to have been U-124) operated with U-172 and other U-boats on U-172’s 3rd patrol,

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	19 August 1942 – 27 December 1942, to Capetown. (O.N.I. Note: U-124 was reported sunk April 1943.)

U-155

	The U-boat commanded by Korvettenkapitän Adolf Piening (known to be U-155) was said to have operated in the vicinity of Gibraltar on her last 4 or 5 patrols. She was at Lorient early September 1943 when U-172 returned there. The insignia of U-155 was described as a coat-of-arms. (O.N.I. Note: The coat-of-arms is most likely that of Schwelm, Rineland, which is the patron city of U-155.)

U-156

	It was stated that U-156 left Lorient with U-172 and U-Mertin 19 August 1942 but returned after attacking and sinking LACONIA (O.N.I. Note: S.S. LACONIA was sunk 12 September 1942.)

U-157

	A prisoner confirmed the information that U-157 was sunk in May or June 1942 and that Korvettenkapitän Henne was a casualty.

U-159

	It was said that U-159 had been sunk. Her C.O. was stated to have been Kapitänleutnant Helmut Witte. (O.N.I. Note: It had been previously reported that Oberleutnant d. R. Beckmann had been C.O. of U-159 since summer 1943.) She was considered U-172’s rival as she was very successful and the careers of Emmermann and Witte have been remarkably parallel. Their patrols usually ran concurrently, out of the same

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	Gibraltar-bound convoy when Emmermann claimed 4 ships, Witte sank one of 8,000 tons. On the patrol when Emmermann sank about 50,000, Witte sank 4,000 more. When Emmermann sank 70,000 tons, Witte sank 6,000 more. Witte’s U-boat was said to have been with U-172 and U-Merten off Capetown during U-172’s third patrol, 19 August 1942 – 27 December 1942. At this time U-Witte was supplied by U-D5 with 10 torpedoes originally intended for U-172 which the latter found she did not need. It was also reported that U-Witte met U-172 on the latter’s fourth patrol, 21 February 1943 – 17 April 1943, in order for the latter to take on Leutnant (Ing.) Josef Hauser to relieve Oberleutnant (Ing.) Dick who was suffering from a stomach ailment.

U-604

	Stated to be sunk. Kapitänleutnant George Lassen was no longer C.O. at the time of her sinking.

U-161

	Stated to have been in Lorient January 1943.

U-170

	The U-boat commanded by Kapitänleutnant Günther Pfeffer (believed to be U-170) was said to belong to the 10th Flotilla. Because the boat is run in a strictly military manor it has been nicknamed “Paragraphenboot”.

U-171

	The mine which sank U-171, according to a prisoner, had been laid by A/C. (O.N.I. Note: U-171 was sank October 1942 off Lorient.)

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U-178

	U-Ibbeken (U-178) was said to have accompanied U-172 on her third patrol, 19 August 1942 – 27 December 1942, in the Capetown area. (O.N.I. Note: U-178 was in South Atlantic at this time, returning from Indian Ocean patrol.)

U-181

	U-Lüth (Known to be U-181) was stated to have returned to Bordeaux in September 1943 from the Indian Ocean. On U-172’s return from her fifth patrol, which ended 7 September 1943, a shadow was seen at night. Torpedoes were readied and Emmermann was on the point of firing when he suddenly realized that the target was a large German U-boat. A recognition signal was flashed and it was learned that the other boat was Korvettenkapitän Wolfgang Lüth. Lüth spoke on the radio with his wife in October 1943. It was claimed that he will make no more patrols.

U-257

	The U-boat commanded by Kapitänleutnant Heinz Rahe (known to be U-257) was a guest boat at Lorient from September to November 1943, according to one prisoner. On 4 patrols she had sunk nothing. Rahe is known as a coward (Angsthase).

U-459

	U-172 was reported to have been supplied early on her 3rd patrol, 19 August 1942 – 27 December 1942, by U-Willamowitz-Mollendorf (U-459). (O.N.I. Note: U-459 was sunk 24 July 1943 off the French Coast.)

U-461

	It was stated that U-461 (C.O. Stiebler) was the second U-boat to supply U-172 on her 3rd or Capetown patrol, 19

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	August 1942 – 27 December 1942. (O.N.I. Note: U-461 was sunk July 1943 off the French Coast.)

U-505

	It was stated that Kapitänleutnant Peter Zschech (know to command U-505) did not return aboard U-505 when she reached Lorient early November 1943. Zschech made 7 false starts out of Lorient and always returned within 3-4 days with some kind of trouble – called “sabotage”. On one of her false starts U-505 was said to have been hit by a torpedo, but the torpedo failed to explode, and the only result was to dent a tank. It was not ascertained whether the torpedo hit was from a plane or a destroyer. Commander-in-Chief U-boats was suspicious of U-505 because Zschech always pleaded ignorance. Later Commander-in-Chief U-boats placed in all secrecy another C.O. on board with Zschech who reported that Zschech was not stupid but a shrewd and able-master of sabotage. U-505 was ordered to sail but did not get through the Bay of Biscay before being attacked by A/C when Zschech mysteriously disappeared from the C/T. Some say that he shot himself, others that he jumped overboard, and many believed that he managed to get to a safe place for the duration. It is possible that he was killed during the attack. U-505’s insignia was described as an axe. Her Executive Officer is named Meyer and the Engineer Officer Hauser (probably Leutnant (Ing.) Josef Hauser). It was also said that U-505 was the only boat of No. 501 – 510 left (O.N.I. Note: If

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	this is correct, it would indicate that U-509 was also sunk and this seems unlikely).

U-508

	U-Staats (known to be U-508) was said to have met U-172 when the latter had been out about a week on her 4th patrol, 21 February 1943 – 17 April 1943. U-508 had been severely damaged by an aircraft attack in crossing the Bay of Biscay and was thought incapable of diving, having 4 holes in her pressure hull. One Diesel was also said to be out of order. The 2 boats proceeded together in a westerly direction to clear the danger zone and at the same time effect repairs. Oxy-acetylene welding equipment was put aboard U-508 and she was made clear for diving in about 2 days of ceaseless work. U-508 then refueled U-172 and headed for Lorient where extensive repairs were commenced.

	U-Staats joined U-172 and U-Lange 2 hours out from Lorient 29 May 1943 when U-172 was leaving on her 5th patrol. U-508 was expected back in St. Nazaire when U-172 was there just before leaving on her last patrol 22 November 1943. Staats had orders to hug the Spanish Coast at Cape Finisterre but was apparently sunk in the Bay of Biscay. He was overdue and his known stock of fuel would have been insufficient. The Executive Officer was reported to be named Buchholz (O.N.I. Note: Jurgen Altmeier, the previous Executive Officer, was due to leave in June but remained for another patrol. He probably left U-508 in September 1943. His successor may have

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	been Leutnant z. S. Armin Buchholz of the 1937 Term).

U-510

	U-Neitzel (known to have been supplied by U-172 on her 4th patrol 16-29 March 1943. Neitzel came aboard that day and was given a cake with the Knight’s Cross of the Iron Cross iced on it in honor of his achievement. The present C.O. of U-510 was reported to be Oberleutnant Alfred Eick. (O.N.I. Note: Neitzel returned in April 1943 and is thought to have left U-510 in May.) The Executive Officer is named Orle (not in G.N.L.). The Second Watch Officer is Leutnant z. S. Gerhard Pokorny, and the Engineer Officer is Oberleutnant (Ing.) Karl Beckmeier. U-510 was in Lorient May 1943 and was reported to have left there late in October 1943, expecting to go to Penang.

U-511

	Stated to have arrived safely in Japan (O.N.I. Note: Her C.O. is Kapitänleutnant Fritz Schneewind). She was expected to return to Lorient on or about Christmas 1943.

U-515

	It was asserted by various prisoners that, having sunk 72,000 tons, U-515 (C.O. Kapitänleutnant Werner Henke) returned to Lorient during the time U-172 was there for overhaul after 7 September 1943. She left 9/10 November 1943. When U-172 was on her way south after leaving St. Nazaire 22 November 1943, she made a detour to avoid a patrol line of 13 – 14 U-boats which was lying in wait for a Gibraltar convoy between the Azores and Portugal. Two boats of this group were those commanded by Henke and Oberleutnant z. S. Jürgen Reese. U-Henke

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	was said to be the contact keeper for “Gruppe Unverzagt” on U-172’s 4th patrol.

	During an attack on a Gibraltar convoy it was said that Henke maneuvered his boat to the center of the convoy and waited for an aircraft carrier. The white-capped water necessitated his painting the C/T white to avoid detection. When warned by the bridge watch that there were 2 destroyers in the vicinity, Henke ridiculed the idea. He was forced to submerge, however, and before he could surface, the entire convoy passed.

U-526

	It was reported that when U-526 ran on an A/C laid mine she was split into 2 parts (O.N.I. Note: This occurred about 500 meters off Port Louis (Lorient) 14 April 1943). The forward half has been raised and towed into drydock at Lorient. It was seen there early in November 1943. The after half is in the process of being raised.

U-530

	Stated to be commanded by an officer named Lange. She was seen at sea June or July 1943.

U-533

	A prisoner described the following attack on U-533 during her 1st patrol April 1943. Proceeding in heavy fog about 6 miles ahead of a convoy, U-533 was rammed, while submerging, by a destroyer which then dropped depth charges. Oil tanks aft were damaged. At dusk near the Azores, U-533 joined 5 or 6 other U-boats which, it was later established, were being

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	chased by 3 convoy destroyers. U-533 was unable, however, to keep pace with other boats due to being heavy with water in her damaged fuel tanks. The destroyer got within 1,500 meters, firing forward guns at U-533 which zigzagged for some distance. When the Engineer Officer reported her speed could not be increased, U-533 submerged. Depth charges were dropped, and one destroyer kept U-533 under for several hours. Due to a heavy oil slick the destroyer probably assumed U-533 was sunk and so left scene of attack. The rest of the patrol and return to Lorient was uneventful. (O.N.I. Note: U-533 was sunk 17 October 1943 in the Persian Gulf.)

U-539

	It was stated that Oberleutnant Hans Jurgen Lauterbach-Emden commands U-539 and not U-378. One prisoner asserted that Lauterbach-Emden’s U-boat belonged to the 10th Flotilla while another called it a guest boat at Lorient. She was still there when U-172 left Lorient 13 November 1943.

U-710

	U-Carlowitz (O.N.I. Note: Reported to be U-710, sunk May/June 1943.) a 500-tonner, was sunk, according to a prisoner, off Iceland on a line from Glasco to Reykjavik. She was attacked by A/C whose bomb explosions could be heard by U-533 when she was submerged. (O.N.I. Note: It appears that U-533 was in the vicinity of U-710 on her 1st patrol, that she was later attacked by gunfire from a Catalina and 3 of her crew wounded, and that these events probably

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occurred before those narrated above.)

U-847

U-Kuppisch (known to be U-847) was said to have supplied U-172 on or about 28 August 1943 with some 30 tons of fuel oil. U-Kuppisch was thought to have been sunk 2 days later as there was no answer to repeated calls from Commander-in-Chief U-boats to report her position. U-847 was en route to Japan at the time. Her fuel capacity was 525 cu. meters and she carried 29 torpedoes and a helicopter. Her armament was described as follows:

On Platform I	-	2 twin 20-mms.

On Platform II	-	1 twin 20-mm.

On after deck	-	1 37-mm.

On forward deck	-	1 105-mm.

U-952

U-Curio (known to be U-952) was reported as belonging to the 10th Flotilla.

U-D5

U-D5 was said to have supplied U-Witte (U-159) with 10 torpedoes in the vicinity of Capetown during U-172’s 3rd patrol, 19 August 1942 – 27 December 1942.

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U-BOATS IDENTIFIED BY COMMANDERS

U-Achilles

	It was reported that Korvettenkapitän Albrecht Achillies once entered Lorient with only half his bridge. He had torpedoed a ship and wanted to escape under her, but she suddenly sank carrying away part of the C/T. (O.N.I. Note: Achilles formerly commanded U-161 and later U-320.)

U-Arco-Zinneburg

	According to a prisoner, Leutnant z. S. Ulrich-Philipp Graf von and zu Arco-Zinneberg, never served on U-617. After leaving U-117 on which he served as Second Watch Officer, he went to C.O. School and now commands a 500-ton schoolboat in the Torpedo Firing Flotilla at Hela.

U-Barleben

	It was said that an officer named Barleben (not in G.N.L.) has a Flak U-boat based on Brest but frequently operating out of Lorient. The Engineer Officer of this boat is named Baumewerd. (O.N.I. Note: This is probably Leutnant (Ing.) Antonius Baumewerd of the December 1939 Naval Class.)

U-Bauer

	A C.O. named Bauer was said to have a 10th Flotilla U-boat.

U-Burghagen

	Kapitänleutnant d. R. Burghagen was reported as having a 1600-ton minelayer. (O.N.I. Note: It was thought at one time that Burghagen had U-490.) She was

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	fitted with twin mounts and carried mines only. Having left Kiel in August 1943, possibly with U-841, she was proceeding to Bordeaux at the end of her first patrol when she supplied U-172 on the night of 10/11 December 1943. A few days earlier she had supplied U-103, C.O. Gustav Adof Janssen, who was also on his way into port. Four other boats had been supplied by Burghagen on this patrol. Burghagen received a Borkum G.S.R. from U-172. Her operation area was said to be close to but a little to the south of the area where U-118 did her supplying (Near Maderia and the Canaries). (O.N.I. Note: Her operational area has also been reported as being the Indian Ocean.)

U-Burkhardt

	U-Burkhardt was said to be a 1600-ton supply boat. It was believed she was sunk late in 1943.

U-Keller

	U-Keller was said to have met U-172 on the latter’s 4th patrol, 21 February 1943 – 17 April 1943 and to have transferred an ailing 48 year old Engineer Officer for transportation to France. (O.N.I. Note: Oberleutnant Siegfried Keller was reported a casualty in May 1943.)

U-Kuhnke

	Korvettenkapitän Kuhnke was still in charge of the 10th Flotilla in November 1943, according to a prisoner.

U-Kummetat

	Oberleutnant Heinz Kummetat was reported to have shot down a plane and escaped from 6 others in June 1943.

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	(O.N.I. Note: Kummetat was reported a casualty in October 1943.)

U-Lange

	A 750-ton U-boat commanded by an officer named Lange was said to have left for Lorient 2 hours before U-172 and then waited for her at a point 2 hours out. Somewhere below the Azores and above the bulge of Brazil U-Lange supplied U-172 and transferred a torpedo rating to her. (It is not known which Lange this might be.)

U-Müller

	It was stated that in April 1943 U-Müller participated with U-172 in an attack on a Gibraltar convoy. U-Müller was depth charged, and 6 torpedoes in the upper deck containers exploded. The explosions could be heard for miles and practically ripped the top deck off. U-Müller reached a depth of 250 meters before regaining control of his boat. U-Müller returned safely, however, to Lorient. It is not known which Müller this might be.)

U-Reese

	When U-172 was on her way south after leaving St. Nazaire 22 November 1943, it was reported she made a detour to avoid a patrol line of 13 – 14 U-boats which was lying in wait for a Gibraltar convoy between the Azores and Portugal. Two boats of this group were those commanded by Oberleutnant Jürgen Reese and Henke (U-515). The Executive Officer on U-Reese is named Perkonig and the Engineer Officer is named Schindler (O.N.I. Note: These officers

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	are probably Leutnant z. S. Winfried Perkonig and Leutnant (Ing.) Rudolf Schindler, both of the December 1939 Naval Class.)

U-Scholz

	Oberleutnant Günther Scholz was said to have been Executive Officer on U-172 at one time and later C.O. of a 500-tonner. He was killed in a motor accident.

U-Wolfram

	The U-boat commanded by Kapitänleutnant Rolf Wolfram was believed to have been sunk.

U-BOATS IDENTIFIED BY INSIGNIA

GALLOPING OR JUMPING HORSE

	A U-boat of the 2nd Flotilla Lorient was said to have a galloping or jumping horse as its C/T insignia.

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CHAPTER XV. BASES

BREMEN

	A prisoner reported having seen 2 U-boats at Bremen, one of which was hidden by piles of lumber in the east corner of Hafen II near the Officers’ Barracks; the other was hidden in the southeast edge of the Werfthafen in such a way as to simulate a continuation of the mole.

DANZIG

	A great amount of repair work on U-boats is done at the Holmwerke, which is described as a tremendous yard. It does not build U-boats.

FLENSBURG

	Between 29 March 1943 and 29 June 1943 the following were instructors of Torpedomaatenlehrgang in Flensburg:

	Obermechaniker Teiss – (now Leutnant)

	Obermechaniker Gelsbirger – Fire Control

	Oberleutnant Wittkopf-Emden – Mathematics

	A Silberling with three stripes taught Chemistry.

	Oberfeldwebel Albers was an instructor in UTWL School in Flensburg, August 1943.

GOTENHAFEN

	The Neuewerft is said to be a branch of the Deutsche Werke of Hamburg. Neuewerft does repair work, but builds no U-boats.

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	Korvettenkapitän Wilhelm Ambrosius is C.O. of the 27th Flotilla at Gotenhafen.

HELA

	Korvettenkapitän (Ing.) Müller is C.O. of the Agru-Front. Kapitänleutnant (Ing.) Gerd Suhren has never been C.O. of the Agru-Front. He is with the O.K.M. in Berlin. He did conceive the idea of the Agru-Front and for a time supervised it a Hela.

KRISTIANSAND

	The 14th Flotilla is being established here, but it had not yet been set up early in November 1943. No C.O. had been appointed. It is to consist of new U-boats from the Baltic. The base at Bodö will come under the administration of this Flotilla.

LORIENT

	F.P.N. of the 10th Flotilla is M-47499.

	When U-172 was at Lorient, it was the only 10th Flotilla boat present. From the 2nd Flotilla only two boats were present. There was a total of only 10 U-boats in Lorient.

	The Flotilla Commander lives in the officers’ shelter, and had his offices and Geheimschreibstube in the Prefektur shelter.

	It was stated that Korvettenkapitän Schaefer was no longer 10th Flotilla Commander when U-172 left Lorient.

	Obermechaniker Reinecke gave a short lecture course on T-5 in Lorient, 9 November 1943.

	Fahrenkamp is now a Kapitänleutnant vom Stabe at Lorient

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	and is known for his incompetence. He is ridiculed as “Die Perle der Flotte”, “Der Sonnenschein von Lorient”, and is also called “Fieseler”, “Gayer Willi” and “Bunkerknacker”.

	Korvettenkapitän (Ing.) Zerpka was shot by a midshipman sentry while Zerpka was snooping about the bunkers. The shooting was said to be “accidental”. (O.N.I. Note: Korvettenkapitän (Ing.) Zerpka has been known to be at Pillau and was said to be at Neustadt July 1943.)

	Anti-invasion measures: A condition of alarm or readiness, known as “Alarmstufe I” has been established in case an invasion strikes. In this case everybody goes to the U-boat shelters. Any U-boat in wet dock (even if only part of the crew is on board) leaves at once. Emergency rations are available for just such a situation. When finally out of the dock, the boat must report on “Kustenschaltung” and is then given its orders. If unable to contact Control, the boat is to be scuttled in shallow water by opening valves and by placing charges against the pressure hull between the torpedo tubes in the Bow and Stern Compartments. This procedure is said to enable the boat to be salvaged easily if invasion is repelled. As for U-boats in dry dock, only the incline up to the shelters is to be blown up. The boats themselves are to be readied for blowing up. But may be blown up only upon receipt of additional orders.

	Hundius: It was confirmed that the Hundius Barracks are still in limited use. Officers of the 10th Flotilla personnel reserve are still there. The Kino is still in operation. There is a new mess in the old Soldatenheim on the other side of Cours Chazelles.

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	Keroman: New wet bunkers are under construction and are to be entered from the Fischerhafen. They will be joined to the old dry bunkers by a roof. The transfer railway is also being extended.

	Northeast and southeast of the wet bunkers, the Atlantic Wall defenses have emplacements for “Mittlere Pak” (Panzerabwehrkanone: anti-tank guns). The latter have not yet been installed. There are also buried revolving turrets (the turrets of old French tanks) with anti-tank and M.G. The A/A for the bunkers is 37-mm. and 40-mm.

	There is a fresh excavation at Keroman 1 and 2. Its purpose is not definitely known.


	Excavation inside dotted line above K1 and K2 in process November 1943. Ps/W thought might be intended for railroad terminal and storage.



	The shelters shown at Kernevel are the only concrete

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	shelters known to P/W. They are no longer used by 10th Flotilla.

	It is confirmed that the main radio station formerly in Lorient is located in a bunker at Kerneval

	It is confirmed that the main radio station formerly in Lorient is located in a bunker at Kerneval

	An extra 2 meters of air-cushioned roofing (“Federdecke”) have been added to the bunkers.

	Lager Caudan: Lager Caudan is located about 8 kilometers from Lorient and about 2 kilometers from Caudan. The camp was first used in the fall of 1943, but was not yet completed in November 1943. The direct road from Lorient to Pont Scorff does not pass by Caudan. Lager Caudan consists of at least 13 buildings, each building capable of housing 60 men. The officers’ barracks are separate. A new mess is under construction. The camp has no A/A and no air-raid shelters.



NEUSTADT

	The 3rd U-boat Training Division is at Neustadt.

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ST. NAZAIRE

	Kapitänleutnant Carl Emmermann is C.O. of the 6th Flotilla here. It was said that in November 1943 there were three 500-ton U-boats and two 750-ton U-boats in the wet bunkers at St. Nazaire. Two minelayers were said to lie nearby.

	It was said to be a new practice for U-boats to put into St. Nazaire before putting to sea on patrol, in order to receive the newest type of torpedoes there. (O.N.I. Note: This was true in the case of U-172 on her last patrol, but how extensive the practice may be is not known. This information should be treated with great reserve.)

REST HOME

	There is a large rest home (Erholungsheim) for U-boat men at Echternach in Luxembourg.

GENERAL

	SCHULTE and KUHNKE are both being relieved of their jobs as Flotilla C.O.s and are going to sea again.

	There is a rule that no officer may serve as Flotilla C.O. for more than two years.

	Flotillas:

	4th Flotilla: P/W heard that Fischer is no longer C.O. of this Flotilla. He does not know who replaced him.

	5th Flotilla: Moehle is still C.O.

	6th Flotilla: Ex Schultz, now Emmermann.

	8th Flotilla: Eckermann (known as Lowen Poll) has left. Von Schmidt

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	now has this Flotilla.

	12th Flotilla: C.O. Scholz.

	20th Flotilla: Hela. Vortaktische Flotilla.

	21st Flotilla: Pillau. C.O. Schuhart.

	22nd Flotilla: C.O. Ambrosius.

	23rd Flotilla: Danzig. Kommandanten Schiess Flotilla. C.O. von Bülow.

	24th Flotilla: Memel. C.O. probably not Barmgarten.

	25th Flotilla: Is in Lebau, 2nd taktische Flotilla.

	26th Flotilla: Pillau. C.O. Wolf.

	27th Flotilla: Gotenhafen. C.O. Topp.

	14th Flotilla has not yet been set up early in November 1943. No Chief had yet been appointed. It was to be composed entirely of new boats from the Baltic and is being established at Kristiansand. The base at Bodö will come under the administration of this Flotilla.

	The target ship of the 26th Flotilla is the torpedo boat VEGA.

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CHAPTER XVI. GENERAL REMARKS ON U-BOATS


NEW U-BOAT SERVICE INSIGNIA

	A badge similar to the regular U-boat Insignia but with an aircraft above the U-boat is now awarded for deck service through three aircraft attacks on a U-boat, which have been successfully driven off.

NEW WANZ

	It was said that a new Wanz was available (presumably Wanz-G3), which covered wavelengths from 1.20 m. to 2.40 m., otherwise it is thought to be identical with Wanz-G2. The reason for going to 2.40 m. was said to be because signals had been received on this wavelength with Metox apparatus.

JAMMING OF ENEMY TRANSMISSIONS

	Distress and other signals of merchant vessels on 600 meter wavelength were always jammed on U-172, whenever they heard such transmissions.

SUPPLY U-BOATS - COMMUNICATIONS PROCEDURE

	Formerly a supply U-boat, when preparing to meet a group of boats she was to supply, would take over Control herself. Long wave only was used for this traffic and the whole communications procedure was, therefore, quite independent of and even unknown to

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	Central Control. This implication seems to be that supply boats carried a special transmitter for this purpose since the prisoner stated that “even the equipment for this has been removed”.

	Now that system has been changed and rendezvous are entirely arranged by Control. The prisoner said that too many supply boats had been lost due to the old system, presumably because our planes could D/F these long-wave transmissions and the volume of traffic put out by the supply boat was too great.

	1. Under the present system Control gives a U-boat to be supplied two rendezvous at different times so that if a boat fails to reach the first rendezvous she can reach the second without the need of making any signals to Control.

	2. U-boats are strictly forbidden to use their radios under any conditions whatever in an area where they are within 200 miles of the supply meeting point. Should a U-boat have a message of great urgency to transmit it must proceed beyond the 200 mile line before transmitting it. After a U-boat has been supplied it will pass the 200 mile line and then make a report to Control on its refueling and also as to which boats are still being supplied as well as any other message which a supply boat whished to have transmitted to Control.

	3. The implication seems to be that supply boats do not use their transmitters at all on patrol.

SUPPLY BOAT PROCEDURE

	Orders were said and have been issued all Supply U-boats to the effect that they remain submerged at all times, surfacing at night only long enough to recharge batteries.

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INFRA-RED SIGNALLING

	The same P/W states that he believes all U-boats are equipped with Infra-Red signaling devices. There are two types of equipment for this purpose. One type operated by a dry cell battery and serves to signal only. A special pair of binoculars mounted on the bridge and separated from this apparatus is then used to read the signals. Another type consists of an apparatus which is plugged into a socket in the Conning Tower and has no batteries but incorporates the special binoculars within the same unit. He states that these apparatus operate on a very high voltage but a very low wattage (1 to 2 watts). He claims these apparatus are only used for signaling and not to observe whether a U-boat is being detected by Infra-Red search lights. He had never heard the word “Seehund” applied to this gear.

ANTI-INFRA RED PAINT ON U-BOATS

	An officer P/W from U-172 states that the Anti-Infra-Red paint formerly used was almost black and that U-boat Commanders objected to it because it made the boats too visible when surfaced in daylight. He states that German scientists have now developed a new Infra-Red paint which is almost white. He believes that boats so painted are now operational.

BISCAY PRACTICES

	The point where escorts meet U-boats approaching Lorient is called “Punkt Gabel”.

	All use of radio by U-boats while in the Bay of Biscay is

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	said to be forbidden.

	There is said to be a permanent group of 15 U-boats, which operates out of the Biscay against convoys between Gibraltar and the United Kingdom.

	It was claimed to be a new practice for U-boats to proceed submerged, as far as the Equator except for brief surfacings at night to recharge the batteries.

	It was claimed that the Bay of Biscay area was very quiet as U-172 passed through it, but that the Azores area had become much more dangerous. It was stated that it now required 3 weeks to get out into the Atlantic.

NEW PATROL TACTICS

	The following procedure would seem to apply to the permanent group mentioned above:

	These boats, following a new tactical procedure, remain submerged at all times, each in its own operational square. They come up at night to charge batteries and come to periscope depth at Programmzeit to receive orders. The area in which the convoy is expected is searched by He 177 planes carrying FX bombs. These planes will attack the convoy if they sight it while they still have sufficient endurance but will in any case report the sighting and the U-boats will then assemble for the attack. P/W says that his tactic was evolved because when a surface patrol line was set up or even one at periscope depth, this was usually detected by Radar and the convoy then made a detour to avoid attack.

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AZORES COURSE

	Since mid-November 1943 U-boats going to the South Atlantic from Biscay Ports have orders to steer a course about halfway between the Azores and the Coast of Portugal. Previously their orders were to keep west of the Azores.

DECK WATCH IN ST. NAZAIRE

	It was claimed that 12 men stood watch on U-172 while she was docked in St. Nazaire.

MAXIMUM DIVE

	It was claimed that on one occasion, U-172 had reached a depth of 280 meters.

DIVING PROCEDURE

	It was the practice of U-172 to run the motors/generators at 3/4 speed when diving until the desired depth was reached - possibly up to 100 meters.

MECURY TO JAPAN

	U-boats running to Japan have their keel plates removed and the space filled with mercury. It was said that a million marks worth of mercury had been shipped to Japan.

U-BOATS IN THE ORIENT

	It was reported that more U-boats were gathering in the Indian Ocean and Gulf of Persia to intercept supplies to Russia and to find a hunting ground less “dangerous” than the Atlantic.

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NEW ARMAMENT

	It was reported that many of the 750-ton U-boats are being still more heavily armed. The machine guns on the Bridge will be dual. The quadruple 20-mm. gun is said to replace the 2 single or twin 20-mm. guns on Platform I, and a 37-mm. automatic gun is being installed on Platform II.

	One prisoner also reported seeing U-boats in St. Nazaire with a 40-mm. gun on Platform II. This was during mid-November 1943

ROCKET PROJECTORS

	A prisoner reported hearing that U-boats are now being equipped with a type of Rocket Projector similar to that in use by the German Army. He described this as a “Nebelwerfer”. It is mounted abaft the Bridge on Platform I and fires a rocket filled with liquid air. He states that this is thought to be effective both against aircraft and surface ships. U-172 was supposed to be fitted with this equipment before leaving on her last cruise but would in any case be so equipped on her return. The material for this fitting had not arrived in St. Nazaire in time before U-172’s scheduled departure. Another rumored mounting was to be in batteries of 4 each to port and starboard on Platforms I and II, or 16 projectors to a boat. The caliber was expected to be between 80 and 100-mm.

NEW TYPE U-BOAT

	It was reported by a reputable prisoner that Type VII-F

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	boats were being built by Germainiawerke at Kiel. They are said to be very similar to the well-known type VII-D boats, and their numbers are believed in the low 300’s. They are definitely not converted VII-D’s. The torpedo room includes the space occupied by the mine-shafts and is said to enable the stowage of 26 torpedoes inboard. These boats are fitted with special loading rails on deck and are the only true double-hulled U-boats in the German Navy. The prisoner was emphatic that these boats were combat vessels, not merely torpedo carriers or supply boats. They were expected to provide a valuable invasion weapon.

TORPEDO CARRIERS

	According to another prisoner, at the school for torpedo ratings at Flensburg in the spring of 1943, one of the instructors said U-boats of the same type as U-215 have been converted from minelayers to torpedo-carriers. (O.N.I. Note: U-215, now sunk, was one of a series of 500-ton Type VII-D U-boats constructed by Germania Kiel. It is believed there were 6 U-boats in this series.) The mine shafts which were between the Control Room and the petty officers’ quarters have been removed and in their place a special torpedo room has been constructed. In this room 30 torpedoes are carried. This number added to the normal number of torpedoes carried in such a U-boat gives a total of 42 torpedoes on board.

FURTHER NEW TYPES

	A new type of U-boat known as VII-C 42 is now in existence.

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	This boat can dive to 400 meters and is guaranteed for this depth. All frames are double. The pressure hull is heavier and hatches and caps proportionally strengthened. He thought these boats were numbered above 1,000.

	It was stated that some 1200-ton U-boats are equipped with 6 V-type Mercedes-Benz engines and that such boats had attained a maximum speed of 24 knots. This type had not performed satisfactorily, however, as the number of R.P.M. was much too high for U-boats, and furthermore these motors frequently blew out their cylinder heads. It is thought that no more boats will be equipped with this type of engine.

NEW DIESEL COMPRESSOR

	P/W states that a new compressor is available for GW Diesels. This gives a maximum surface speed of 20 knots with the existing GW Diesels. M.A.N. has developed a new type of 6-cylinder motor for U-boats much smaller than previous models but very effective.

EXTENSIBLE DIESEL INTAKE AND OUTLET

	P/W claims that a number of U-boats have been equipped so as to enable them to proceed on their Diesels at periscope depth, (13 meters). This is done by means of a streamlined intake shaft mounted directly abaft the Bridge. The exhaust is 30 cm. below the intake so that exhaust gases and fumes are absorbed up to 60% by the water. When not in use the intake and exhaust shaft is lowered horizontally to the deck, much as was the case with the extensible

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	lookout masts in use at one time. The shaft is raised and lowered hydraulically. This is the only method for submerged Diesel propulsion of which the prisoner has heard and is related to previous Dutch experiments. It is a great improvement over them, particularly the provision for hydraulic raising and lowering. He believes this system has only been fitted to 500ers to date. Early experimental models had had the intake mounted with the large periscope, but they had proved unsatisfactory.

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CHAPTER XVII. SUBMERSIBLE SPEED BOATS

An officer prisoner of U-172 has seen and known of a type of submersible speed boat known as the “Walterboot”. This boat bears the name of its inventor, Professor Walter. The prisoner saw Walterboote on several occasions, for the first time at Hela in the summer of 1942. In the fall of 1943 he saw such a boat in dry-dock in Gotenhafen, but was unable to approach sufficiently close to get a detailed view of the hull. His drawing (Plate 11) gives his impression of a Walterboot.

It was stated that the German High Command would use these submersible speed boats to blockade British ports, and for other counter-invasion measures. The operational area might be chiefly the Bristol Channel and St. Georges Channel. These boats are supposed to proceed to their operational area without assistance. All attacks are to be carried out on the surface.

Walterboote are being built by Howaldt Werke and the Deutsche Werke at Kiel. Some are also being built at Pillau. The position of the slips for Walterboote at the Deutsche Werke at Kiel is in the S-Boot Werft, in the place where the GRAF ZEPPELIN lay in the summer of 1941. The position of the slip at the Howaldt Werke is believed to be in the front of the yard. Slips at the Deutsche Werke and Howaldt are covered. The Walterboote at Pillau are located in Neuer Hafen, where the 26th U-boat Flotilla used to lie. Positions at Hela are in a covered dock on the landward side of the harbor opposite “Swakopmund” in a corner formed by two

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wooden piers (see U-boat Bases File, Map of Hela, between positions 5 and 8). Exercises are carried out in the Danziger Bucht. Walterboote are not built at Gotenhafen. The number of Walterboote under construction or already in service is not known. The prisoner said that in October 1943 there were 20 such boats on the ways at Deutsche Werke, Kiel, and that a building program of 100 to 150 boats was in progress.

It is believed that the maximum effective range of these boats is 500 to 600 miles at flank speed (A.K.). The submerged endurance is of 50 to 60 hours, and this depends on the success the boat has in producing its own oxygen. The surface speed is said to be somewhat in excess of 40 knots, and the submerged speed (at a depth of 30 meters) is 30 knots. For diving, the Walterboot uses diving tanks and hydroplanes. Depth control gear is fitted.

It is the prisoner’s opinion that Walterboote would be difficult to detect. When surfaced and proceeding in a sea strength of four or five, they probably could not be seen, or detected by radar, as only a small part of the plastic C/T would protrude occasionally from the waves.

Propulsion is accomplished by an internal combustion turbine. This turbine requires for its construction special metals to withstand extremely high temperatures. It was the scarcity of such materials which at first delayed the building program of Walterboote, but the difficulty has now been overcome.

The fuel consists of a powder which is packed in sacks and which is of such a composition that it requires very little

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oxygen during combustion. In its use the fuel is combined with seawater. In some manor not understood, the exhaust gasses are used to produce oxygen. Walterboote could be refueled by supply boats.

The Walterboot is said to have two torpedo tubes forward. Torpedoes are said to be smaller than 21 inches. They can be loaded normally only when the boat is in dry-dock or is hoisted out of the water. The prisoner has heard, however, of a method of loading torpedoes while afloat by means of a pressure chamber. No reloads are carried.

According to various sources: A Walterboot has a displacement of 150 tons; its pressure hull is not proof against A.P. 37-mm.; it might carry demountable M.G.s; it is not fitted with a periscope; it has no degaussing gear; and protection against magnetic mines consists of keeping the whole boat shorted on low tension current. Reliance is placed on speed to avoid depth charge attacks. It was stated to carry a crew of 18 men.

The prisoner states that the Germans have abandoned the building of midget U-boats, and that the proposed use of human torpedoes has been dropped, as German naval personnel is considered temperamentally unsuited for the execution of “suicide missions”. It would seem that the Walterboote are considered superior to midget U-boats and human torpedoes.

The prisoner stated that a friend of his, Kapitänleutnant Werner Klug, who was formerly in the U-boat service as executive officer under the outstanding U-boat ace Korvettenkapitän Topp, is now commanding one of the new Walterboote.

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CHAPTER XVIII. GERMAN DESTROYERS

DESTROYERS

A P/W from U-172 stated that the only destroyers and torpedo boats in Bay of Biscay ports are one of the so-called Fleet Torpedo Boat types, which he saw in St. Nazaire, and 8 Narvik types in Bordeaux.

The P/W knew nothing of two destroyers recently sent to the Bay from Germany. He thought that there were no destroyers there in the summer of 1943, and that all those which are now there came in the fall of that year. He believed that they were used for escort work, but that their main purpose was to prevent British destroyers from coming too close to the coast, and to assist in repelling an eventual invasion.

The prisoner did not believe that destroyers or torpedo boats were operating in the Channel. He stated that escort duties in the Channel were carried on by smaller craft.

According to the prisoner, the main base for destroyers and torpedo boats is at Brest, which has a very suitable anchorage and adequate fuel facilities. The only other port with suitable fuel facilities, the prisoner stated, is Bordeaux. He explained that St. Nazaire is undesirable because of its narrow locks, and that Lorient and La Pallice are poorly equipped for fueling.

The prisoner stated that other units on the French Coast are employed for mine-laying and escort duties, and that destroyers and torpedo boats are used for training personnel only when in port.

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The prisoner stated that destroyers and torpedo boats hold the highest priority for fuel, whereas large units more or less immobilized in the Baltic are supplied with steam for heating and for accelerating the machinery from ashore.

The prisoner believed that the HIPPER was being refitted for training purposes, and that the LUTZOW, which returned from Norway to Gotenhafen the first or second of October 1943, was also to be refitted for such purposes. But he claimed that the SCHEER and the EUGEN were not used for training.

The prisoner believed that U-boats and surface vessels are always escorted out of harbor by Sperrbrechers, normally to the 200 meter line. If the weather is too rough, escorts frequently turn back. V-boats, UJ-boats and minesweepers are also used for escort duties in the Bay.

P/W had very little information on German minefields in the Bay, but believed that minefields have been laid only close to port.

P/W said that the secondary armament of the LEIPZIG, NUREMBERG, and KOLN consists of 88-mm. guns used as A/A. He did not think that they carry any 105-mm. guns.

P/W said there are two types of Elbing class destroyers, which he described as follows:

One stack type: Displacement, 600 tons.

Speed, 34 knots.

Machines, high pressure steam.

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Armament, one 37-mm. forward.
two 20-mm. A/A on Bridge.
two twin 20-mm. A/A aft.
one 105-mm. aft.
six torpedo tubes amidships.

Propellers, two

Identification numbers, T1 to T20.

This type probably does not carry mines.

Two stack type:

Armament, one 105-mm. forward.
one 105-mm. amidships.
two 105-mm. aft.
four torpedo tubes.

DESTROYER ENGINES

An officer P/W from U-172 claims to know that M.A.N. has built a new type of Diesel engine for destroyers. These are to be mounted on a new type of 1500-ton destroyers now under construction, to be ready in the Spring. These Diesels are said to produce 60,000 H.P. (this figure is dubious). On three shafts - the two outer shafts 10,000 H.P. each, the central shaft 40,000 H.P. Cruising speed is 31 knots, maximum speed 41 knots. Cruising radius at cruising speed 10,000 miles. At top speed, 6,000 miles. The engines are said to be laid on special mountings so designed that practically no vibration is transmitted to the hulls.

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CHAPTER XIX. MISCELANEOUS

FOXERS (FX GEAR)

The Chief Radioman of U-172 amplified the statements previously made by a radioman of the same boat concerning the use, by the destroyers which hunted and sank their U-boat, of what he called “Heulbojen”. He stated that the destroyers were towing some sort of buoys which made a high-pitched buzzing sound. He stated that this buzzing so filled the water with sound that it was impossible to get a bearing on the destroyer until she was almost right on top of the U-boat. Only at short range was it possible to get a bearing on the propellers. The buzzing sound could not be located within 180⁰.

The Chief Radioman stated that if a man had sufficient practice on the listening gear and kept his frequency around 500 to 600 cycles, he should be able to distinguish the propeller noise from the buzzing noise, but the Chief Radioman thought this would take considerable skill.

The Chief Radioman was surprised that the other radioman had been unable to get a bearing on the destroyer.

HAMBURG RAIDS

An officer P/W from U-172 who was in Hamburg in October 1943 stated that during the heavy air raids on Hamburg 13,000 people were burned to death in an air raid shelter, apparently in the port area. Phosphorous from incendiaries, carried inside by refugees on their clothing, ignited. This heat, plus that penetrating


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the thin walls of this shelter, literally roasted the inmates, whose bodies later were found to be charred masses about a yard long. Egress from this shelter was impossible on account of exits being blocked by debris from surrounding buildings. Several heavy air raid shelters of the bunker type located in the central part of the city were stated to have withstood the attacks and saved the people inside. The informant did not know whether or not the Elbe tunnel had collapsed.

BATHYTHERMOGRAPHS ON U-BOATS

A reliable prisoner stated that he was acquainted with the Bathythermograph which bears the German nick-name of “Lachs” (literally “salmon”). As far as he knows this is never carried by U-boats on patrol but he thought that it was built into weather buoys. It might be carried by boats carrying meteorologists. If a boat remains submerged for a long time it is constantly to take samples of the water every half hour to determine the density. This might be done more frequently if the boat shows a tendency to rise or fall.

WW WEATHER REPORTING

A reliable prisoner states that it is a very rare occurrence for a U-boat to be called on to transmit a weather report. U-172, on six cruises, was only called on once to transmit a weather report. He states that some boats now carry a meteorologist. Such meteorologists have a special code of their own which is not known to the radioman on the U-boat. The radioman is simply handed the

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encoded message by the meteorologist and puts it through the machine in the usual manor. One of the boats said to have carried a meteorologist is the one commanded by Hungershausen (believed to command U-91).

OFFICER OF WALTER BOAT

Kapitänleutnant Werner Klug formerly Executive Officer under Topp has command of one of these boats.

JAPANESE SUBMARINE PASSENGERS

Japanese submarines, one of which came to Brest in 1942 and one to Lorient in 1943, brought what were officially described as diplomats but what P/W thought to be technical experts. He was conceived that they had come to Germany to learn, not to teach. The Japanese U-boats were fitted with German A/A/ armament while in Biscay Ports.

BOOBY TAPS

A radioman from U-172 stated that a message was received by their boat from B.d.U. warning all U-boats to keep away from drifting rafts, lifeboats and airplane wrecks, as such objects were believed to be fitted with booby traps in the form of mines or depth charges. The radioman stated that one U-boat had been destroyed by such a device.

HUMAN TORPEDOES

A prisoner from U-172 saw a new type of human torpedo at Hela. This was said to be different from the Italian model which

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the Germans have now rejected. In this new type, a special tail piece remains after the torpedo has been fired. The operator is supposed to be able to get away on this tail piece. It is said to have enough power to last one day. It is not clear whether by one day is meant 12 hours or 24 hours.

GERMAN GUN BARRELS

Centrifugal casting of gun barrels is unknown in Germany. Conventional methods are still in use. A/A guns of unstated bore are said to be extremely long, being of 60 to 65 caliber.

NEW DRY BATTERY

There are said to be very small dry batteries built by Hagen. Prisoner stated that these had twice the power of ordinary batteries in one half the volume. This he thought would permit greatly increased submerged endurance and increased submerged speed.

POLICY WITH REGARD TO SPAIN

A radioman from U-172 stated that on her last voyage U-172 received a message from Control to the effect that Spain was under British pressure. Spanish ports were to be used only in case of extreme emergency. If used, the boats must leave the port by the standard specified time and not considerably later as had frequently been the case. U-boats were instructed to accept no help whatever from Spanish tugs, trawlers, etc.

A prisoner who formerly served on U-66 under Kapitänleutnant Markworth stated that when U-66 was returning from the cruise on which

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she laid mines in the entrance to Port Castries, in late September 1942, the Chief Engineer realized that she had insufficient fuel to make Lorient. Standing orders at that time were that the Bay of Biscay must be crossed at full speed. The amount of oil available four days before entering Lorient was very carefully established by pumping all fuel tanks. The Chief Engineer then realized that he was short 7 to 8 tons and a signal was sent to Control to this effect. An order was then received from Control to proceed to square so-and-so. This square turned out to be the harbor of El Ferrol. The German tanker “GEORG ALBRECHT” (6-7,000 tons) was anchored here, approximately 200 meters from the pier. U-66 entered the harbor about 2300 and left again between 0330 and 0400. Twelve tons of fuel were transferred in less than an hour by the tanker’s very powerful pumps.

U-66 had on board a fireman 3rd class (Maschinengefreiter), Helmut Ehrilichmann, who was seriously ill. He was transferred to the tanker and sent to a hospital in El Ferrol where he was operated on. After about 18 days he reported to the German Embassy in Madrid in civilian clothes and was sent back to Germany where he was given convalescent leave but turned up again at Lorient in time to participate in U-66’s next cruise which began on the 9th of November 1942.

Prisoner also knew of 2 tankers, one of 10,000 tons and one of 15,000 tons, which are anchored in Vigo and frequently refuel submarines. The crews of these tankers he believes to be civilians and are given leave in Germany once a year.

SPANISH OFFICERS AND RATINGS

An officer P/W from U-172 states that he had seen a number

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of Spanish officers and ratings in Baltic ports. He states that a Spanish naval officer with two and one-half stripes had made the tactical exercises, and had stood by for the construction of U-533. The officer P/W understood that this Spanish officer was to command U-573, which had been sold to Spain.













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ANNEX: CREW LIST OF U-172 AND U.S. EQUIVALENTS

OF GERMAN NAVAL RANKS.

	Name	Rank	USN Equivalent	Age

		Kapitän z. S.	Captain
		Fregattenkapitän	Commander
		Korvettenkapitän	Lieut. Commander
		Kapitänleutnant	Lieutenant
	Hoffmann, Hermann	Oberleutnant z. S.	Lieutenant (j.g.)	22
	Coreth, Maximilian	Oberleutnant z. S.	Lieutenant (j.g.)	24
	Heitz, Friedrich Wilhelm	Leutnant z. S.	Ensign	23
	Löffler, Alfred	Leutnant (Ing.)	Ensign (Engineering)	25
*	Vole	Oberassistenzarzt
	Schröter	P.K. und Artilleriemaat	Press Correspondent and
			Gunner’s Mate 3cl
	Duwe, Karl	Obersteuermann	Quartermaster of Warrant Rank	24
	Schmidt, Erich	Oberbootsmaat	Boatswain’s Mate 2cl	25
	Plottke, Herbert	Bootsmaat	Coxswain	23
*	Pardayke	Bootsmaat	Coxswain
	Gehrke, Walter	Obermaschinist	Machinist	30
	Schubert, Max	Obermaschinist	Machinist	29
	Holzke, Heinz	Maschinenobermaat	Machinist’s M. 2cl	23
	Lemke, Otto	Maschinenobermaat	Machinist’s M. 2cl	24
	Markgraf, Arno	Maschinenobermaat	Machinist’s M. 2cl	26
	Banse, Ewald	Maschinenmaat	Fireman 1cl	23
	Hoffmann, Walter	Maschinenmaat	Fireman 1cl	26
	Peter, Alfred	Maschinenmaat	Fireman 1cl	23
*	Schuy, Baldazar	Maschinenmaat	Fireman 1cl
	Hässler, Hans	Oberfunkmaat	Radioman 2cl	24
	Birnstiel, Werner	Funkmaat	Radioman 3cl	21
	Schneck, Karl	Mechanikermaat	Torpedoman’s Mate 3cl	20
	Christiani, Heinz	Matrosenobergefreiter	Seaman 1cl	21
	Hülsmann, Ernst	Matrosenobergefreiter	Seaman 1cl	18
	Krüger, Bernhard	Matrosenobergefreiter	Seaman 1cl	21
	Leuthner, Willi	Matrosenobergefreiter	Seaman 1cl	22
	Missfeldt, Erdmann	Matrosenobergefreiter	Seaman 1cl	21
	Rose, Gerhard	Matrosenobergefreiter	Seaman 1cl	21
	Sager, Hermann	Matrosenobergefreiter	Seaman 1cl	21
*	Schäffer, Helmut	Matrosenobergefreiter	Seaman 1cl
*	Schmied, Alfred	Matrosenobergefreiter	Seaman 1cl
	Wieser, Josef	Matrosenobergefreiter	Seaman 1cl	21
	Höhmann, Horst	Matrosengefreiter	Seaman 2cl	18
*	Look	Matrosengefreiter	Seaman 2cl
	Schulze, Alfred	Matrosengefreiter	Seaman 2cl	18
	Bender, Rudi	Matrose	Apprentice Seaman	20
	Brandner, Wilhelm	Matrose	Apprentice Seaman	20
	Braunagel, Helmut	Matrose	Apprentice Seaman	21
	Heiden, Otto	Matrose	Apprentice Seaman	19
*	Waltl	Matrose (cook)	Apprentice Seaman
	Bierwolf, Hans	Maschinenobergefreiter	Fireman 2cl	19

S E C R E T

	Name	Rank	USN Equivalent	Age
	Dür, Peter	Maschinenobergefreiter	Fireman 2cl	20
	Heil, Kurt	Maschinenobergefreiter	Fireman 2cl	20
	Köhler, Anton	Maschinenobergefreiter	Fireman 2cl	20
	Lindmoser	Maschinenobergefreiter	Fireman 2cl	22
*	Madrosky, Willi	Maschinenobergefreiter	Fireman 2cl
*	Stenzel, Walther	Maschinenobergefreiter	Fireman 2cl
	Bunde, Karl	Maschinengefreiter	Fireman 3cl	19
	Burger, Heinrich	Maschinengefreiter	Fireman 3cl	19
*	Fuhrmann	Maschinengefreiter	Fireman 3cl
	Gutzeit, Günther	Maschinengefreiter	Fireman 3cl	19
	Kutsch, Walter	Maschinengefreiter	Fireman 3cl	19
	Peter, Ernst	Maschinengefreiter	Fireman 3cl	22
	Kühn, Isidor	Funkgefreiter	Seaman 2cl	22
*	Liebsch, Egon	Funkgefreiter	Seaman 2cl
	Meissner, Günther	Mechanikerobergefreiter	Seaman 1cl	20
	Bender, Egon	Mechanikergefreiter	Seaman 2cl	18
	Bierfreund, Martin	Mechanikergefreiter	Seaman 2cl	19
*	Feind	Mechanikergefreiter (A)	Seaman 2cl (Gunnery)

*	Denotes casualty.
	(Ing.) denotes engineering duties only.

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