U-boat Archive - U-boat KTB - UIT-24 1st War Patrol

K R I E G S T A G E B U C H

Section Maschine.

1.	Operation U I T 24
Beginning : 2.2.1944
Concluding : 3.4.1944
Operation :
		Put to sea from Penang 8.2.44
		Arrived Penang 3.4.44


1.	Commissioning (take over) of the boat on 25.10.43

2.	a)	Operating time in hours
	b)	RPM

		Since commissioning On last operation

		Starboard diesel engine
	a)	1024 hours 57 minutes 895 hours 20 minutes
	b)	10 602 167 7 965 047

		Port diesel engine
	a)	1024 hours 21 minutes 913 hours 11 minutes
	b)	10 135 485 7 831 505

Click the flag to view the above page from the original German KTB

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A. Malfunction, type and correction

I.	Engine installation
	1.	Pressure failed in the pressure water installation.
	2.	Fuel vale leaked.
	3.	Cooling pipe on the fuel valve broken


II.	E-installation
	1.	E-motor air cooler leaked.

III.	Control room and diving mechanism
	1.	Port E-compresor out of service.
	2.	Vent of the forward ballast tank out of service
	3.	Blowing piping aft ballast tank rusted through.
	4.	Connecting tube between air flasks leaked
	5.	Vent tube ballast tank II broken.



B. Experiences



I.	Machinery and diving mechanisms

II.	Personnel


C. Installations

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To A X ; 1.	On 10 February the pressure fell in the pressure water installation. Examination showed that the test piping from the high reservoir was broken before the pressure hull pass trough. The break point was heavily rusted. The test valve in the diesel room was closed. The damage was corrected. The test piping remained out of service.

To A X ; 2	The gasket rings in the fuel vent had to be renewed very often. The rubber was completely disintegrated, despite asbestos wrapping. The rings were replaced with new. You would have to try copper asbestos rings

To A I ; 3	A fuel valve cooling tube on the starboard engine broke at the bolt connection. Replaced with a spare.

To A II ; 1	In 27 February the cooling installation of the aft air cooler in the E-motor leaked, although it was overhauled and pressure tested during the shipyard period. The cooler was opened up. One cooling coil was blind flanged, because overhaul was not possible. Duration 5 hours.

To A III ; 1	On 28 February after running the compressor for one hour strong knocking was determined. The babbitt of the crank bearing half at the foot of the connecting rod of compressor stage II was worn. The red brass unbore half crank bearings were normal. Examination showed that the oil supply from the support bearing was interrupted. An unidentified foreign body had closed the oil conduit with feed hole. The support bearing was replaced with a spare. The crank bearing half at the foot of the connecting rod was lined with bearing metal and refitted. The compressor ran up to the end of the operation without malfunction.

To A III ; 2	On 1 March it was determined that the vent of the forward ballast tank was blocked open. The indicator on the oil pressure meter was in the "closed" position. Manual operation found the restriction in the limit switch. After opening the manhole on the upper deck, it was found that a wedge was missing and that a second wedge in the operating linkage was completely worn out. The joint pieces were removed and installed with newly made wedges. Duration 12 hours.

To A III ; 3	On 4 March a 2 mm hole was found in the blowing line of the rear ballast tank in the upper deck. The defective part had rested through and was positioned in such a way that the cell is slowly venting. It was quickly covered with a rubber pad and bolted over the hole. Further venting was not observed.

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To A III ; 4	On 2 March a connecting pipe of two diesel starter air bottles needed to be be sealed while proceeding submerged. The pipe had ruptured. The starting bottle group was vented. As was established when the line was removed, it was not the starter bottle group, but 8 air bottles of air group IV. These were suddenly emptied from 200 to 50 atü. According to statements by the petty officer who carried out the work, there was no escape of air until the last turn of the union nut. This created an overpressure of 80 mm in the boat. Surfaced and slowly equalized pressure. The ruptured pipe was sealed on both sides with a copper washer. The air bottles remained in operation via the drainage line.

To A III ; 5	On 23 March while blowing ballast tank II hissing noises were heard. The examination showed that the starboard vent tube for fuel loading was broken. The tube was sealed with a wood plug with a rubber cover. The tube was heavily rusted. Further venting was not determined.

To B I ; 1	In the first days frequent breaking of the thin pipelines in the over deck was found. There were drainage lines from head valves, air lines and emergency blowing lines. These malfunctions brought about a slow venting of the ballast and fuel oil tanks and ballast tanks on the surface as well as the formation of air pockets in the air ducts under water. The drain piping was heavily rusted, which could easily lead to fractures. The cause could also be found in the rubber bails drifting loosely beneath the upper deck.

To B I ; 2	The pressure water piping is very heavily rusted and broken in a few places. The damaged areas were over wound, where not absolutely necessary, tightly set. A lot of it is due to the missing side plating in places. The pipelines were exposed to the swell and began to work.

To B I ; 3	The boat is only fitted with 50 potash cartridges. There are no retaining rings in the exhaust air line for these. It is not equipped with emergency hoses or bellows fans. There is no possibility of air renewal with longer listening pursuits. Air renewal after surfacing is very poor in the forecastle.

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To B I ; 4	The overdeck makes a very run down impression after the operation. Due to the partial absence of the outer hull cladding, the piping and exhaust mufflers, which mostly only consist of rust, have suffered greatly. The brackets for the exhaust mufflers were welded over again because they came loose on the pressure hull after a short time. New stiffeners were installed. The holes and slits that were getting bigger and bigger could no longer be sealed with on-board means. Pipes broke at rusted spots, which greatly reduced the safety of the boat. The boat is particularly endangered by the fact that these signs of aging not only occur in places that can be easily monitored and checked, but also in ballast tanks and fuel bunkers.
	The malfunction in the forward ballast tank could only be remedied because ballast and reserve fuel oil tank I was operated as a ballast tank and the boat already had the necessary buoyancy.

To B I ; 5	When proceeding on the surface with both diesels, critical vibrations occur in the boat from 290 to 310 RPM. This is particularly noticeable in calm weather.
	When diving with ballast and reserve fuel oil tanks blown, it takes a very long time for the boat to get under. It is probably due to the small cross-sections of the vents. The boat is very unstable submerged, it reacts to the slightest dive plane angle. With the boat steered to 30 meters, it takes a long time to go to greater depths without flooding. In order to maintain the depths reached with less motor power, it is necessary to flood. This resulted in 1 ton from 40 to 70 meters.
	Other depth have not been tested. It can be explained like this. The approximately 50 tons of rubber around the pressure hull are compressed by mechanical forces when going deeper. When these forces are removed, the rubber expands again until the force imposed at the steered for depth is reached.




	The Chief Engineer

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Compilation of Consumption

I.	Fuel oil inventory when putting to sea	191.2 m³
	Taken over from "U-532"	90.0 m³
	Fuel oil inventory when arriving	4.0 m³

	Amp hours : charged	138 195 Ah
	Amp hours : discharged	136 252 Ah

	Lowest compressed air inventory	120 Kg/cm²

	Longest uninterrupted submerged cruise:	12 hours 7 minutes

II.	Provisions

	Provisions taken over before departure	11000 Kg
	Provisions offloaded after arrival	2500 Kg

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Enclosure I

Enclosure to Kriegstagebuch Section Maschine "UIT 24"

Operation from 8.2.44 - 3.4.44

Sea days Distance covered			Cruise Duration				Operating time
							Evaporator
	nm	nm	Hours	Min.	Hours	Min.	Hours	Min.

1.	87	--	7	00	--	--
2.	204	2	20	00	1	--
3.	223	3	22	50	1	10
4.	214	2	23	15	--	45
5.	227	8	22	25	1	35	21	33
6.	240	3	24	30	--	30	24	05
7.	180	2	23	28	--	32	8	--
8.	150	2	23	35	--	25	22	50
9.	180	2	23	37	--	23	20	15
10.	80	19	11	00	13	--	4	15
11.	82	20	15	55	8	05	14	--
12.	130	2	23	25	--	35	22	14
13	146	1	23	29	--	31	15	45
14.	205	1	24	35	--	25	26	--
15.	225	--	24	00	--	--	24	--
16.	240	1	23	44	--	16	24	--
17.	140	1	23	24	--	36	24	--
18.	255	--	24	00	--	--	24	--
19.	250	--	24	00	--	--	19	--

[This page covers 8-26 February.]

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Sea days Fuel oil		Lubricating oil	Drinking water	Potash cartridges	Oxygen	Provisions
	m³	Kg	Ltr	Units	Atü	Kg

39	25.1	9225	7940	50	90
40	20.9	9200	7740
41	17.5	9175	7800
42	106.5	9150	7540
43	100.6	9125	7240
44	96.4	9100	7140
45	91.6	9075	7040
46	91.5	9050	6940
47	86.1	9025	6740
48	80.8	9000	6080
49	78.4	8975	5980
50	66.7	8950	5780
51	62.1	7150	5580
52	56.7	7110	5360
53	49.4	7075	5100
54	42.2	7035	4800
55	35.2	7000	4400
56	24.7	6960	4000

Boat after the voyage				50	90	2500

[This table covers 17 March to 3 April.]

Battery I total charged: 138 195 Ah ; Total discharged: 136 252 Ah

Battery II total charged 138 195 Ah ; Total discharged: 136 252 Ah

Longest uninterrupted submerged cruise: 12 hours 7 minutes

Deepest reached diving depth: 100 meters