5
REPORT ON INTERROGATION OF SURVIVORS FROM U.331, A 500-TON
	U-BOAT, SUNK AT ABOUT 1430 ON 17th NOVEMBER, 1942.
	________________
	I.  INTRODUCTORY REMARKS
	"U 331," one of the best known U-Boats operating in the Mediterranean, was sunk at about 1430 on 17th November, 1942 in approximate position 37° 00' N., 02° 5' E.
	This U-Boat was first attacked at 1315 on 17th November by Hudson aircraft of 500 Squadron, Coastal Command.
	The attack so disabled the U-Boat that she was unable to dive.  Following the report of Z/500 of this squadron, H.M.S. "Wilton" was despatched from Algiers with the intention of capturing both U-Boat and crew.
	When "Wilton" was still 10 miles from the U-Boat a Martlet was seen to make a machine-gun attack, and an Albacore from H.M.S. "Formidable" came in and before it could be prevented sank the U-Boat with a torpedo.
	There were seventeen survivors, of which five were wounded.  The commanding officer, Kapitänleutnant von Tiesenhausen, was not available for interrogation until mid-January, 1943.  The Second Lieutenant was not available until the end of January.
	One survivor attempted to escape from escort while at Gibraltar, and was killed.
	The general level of security-consciousness was high.
	Features of this report are:
	(1)  Account of sinking of H.M.S. "Barham" on 25th November, 1941.  (See Appendix "B.")
	(2)  Landing of sabotage party on North African coast on 17th November, 1941.  (See Appendix "B.")
	(3)  Description of Italian machine guns fitted in "U 331" and stated to be now usual for all Mediterranean U-Boats.  (See Section II (iv) and also C.B. 04051(54) Section XI (viii).)
	(4)  Organisation of U-Boat and other commands in Mediterranean.  (See Section VI.)
	(5)  General remarks on Mediterranean U-Boat tactics.  (See Section VI.)
	(6)  Mediterranean U-Boat situation.  (See Section VI.)
	Statements by a German officer prisoner from the Italian blockade-runner "Cortelazzo" (5,292 gross tons, Lloyd Triestino, sunk on 1st December, 1942) and from a prisoner from "U 357" (sunk on 26th December, 1942, see C.B. 04051 (57) ), who was not available for interrogation until recently have been included in this report.
	The following are the British equivalents for German naval ranks mentioned in this report:
	Admiral Admiral. Vizeadmiral Vice-Admiral. Konteradmiral Rear Admiral. Kapitän zur See Captain. Fregattenkapitän Commander (Senior Grade). Korvettenkapitän Commander (Junior Grade). Kapitänleutnant Lieutenant-Commander. Oberleutnant zur See Lieutenant. Leutnant zur See Sub-Lieutenant. Oberfähnrich sur See Midshipman (Senior Grade). Fähnrich zur See Midshipman (Junior Grade).
	II.  DETAILS OF "U 331"
	(i)  Displacement
	500 tons.
	(ii)  Type
	VII C.  (first of type from her yard).
	(iii)  Builders
	Nordseewerke, Emden.
	(C48270)                                                                                                                    B* 2

 

	6
	(iv)  Armament
	Guns:  One 88 mm. (3.46 in.) forward.
	One 20 mm. (0.79 in.) on bridge.
	Two M.G., Type C.30 on bridge.
	Two M.G., Type C.34 on bridge.
	Two twin 12.7 mm. Breda M.G. on bridge.
	These twin Italian 12.7 mm. (0.46 in.) guns were forward of the 20 mm. gun, on either side of the bridge.  They were on retractable mountings and were raised and lowered by rotating a handle on a fixed gun casing.  The gun itself was mounted and pivoted on a conical-shaped pedestal, which in turn was fixed to a retractable circular plate.  To lower the gun, it had to be elevated to an almost vertical position, and by means of a catch under the stock, the latter could be folded backwards so that it lay between the gun barrels.  The gun was then ready for lowering into the casing.
	In "U 331" it is believed that the guns were lowered and raised by a system of pulleys inside the casing, but in later U-Boats this operation may be by air.
	The guns can be raised and ready for action in 30 seconds.
	They have an all-round arc of fire and the same range as the 20 mm. gun.
	In order to fit these Italian guns the bridge had to be widened and lengthened as far aft as the galley hatch.
	A ladder leading to the deck was fitted immediately abaft this extension.
	Ammunition
	The ammunition for the four forward machine guns was stowed inside the conning-tower.
	Ammunition boxes contained ten clips for the 20 mm. and fifteen clips for the 12.7 mm. machine guns.  Each clip held 20-30 rounds in the following order:  two tracer bullets, one explosive bullet and one ordinary bullet.
	Torpedoes  12 electric torpedoes.
	No air torpedoes are carried in upper deck containers by U-Boats operating in the Mediterranean on account of the frequency of air attacks.
	Torpedo Tubes.  Five - four forward and one aft.
	(v)  Diving
	Maximum Depth.  She was only tested to about 90 m.  (295 ft.), but her depth-gauges were marked to 200 m. (656 ft.).  Survivors said that when she sank H.M.S. "Barham" (see Appendix "B") she submerged to about 250 m.  (820 ft.)
	Crash-Diving Time.  To 30 m. (98 ft.) in 27 seconds.
	To 60 m. (197 ft.) in 60 seconds.
	(vi)  Propulsion
	(a)  Diesels.  Manufactured by G.W.:  4-stroke, 6 cylinder, developing about 1,200 h.p. without supercharger.
	Maximum speed.  About 17 knots.
	Supercharger.  "Kapsel" type, directly driven from main engines.
	(b)  Motors.  A.E.G. manufacture.
	60 r.p.m.   ("Kieine Fahrt" = dead slow). 90 r.p.m.   ("Schleichfahrt" = silent approach speed). 110 r.p.m.   ("Langsame Fahrt" = slow speed). 160 r.p.m.   ("Halbe Fahrt" = slow speed). 180 r.p.m.   ("Grosse Fahrt" = three-quarters speed). 210 r.p.m.   ("Ausserste Kraft" = full speed).
	Estimated speed at 210 r.p.m. - 7 knots.
	(c)  Batteries.  Each contained 62 cells.
	(vii)  Fuel
	Capacity.  128 tons.
	Consumption.  Slow speed on Diesel-Electric, 1.7 tons per day.
	Slow speed on both Diesels 2.8-3.2 tons per day.
	(viii)  Communications
	W/T sets.  Normal equipment.
	U/T.  Fitted.
	V.H/F.  Fitted.
	Extensible Aerial.  Fitted.  Usable to depths up to 15 m. (49 ft.).

 

	7
	(ix)  Hydrophones.  G.H.G.
	Operators found 80 metres (164 ft.) the best listening depth in the Mediterranean.
	(x)  S-Grear
	None.
	(xi)  R.D.F.
	None.
	(xii)  D/F Loop
	Carried.
	(xiii)  K.D.B.
	Carried.
	(xiv)  Echo-Sounder
	Fitted.
	(xv)  Elektrolot
	Carried.
	(xvi)  S.B.T.
	Fitted in Salamis.
	(xvii)  German Search Receiver
	Fitted in La Spezia before last patrol. This appears to have been of the "U 660" type, with central "jam-jars."  It has the same frequency range as "U 660's" set.  (See C.B. 04051(53). page 13.)
	(xviii) Look-Out Platform
	She was fitted with a portable look-out platform between the two periscopes.
	(xix)  Badge
	A serpent.
	A donkey is the badge of the 29th Flotilla.  (See Section VI (ii).)
	(xx)  Town of Adoption
	Düsseldorf.
	III. LAST PATROL OF "U 331"
	(i)  Departure from La Spezia
	"U 331" sailed from her berth in Bassin No. 1 at La Spezia about 1100 on 7th November, 1942.
	It had originally been intended that she should sail about 15th November, but the sailing date had been advanced owing to the receipt of news about the projected Allied landings in North Africa.  Before sailing, Tiesenhausen told his men that Hitler had sent the Captain (S) (Mediterranean) a signal of the "do or die" variety to be issued to all boats.  He himself did not know the destination of the Allied convoys.
	"U 331" sailed north of Corsica and then south at full speed on the surface.  Her operational area was to be in the neighbourhood of Algiers.
	(ii)  Sinking of 15,000-ton ship
	On 9th November, 1942, "U 331" approached a bay immediately to the east of Cape Matalou, at periscope depth.  There she sighted a ship described as of about 15,000 tons, thought to be a trooper, accompanied by one destroyer.  Both were stationary.
	From periscope depth, at 800 yards, "U 331" fired a salvo of four angled torpedoes from seaward.  This was followed by three detonations.
	She then withdrew submerged.  No D/C attack developed.  Prisoners said that when they made this attack, the echo-sounder only showed 29 metres (95 ft.) of water under their keel.
	(N.I.D. Note.  This was the U.S. army transport "Leedstown," of 9,135 gross tons.)
	(iii)  Ships Sighted on same Evening
	The same evening, "U 331" surfaced and sighted one, possibly two, aircraft-carriers proceeding westward with destroyer escort.  She was, however, unable to attack owing to the high speed and zig-zagging tactics of the formation.
	Later that night, "U 331" sighted a troop transport proceeding towards Gibraltar, escorted by one destroyer.  She could not overhaul her, owing to her speed.
	(C48270)                                                                                                                       B* 3

 

	8
	(iv)  D/C Attack by Destroyers
	At about 1100 on Friday, 13th November, "U 331" surfaced to periscope depth to receive signals from the Captain (S) (Mediterranean).  The First Lieutenant was at the periscope and reported enemy destroyers on either beam.  Tiesenhausen satisfied himself that this was the case and promptly dived deeper.  He intended to submerge to 30 metres (98 ft.).
	At 20 metres (66 ft.), however, a D/C attack developed and "U 331" promptly altered course.  Shortly afterwards, another twenty-five D/Cs were counted.  Survivors gained the impression that several destroyers were attacking.
	Tiesenhausen then ordered one S.B.T. charge to be ejected, and shortly afterwards the sound of asdics ceased.
	Half an hour later the sound of asdics was once more evident, and thirty more D/C explosions were counted.  Another S.B.T. charge was ejected.  This was followed by the detonation of another ten D/Cs, all of which sounded much fainter than previously.  The only damage caused in this attack was to the forward hydroplane motor.  Survivors said the could not say how deep their boat had dived in this attack, as all the depth-gauges but one had been disconnected.
	This attack lasted for six or seven hours, and when "U 331" finally surfaced it was already growing dark.
	(v)  Destroyer Sighting
	In the night of 15th/16th November, "U 331" sighted one destroyer, but took no action.  "U 331" was throughout on "Freijagd"  (operating independently).
	IV.  SINKING OF "U 331"
	(i)  "U 331" Surfaces North-West of Algiers
	At about 1300 C.E.T. on 17th November, 1942, "U 331" was proceeding westward at periscope depth north-west of Algiers.  There was no sign of enemy activity and Tiesenhausen gave the order to surface, and the boat continued at slow speed westward.  The German Search Receiver was not in position, a fact which prisoners found it difficult to excuse, other than by saying that in daytime they normally relied more on visual than other methods for spotting aircraft.  It was usually, they said, the officer of the watch's duty to mount it in position.
	(ii)  Appearance of First Aircraft
	Soon after surfacing an aircraft suddenly appeared astern out of the sun.  (N.I.D. Note.  This aircraft was "Z," of 500 Squadron, Coastal Command, on A/S patrol.  According to the pilot's report he first sighted the boat on the surface in approximate position 37° 05' N., 02° 24' W., at 1315 C.E.T.)  At this time the sea was calm; there was high cloud, visibility being about 30 miles.  Tiesenhausen said that the responsibility for not having spotted the aircraft lay with Bootsmaat Meier, the starboard quarter look-out, but other survivors blamed Bootsmaat Siebels, who had the port quarter, whence the attack came.  Siebels was on his first operational patrol.
	It was too late, when the aircraft was spotted, for Tiesenhausen himself to sound the alarm, but it was ordered by someone else, and "U 331" started to dive.  At this moment the aircraft, attacking from 10° abaft the U-Boat's port beam from a height of 20 feet, released four Mark XI Torpex depth-charges set to shallow depth and spaced 35 feet apart.  The pilot claimed that the stick straddled, exploding on each side of the U-Boat and lifting her up in the water.  Tiesenhausen was under the impression that three "bombs" only were dropped and that they exploded 15 yards distant to port.  He at once ordered the crew to put on life-jackets in case a larger scale attack developed, necessitating abandoning ship.
	(iii)  Hatch Jams and "U 331" forced to Surface
	Tiesenhausen and others admitted that the effect of the D/Cs was terrific, causing the 88 mm. gun to be put out of action and the forward hatch to burst open and jam.
	This resulted in a water entry in the forward compartment, which Tiesenhausen then ordered to be cleared and the forward watertight bulkhead closed.
	The diesels were also damaged and one battery put out of action.  Tiesenhausen then switched over to the other battery and continued ahead as fast as possible.  The pressure hull was still undamaged.
	It was alleged that one of the crew named Gotze was wounded by machine-gun fire from the aircraft, but confirmation of a machine-gun attack at this stage is not contained in the pilot's report.  The crew appeared to be under the impression that "Z/500" bore United States markings.

 

	9
	(iv)  Two Further Aircraft Attacks
	Two further aircraft then appeared.  These were "L" and "C," both of 500 Squadron.  Attacking from the boat's starboard quarter at 60° to track, from a height of 50 feet, "L" released four Mark XI Torpex depth-charges set to shallow and spaced 36 feet apart.  The pilot stated that No. 1 depth charge exploded on the starboard side, No. 2 against the port side and Nos. 3 and 4 over on the port side.  When spray subsided the U-Boat remained stationary on the surface.
	Once more survivors believed that only three "bombs" were dropped.  These, they stated, wrecked all the depth-gauges and compasses and put the steering gear out of order, so that "U 331" inclined to circle.
	Tiesenhausen then ordered all men not on duty below on to the upper deck, in case it should be necessary to abandon ship.  All were now wearing life-jackets.
	The remaining aircraft, "C/500," now dropped a further three Mark XI Torpex depth-charges released from a height of 50 feet in an attack made from the U-Boat's port quarter at 60° to track.  The depth-charges were set at shallow depth and spaced about 38 feet apart.  At this point the U-Boat was fully surfaced and several of the crew were seen on the bridge.  No. 4 depth-charge failed to release.  The stick straddled the U-Boat and explosions were seen on either side of the conning-tower.  After the spray had settled some of the crew, presumably those who had been on the bridge, were seen in the water.  The U-Boat was still on the surface and stopped.
	According to prisoners the depth-charges dropped in this attack blasted a number of those on deck overboard and killed a man named Niklas.
	Another attack was then made by "Z/500" from the U-Boat's starboard quarter, in which two 100 lb. A/S bombs were released and scored near misses alongside to starboard.
	It was now observed that the U-Boat was making attempts to man the guns, but this was prevented by machine-gun fire from the aircraft.  After this attack the U-Boat was stopped and some of the crew began to jump overboard.  Finally a white flag was waved.
	The German version of the machine-gun attack was, as might be expected, that their men were deliberately machine-gunned in the water and that only after this did they return the fire with their own guns.  It was claimed that a white flag was not waved until a later stage.  Survivors stated that a number of the crew were wounded, including men named Wahrstadt, Fischer and Krischen.
	"Z/500" having by this time reached her prudent limit of endurance returned to base and made a report.  The destroyer "Wilton" was then despatched from Algiers with the intention of capturing both the U-Boat and her crew and was led to the position by "X/500," who had in the meantime, re-fuelled and re-ammunitioned.
	(v)  "U 331" tries to make Land
	Concurrently, those remaining on board "U 331" had been making efforts to rescue their shipmates swimming in the water.  One of them, named Siebels, was pronounced dead after artificial respiration had been attempted.
	By this time, as a result of the flooding of her forward compartment, "U 331" was down by the bows to the extent that her screws were practically out of the water.  Tiesenhausen gave the order to go astern on the motors, realising that this would be their only chance of escape.
	Meanwhile, the engine-room personnel had managed to repair the Diesels so that they could be made to function at slow speed.  "U 331" therefore proceeded very slowly towards the North African coast, estimated by Tiesenhausen to be about 12 miles distant, partly on her Diesels and partly on her motors.
	Survivors all admitted that their aim in proceeding astern towards the coast was not so much to save their lives as to make land and escape.  They were under the impression that crews from other boats had done this.  Tiesenhausen said that it was hopeless to proceed to sea as he was already so close to the coast and could not submerge.
	It was then about 1530 C.E.T.  Tiesenhausen ordered "U 331" to be prepared for sinking and destroyed all secret documents.  He made an open signal to the Captain (S) Mediterranean informing him of the position.
	(vi)  Appearance of Flying-Boat
	A flying-boat, described by survivors as bearing U.S. markings, then made its appearance and fired warning shots.
	It circled over "U 331" and made light signals, which prisoners said that they were unable to identify, apart from the one word "Algiers."  One man said, however, that he thought that the signal meant that a destroyer was being sent to their assistance.
	Tiesenhausen said he signalled to the flying-boat that he was unable to dive and had surrendered, and that it was then that he ordered the white flag to be hoisted.
	The flying-boat then flew back in the direction of land, after dropping a smoke-float.
	(C48270)                                                                                                                         B* 4

 

	10
	(vii)  Torpedoing of "U 331"
	"U 331" then abandoned all attempts to make land, as her propellers were practically exposed.  The ship's company tended their wounded and "U 331" remained stopped.  Some of the men tried to make rafts out of sections of the deck covering, their rubber dinghies having been destroyed by blast from the depth-charges.
	Shortly afterwards, a further "United States" bomber made its appearance, accompanied by one Spitfire, and circled "U 331" several times.  Several other British and United States aircraft also appeared.  Some survivors said there were 15 or 20 of these.
	At this moment, although the white flag was still in position, "U 331" started up her Diesels once more.  This made a loud noise, especially as the propellers were more than half out of the water, the exhaust plainly visible.  Several survivors said the responsibility for this action lay with an E.R.A., who acted without orders, but Tiesenhausen insisted that he had himself ordered this and it was therefore his responsibility.
	Apparently observing this, a Martlet (described as a Spitfire by prisoners) flew towards "U 331" from port and machine-gunned her.  Its gunfire penetrated "U 331's" conning-tower, killing some and wounding others.  Some sprang into the water in alarm.  Tiesenhausen and his Second Lieutenant, Leutnant zur See Hartwig, were on the bridge and were both wounded.
	What survivors described as a biplane then approached them from starboard and fired a torpedo.  The torpedo-track was clearly evident and Tiesenhausen ordered hard-a-starboard, but it was too late.  (N.I.D. Note.  This was an Albacore aircraft from H.M.S. "Formidable," which later reported that one 18 in. Torpedo Mark XII*, Duplex pistol , set to 12 ft., speed 40 knots, was released 700 yards from the U-Boat.  The U-Boat disappeared after the explosion of the torpedo and a second explosion was observed under water and wreckage was seen.)
	The torpedo struck "U 331" on her starboard side, killing 32 men who were still below.  The remainder were thrown into the water and some were rescued by what they described as a United States flying-boat which alighted nearby.  When they recovered their senses, there was no sign of their boat except wreckage and oil.
	The attacks by the Martlet and the Albacore were observed aboard "Wilton" who was, however, still some 10 miles away and was not in time to prevent the final torpedoing.
	A Walrus flying-boat then appeared on the scene picked up the survivors, about nine in number, endeavoured to take off but fond that her cargo was too heavy.  She accordingly put some of the men back in the water and took off with the remainder.  Those left swimming were picked up by "Wilton."  Prisoners said that the destroyer searched for a long period for further survivors, but found none.  A man named Karls was brought on board dead.
	Prisoners, especially Tiesenhausen, were all very bitter at what they termed the unfair action of the "United States" bombers in machine-gunning their shipmates swimming in the water.  They all admitted, however, that the aircraft which fired at them when they later started up their Diesels was quite justified in doing so.  (N.I.D. Note.  There is no evidence that any United States aircraft were concerned in these attacks.)
	V.  MEDITERRANEAN U-BOAT SITUATION
	(i)  Some of the Boats believed Operating in November, 1942
	"U 73"   (Oberleutnant zur See Deckert). "U 77"   (C.O. unknown.  Formerly Kapitänleutnant Schonder). "U 81"   (Kapitänleutnant Fritz Guggenberger). "U 83"   (Kapitänleutnant Hans Werner Kraus). "U 97"   (C.O. unknown.  Formerly Kapitänleutnant Udo Heilmann). "U 205"   (C.O. unknown.  Formerly Kapitänleutnant Reschke). "U 431"   (Kapitänleutnant Dornmes). "U 561"   (C.O. unknown.  Formerly Kapitänleutnant Bartels). "U 565"   (Oberleutnant zur See Franken ) "U 605"   (Kapitänleutnant Herbert Victor Schütze). U-Boat commanded by Oberleutnant zur See Heinz Schomburg. U-Boat commanded by Oberleutnant zur See Kelbling.
	(ii)  Boats known to have been Lost in Mediterranean.
	"U 75"   (Kapitänleutnant Ringelmann)  (28.12.41). "U 79"   (Kapitänleutnant Kaufmann)  (23.12.41). "U 95"   (Kapitänleutnant Schreiber)  (28.11.41). "U 331"   (Kapitänleutnant Freiherr von Tiesenhausen)  (17.11.42). "U 372"   (Kapitänleutnant Heinz Joachim Neumann)  (4.8.42). "U 374"   (Oberleutnant zur See von Fischel)  (12.1.42). "U 433"   (Oberleutnant zur See Ey)  (16.11.41).

 

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	"U 557"   (Kapitänleutnant Paulssen)  (17.12.41). "U 559"   (Kapitänleutnant Hans Heidtmann)  (30.10.42). "U 568"   (Kapitänleutnant Joachim Preuss)  (28.5.42). "U 595"   (Kapitänleutnant Quaet-Faslem)  (14.11.42). "U 652"   (Kapitänleutnant Fraatz)  (June/July, 1942). "U 660"   (Oberleutnant zur See Baur)  (12.11.42). U-Boat commanded by Kapitänleutnant Diggins (Oct./Nov., 1942).
	(iii)  General
	Though some prisoners exaggerate greatly in their favour, it does not appear from a collation of prisoners' statements that more than about 40 U-Boats have entered the Mediterranean since the war began and up to the time of "U 331's" sinking.
	It is believed that, in addition to those mentioned in (ii) above, some four or five may have been sunk without trace.
	(N.I.D. Note.  The above lists are not comprehensive.  Over 20 U-Boats are believed to be in the Mediterranean.  Some of the Commanding Officers mentioned may have been relieved.)
	VI.  GENERAL REMARKS ON U-BOATS IN MEDITERRANEAN
	(i)  Captain (S), Mediterranean
	The Captain (S), Mediterranean, is Kapitän zur See Kreisch, of the 1914 term, who was promoted Captain on 1st April, 1939.  His H.Q. are at Rome, in the same building as the "Deutsches Marine Kommando," and his duties are the operational control of all U-Boats in the Mediterranean.  His title is "Führer der Unterseeboote," generally shortened to "F.d.U."  His predecessor in office was Korvettenkapitän Victor Oehrn, captured on 13th July, 1942, on the North African coast while on land reconnaissance.  (See also C.B. 04051 (54), page 16.)
	(ii)  Mediterranean U-Boat Flotillas
	Since the dissolution of the 23rd U-Boat flotilla at Salamis early in 1942, there has been only one U-Boat flotilla in the Mediterranean.  This is the 29th, based on La Spezia.  The Senior Officer is Kapitänleutnant Fritz Frauenheim.
	Just prior to the North African operations, five new U-Boats arrived, and another ten were expected.
	(iii)  Mediterranean U-Boat Bases
	(a)  Cagliari (Southern Sardinia).  Tiesenhausen said that he had visited Admiral Fricke (Chief of Operations Division of Naval Staff) in Berlin shortly before sailing on his last patrol.  He urged on him the necessity of the Mediterranean U-Boats being allotted another base near enough to their operational areas, where they might refuel, or where they could lie until conditions justified a sortie.  He urged that Cagliari should be opened as such a base.
	(b)  Messina.  It is customary for U-Boats desiring to make minor repairs to do so at Messina.
	(c)  Pola.  Pola is extensively used by U-Boats requiring a lengthy refit.  It is not used operationally.
	(d)  Philippeville.  Tiesenhausen said that when he was last in Berlin, he had urged on Admiral Fricke the desirability of acquiring Philippeville as an advanced U-Boat base (see also under Cagliari above).  Fricke had replied, however, that the political difficulties involved were too great.
	(e)  Salamis.  As far as survivors knew, Salamis was still being used as a base for effecting minor repairs.
	(iv)  German Naval Organisation in Mediterranean
	(a)  Command.  Vizeadmiral Weichold, of the 1911 term, is in command of the German Naval H.Q. at Rome.  His duties are to control the entire German naval situation in the Mediterranean, including vessels employed on the North African Coast.  In practice, however, the Captain (S) (Mediterranean) operates almost entirely independently of Weichold.
	(b)  Captain (S) Mediterranean.  See above.
	(c)  Sea Transport Officer.  The "Seetransportchef" (Sea Transport Officer) is Konteradmiral Horstmann, of the 1913 term, whose offices are in the same building as those of Weichold and Kreisch.  He is said to have the most exacting duty of all officers, since he is responsible for the transport of all supplies to the Afrika Corps.  One of his staff officers is named Korvettenkapitän (Ing.) Wagner.  Horstmann maintains an organisation at all Italian ports.
	(d)  Fuel Supply Officer.  Vizeadmiral Weichold also has the duty of keeping the Italian Navy supplied with as much fuel from Germany as possible.  He maintains a special officer on his staff for this purpose, named Kapitan zur See (Ing.) Graef.
	(C48270)                                                                                                                             B**

 

	12
	(v)  Mediterranean W/T Routine
	Rome and Salamis are the two Mediterranean W/T stations to which U-Boats listen for orders.  These stations work an "I" method routine with Salamis as control.  Series numbers are used.
	Regular transmission periods begin five times daily, of which three are 1100, 1500 and 2100.  To receive, boats must surface, at least to aerial depth.  (N.I.D. Note.  The routines mentioned are probably the Berlin transmissions on VL/F, repeating traffic previously made on H/F by Rome and Salamis.
	(vi)  Mediterranean Tactics
	Tiesenhausen said that it was virtually impossible to carry out the tactics normally applied in the Atlantic in the Mediterranean, owing to the confined space.  It was now more usual, he added, for boats to be given an operational area, generally somewhat restricted, to proceed there and to act according to their commanding officer's discretion.
	Other prisoners said that most boats waited in what was known in tactics as a "Lauerstellung."  This involved waiting submerged and listening with hydrophones for any approaching target.  They added that "Vorpostenstreifen" (Patrol sweeps) were occasionally formed, but never consisted of more than five boats.
	(vii)  Dangers Peculiar to Mediterranean
	Tiesenhausen mentioned the following disadvantages peculiar to the Mediterranean:
	(a)  The large bow wave made on the surface in calm weather.  He believed this could be seen for miles.
	(b)  Enemy aircraft.  He regarded these as a far greater danger than surface craft, with which he felt relatively safe.  He realised, however, that the efficacy of aircraft in confined waters such as those of the Mediterranean cut both ways; it might mean that surfaced U-Boats could be easily detected, but it also meant that Allied shipping movements could be constantly and accurately observed.
	(c)  The shorter seas in the Mediterranean are, he said more of a strain to a U-Boat than the longer Atlantic seas.
	(d)  The lighter nights in the Mediterranean are a great strain on a U-Boat's ship's company.
	(viii)  Co-operation with Aircraft
	U-Boats in the Mediterranean do not normally communicate direct with aircraft.  They rely principally on them, however, for information regarding convoy movements.  The aircraft communicate these direct to the Captain (S) Mediterranean, who passes them on to the U-Boats concerned.  One man said that much of this reconnaissance was done by Ju.88s based at or near Messina.
	(ix)  British Submarine Patrols
	Tiesenhausen expressed considerable apprehension regarding British submarines in the Mediterranean.  He was under the impression that the British maintained a permanent submarine patrol in the neighborhood of the Island of Ustica.
	(x)  Time-keeping in the Mediterranean
	Tiesenhausen said that between 1st October and 31st April, German U-Boats in the Mediterranean set their chronometers to Central European Time (M.E.Z.), which he said was one hour ahead of G.M.T.  Between 1st May and 30th September, the chronometers are set to German Summer Time (D.S.Z.), which he said is one hour ahead of Central European Time and therefore two hours ahead of G.M.T.
	(xi)  Need for U-Boat Surface Search Gear
	Tiesenhausen said that he had often spent the entire night searching for targets which he knew to be in the vicinity without finding one.  This was a defect which could obviously be remedied by fitting some kind of surface search gear.  He had accordingly proceeded to Berlin and Kiel in the latter half of 1942, to put forward such a request.  All that he had received as a result of his visit was a German search receiver, of which he had no high opinion.
	(xii)  Opinion of German Search Receiver
	Tiesenhausen thought that the German search receiver, as fitted to his boat, was of little practical value.  Firstly, it rarely functioned properly.  Secondly, the long cable that had to be connected to the aerial seriously hindered crash-diving, as it and the aerial had first to be stowed below.  He regarded the whole apparatus as provisional
	(xiii)  Torpedoes in Mediterranean
	One of the disadvantages of firing any kind of torpedo in the Mediterranean is that the high phosphorescence of the water betrays its course very easily.

 

	13
	VII.  GENERAL REMARKS ON U-BOATS
	(i)  Avoiding Action against Aircraft
	It is usual when diving to avoid aircraft attack for a U-Boat to turn towards the attacking machine.
	(ii)  Yellow Pennants
	A U-Boat entering or leaving port flying a yellow pennant indicates that she is about to engage upon, or has been engaged upon, special duties, such as minelaying.
	(iii)  Sea Trials
	Each time that a U-Boat leaves a yard after repairs, etc., she does one day's sea trial.
	(iv)  750-ton Minelaying U-Boats
	One man said that he saw a 750-ton minelaying U-Boat at Pillau in January, 1942, when he was allowed to inspect her.  She had six mine-shafts between the control room and the P.O.'s mess, three on either side.  Her yard sign was a red square with a diagonal white stripe.
	(v)  1,200-ton U-Boats
	A rating who had inspected one, said that 1,200-ton U-boats were fitted with two different seta of engines.  Some fit a six-cylinder G.W. engine for each shaft, abaft which is coupled a four-cylinder engine; others a nine-cylinder with a six-cylinder engine abaft it.  The former arrangement gives 2,200 h.p. per shaft, and the latter 3,600 h.p.  No decision has yet been taken regarding which is to become standard.  It is thought possible that both arrangements may be retained.
	(vi)  New Type 20 mm. (.79 in.) Ammunition
	A rating from "U 517" (sunk 21st November, 1942) said that she was the first boat to carry a new type of 20 mm. ammunition.  Rounds were slightly longer than usual and much more sensitive to percussion.
	(vii)  Nickel Batteries
	Some prisoners thought that nickel batteries were to be fitted to U-Boats to replace the older type lead battery.
	A German Transocean Agency report of 8th January, 1943, mentions the replacement of lead batteries, which weigh from 16 to 20 tons, by nickel batteries, with a saving of weight of one nineteenth.
	The reduced weight, it was claimed, resulted in a greater surface speed.
	It added that the nickel is being obtained from Scandinavia.
	(N.I.D. Note.  The nickel-iron type of alkaline battery, in place of lead-acid battery, was previously used in the U.S. Navy but was abandoned in favor of the lead type.  The advantages of using nickel have probably been deliberately been overstated and, if adopted, it is more likely on account of difficulties of supply rather than improvement in performance.  The whole lead battery of 124 cells weighs about 55 to 60 tons of which the lead content is about 45 tons.)
	(viii)  Depth-Gauges at Silent Approach
	It was customary in "U 331," when at silent approach and consequently when there was a risk of D/C attack, to disconnect all depth-gauges except that in the control room nearest the coxswain.  The object of this was to preserve the gauges from unnecessary damage in the event of an attack developing.
	VIII.  SURFACE SHIPS
	(i)  "Leipzig"
	The officers of the 6,000-ton light cruiser "Leipzig" at October, 1942, included the following:
	Captain:  Kapitan zur See Winter (retired after service in 1914-18 war).
	Commander:  Fregattenkapitän Joachim Asmus, of the 1921 term.
	Other Officers:  Oberleutnant zur See König, of the October, 1937 term; Oberleutnant zur See Winter, of the October, 1938, term.
	In September, 1941, the cruisers "Leipzig" and "Emden" bombarded Oesel Island.  Otherwise "Leipzig" was used largely as a training ship between April, 1941, and October, 1942.
	(ii)  "Admiral von Tirpitz"
	Tiesenhausen related how, when he visited Berlin in autumn, 1942, Admiral Fricke told him that it would become necessary to order the 45,000-ton battleship "Admiral von Tirpitz" home from Norway because of shortage of fuel.

 

	14
	(iii)  "Rex"
	Tiesenhausen said that the Italian liner "Rex" (51,062 gross tons) was being converted in Italy into an aircraft carrier.
	(iv)  Hanomag E-Boat
	Tiesenhausen described a semi-sumersible craft which he had seen building at Kiel.  He said it consisted of a cigar-shaped hull under water, resembling a U-Boat.  This was topped by a narrower superstructure, on top of which was built a form of look-out for the captain.  This look-out was all that could be seen above water.  Tiesenhausen did not know the purpose of such a craft.
	(N.I.D. Note.  He was probably referring to a type of Hanomag E-Boat.  Although this type of craft has been reported as building for more than a year, it has never been located by reconnaissance or met with on service.)
	IX.  BASES, TRAINING ESTABLISHMENTS, ETC.
	A.  Germany
	(i)  Bremen
	The A.G. Weser at Bremen was said to be building two-man U-Boats before the war.
	(ii)  Danzig
	Danzig is the base of the 8th U-Boat Flotilla, known as the "Schiessflottille." All boat working up are attached to this flotilla for a short time in order to put in torpedo-firing practice.
	(iii)  Memel
	Memel is the base of the 24th U-Boat Flotilla.  It is a "Schiessflottille" for the instruction of future commanding officers in torpedo-firing.  It was commanded in September, 1941, by Kapitänleutnant (Ing.) Baumgarten, of the 1926 term.  Boats working up do not normally proceed to this flotilla.
	On 1st June, 1941, the 24th Flotilla proceeded to Hopla Fjord, near Trondheim, owing to the danger of the Russian war, but returned in September, 1941.
	Boats attached to this flotilla in September, 1941, were Type II D 300-tonners of the series "U 137-151" and a number of old 500-tonners, including "U 28," "U 29," "U 30" and "U 34," also "U 554," "U 555" and "U 560."  The last three were only fitted with two operative torpedo tubes forward.
	(iv)  Pillau
	The 26th U-Boat Flotilla based on Pillau is commanded by Korvettenkapitän Hans Gerrit von Stockhausen, of the 1926 term, formerly of "U 65."  New U-Boats practising torpedo firing are often attached to it.  It was rumoured in May, 1942, that the flotilla was to be disbanded, but it was still in being in August, 1942.
	The 21st U-Boat Flotilla, based on Pillau, is commanded by Korvettenkapitän Büchel, of the 1925 term.  It is a school-boat flotilla, and is directly controlled by the 1st U-Boats Training Division, also based on Pillau.  The celebrated Kapitänleutnant Schuhart is also attached to this flotilla.  He has his headquarters in the depôt-ship "Pretoria."
	The senior officer of the 1st U-Boats Training Division is Kapitan zur See Schmidt (as at February 1942).  The 1st Section of the Division is for officers, C.P.O.s and P.O.s, accommodated in "Pretoria," and the 2nd is for ratings who are accommodated in "Robert Ley."
	The 1st section is commanded by Korvettenkapitän (Ing.) der Reserve Giloi, who also commands its 1st Company, which is for midshipmen.  (All information as at February, 1942.)
	B.  Greece
	Salamis
	The 23rd U-Boat Flotilla formerly at Salamis under the command of Kapitänleutnant Fritz Frauenheim, has been dissolved since the early part of 1942.
	The senior officer in command of the port early in 1942 was Kapitänleutnant der Reserve Hornjak.  He has since died.  A Kapitänleutnant Zahn was also formerly stationed there.
	C.  Italy
	(i)  La Spezia (see also C.B. 04051(54), page 14)
	The officer commanding the Drafting Depot at La Spezia is named Kapitänleutnant Mehl.  (N.I.D. Note.  This may be Mehl of the 1933 term.)
	The administrative offices of the 29th U-Boat Flotilla are in a former barracks opposite Bassin No. 1 to port on entering the inner harbour.

 

	15
	There is a boom at the entrance to the outer harbour, opening outward and moored to the western shore.  It is operated by a tug.  There is also a boom between the breakwater and Santa Maria Point, opening inward and pivoting on the point.  It is also operated by a tug.
	The senior officer of the 29th U-Boat Flotilla prior to Frauenheim's appointment was named Korvettenkapitän Edouard Becker, who served with distinction in U-Boats in the last war and was recalled to active service in September, 1939.  On relinquishing his appointment at La Spezia, he was given an important shore post in France.
	Other officers of the drafting depot are Oberleutnant zur See Sürenhagen, of the 1936 term, and Oberleutnant (Ing.) Hockner.
	(ii)  Messina
	There are facilities at Messina for U-Boats to effect minor repairs.  Labour is all Italian.  There are no dry dock facilities.
	(iii)  Pola
	Pola is used as a repair base for U-Boats.  The number there at one time is not thought to be large.
	(iv)  Rome
	Headquarters of Vizeadmiral Weichold, of the 1911 term, German Naval C.-in-C., Mediterranean.  Has five staff officers.
	Headquarters of Konteradmiral Horstmann, of the 1913 term, Naval Transport Officer (Mediterranean).  Korvettenkapitän (ing.) Wagner is on his staff.
	Headquarters of Kapitan zur See Kreisch, of the 1914 term, Captain (S) Mediterranean.
	Headquarters of Kapitan zur See (ing.) Greaf, German Fuel Officer for the Mediterranean.
	All these officers are accommodated in the same building.
	(v)  Trieste
	Trieste is the Italian port whence most supplies are shipped to Greece.  It is also a centre for the transshipment overland of oil from Germany to Italy, largely for the consumption of the Italian navy.  An officer formerly stationed there admitted that the German troops had had to be withdrawn owing to their unpopularity.  The same officer added that the Italians are so apprehensive of Trieste being bombed that they are now trying to divert all traffic to Venice.
	D.  Poland
	Gdynia
	The 25th U-Boat Flotilla based on Gdynia moved to Lo Fjord, near Trondheim, on 1st June, 1941, but returned to Gdynia at the end of September, 1941.  It is said to be a tactical training flotilla.
	The 22nd U-Boat Flotilla based on Gdynia is a school-boat flotilla administered by the 2nd U-Boats Training Division at Gdynia.
	X.  MISCELLANEOUS REMARKS
	(i)  Espionage in Mediterranean
	Tiesenhausen said his sources of convoy information in the Mediterranean had always been very reliable.  The Axis had agents in Algeria who constantly reported convoy movements to the German Naval Attaché at Madrid.  These agents reported faithfully every event at Gibraltar.
	(ii)  Possible Evacuation of Afrika Korps
	Tiesenhausen said that, in the event of the Afrika Korps having to be evacuated, it might be possible to do so, given sufficient air support.  He added that the French ships recently seized by Germany had been requisitioned with this purpose in mind.

 

	16
	APPENDIX "A"
	EARLY HISTORY OF "U 331"
	(i)  Launching
	"U 331" was launched from the yards of the Nordseewerke, Emden, towards the end of October, 1940.
	(ii)  Commissioning
	She commissioned at the end of March, 1941.
	(iii)  Working-up, Final Adjustments, etc.
	Working-up lasted until 1st June, 1941.  She returned to the Nordseewerke, Emden, for final adjustments which lasted about one month.  She then proceeded to Kiel for fitting-out before sailing on her first patrol.
	________________
	APPENDIX "B"
	PREVIOUS PATROLS OF "U 331"
	(i)  First Patrol
	"U 331" sailed from Kiel on her first patrol early in July, 1941.  She called at a Norwegian port, believed to be Kristiansand S., to top up with fuel.  As far as survivors were aware, she proceeded through the Rosengarten into the Atlantic.
	Her operational area was off Cape St. Vincent.  Here she joined a patrol line of boats and remained in position for some weeks without, however, making frequent sightings.  On only one occasion did she make an attack, firing a salvo of four torpedoes, all of which missed.  On one occasion she met another U-Boat, which came alongside to exchange mail, and in so doing damaged "U 331's" No. 1 diving tank.
	In mid-August, 1941, "U 331" made Lorient, where she was attached to the 2nd U-Boat Flotilla.
	Her officers were:
	Captain   Oberleutnant zur See von Tiesenhausen. 1st Lieutenant   Oberleutnant zur See Franken. 2nd Lieutenant   Lieutenant zur See Koch. Engineer Officer   Oberleutnant (Ing.) Wintermann.
	(ii)  Second Patrol
	(a)  Departure from Lorient.  "U 331" left Lorient on her second patrol at the end of September, 1941.  She proceeded across the Bay of Biscay, partly submerged and partly surfaced.  It is not clear when she received her orders to enter the Mediterranean, though this probably occurred on passage.
	(b)  Passage of Straits of Gibraltar.  She passed through the Straits of Gibraltar alone one night in early October.  One man said the passage began late in the afternoon, when "U 331" submerged.  She remained submerged until early the following morning, when she surfaced, only to submerge again as daylight broke and remain so until well clear of the Straits.  Tiesenhausen said he was not attacked at any time during the passage.
	(c)  Attack by T.I.Cs.  "U 331" proceeded direct to her area of operations in the Eastern Mediterranean.  While between Sollum and Alexandria she was attacked by what prisoners described as T.I.Cs.  Two of the men were wounded, one fatally.  He was buried at sea four hours later.
	"U 331" then proceeded immediately to Salamis, her new base, where she was attached to the 23rd U-Boat Flotilla (Senior Officer Kapitänleutnant Fritz Franenheim).  She arrived at Salamis at the end of October, 1941.
	(iii)  Third Patrol
	(a)  Departure from Salamis.  "U 331" sailed from Salamis on her third patrol at 1900 on 12th November, 1941.  Before sailing she embarked a sabotage party, which Tiesenhausen had been ordered to land at a given point on the North African coast, its mission being to destroy a section of British railway line.  He was then to wait for them and bring them back to Salamis.  The embarkation of the sabotage party had been kept secret from "U 331's" ship's company until the last minute.  The party brought its own rubber dinghy, in which it was to be landed.
	(N.I.D. Note.  The party consisted of:
	Leutnant Josef Kiefer, 17th Co., 2nd Batallion Lehrregiment Brandenburg (in command).
	Feldwebel Adolf Risch, 1st Co., 1st Battalion Lehrregiment Brandenburg.