Op-16-Z

NAVY DEPARTMENT

CHIEF OF NAVAL OPERTIONS

WASHINGTON

Final Report - G/Serial 25

REPORT ON THE

INTERROGATION OF SURVIVORS FROM U-662

SUNK 21 JULY 1943

Cominch (F-21)

Cominch (FX-40)

Op-16

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BAD

DNI, Ottawa

SONRD

Comnaveu

Ensign Tweedy (CSDIC, ME

Lieut. Plaut (CSDIC, AFHQ)

Lt. (jg) Mullen

Lt. V. R. Taylor

Lt. K.W. Dowie

G-2 (Col. Jones)

Com 4th Fleet

Op-35

28 October 1943

TABLE OF CONTENTS

			Page
Chapter	I.		INTRODUCTORY REMARKS	1
	II.		DETAILS OF U-662	2
	III.		SPECIAL TECHNICAL DETAILS	6
	IV.		CREW OF U-662	14
	V.		EARLY HISTORY OF U-662	17
	VI.		FIRST PATROL OF U-662	19
	VII.		SECOND PATROL OF U-662	21
	VIII.		THIRD PATROL OF U-662	24
	IX.		FOUTRH AND LAST PATROL OF U-662	26
	X.		SINKING OF U-662	28
ANNEX	A.		U.S.N. EQUIVALENTS OF GERMAN RANKS	31
	B.		CREW LIST OF U-662	32

Chapter I.  INTRODUCTORY REMARKS

        U-662 was sunk 21 July1943, by a Catalina of VP 94 Squadron in position 03⁰ 56' N., 48⁰ 46' W.

        At the time of the sinking she was commanded by Kapitänleutnant Heinz-Eberhard Müller, who was severely wounded but survived.  Originally there were four other survivors, including a coxswain and three seamen.  The coxswain died before he could be hauled aboard a liferaft, and one of the seamen died aboard the rescuing vessel, U.S.S. Siren, after surviving the ordeal of being adrift on a life raft for 16 days.

        U-662 was a 500-ton U-boat and carried a complement of 47; this was made up of 5 officers, including a surgeon, and 42 petty officers and men.

        Particular attention is called to Chapter III, Special Technical Details, with reference to the following:  (a) a provisional but detailed description of the new German Radar Decoy Balloons, with sketches;  (b) some details of the various types of anti-aircraft ammunition in operational use by U-boats;  (c) a non-specialist's description of a new G.S.R. with visual indicator; and (d) a description of new collapsible life rafts carried in the Conning Tower of U-662.

        Interrogation was hampered by the fact that only two survivors, one a seaman 21 years old, the other a seaman 20 years old, were available for questioning.  Both were security-conscious, one of them extremely so, but nevertheless they did eventually respond to persistent interrogation.

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Chapter II.  DETAILS OF U-662

TONNAGE.

        500 tons.

TYPE.

        VII C.

BUILDING YARD.

        Howaldts Werke, Hamburg.

FLOTILLA.

        7th, St. Nazaire, under command of Korvettenkapitän Herbert Schler.

FELDPOSTNUMBER.

        M 43109.

PATRON.

        Hamburg Opera.

CODE NAME.

        Hammut.

INSIGNIA.

        Front of conning tower:  Red elephant crushing a tanker with his foot and holding another tanker aloft in his trunk.

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C/T CONSTRUCTION.

        Both sides of the conning tower were armor plated.

ARMAMENT.

        Guns:  2 demountable machine-guns, type C-34, on bridge.

                  2 fixed machine-guns, type M.G. 81; dual mount; on bridge.

                  1 cannon, 20 mm., on Platform I.

                  1 cannon, 20 mm., on Platform II.

                  (88-mm. gun forward, removed after 3rd patrol.)

                  10 Mauser 7.65-mm. automatic pistols.

        Ammunition:  5 types.  (See Chapter III, Special Technical Details).

        Torpedo Tubes:  4 forward, 1 aft.

        Torpedoes:  12 stowed inboard on last patrol.  Forward, there were 4 in tubes, 4 below plates,, 2 on plates.  Aft, there were 1 in tube and 1 below plates.  According to types, there were 9 electric torpedoes (G7e) and 3 air-propelled torpedoes (G7a), the latter fitted with F.A.T. gear.

        Torpedo Pistols:  F.A.T. torpedoes were fitted with "MZ" pistols (long type, magnetically activated).  (O.N.I. Note:  Informant was not torpedoman and may have confused details).  For the electric torpedoes U-662 carried 5 or 6 short pistols and 4 long "MZ" pistols.

SUBMARINE BUBBLE TARGET.

        Fitted, in the electric motor compartment.

DIESEL ENGINES.

        2 G.W., 6-cylinder Diesels.  Surface speed given as 17 knots.

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PROPULSION MOTOR GENERATORS.

        2 Siemens motors generators.  Submerged speed 7 to 8 knots.

RADAR.

        Not fitted.

R.D.B.

        Carried probably 50 or more Radar decoy balloons.  See Chapter III, Special Technical Details.

G.S.R.

        Diamond-shaped aerial fitted after 1st patrol.  Fixed drum-shaped diploe-type aerial replaced it after 3rd patrol.

D/F/ GEAR.

        Fitted.

COMMUNICATIONS.

        Stated to be "standard".  Call letters during trials:  X G S.

HYDROPHONES.

        G.H.G. (multiple unit hydrophones) fitted.

        Quartz hydrophones (K.D.B.) removed before 1st patrol.

ECHO-SOUNDER.

        Fitted.

"ELEKTROT."

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LIFE RAFTS.

        Carried 3 collapsible rafts of new type on last patrol.  See Chapter III, Special Technical Details.

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Chapter III.  SPECIAL TECHNICAL DETAILS

RADAR DECOY BALLOONS.

        The balloons carried on the last patrol of U-662 were of red gutta-percha.  These balloons, as per sketch 1 on page 7, were fitted with a small bottle-shaped valve, through which the balloons were filled.  This valve was so fitted that once the balloon was filled, it produced a slow leak that gave off a low hissing sound.  The balloon was attached to a float by means of a catgut, similar to a violin string.  About 25 meters below the balloon and about 5 meters above the float wa a metal container or cylinder said to be approximately 25 cm. high and 8 cm. in diameter.  The float was somewhat larger.  The diameter of the balloon itself was estimated to be 50 cm.

        At the bottom of the metal container was a hook from which several strips of tinfoil were suspended (prisoners believed there were 4 or more of these).

        Prisoners believed that the float was fitted with a soluble plug, so that it eventually filled with water and dragged the entire device down after a period of time, just how long they did not know.  The slow leak in the valve of the balloon also helped the sinking of the entire device.

        It is the cylinder or container that is intended to act as a radar target; the purpose of the balloons is solely to hold the cylinder suspended at the proper height.  The contents, if any, of the cylinder were unknown to the prisoners, who stated that only officers were familiar with them.

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        In port at St. Nazaire prisoners had seen balloons with a band of wire mesh around them, used experimentally.  The use of these wire mesh bands, was discontinued, since they had to be placed on the balloon after it was inflated and fell off very quickly.

        Two different experimental types have been seen, as illustrated in sketch 2 and sketch 3 on page 7.  On the type shown in sketch 2 the strips of tinfoil were above the cylinder instead of below.  In sketch 3 the 4 wires shown connecting the cylinder with the balloon were said to be of "silvery" metal.  The cylinder used was the same on all types.

        On patrol the balloons were inflated by the deck watch, but the cylinder and float were attached by the engineer officer personally.  It was stated that on one occasion 4 balloons were released simultaneously just before an attack on a convoy at night.  The method was to release the balloons, submerge to periscope depth, and then later resurface some distance away to attack the convoy.

        Two steel flasks containing hydrogen (about 1 m. high and about 20 cm. in diameter) were mounted aft on the bridge, one on each side.  The balloons were filled from these cylinders by a special attachment at the valve.

        U-Dietrich was stated positively to have carried the same equipment and the same number of balloons.

AMMUNITION

        The magazines for the 20-mm. anti-aircraft cannon were said to have held 20 shells each.  The shells themselves were of the following 5 types:

 

1)

"Brandspreng mit Leuchtspur" or incendiary tracer.  This

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		is a flat-nosed incendiary tracer.  The head is painted yellow and has a red band around the base of the head.  This was described as a "soft-headed" shell.  The color of the band indicates the color of the tracer.  It comes packed in wooden cases.  Self destroying at 2,000 meters.
	2)	"Brandspeng" or incendiary, non-tracer.  This is identical in appearance with the above except that there is no color band around the shell, since it is non-tracer.  It also comes packed in wooden cases.
	3)	"Panzerspreng" or armor-piercing, non-tracer.  This is a pointed shell, painted black.  It comes packed in steel cases.
	4)	"Panzerspreng mit Leuchtspur" or armor-piercing tracer.  This is a pointed shell painted black with a yellow band around the base of the head, indicating a yellow tracer.  It comes packed in steel cases.
	5)	"Panzerspreng mit Leuchtspur (PH)" or armor-piercing tracer PH.  This is a new shell carried by U-662 on her last patrol only.  It is an armor-piercing tracer painted blue with a red band (red tracer).  It also contains an incendiary phosphorous charge (hence the PH marking on the case), which explodes after piercing the armour.  This also comes packed in steel cases.

        A prisoner stated that he had also seen shells with a white band (white tracer) when he attended the anti-aircraft course at Misdroy, but that none of them was ever carried on patrol by U-662.

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        Ammunition for the new MG 81 (7.9 mm.) had an orange band around the shell, indicating an orange tracer.  The belts of ammunition for this gun were said to be 2 meters long and to hang down into the conning tower; by means of links fresh belts could be attached to permit continuous fire.

        Ammunition carried was as follows:  5,000 rounds for 20-mm., 6,000 rounds for machine guns, and 200 rounds for automatic pistols.  Ready ammunition for the 20-mm. to the extent of 8 drums of 20 rounds each was carried in pressure proof containers built into the deck 1 meter abaft the Conning Tower on the starboard side.  Another 42 drums were carried below with 4,000 reserve rounds in cases.

PLATFORM III.

        Prisoners stated that at the conclusion of the patrol on which she was sunk, U-662 would have been fitted with a further gun platform aft between the Diesel and after torpedo hatches; it was to be connected with Platform II by a catwalk.  One prisoner knew further of the plan to mount a quadruple 20-mm. anti-aircraft gun on U-662 at the same time, and he was inclined to believe that it would have been mounted on the new platform.

PREFABRICATED U-BOAT BRIDGES.

        According to one prisoner, some of the U-boats are having their bridges removed at St. Nazaire and replaced by new ones.  He stated that he had seen some of the prefabricated bridges, complete with Platform I and Platform II, loaded on flat cars.

NEW LIFE RAFTS.

        A prisoner who had helped dismantle them described the 3 new collapsible life rafts carried in the Conning Tower fairing by U-662 on

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her last patrol.  They had an interior length of approximately 2 meters and carried a yellow triangular sail, a lightweight metal mast about 2 meters high, and a few provisions in cans and boxes.  The sail was stiffened at the foot to provide the equivalent of a boom.  As a further indication of their size, the prisoner said they were about three-forth's as large as the life rafts dropped by the American plane at the time of sinking U-662.

NEW G.S.R.

        U-662 carried a new G.S.R. (make unknown with fixed, drum-shaped, dipole-type aerial.  This was fitted prior to her last patrol.  The prisoner who described it was a seaman who had never actually manned it, but he was certain that it incorporated a visual indicator.  This consisted of what he believed to be an ordinary light which lit up when the U-boat was located by radar.  He stated that the radio operator would call out to the commander that "the light is burning," whereupon the commander would order the U-boat to dive.  He affirmed the light was white and not green.

AVOIDING ACTION ON APPROACH OF PLANES.

        One prisoner made an interesting comment on U-boat tactics.  While it was true, he said, that U-boats as of summer 1943 elected to fight it out with aircraft that surprised them or were no more than 5,000 meters away when first sighted, they still made it a practice to avoid action by diving whenever the plane was as much as 6,000 meters away.

DETAILS ON TORPEDOES.

        The depth setting on F.A.T. torpedoes, it was stated, was always

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an even number; for instance, they were set to run at four, six, or eight meters.  Torpedoes with the magnetically activated pistols were said to have been set at four meters.

        The F.A.T. torpedoes, according to a prisoner who had fired several of them, had only two speed settings:  40 and 44 knots.

        None of the torpedoes carried by U-662 were simultaneously contact and magnetic, it was asserted (See O.N.I. Note:  page 3).

        All torpedoes were fitted at not more than 3,000 meters from the target, usually at 2,000 meters.

DIVING TANKS AND DIVING SPEED.

It was stated that the principal difference between U-boats of type VII-B and VII-C was the addition on the latter of two quick diving tanks.  The best diving speed of U-662 to a depth of 11 meters was given as 22 seconds.  The interval between the first alarm and the beginning of flooding of tanks was set at 7 seconds.

RED SEARCHLIGHTS.

        One prisoner had heard of red searchlights being used on Allied planes but had not himself seen any.

COLLAPSIBLE MASTS.

        In Hola a prisoner saw a 750-ton U-boat equipped with a collapsible lookout mast.  It was placed on the afterdeck.  They were found impracticable, he said, and are no longer being installed.

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Chapter IV.  CREW OF U-662

        The total complement of U-662 was 47 officers and men:  the Commanding Officer, a surgeon, and engineer officer, two watch officers, 15 petty officers, 27 enlisted men.

        Morale aboard U-662 was in general bad.  This was no doubt in part the fault of her first Commander, Korvettenkapitän Hermann, who was described as lacking in aggressiveness to the point of cowardice.  Had he remained on board, according to the belief of the crew, U-662 would never have been sunk; and had it not been for the aggressiveness, even recklessness, of the 1st Watch Officer and later Commanding Officer Müller, this U-boat might never have risked any attacks at all.

        Conversation on board frequently touched upon the prospect of Germany's  losing the war and upon the likelihood that, under Müller, U-662 would be sunk.  The general mood of the crew was pessimistic and depressed.

COMMANDING OFFICER.

        The Commanding Officer on the last two patrols, Kapitänleutnant Heinz-Eberhard Müller, although pleasant enough to talk with, would never vouchsafe any information except such as was deliberately at variance with the facts.  He does not seem to have enjoyed the absolute loyalty of his men.  The claim was made by one of the surviving seamen that it was the custom on board for the officers to smoke the best cigarettes and to drink the finest Hennessy, even though the 2,000 "North State" cigarettes, for instance, had been issued to the boat for equal distribution to all on board.

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        Müller was born in Stuttgart in 1916.  His wife and year-old son reside in a suburb of Flensburg.  He entered the German Naval Academy in 1936, making a trip to the Far East as a cadet on Emden in 1937.  The following year he served as 2nd Watch Officer on U-45 under Gelhaar and made a trip to Spain.  At one time he served as a torpedo instructor, and on board his U-boat he enjoyed the reputation of at least being "a good shot".  (O.N.I. Note:  Müller is listed in the German Naval Lists as Heinrich Müller.)

OTHER OFFICERS.

        Another reason for bad morale was found in the personality of the 2nd Watch Officer, Leutnant z. S. Wolfgang Seysen, who was characterized as "an unpopular martinet."

        The 1st Watch Officer, Leutnant z. S. Karl Janssen, was as popular as Seysen was unpopular.  He was scheduled to go to the training school for commanding officers after the 4th patrol of U-662.  He was known to be strict but was held in high esteem by his superior officers as well as by his subordinates.

        The Engineering Officer, Oberleutnant (Ing) Walter Heller, was said to be very able and very calm.

        Leutnant z. S. Jürgen Wagner, 1st Watch Officer during the tactical trials, was described as about average in ability and very kind to the crew.

SURVIVING CREW.

        The experience of being 16 days at sea on a life raft with no food and practically no water left its mark on the two seamen.  They each lost about 40 pounds in weight.  Seaman Grauff, in fact, seems to have become

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somewhat mentally unbalanced by his ordeal, although his memory for details, facts, and names has certainly not been impaired.

        Decorations distributed to the complement of U-662 included the following:  Iron Cross, First Class, to Müller, Hermann, Janssen, Mohrherr, Lisse, and Kuhr; Iron Cross, Second Class, to all the officers and petty officers and to 7 of the men; the U-boat Badge was worn by all but 7 of the crew; Mohrherr had the Spanish Cross and the Destroyer Badge; Weiler had the Narvik Shield and the Minesweeper Badge; Lejewski had the Minesweeper Badge and a wound stripe from service in the Polish Campaign.

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Chapter V.  EARLY HISTORY OF U-662

LAUNCHING.

        U-662 was launched, probably in December 1941, at the Nowaldts-werke, Hamburg.

STANDING BY.

        In January 1942, some members of the crew arrived to stand by for instruction during the final stages of construction.

COMMISSIONING.

        The boat was commissioned 9 April 1942.

ACCEPTANCE TRAILS.  

        The trials under the U-boat Acceptance Commission, including the usual test in the pressure dock, took place at Kiel in May 1942.

OFFICERS.

        During her trials the boat had the following officers:

Commander.................	Korvettenkapitän Wolfgang Hermann
Executive (1 W.O.) .....	Leutnant z. S. Jürgen Wagner
(2 W.O.).....	Leutnant z. S. Seysen
Engineer Officer............	Oberleutnant (Ing) Holler

WORKING UP.

        The working-up period required two full months, presumably June and July 1942.  It included a long stay at Pillau, trials by the Active Service Training Group (Agru-Front) at Hela, torpedo firing at Gotenhafen,

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and a stay at Danzig, where all repairs were made.

        The most noteworthy incident during this period was an encounter with a Russian submarine off Hela, when the latter brazenly joined in the tactical exercises of the German U-boats.  Although U-662 was armed only with machine-gun ammunition, survivors claim they pursued the Russian boat, which apparently was full informed about the location of the minefields and escaped by diving.  It was admitted that this submarine (or other Russian submarines) sank two or more German ships off Memel in July 1942.  After remaining in the area for days after the above incident, the Russian submarine was reported as finally having been sunk.

        U-662 was at Danzig, Russian planes made a raid on that city and set numerous fires.

        During her tactical trials U-662 was one of a group of 15 U-boats; two or three were 750-tonners, the rest 500-tonners.

FINAL OVERHAUL.

        The final overhaul of U-662 took place in August at the Howaldte-werke, Hamburg, and lasted two or three weeks.  Two days before leaving on the first patrol, the electric motors caught fire from some oily rags, which were ignited by the overheated Junkers compressors behind which they were lying.  Only slight damage resulted.

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Chapter VI.  FIRST PATROL OF U-662

DEPARTURE FROM KIEL.

        After leaving Hamburg, U-662 spent two days at Kiel.  On 22 September 1942, under the command of Korvettenkapitän Wolfgang Hermann she sailed on the first of her four patrols.  Two other 500-ton U-boats left Kiel at the same time.  (O.N.I. Note:  They are known to have been U-353 and U-706; both have now been sunk.)

STOPOVERS AT NORWEGIAN PORTS.

        Overnight stops were made at Kristiansand, Stavanger, and Bergen.  Before putting into Kristiansand, U-662 made a test dive of 180 meters and thereby damaged the hoisting mechanism of the periscope; it was also noticed that the propeller shaft bearings vibrated excessively at this depth.  It did not prove possible to remedy these defects at Kristiansand nor at Stavanger, but they were readily taken care of at Bergen.  Provisions, including meat and eggs, were taken on at Stavanger.

OPERATIONAL AREA.  

        U-662 proceeded through the "Rosengarten" area (63⁰ 30' N., 11⁰ 30' W.) to her operational area off Newfoundland.  Very heavy seas were running, and the U-boat could claim no sinkings.  (O.N.I. Note:  This boat is known to have been one of the 19 that made up Group Panther.  Between 6 and 10 October 1942, this wolfpack formed roughly a 360 mile patrol line making a 340 sweep in mid-North Atlantic; each boat was responsible for a range of 10 miles to port and starboard.  At least 6 of these boats have since been sunk.)

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ATTACK ON DESTROYER.

        Only once on her first patrol was U-662 in action.  On 24 October she fired 4 torpedoes at a destroyer without making any hits.  The Commander was very nervous during this attack, and it was only with difficulty that Müller, who was then the First Watch Officer, persuaded him to attack at all.

COUNTERATTACK.

        After this attack, the U-boat was heavily depth-charged.  By using the S.B.T. (Submarine Bubble Target) and by diving to a depth of 250 meters, she escaped without damage.

RENDEZVOUS WITH SUPPLY U-BOAT.

        On this patrol U-662 was once met and supplied by a 1600-ton supply U-boat under the command of Korvettenkapitän der Reserve Wolfbauer.  (O.N.I. Note:  U-463 under Wolfbauer supplied many U-boats late 1942 and early 1943, among them U-598 probably in early September and U-706 probably in late October.  Both these latter boats have recently been sunk.  U-463 has also been sunk even more recently.)

ARRIVAL AT LORIENT.

        U-662 had been assigned to the 7th Flotilla, St. Nazaire, but because of damage to the locks and also due to the overcrowded condition there, she was ordered into Lorient instead.  She arrived 18 November 1942 and remained there as a "guest boat" for a month and a day.  Ten torpedoes were brought back from this patrol.

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