2. NARA, KTB-U-515, 21.2.43–24.6.43, RG 242, PG 30553/1–6, National Archives Microfilm Publication T1022, roll 3067, p. 4. Additional data are found in Timothy Mulligan, ed., Guides to the Microfilmed Records of the German Navy, 1850–1945, No. 2: Records Relating to U-Boat Warfare, 1939–1945 (Washington, D.C.: National Archives and Records Administration, 1985).
3. Ibid., 9 April 1943.
4. Notable exceptions to this observation are Vice-Admiral Sir Peter Gretton, K.C.B., D.S.O., C.B.E., D.S.C., Crisis Convoy (New York: Kensington Publishing Corp., 1974); and Martin Middlebrook, Convoy (New York: William Morrow, 1976).
5. Mulligan, Lone Wolf, p. 55.
6. Ibid., p. 62. Off Freetown, West Africa, the Type IXB U-123 (von Schroeter) once got under in 30 seconds; interview with von Schroeter.
7. NARA, KTB-BdU, 5 May 1943.
8. Ibid., 1 May 1943. The order of 16 April was “lifted with immediate effect” on 5 May. The reason for the Type IX losses was given as “their more complicated structure.”
9. For use of gunfire against shipping by World War I German submarines, see Anthony Preston, Submarines (New York: W. H. Smith Publishers, Inc., 1982), pp. 18–19.
10. NARA, KTB-BdU, 6 May 1943. The Type VIIC had two such external storage containers.
11. Eberhard Rössler, Die Torpedos der deutschen U-Boote: Entwicklung, Herstellung und Eigenschaften der deutschen Marine-Torpedos (Herford, Germany: Koehlers Verlags GmbH, 1984). On p. 76 of this work Rössler gives the weight of the G7a and G7e warhead charge (Ladung) as 300 kg, whereas in his earlier cited U-Boat he gives the weight as 280 kg; p. 344. On the same page of the latter work he gives the ranges of the two torpedo types as 75 and 50 km, respectively, which are obvious typographical errors. In Die Torpedos he gives the range of the G7e as 5,000 meters (5 km). An excellent summary of torpedo types and pistols is Robert C. Stern, Type VII U-Boats (Annapolis, MD: Naval Institute Press, 1991), Part Three: “Weapons and Targeting Systems,” pp. 78–93.
12. Marc Milner, The U-Boat Hunters: The Royal Canadian Navy and the Offensive Against Germany’s Submarines (Annapolis, MD: Naval Institute Press, 1994), pp. 62–71. The formal Allied name for the Zaunkönig was GNAT, the acronym for German Naval Acoustic Torpedo.
13. Timothy P. Mulligan discusses crew ages in his excellent article, “German U-Boat Crews in World War II: Sociology of an Elit Journal of Military History, Vol. 56, No. 2 (April 1992), pp. 261–281; cf. Mulligan, Lone Wolf, pp. 75–76, 80, for U-515 crew ages, and p. 83 for the information that, “At the time of her [U-515's] loss [9 April 1944] 19 of the 54 crewmen had served on all 6 of her patrols; 15 others had served on 3 to 5 patrols.”
14. Mulligan, Lone Wolf, pp. 85–86.
15. Ibid., pp. 3, 21, 216.
16. Ibid., pp. 26–57,122–123,128.
17. NARA, KTB-U-515, pp. 14–18, 13–29 April 1943. Cf. Mulligan, Lone Wolf, pp. 143–146.
18. NARA, KTB-U-515, p. 19, 30 April 1943.
19. Roskill, War at Sea, Vol. II, pp. 371–372; Mulligan, Lone Wolf, pp. 146–147; PRO, CAB 86/4, A.U.(43)144, Minute from the Secretary of State for Air to the Prime Minister, 5 May 1943.
20. NARA, KTB-U-515, 3° April 1943, P-19.
21. Lloyd’s War Losses, The Second World War, 3 September 1939–14 August 1945, Volume I, British, Allied, and Neutral Merchant Vessels Sunk or Destroyed by War Causes (London: Lloyd’s of London Press, Ltd., 1989), p. 667.
22. Ibid., p. 666.
23. PRO, 199/2145, Reports of Interviews with Survivors from British Merchant Vessels Attacked, Damaged or Lost by Enemy Action; from 1st April, 1943 to 30th September, 1943; Shipping Casualties Section, Trade Division, Admiralty [hereafter Interviews with Survivors], Captain W. Bird, S.S. Nagina, 8th June, 1943, ff. 92–93. The order in which the ships were hit is given by Bird; by Captain E. Gough, of S.S. Clan Macpherson, f. 97; and by Captain A. G. Freeman, of S.S. City of Singapore, f. 105 (except that Freeman, or more likely his interrogator, names No. 12 ship twice).
24. Ibid., Captain W. A. Chappell, S.S. Bandar Shahpour, 10th June, 1943, ff. 90–91.
25. Ibid., Captain P. Leggett, S.S. Corabella, 18th June, 1943, ff. 87–89.
26. NARA, KTB-U-515, 1 May 1943, P-19.
27. Cited in Padfield, Dönitz, pp. 287, 552 n. 135. Cf. John Terraine, The U-Boat Wars 1916–1945 (New York: G. P. Putnams’ Sons, 1989), pp. 467–468.
28. NARA, PG 32173, Microfilm Publication T1022, roll 1724, RG 242, War Diary of the Operations Division, German Naval Staff, Kriegstagebuch der Seekriegsleitung [hereafer KTB-1/Skl], 16 December 1942.
29. Padfield, Dönitz, pp. 392–396; cf. John Cameron, The “Peleus” Trial. Vol. I of the War Crimes Trial series, ed. by Sir David Maxwell Fyfe (London: William Hodge and Co., Ltd., 1948).
30. Clay Blair, Jr., Silent Victory: The U.S. Submarine War Against Japan (Philadelphia and New York: J. B. Lippincott Company, 1975), pp. 383–386.
31. Mulligan, Lone Wolf, p. 216.
32. NARA, KTB-U-515, 1 May 1943, p. 20. The depth charges (D/Cs) came from H.M.S. Rapid, which dropped 42 D/Cs on a contact of which she was “fairly certain” initially, but not so certain later on; PRO, ADM 199/434, “Report of Attack on U-Boat,” H.M.S. Rapid, 0358 through 0559Z, 1 May 1943, at 07058'N, 14 011'W.
33. Rohwer, Axis Submarine Successes, pp. 32–34.
34. Lloyd’s War Losses, p. 669.
35. PRO, ADM 199/2145, Interviews with Survivors, Captain A. G. Freeman, City of Singapore, ff. 105–106.
36. Lloyd’s War Losses, p. 669.
37. PRO, ADM 199/2145, Interviews with Survivors, S.S. Clan Macpherson, Captain E. Gough, 10th june, 1943, ff. 97–01.
38. Cited in Roskill, War at Sea, Vol. II, p. 372.
39. PRO, CAB 86/2, War Cabinet, Anti-U-Boat Warfare, Minutes of the Meeting held in the Cabinet War Room, on Wednesday, 12th May, 1943, pp. 2–3; CAB 86/4, A.U.(43)144, Minute from the Secretary of State for Air to the Prime Minister, 5 May 1943.
40. NARA, KTB-U-515,1 May 1943, p. 20.
41. NARA, KTB-U-107, Roll 3034–3035, 24.4.43–26.5.43, 1 May 1943, pp. 4–5.
42. PRO, ADM 199/2145, Interviews with Survivors, Captain W. G. Higgs, M.V. Port Victor, 7th May 1943, ff. 94–96.
43. Interview with Harald Gelhaus, Bochum, Germany, r July 1997.
44. Hessler, U-Boat War, p. 104 and Diagram 21. One of the eleven boats did not make it on station: U-332 was sunk in the Bay of Biscay on 29 April by a Consolidated B—24 Liberator bomber “D” of 224 Squadron, Royal Air Force (RAF) Bomber Command.
45. PRO, ADM 186/808, “U 301, U 439 and U 659, Interrogation of Survivors, June 1943,” p. 24. The first convoy was an operational formation of fifteen Coastal Forces craft including Motor Torpedo Boats, escorted by three trawlers. The second convoy was probably L.C. Flight “D” consisting of twenty-eight Landing Craft (LCs), escorted by two trawlers and one minesweeper. Torpedoes would have been of little use against these shallow-draft vessels, only the small escorts being minimally vulnerable.
46. For this description of the Type VIIC interior the writer has relied on Stern, Type VII U-Boats, passim.
47. See Jordan Vause, Wolf: U-Boat Commanders in World War II (Annapolis, MD: Naval Institute Press, 1997), PP-82–85. Mulligan, “U-boat Crews,” passim. After November 1940 the U-boat training school for ratings was changed in name to (in English) U-Boat Instructional Division. Because of the urgency of getting trained men to the front, between 1941 and 1944 the length of courses for officers was cut from twelve to eight weeks and that for ratings from six to three months. A study of U-boat training is given in NARA, RG 457, Historic Cryptographic Collection, World War I through World War II, Box 94, G.C.& C.S. Naval History, Vol. VII, “The U-Boat Arm-Organisation” (typescript), by Lieutenant H. M. Anderson, R.N.V.R., pp. 90–106.
48. PRO, ADM 186/808, “U 301, U 439 and U 659 Interrogation of Survivors, June 1943,” p. 24.
49. Ibid., p. 24. PRO, WO 208/4145, Combined Services Detailed Interrogation Centre, U.K.[hereaf
ter CSDIC (U.K.)], Kriegsmarine, March-June 1943; S.R.N. 1802, recorded 13 May 1943. Ibid., S.R.N. 1835. There is no sign in the message traffic decrypted by British and American cryptographers that the distress message from U-439 was intercepted. The BdU war diary indicates that the message was not received there: on 5 May U-439 was ordered to a new position; on 8 May BdU noted that U-439 had not reported since leaving Brest and must be presumed lost “during the last few days in April when air patrolling was very strong.” The BdU’s knowledge of U-659's fate was even more delayed: on 5 May the boat was ordered (along with U-447) to proceed through the Strait of Gibraltar into the Mediterranean; not until the 19th, when BdU acknowledged that it had heard nothing from the boat, was U-639 “considered lost.” NARA, KTB-BdU, 5, 8,19 May 1943.
50. PRO, ADM 186/808, “U 301, U 439 and U 659 Interrogation of Survivors, June 1943,” p. 6.
51. PRO, WO 208/4145, CSDIC (U.K.), Kriegsmarine, March-June 1943; S.R.N. 1837, recorded 21 May 1943.
52. Ibid., S.R.N. 1789, 1803, recorded 13 May 1943.
CHAPTER 2
1. Hessler, U-Boat War, Plan 59, facing Vol. II, p. 112; Plan 60 facing Vol. II, p. 113; Diagram 7, “The U-Boat War in the Atlantic from the Outbreak of War to December 1941”; Diagram 31, “Growth of the U-Boat Arm 1939 to 1945.” The reader’s attention is invited to the point made in the Prologue, n.12, that these are the true figures based on postwar analysis, and are lower than German Naval Staff estimates of the time.
2. Ibid., Vol. I, pp. 71, 73; and Diagram 31 for numbers of operational boats.
3. The statistics are from Mulligan, Lone Wolf, p. 221 and n. 1; Jak P. Mallmann Showell, U-Boats Under the Swastika (Annapolis, MD: Naval Institute Press, 1987), p. 18. The quotation is from David K. Brown, “Atlantic Escorts, 1939–45,” in Howarth and Law, eds., Battle of the Atlantic, p. 468.
4. F. H. Hinsley, et al., British Intelligence in the Second World War: Its Influence on Strategy and Operations, 3 vols. (New York: Cambridge University Press, 1981–1984), Vol. I., pp. 337–338, Vol. II, pp. 163, 170–174, 664; David Kahn, Seizing the Enigma: The Race to Break the German U-Boat Codes, 1919–1943 (Boston: Houghton Mifflin, 1991), pp. 104–184. See PRO, ADM 223/88, Use of Special Intelligence in the Battle of the Atlantic, f. 235.
5. An outline of the process of getting the decrypts from G.C.&C.S. to the Tracking Room and a physical description of the Tracking Room are given in Michael Gannon, Operation Drumbeat: The Dramatic True Story of Germany’s First U-Boat Attacks Along the American Coast in World War II (New York: Harper & Row, 1990), pp. 153–156. The information comes from interviews conducted by the writer with Beesly on 9 July 1986 and with Kenneth A. Knowles (Captain, U.S.N., Ret.), who served a two-week stint in the Tracking Room during May 1942, on 12 July 1986.
6. E.g., Jürgen Rohwer, “The Operational Use of ‘Ultra’ in the Battle of the Atlantic,” unpublished paper, Medlicott Symposium, 1985; V. E. Tarrant, The U-Boat Offensive 1914–1945 (London: Arms and Armour Press, 1989), p. 100; Terraine, U-Boat Wars, pp. 400–401; and Correlli Barnett, Engage the Enemy More Closely: The Royal Navy in the Second World War (London: Hodder, 1991), p. 267 and n.19. Professor Rohwer is particularly convinced that the Ultra triumph, leading to evasive convoy routing in the second half of 1941, was “more decisive to the outcome of the Battle (of the Atlantic) than the U-sunk in the convoy battles of 1943 or in the Bay offenses”; quoted in Terraine, U-Boat Wars, p. 400.
7. Hinsley, et al., British Intelligence, Vol. II, pp. 177, 636. A postwar U.S. Navy study estimated that 70 percent of all convoys intercepted by U-boats in the period 1 December 1942–31 May 1943 owed their contacts to Naval Cipher No. 3; see David Syrett, The Defeat of the U-Boats: The Battle of the Atlantic (Columbia, SC: University of South Carolina Press, 1994), p. 148, n. 10. Hessler, U-Boat War, says that in February and March 1943, “It was almost entirely due to [B-Dienst] that the U-boats still succeeded in finding convoys”; Vol. II, p. 89.
8. Hessler, U-Boat War, Vol. I, pp. 77–79; Rohwer, “Codes and Ciphers” in Runyan and Copes, eds., Die Gallantly, p. 52; Hinsley, et al., British Intelligence, Vol. II, Appendix 9, “Devices Adopted for Disguising U-Boat Positions in Enigma Signals,” pp. 681–682; Timothy Mulligan, “The German Navy Evaluates Its Cryptographic Security,” Military Affairs, Vol. XLIX, No. 2 (April 1985), pp. 75–79. Dönitz reported his security concerns to Hitler at the Führer’s eastern headquarters, Wolfsschanze, on 8 February 1943: “The C-in-C Navy explains with the aid of maps that during this month the enemy, surprisingly enough, found out the locations of our submarines, and, in some cases, even the exact number of [boats]. It was confirmed later on that his convoys evaded the known submarine formation. This detailed information can come from two sources: (a) Treason, (b) Undetected reconnaissance planes locating the formation.” Fuehrer Conferences, pp. 308–309.
9. PRO, ADM 223/297, “German Success Against British Codes and Cyphers, by R. T. Barrett, based on a report by Tighe,” 19 pp. The writer is indebted to the late John Costello for alerting him to the existence of this document. Tighe worked on Anglo-French ciphers before the war. He was withdrawn from sea duty in 1942 to work in the Signals Division, Admiralty.
10. Ibid., pp. 1, 8.
11. PRO, ADM 223/88, “Admiralty Use of Special Intelligence in Battle of Atlantic,” Chapter XV, “Convoys HX 229 and SC 122, March 1943,” ff. 258–259. Interview with J. David Brown, Head, Naval Historical Branch, Ministry of Defence, London, 29 May 1997. Brown, furthermore, is reluctant to call HX.229/SC.122 a German “victory,” since only 19 of the 40 U-boats involved made contact with either of the two convoys. “That was no way to win a war,” he told the writer.
12. See Syrett, Defeat of the U-Boats, pp. 117–118 and n. 65, 147–148 and nn. 9, 10. See also Kahn, Seizing the Enigma, p. 263.
13. Kahn, Seizing the Enigma, p. 263; Hinsley, et al., British Intelligence, Vol. II, p. 554.
14. Telephone interview from London with Sir Harry Hinsley, 19 June 1996.
15. See for example Barnett, Engage the Enemy, pp. 276–277: “Yet for all the endurance and professional skill of His Majesty’s ships and aircraft and of the Merchant Marine on the High Seas, the decisive instrument of the deliverance lay in the teams of civilians in the quiet huts of Bletchley Park who had broken Dönitz’s Enigma cypher. To them for the time being belonged the place of honour ‘on the right of the line.’” Also Peter Calvocoressi, Top Secret Ultra (New York: Ballantine Books, 1980), p. 97: “The Battle of the Atlantic is the battle which Hitler would have won and nearly won, but which he lost because of Ultra.” Terraine, U-Boat Wars, quotes approvingly a paper by Jürgen Rohwer, “The Operational Use of Ultra in the Battle of the Atlantic,” in which the latter is cited as saying: “There were many factors which influenced the outcome of the decisive Battle of the Atlantic…. I would put ‘Ultra’ at the top of this list of factors”; pp. 400–401.
16. Hinsley, et al., British Intelligence, Vol. II, pp. 169–170. This point is developed by W. J. R. “Jock” Gardner, “The Battle of the Atlantic, 1941—The First Turning Point?” The Journal of Strategic Studies, Vol. 17, No. 1 (March 1994), PP-109–123.
17. Kahn, Seizing the Enigma, p. 183.
18. Hessler, U-Boat War, pp. 64–67; Rohwer, “Codes and Ciphers,” in Runyan and Copes, eds., Die Gallantly, pp. 39–42.
19. See the excellent studies of RCN escorts and anti-submarine warfare by Marc Milner, North Atlantic Run: The Royal Canadian Navy and the Battle for the Convoys (Toronto: University of Toronto Press, 1985); and U-Boat Hunters.
20. Hessler, U-Boat War, p. 82.
21. J. David Brown, “The Battle of the Atlantic, 1941–1943: Peaks and Troughs,” in Runyan and Copes, eds., Die Gallantly, p. 140, 151.
22. Robert Hugh Cole, Underwater Explosions (Princeton, NJ: Princeton University Press, 1948); T. Benzinger, “Physiological Effects of Blast in Air and Water,” in German Aviation Medicine, World War II (Washington, D.C.: U.S. Government Printing Office, 1950), Vo. II, pp. 1225
–1259; Nelson M. Wolf, Lt. M.C., U.S.N.R., Report Number 646, “Underwater Blast Injury—A Review of the Literature” (Groton, CT: Naval Submarine Medical Center, 1970). The writer is grateful to Captain Claude A. Harvery, M.C., U.S.N., for these citations.
23. Interview with Sir Robert Atkinson, Winchester, England, 2 June 1997.
24. David K. Brown, “Atlantic Escorts, 1939–45,” in Howarth and Law, Battle of the Atlantic, p. 462.
25. Willem Hackmann, Seek & Strike: Sonar, Anti-submarine Warfare and the Royal Navy 1914–54 (London: Her Majesty’s Stationery Office, 1984), p. 281 and n.46. For asdic technology the writer has relied on this volume throughout. See pp. 216, 279, 281, 283, 296, 337, and 279–280 on the “Q Attachment” for holding contact with deep-diving boats. See Hessler, U-Boat War, Vol. II, p. 47.
26. PRO, ADM 186/808, “Interrogation of U-Boat Survivors, Cumulative Edition,” June 1944, Chapter IX, “Diving,” f. 299.
27. Middlebrook, Convoy, p. 69; Vice-Admiral Sir Arthur Hezlet, K.B.E., C.B., D.S.O., D.S.C., Electronics and Sea Power (New York: Stein and Day, 1975), p. 229; Hackmann, Seek & Strike, p. 280 and n.44.
28. PRO, ADM 186/808, “Interrogation of U-Boat Survivors,” f. 295; Hackmann, Seek & Strike, p. 321.
29. Beesly, Special Intelligence, pp. 20–21, 116; Kahn, Seizing the Enigma, pp. 144–145.
30. NARA, RG 457, SRH 149, Lawrence F. Safford, “A Brief History of Communications Intelligence in the United States, March 1952; SRH 305, Safford, “History of Radio Intelligence: The Undeclared War,” November 1943; War Diary, Eastern Sea Frontier, July 1942, p. 30.
31. NARA, RG 38, Box 14, Collection of Memoranda on Operations of SIS, Intercept Activities and Dissemination, 1942–45, “Report of Technical Mission to England,” 11 April 1941.
32. Kathleen Broome Williams, Secret Weapon: U.S. High-Frequency Direction Finding in the Battle of the Atlantic (Annapolis, MD: Naval Institute Press, 1996), passim; Rohwer, Convoy Battles, p. 21.
33. Jürgen Rohwer states that by spring 1943 B-Dienst had amassed “clear proof” that Allied surface escorts carried HF/DF (Kurzwellenpeilerj. He reproduces X-B-Bericht (cryptographic service report) No. 16/43, dated 22 April 1943, to this effect. Distribution of the proof included Dönitz’s Operational and Signals staffs, where apparently it was ignored. From a house near Algeciras in Spain, German photographers of British warships anchored in the roads of Gibraltar recorded the six-sided basket or birdcagelike Adcock HF/DF antennas on the aftermasts of certain ships, but these were interpreted by analysts as being connected to radar. Furthermore, since June 1942, when U-94 (Obit. z.S. Otto Ites) reported being depth-charged after making a HF transmission, Commanders had frequently voiced their suspicions about the matter. Rohwer, Convoy Battles, pp. 199–200 and photographs between pp. 192–193. Axel Niestlé states that the Kriegsmarine became aware of shipborne HF/DF in June 1944; “German Technical and Electronic Development,” in Howarth and Law, eds., Battle of the Atlantic, p. 438.
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