Authors: Michael Gannon
19
. Dönitz,
Memoirs,
pp. 207–208; Hessler,
U-Boat War,
Vol. II, p. 16. While the new boats would eventually become available with the Baltic thaw, Hessler writes: “Yet it was the dearth of new boats in the critical early months of 1942 that constituted an irreparable handicap to the whole [American] campaign.”
20
.
Triton
(called SHARK at GC&CS) was first introduced operationally on 5 October 1941 and overlapped with three-rotor
Heimische Gewässer
(called DOLPHIN at GC&CS) until 1 February 1942. See Ralph Erskine and Trade Weierud, “Naval Enigma: M4 and Its Rotors,”
Cryptologia,
Vol. XI, No. 4 (October 1987), pp. 235–244. Triton was introduced not to make decryption more difficult for the Allies—Dönitz had no idea his signals were being decrypted by the Allies—but as an internal security measure: to keep signals traffic out of the hands of German personnel with no “need to know.”
21
. Hinsley speculates: “Had the U-boats continued to give priority to attacks on Atlantic convoys after the Enigma had been changed, it is likely that there would have been such an improvement in their performance against convoys that the U-boat Command might have concluded that its earlier difficulties had been due to the fact that the three-wheel Enigma was insecure”; Hinsley, et al.,
British Intelligence,
Vol. II, p. 230.
22
. Donald Macintyre,
The Battle of the Atlantic
(New York: MacMillan, 1961), p. 140; John Keegan,
The Price of Admiralty: The Evolution of Naval Warfare
(New York: Viking Penguin, 1989), pp. 218–219.
23
. From an appreciation of Blackett by Sir Edward Bullard, quoted in Sir Bernard Lovell, F.R.S.,
P.M.S. Blackett: A Biographical Memoir
(London: The Royal Society, 1976), preface.
24
. Clark,
Boffins,
p. 141.
25
. Quoted in ibid., pp. 146, 215.
26
.
Blackett, Studies of War, pp. 216–217.
27
. Ibid., pp. 214–215. Professor C. H. Waddington, who was a member and later head of the Operational Research Section, provides statistics that show the rise in lethality of attacks following adoption of the 25-foot setting through December 1942. He suggests, however: “Some part in the overall improvement
was undoubtedly contributed by the more powerful filling employed [Torpex Mark XI after July 1942] and another part by the gradual increase in the number of heavy aircraft, and thus in the average weight of bomb-load”; Wadding-ton,
O.R.,
pp. 177–178.
28
. Ibid., pp. 220–225.
29
. Ibid., passim; Brian McCue,
U-Boats in the Bay of Biscay: An Essay in Operations Analysis
(Washington, D.C.: National Defense University Press, 1990), passim.
30
. Waddington,
O.R.,
pp. xvi-xvii. In 1942 the U.S. Navy formed a civilian research group corresponding to O.R.S., which it called Anti-Submarine Warfare Operational Research Group (ASWORG).
31
. PRO, AIR 41/45–48, “The Royal Air Force in the Maritime War” (typescript), four volumes.
32
. Unnamed crewman quoted in Price,
Aircraft versus Submarine,
p. 166. O.R.S. studies found that it took an average of 200 hours of flying time to result in one attack; Waddington,
O.R.,
p. 168.
33
. NARA, Box 419, folder marked Command File World War II. Shore Est. Hydrographie Office, “Submarine Supplement to Sailing Directions for the Bay of Biscay,” June 1943.
34
. PRO, CAB 86/3, A.U.(43)98, The A/S Offensive by Aircraft in the Bay of Biscay, Memorandum by the First Lord of the Admiralty, 28 March 1943.
35
. Until recently it was thought that U-206 (Kptlt. Herbert Opitz) was sunk in the Bay on 30 November 1941 by a Whitley bomber of 502 Squadron, but a reassessment by the Naval Historical Branch, Ministry of Defence, establishes that U
-206
struck a mine off St.-Nazaire on 29 November.
36
. Quoted in Price,
Aircraft versus Submarine,
p. 65, which is an excellent source on the Leigh Light. The best source for actual in-flight operation of the L/L is “Leigh Light Wellingtons of Coastal Command” by Air Commodore Jeaff H. Greswell, C.B., C.B.E., D.S.O., D.F.C., R.A.F. (Ret.), typescript, May 1995; letter, Greswell to author, 6 November 1997. Greswell participated in the development and testing of the L/L and made the first damaging attack employing it.
37
. An account of the unusual adventures of
Luigi Torelli
is given by Price, ibid., pp. 88–91. The first destruction of a U-boat at night was achieved by a conventionally equipped Swordfish of No. 812 Squadron, Fleet Air Arm, on 21 December 1941 off the Strait of Gibraltar. The victim was U-457 (Kptlt. Eberhard Hoffmann). A detailed account of the procedures to be followed in making a Leigh Light attack is given in PRO, AIR 41/47, Peyton Ward, “R.A.F. in Maritime War,” Vol. Ill, Appendix VI, ff. 595–596. In the Wellington the Light was mounted in a retractable under-turret. Later the Light was mounted on Liberators and Catalinas in a nacelle slung from bomb lugs on the wing.
38
. NARA, KTB-BdU, 16 July 1942.
39
. PRO, AIR 41/47, Peyton Ward, “R.A.F. in Maritime War,” Vol. Ill, ff. 535–536.
40
. Ibid., Vol. Ill, ff. 495–497.
41
.
Richard Baker, The Terror of Tobermory: An Informal Biography of Vice Admiral Sir Gilbert Stephenson, KBE, CB, CMG (London: W. H. Allen, 1972).
42
.
Quoted in Mark Williams, Captain Gilbert Roberts R.N. and the Anti-U-Boat School (London: Cassell, 1979), p.
III.
43
. Ibid., pp. 94–95.
44
. “Artichoke” and “Observant” are described in chap. 4. “Beta Search” evolved from the fact that the W/T transmissions of a shadower U-boat began with the Morse B (Beta), or B-bar. The new tactic forced the shadower to dive while, unseen to the enemy, the convoy changed course.
45
. McCue,
U-Boats in the Bay
, pp. 30–31; Hinsley, et al.,
British Intelligence,
Vol. Ill, Pt.
i
, p. 212. Historian J. David Brown considers August 1942 a more dangerous period for Allied shipping than early spring 1943. Comments to author.
46
. PRO, AIR 41/47, Peyton Ward, “R.A.F. in Maritime War,” Vol. Ill, ff. 512, 515. The ship torpedoed, but not sunk, was U.S.S.
Thomas Stone.
47
. Quoted in Rear-Admiral W. S. Chalmers, C.B.E., D.S.C.,
Max Horton and the Western Approaches
(London: Hodder and Stoughton, 1954), p. 143.
48
. Williams,
Gilbert Roberts,
p. 117.
49
. Chalmers,
Max Horton,
pp. 150–155 and passim; Terraine,
U-Boat Wars,
pp. 502–503.
50
. NARA, KTB-BdU, 31 December 1942.
51
. Quoted in Padfield,
Dönitz,
p. 295. Raeder also nominated Generaladmiral Rolf Carls.
52
. Graham Rhys-Jones, “The German System: A Staff Perspective,” in Howarth and Law, eds.,
Battle of the Atlantic,
pp. 138–157; Chalmers,
Max Horton,
p. 152.
53
. Michael Howard,
Grand Strategy,
Volume IV,
August 1942-September
1943 (London: Her Majesty’s Stationery Office, 1972), Appendix III(D), “Conduct of the War in 1943,” p. 621.
54
. Slessor,
Central Blue,
pp. 446, 464; Thomas B. Buell,
Master of Sea
Power: A Biography of Fleet Admiral Ernest J. King (Boston: Little, Brown, 1980), p. 276.
55
. PRO, AIR 41/47, Peyton Ward, “R.A.F. in Maritime War,” Vol. Ill, f. 500.
56
. The various volumes of A.U. Committee papers are found in PRO, CAB 86/1,2,3,4. After 12 May, when the Atlantic struggle was turning in the Allies’ favor, the Committee met several times fortnightly, then, after June, monthly. W. J. R. Gardner, “An Allied Perspective,” in Howarth and Law, eds.,
Battle of the Atlantic,
p. 524.
57
. PRO, CAB 86/3, A.U.(43)84, “The Value of the Bay of Biscay Patrols, Note by Air Officer Commanding in Chief Coastal Command.” Slessor made the interesting comment on the O.R.S. analysis: “It will be observed that the proportion of attacks to sightings round the convoys is only about 47% as compared with 75% in the Bay. The reason for this is of course, that only very rarely does an aircraft get more than one sighting on a patrol in the Bay, while round the convoys 3 or 4 is not exceptional, and the number has been known to be as high as 7 on one sortie”; f. 352.
58
. Blackett,
Studies of War,
p. 232. The comparison of escort perimeter to convoy size is further elaborated in NARA, RG 38 Chief of Naval Operations, Intelligence Division, Secret Reports of Naval Attachés, 1940–1946, File F-6-e, Stack Area 10W4, Box 252, Folder “Anti-Submarine Operations, Great Britain, Various, 1943–1944, Intelligence Report, Naval Attaché, London, 12 May 1943”: The perimeter of a convoy of 40 ships (4 columns of 10) was 23 miles long when the escort vessels were stationed 4,000–5,000 yards from the outside ships. With 78 ships (6 columns of 13) the perimeter was 27 miles long, which was an increase of only 1/6th. Where the 40-ship convoy required six escort vessels, the 78-ship convoy needed only seven. When the speeds of the two convoys were about the same, the percentage of stragglers from the larger convoys was a little less. The argument for 60
-plus
convoys was the following: If according to operational data six escort vessels lost four merchant ships, nine escorts would lose only three ships per convoy; therefore, 180 ships sailing in three convoys of 60 ships with six escorts each (on the current eight-day cycle) could be expected to result in a loss of 12 ships; the same ships sailing in 2 convoys of 90 ships each with 9 escorts each would lose only 6, cutting losses in half.
59
. PRO, CAB 86/2, War Cabinet Anti-U-Boat Warfare, Minutes of the Meeting on 3rd March 1943, f. 125.
60
. Blackett,
Studies of War,
p. 233; F. W. Barley and D. Waters,
Defeat of
the Enemy Attack on Shipping, Vol. 1B, Plan 35; Howard, Strategy, p. 304 and n.
61
. PRO, CAB 86/3,
A
.
U
.(43)4o, Progress of Analysis of the Value of Escort Vessels and Aircraft in the Anti U-Boat Campaign, Report by Professor Blackett, ff. 241–243.
62
. PRO, ADM 199/434, “The Commander-in-Chief, Western Approaches to All British and Canadian Escort Vessels Operated by Western Approaches Including Support Groups, 27th April 1943.” The Tactical Policy of Coastal Command was overtly offensive: “The Primary object of A/S patrols and A/S escort is the destruction of U-Boats”; Directorate of History, National Defence Headquarters, Ottowa, Canada [hereafter DHIST/NDHQ], Admiralty Atlantic Convoy Instructions (September 1942), Air Operations, p. 201.
C
HAPTER 4
1. The ONS series, which had reached ONS.171, was renumbered beginning with ONS.1 in March 1943, when this series was sailed to Halifax instead of to New York. The restarted ONS convoys sailed every eight days. The principal sources for ONS.5 are: NARA, “Allied Commands, Canadian, Captain (D) Newfoundland, 19 May 1943 (Vols, r-2)” [hereafter Captain (D) Newfoundland], Boxes 1718–1719; and PRO, ADM 237/113, “Report on Convoy ONS.5.” The NARA collection contains Form S.1203 reports of attacks on U-boats, track charts, plotting table diagrams, asdic recorder tracings, and original hand-copied between-ships messages, all of which are lacking in the PRO file. Ship-to-shore messages of ONS.5 are given in NARA, “Tenth Fleet Convoy and Routing Files,” Box 113, ON 304-ONS 9.
2
.
Gretton, Convoy Escort Commander, p. 108.
3
. Ibid., p. 108. The obituary writer in
The Times
(London) called him “ruthless” in this respect; 13 November 1992, p. 21. One of Gretton’s escort group Captains, Lieutenant (now Sir) Robert Atkinson, R.N.R., of H.M.S.
Tay,
described to the writer one of Gretton’s practices. Each morning at sea, at first light, Gretton sent a visual signal to all ships
in Latin.
At voyage’s end copies of those signals had to be produced by all ships. Any that got the messages wrong were detailed for extra training in port. Interview with Atkinson, Winchester, England, 2 June 1997.
4
. Gretton,
Convoy Escort Commander,
p. 120. The corvette
Pink
was later ordered to search astern for survivors but she found none. Seven men out of the crew of 78 were eventually located by a PBY-5 Catalina flying boat on 12 April and picked up by the rescue ship
Zamalek.
Frostbite forced the amputation
of the legs of three men and the feet of a fourth. See Vice-Admiral Sir Peter Gretton,
Crisis Convoy
(New York: Kensington, 1974), pp. 131–134. The U-boats that attacked HX.231 formed Group
Löwenhen.
Most were on their first mission, and only five launched torpedoes. The same choice had been made during the battle of convoys HX.229 and SC.122 on 16–20 March by Lieutenant-Commander Gordon John Luther, captain of the destroyer
Volunteer
and SO of the HX.229 Escort Group B4. On the night of 16/17 March Luther left the convoy undefended in order to rescue survivors from the U.S. Liberty ship
William Eustis.
But later on the same night, realizing that he could not leave the convoy without cover again, Luther ordered the survivors of a second torpedoed American freighter, S.S.
Harry Luckenbach,
to be left in lifeboats, where they died. Middlebrook,
Convoy
, pp. 181–186, 305–307.
5
.
Gretton, Convoy Escort Commander, p. 127.
6
. PRO, ADM 223/15, Operational Intelligence Centre, Special Intelligence Summary [hereafter S.I. Summary], for the week ending 19 April 1943; f. 195. Gretton stated in his report on ONS.5 that on 26 April he made “a study of the submarine dispositions”; PRO ADM 237/113, Report of Proceedings—Senior Officer in H.M.S.
Duncan,
p. 1. The X-B-Bericht Weekly Summary of B-Dienst for 10–16 May is found in Bundesarchiv-Militararchiv, Bestand RM 7/755, X-B-Bericht No. 20/43, Woche vom 10.-16.5. 19433 f-126V. (s.X-B-Bericht No. 19/43).