Authors: Michael Gannon
The next development will be the establishment of new patrols on an arc between 020° and 140° from Virgin Rocks at a radius of 600 miles from Gander, Newfoundland. Twenty or more U/boats are now moving to take these up and the apparent gap through which
SC 130 has been routed is rapidly closing: it will be touch and go whether this convoy scrapes through.
49
But Gretton’s first warning did not come until 2219 on the 18th, when the rescue ship
Zamalek
reported HF/DF contact. Later, on reaching port—he knew nothing of B-Dienst’s or of Bletchley Park’s cryptographic penetrations—he wondered aloud how it happened that so large a concentration of U-boats had been assembled without warning to him from the Admiralty’s shore-based HF/DF.
50
The answer no doubt was that the patrol lines were formed under orders of radio silence.
51
Now, at 0300, just before dawn on the 19th, when he knew that he was being shadowed if not surrounded, Gretton turned the convoy 90° to starboard in order to avoid a dawn submerged attack. The stratagem worked, and when the first VLR Liberator (T/120) arrived from Reykjavik and made two attacks on
U—731
(Oblt.z.S. Werner Techand), which was undamaged, the enemy boat was approximately where SC.130 would have been had not the foxing course alteration been made. The course 081° was resumed at 0400.
Liberator T/120 went on to sight five additional boats in the vicinity, a record six for one sortie.
52
With so many boats about, Gretton had to be cheered to know not only that aircraft from Iceland and Northern Ireland would watch over him but that a Support Group was on its way to firm up the surface screen: it was the same First Escort Group that had ridden out to assist B7 in the final hours of the ONS.5 struggle. EGI’s frigates
Wear
(S.O.),
Spey,
and
Jed,
together with the former U.S.C.G. cutter
Sennen (Pelican
had to return with engine defects) cleared St. John’s at 1930 on the 16th, and in the late morning of the 19th, while closing the convoy 15 miles off from the starboard quarters,
Wear
sighted a U-boat on the surface bearing 034° 12 miles. At 1135 the boat, identified later as U-952 (Oblt.z.S. Oskar Curio), was seen to dive. At 1209 the crow’s nest lookout in
Jed
sighted a second U-boat, which
Jed
and
Sennen
would later hunt.
At 1228 the first boat launched a salvo of four eels that passed between
Wear
and
Jed. Wear
then altered course up the torpedo tracks and obtained asdic contact at a range of 1,800 yards. At 1245 she made a Hedgehog attack, but only twelve projectiles fired because a safety
ready switch handle retaining spring broke. There were no explosions. What was worse,
Wear’s
helm jammed hard aport and took an hour to fix. In the meantime,
Spey
closed, obtained contact, and made three D/C attacks, at 1319, 1335, and 1415. The repaired
Wear
joined
Spey
in a fourth, barrage-type attack—sixteen D/Cs fired deep from each ship at six-second intervals—at 1533. No evidence appeared on the surface, but U-952 was extensively damaged at 170 meters depth by the last bombardment, and forced back to base.
The second U-boat, meanwhile, was visible to
Jed’s
bridge by 1227 at an estimated range of 8 miles. Observing
Jed
in pursuit, the boat dived at 1245 when 5 miles intervened.
Jed
made asdic contact at 1312; moments later, the U-boat unaccountably blew tanks, broached the surface, and dived again.
Jed
fired a five-charge pattern at 1316, and a D/C from the starboard thrower fell directly into the swirl, after which an oil patch appeared on the surface. Contact was not regained until a weak echo was received at 1324 and
Jed
reduced speed to 10 knots in order to carry out a Hedgehog attack, which she delivered at 1334. There were no explosions, and subsequent loss of echo led
Jed
to question the contact.
While the frigate started an “Observant” around the position of the first attack, the cutter
Sennen
came on the scene, obtained a contact of her own, and fired a ten-pattern at 1405. The explosion plumes were followed at 1427 by oil and bubbles, then, at 1440, by splintered woodwork and a small red object resembling meat or remains. At 1443 the asdic operator reported strange noises like escaping compressed air, and
Jed
made a H.H. attack on the noise source, with no explosions, at 1447. Oil continued to rise and by 1515, when the two escorts were ordered to rejoin the convoy if no longer in contact, the oil patch was estimated to be over a quarter of a mile wide. In the latest assessment of this engagement, U-760 (Oblt.z.S. Otto Erich Blum) is thought to have been the target of the first two attacks; she sustained damage to upper-deck containers. The second two attacks were made against U-954 (Kptlt. Odo Loewe), which was destroyed by
Sennen’s
ten-pattern at 1405.
53
There were no survivors from U-954, which was on her first combat patrol, having sortied from Kiel, Germany, on 8 April. Among the dead was
twenty-one-year-old Leutnant zur See Peter Dönitz, the Grand Admiral’s younger son.
54
A second U-boat would be sunk in the vicinity of SC.130 that day, though it was not a member of the
Donau
and
Oder
groups, and when it was found by Hudson “M” of 269 Sqdn. it was proceeding due west some four degrees latitude north of the convoy’s known position. This was U-273 (Oblt.z.S. Hermann Rossmann), another boat on her first patrol. At 1627 the Hudson pilot dived on the neophyte boat and delivered a four-D/C straddle of the conning tower, No. 3 being observed to enter the water on the starboard side within ten yards of the surfaced hull. Almost immediately afterwards, oil spread from the U-boat’s stern, eventually covering an area 100 feet wide and 600 yards long. U-273 remained on the surface for seven minutes, turning continually to starboard, and fighting back with flak. The Hudson returned fire, scoring hits around the tower and causing panic among the lookouts and gunners.
Finally, at 1634, the U-boat attempted a dive, from which she would not resurface, though floating wreckage did. Another forty-four men descended to their deaths while Hudson pilot Flying Officer J. N. F. Bell returned to base (and to a postwar career as a British Airways Captain). It was another of the Atlantic war’s fateful exchanges, now almost always unfavorable to the German side.
55
More mysterious was the disappearance of U
—381
(Kptlt. Graf von Pückler und Limpurg), which had sortied from St.-Nazaire on 31 March and made her last transmission to BdU at 1502 on 9 May from qu AK 7962. Subsequently, she was ordered, with three other boats, to form Group
Inn,
and later to join
Donau I.
Whether she did either is not known. On the 21st, BdU, not having received any further signals from the boat, asked her to report her position. When no response was received, U-
381
was posted as missing with effect from that date. Her loss has not been matched to any of the attacks made by the surface ships of EGI or B7 or by any of the air escorts.
56
Prior to and following
Jed
and
Sennen’s
kill of U—954, indeed throughout the 19th and continuing until dawn on the 20th, SC.130's surface escorts made no fewer than twenty-seven individual attacks on
U-boats sighted from the cockpit of an aircraft or from an escort’s crow’s nest or bridge, or detected by HF/DF or radar, and/or tracked underwater by asdic.
57
Each sighting or contact was pursued energetically in keeping with Western Approaches’ finding that most U-boats sunk by surface vessels during the year prior to May were destroyed prior to their attacks, not afterward (see chapter 3). As it happened, however, none of B7'S attacks and none further of EGI’s resulted in a kill.
Duncan
and
Snowflake
were certain, because of the accurate placement of the D/Cs and one Hedgehog explosion seven seconds after the pattern struck the water, that they had destroyed a U-boat in a series of six attacks that they carried out jointly between 0755 and 0918 on the 19th,
Duncan
getting in what he thought was the fatal blow. But a recent reassessment finds that
Snowflake
s contact, U-304 (Oblt.z.S. Heinz Koch), was undamaged except for a tank put out of action, and that
Duncans
contact, a different boat altogether, probably U
-636
(Kptlt. Hans Hildebrandt), was undamaged.
58
Wear
and
Spey
severely damaged U-952 at 1245 through 1533 on the 19th, as shown above;
Spey
slightly damaged U
-413
(Poel) at 0346 through 0542 on the 20th; and
Jed
lightly damaged U-91 (Oblt.z.S. Heinz Hungershausen) at 0420 through 0439, also on the 20th.
59
Despite that apparent lack of success in destroying U-boats, the surface escorts achieved a success that, on shore, was more highly valued than U-boat trophies hung on a wardroom wall: they saved every merchant ship in the convoy from harm. They did that, under Commander Gretton’s skillful command, by aggressively running to ground every enemy craft sighted or detected, and by directing the VLR Liberators in the cloud cover overhead to every W/T transmission source. The number of HF/DF contacts was striking even by the usual standard of talkative German radiomen: during the 19th and 20th
Duncan
counted fifty-one,
Tay
thirty-one, and
Sennen
twenty-three.
60
As each cross-cut came into his plotting room, Gretton vectored the VLRs to the transmitting boat from their overhead air search patterns, which were called by such code names as “Frog,” “Adder,” and “Viper.” On more occasions than a few, U-boat Commanders were stunned to find that at or before the close of an
Ausgang F.T.
(outgoing W/T transmission), a
Liberator was bearing down on their positions. In his war diary entries for 19 and 20 May, Dönitz/Godt complained about the “continual surprise attacks by land-based aircraft out of low-hanging clouds.”
61
Of course, BdU attributed them to radar, but the attacks were instead additional evidence of the importance in the Atlantic war of what the Allies affectionately called Huff-Duff.
The final U-boat kill of the SC.130 crossing came from the air at the hands of No. 120 Sqdn. out of Reykjavik, whose aircraft made twenty-seven sightings on the 19th and 20th. Two VLRs struck at U—707 (Kptlt. Günter Gretschel), which like U
-413
(Poel) had operated against ONS.5: at 1340 on the 19th, P/120 dropped four D/Cs on the surfaced Gretschel boat without inflicting injury, but at 0810 the next day, N/120, sighting the same boat and attacking ten seconds after Gretschel submerged, caused severe damage, forcing that boat to retire from the field. At 0745 on the 20th, U
-418
(Oblt.z.S. Gerhard Lange) was injured by four D/Cs dropped by Liberator “X” of 59 Sqdn. based in Ballykelly, Northern Ireland. The kill was made on the 20th by P/120, whose pilot, Squadron Leader J. R. E. Proctor, lifted off from Reykjavik at 0954 and met SC.130 at 1430 in 55°N, 30°W, where, at Gretton’s direction, he began a series of searches, sighting one U-boat at 1448 that he was not able to attack and another at 1710, Red 15° six miles, that he dived on, dropping four D/Cs and obtaining a straddle on the partially submerged boat. It was U
-238
(von Mässenhausen), another ONS.5 boat, which had sunk the American
McKeesport
twenty-two days before.
The Liberator’s rear gunner saw the boat’s conning tower lifted out of the water for three seconds by the explosions. When the spray of the plumes subsided, the boat was no longer visible, but an oil patch appeared that during the next thirty minutes spread to about 200 feet in diameter, with an “almost white patch” at its head looking like air bubbles. Ironically, at just one hour and eight minutes after this attack, U
-258
was sent a signal by BdU ordering her to return to base and to make frequent transmissions over the next three days for purposes of deception. Von Mässenhausen and his crew would not be able to obey that order.
62
Meanwhile, P/120 carried on her patrol, and at 1924
sighted a surfacing U-boat three miles distant. Diving, Squadron Leader Proctor decided to strafe the conning tower with machine-gun fire in an apparent attempt to force the boat back under water so that he could drop a Mk.24 Mine. Six crewmen sighted on the bridge returned his fire and the boat remained on the surface.
Proctor swung the heavy craft around and made another pass, expending 180 cannon rounds against the tower and foredeck. Though his report does not state that the U-boat finally did dive, Proctor released a FIDO at 1931. Three minutes later, he reported, the U-boat could be seen on the surface down by the stern, circling, “in difficulties.” At 2143, he began the return flight to base, where he arrived at 0115 on the 21st. Proctor’s after-action report in the Squadron’s Operations Record Book makes no mention of the Mk.24 but states instead that he released a “600 lb D/C.” This was the code for Mk.24, and a cleverly chosen one, since there was a Mark I 600 lb. depth bomb just coming into service. When a weapon was cited in print as a depth “bomb (D/B)” it was in fact a large depth charge; when the citation read “600 lb. D/C” it was the Mk.24. One may have further confidence here that Proctor’s weapon was indeed the Mk.24 because No. 120 Sqdn. had not yet been equipped with the 600-lb. D/B.
63
In any event, the Mk.24 was dropped on this occasion without effect: the intended target, U
-418,
made off with no further injury (until 1 June when, homeward bound, she was destroyed by Beaufighter “B” of 236 Sqdn. in the Bay of Biscay).
64
Among the merchant ship columns of SC.130, stationkeeping was excellent throughout the battle, even during the twenty emergency turns that Gretton ordered in its course. As he commented in his Report of Proceedings, “The convoy was executing blue turns with the precision of a battlefleet.”
65
The last such evasive alteration was made at dawn on the 21st, but it was an unnecessary precaution by that time, since, on the evening before, BdU signaled the U-boats to break off the operation and move away westward.
66
The remainder of the passage was uneventful, except that the weather deteriorated and the convoy’s speed on the 22nd dropped to 4 knots in an easterly gale. At 1100 that day, on orders from CinCWA, Gretton detached EGI. The major
escort work was done. Though heavily beset during its passage, SC.130 arrived unscathed in home waters on the 25th. Some merchant ships entered Loch Ewe escorted by
Loosestrife,
the remainder, with
Vidette,
anchored at the Mull of Kintyre.
Duncan
and the other B7 escorts put into Moville near Londonderry, and, to relieve the reader’s suspense, Gretton got himself to the church on time. A “safe and timely arrival” indeed!