Black May (16 page)

Before the Wellingtons could improve on that record, Admiral Donitz ordered his boats in the Bay: “Because the danger of attacks without warning from radar-equipped aircraft is [now] greater by night than by day, in future U-boats are to surface by day…. ”
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In a month and a half’s time the Leigh Light had taken the night away from
U-boats in the Bay, but that, it turned out, would be for now their major contribution. The air war in the Bay returned to daylight hours, and with slightly better returns than before, as between mid-July and the end of September, conventionally equipped aircraft made over seventy sightings and sank three additional boats.

Still, the great opportunity that the Bay presented eluded Coastal’s grasp. The ratio of kills to daytime sightings remained disappointingly low throughout the remainder of 1942 and well into the new year. Whereas Coastal had expected that with increased time given to practice attacks, with, at last, 25-foot depth pistols, and with Torpex fillings, the percentage of lethal attacks would rise to 20 percent, it hovered instead at 6 percent. The lethality problem prevailed everywhere in waters that the U-boats infested, even where attacks were made from unseen cloud approaches on Class A targets, that is, those in which the U-boat was on the surface or had been submerged fewer than 15 seconds. Coastal was divided on the question of where blame should be placed: on poor weapons or on poor aim? Rear gunner reports and photographs suggested that the 250-pound Torpex D/C did not seem to injure boats even when perfect straddles were achieved. The O.R.S., however, defended the weapon, and, after intense study, determined that, photographs seemingly to the contrary, the problem was aiming, which could be corrected by more and better training.

In support of this conclusion the O.R.S. produced evidence that three outstanding squadrons, No. 120 (6 kills, 10 damaged), No. 202 (4 kills, 5 damaged), and No. 500 (4 kills, 9 damaged) also had solid records in practice bombing. It pointed as well to certain individual pilots, such as Squadron Leader Terence M. Bulloch, of No. 120 Squadron, with three boats sunk and three damaged, and Flying Officer M. A. “Mike” Ensor of No. 500, with one sunk and three damaged. In each case, the former in a Liberator, the latter in a Hudson, painstaking practice had translated into successful performance in combat.
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There was nothing wrong with the weapon. O.R.S.'s findings set in train intensive drills in marksmanship.

Another problem that the daylight bombers had to face was an increase in opposition from the Luftwaffe, which in the summer and
fall of 1942 attempted to interdict Coastal patrols in the Bay, employing Focke-Wulf 190s, Heinkel 115s, Junkers 88s, Messerschmitt 210s, and Arado 196s. Some aircraft and crew casualties resulted, but No. 235 Beaufighter Squadron at Chivenor in Devon successfully fought the attackers off, and the enemy air effort died away.

The nighttime bombers, which continued busy in the Bay Offensive, had problems of their own. The first was the French tunny (tuna) fleet, which followed the shoals of tunny into the middle Bay where most of the Leigh Light aircraft were operating. Numerous A.S.V. blips, when illuminated, turned out to be tunny craft. Their radar signature was indistinguishable from that of a U-boat. Use of the searchlight in these cases not only caused a 25 percent waste of effort and ran down the electrical power in the batteries, it gave fair warning to U-boats nearby that an L/L Wellington was in the area. In August the problem was so severe that L/L missions were considered futile and Coastal attempted to warn off the fishing craft by BBC broadcasts, leaflets, and threats to shoot, but nothing worked and the interference remained intractable until the end of the tunny season in October.

In the meantime the L/L flights, indeed all flights, were confronted by a far more serious problem. Admiral Dönitz’s technical staff had concluded, correctly, that the illuminated attacks in the Bay had been made possible by airborne metric radar. Helped by an A.S.V. Mark II set captured in Tunisia, BdU technicians developed a radar receiver (Type R.600) that could detect the presence of 1.5-meter pulses and give a U-boat time to dive out of danger. In fact, it produced a warning signal at a greater range than that at which an aircraft could acquire the blip (plus or minus 10 miles). Manufactured by the Paris firm Metox (also later by Grandin), the equipment was put to sea in August on three boats, U—214, U—107, and U—
69.
Except for problems encountered with the antenna, which was affixed to a crude wooden crosspiece
(Biskayakreuz
, the “Biscay cross,” as it came to be called) that had to be carried up and down the tower ladder when surfacing and diving, causing troublesome delays, the three boats reported favorably on the device’s effectiveness. Donitz then ordered the equipment fitted to every boat in the fleet, a process that was nearly complete by the end of
the year. This logical German countermeasure enabled the boats to resume surfacing by night.

A dramatic falloff in Coastal sightings, both day and night, together with intelligence drawn by Winn and Beesly from naval Enigma, gave Northwood a strong clue to what had happened. The value of the Bay campaign in these circumstances came under strong questioning, and AOC-in-C Joubert pressed London hard for 10-centimeter equipment with which to defeat the German Search Receiver (G.S.R.). But the first squadron to be so equipped did not become operational until the following March. In the meantime, Coastal relied on the only expedient available: flooding. In this tactic all the aircraft over the Bay except the L/L Wellingtons, which, it was hoped, might catch a U-boat off its guard, were to use their A.S.V. continuously. The expectation was that with the G.S.R. alarm ringing without stop, U-boats would not know when they were being targeted—an alarm that rang all the time was as useless as one that rang not at all—and so might become complacent or careless. But the tactic did not lead to additional sightings and attacks. In fact, during January 1943 a total of 3,136 day hours led to only five sightings, and 827 hours of combined L/L and conventional night patrols produced only three sightings.
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These were a new low record in the Bay.

During the U-boats’ six-month-long picnic on the North American seaboard, overstretched and weary RN surface escorts had a respite in which to fit new detection gear, practice use of weapons, including, on some ships, the new Hedgehog, and train ranks and ratings. The ratings’ first training experience, and in many cases, their first glimpse of the sea came when newly commissioned escort vessels received their working up at H.M.S.
Western Isles
in Tobermory harbor on the Isle of Mull off the west coast of Scotland. There the legendary (and quirky) Commodore Gilbert “Puggy” (or “Monkey”) Stephenson took callow “Hostilities Only” landlubbers—1,132 groups in all during the war— and, within two to three weeks’ time, shaped them into disciplined, semiskilled seamen who went directly into convoy escort service.
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While Stephenson’s work with new crews did not require a respite
from combat to carry on, the efficiency training of Captains and Watch-Keeping Officers did. This was particularly true of the Western Approaches Tactical Unit (WATU), an operational ASW analysis facility established at the suggestion of Churchill in January 1942, coincidentally the beginning month of the U-boats’ American campaign. The facility was erected on the bomb-damaged top floor of the Tate and Lyle Exchange Buildings to the east of Commander-in-Chief Western Approaches (CinCWA) in Derby House, Liverpool. To organize and direct the WATU, Churchill sent an RN Commander (later Captain) named Gilbert Howlands Roberts who, like Peyton Ward at Northwood, had been invalided out of the Navy, in his case because of tuberculosis.

A former destroyer Captain who was trained as a gunnery officer, Roberts modeled his facility on the floor plot used at gunnery school. He divided off a large linoleum-covered floor representing the open sea with lines ten inches apart indicating miles, and placed on that “Tactical Table” wooden models of convoy ships, escort vessels, and U-boats. Then, with canvas and string, he screened off any view of the ocean except for small apertures that gave only restricted views of an operational situation, akin to the restrictions prevailing at sea, particularly at night. Twenty-four “players” could work at the full floor plot, or three groups of eight players each could work at partitions of the plot. They sat at plotting tables around the viewscreens.

While a staff mainly of seventeen-to twenty-year-old Wrens (Women’s Royal Naval Service, or WRNS) manipulated both the models and the views allowed of them, combat situations were simulated and escort group Captains and Watch-Keeping Officers were asked to make decisions about appropriate actions to take in the circumstances shown—the circumstances being based on intensive interviews Roberts had conducted with Senior Officers of Escort Groups. Every movement was tracked, those of the U-boats in green chalk, those of the escorts in white, so that at the conclusion of “The Game,” as the exercise was called, the participants could inspect their successes and failures in pursuit and attack. The tactical course lasted six days, and as the months progressed, the teenage Wrens gained sufficient
competence to be able, discreetly, to advise sea-hardened officers on what might be their next best course of action—as remembered by a Lieutenant (later novelist) named Nicholas Monsarrat, who allowed in his
The Cruel Sea,
“Rather unfairly they seemed to know all about everything…. ”
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Numerous innovative attack procedures evolved from these exercises, the first of them based on reports of U-boat attack behavior during the passage of Convoy HG.76 from Gibraltar to the U.K. in December 1941 that were given Roberts by an offensive-minded Senior Officer Escort (SO) named Commander (later Captain) Frederic John Walker, who commanded the convoy’s Escort Group 36. Whereas Walker’s escorts thought that a U-boat that attacked HG.76 was about a mile outside the convoy, Roberts deduced from a simulation on his plot that the boat attacked from within the convoy columns, having infiltrated from astern. He thereupon devised a countermeasure to catch such a boat as it attempted escape. Since one of the Wrens suggested that the new tactic would give a “raspberry” to Hitler, Roberts assigned it that name. CinCWA Admiral Noble informed Churchill of this correction to “a cardinal error in anti-U-boat tactics” and within twenty-four hours signaled instructions for Raspberry to the Fleet.
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This tactic and a modification called Half-Raspberry were the first universally prescribed escort counterattack maneuvers; prior to their decree each SO was free to devise his own maneuvers. Soon, after trials on the Tactical Table, other fruit-named tactics were developed: “Pineapple,” “Gooseberry,” and “Strawberry”; to be joined by “Beta Search,” “Artichoke,” and “Observant.”
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Meanwhile, sea training in these maneuvers went on at Londonderry, Greenock, Birkenhead, Freetown, Bombay, St. John’s, Newfoundland, and Sydney, Nova Scotia, where escort groups practiced as teams under their own SOs.

It was these finely honed escort teams who met the U-boat men when the latter returned in force to the mid-Atlantic in early August, 1942. The slugging match between these two old enemies from that date until the start of May 1943 was fierce and relentless, but, as already indicated in this chapter and in the prologue, neither side was able to deliver a knockout blow. Nor was the renewed German effort against
convoys limited to the major transatlantic trade routes. Admiral Donitz probed for soft spots in the Outer Seas where Allied defenses might have been attenuated by the need to reinforce the northern lanes; thus, he deployed boats to Freetown, Cape Town, and Madagascar, to the Atlantic Narrows between West Africa and Brazil, to the Brazilian and Panamanian coasts, and to the traffic area eastward of Trinidad in the Caribbean.

In raw numbers the U-boats enjoyed commendable successes. During August, with 86 boats at sea, the U-Bootwaffe made an impressive number of convoy contacts per boat and sank 105 ships for 517,295 GRT; and in November, as noted earlier, the boats scored their highest monthly total of tonnage sunk in the entire Atlantic war. But throughout the period August 1942 to April 1943, their ever-increasing number of operational boats at sea generated
diminishing returns in tonnage sunk per boat per day at sea
—this despite the fact that U-tankers in midocean were multiplying their days at sea, deferring their maintenance, alleviating operational delays caused by the backlog of boats needing fuel at base, and frustrating Coastal Command’s Bay Offensive by eliminating the need for two transits per boat through the Bay. (In the twelvemonth period prior to the end of May 1943 the supply U-boats replenished 220 U-boats operating against Atlantic convoys as well as 170 boats assigned to Outer Seas.
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All the while, the experience and proficiency levels of the U-boat crews were declining, owing both to losses and to rapid expansion, while those of the escort crews were waxing, thanks in great part to the intense training regimen of January-July 1942, and to the fitting during the same period of new equipment such as HF/DF and 10-centimeter radar. From August through April 1943 the U-boats were being sunk at a monthly rate of 9.7, including February’s record 19. In the same period, three out of four ocean convoys made port without loss and 90 percent of those convoys that were attacked similarly reached their destinations. German intelligence and BdU completely missed the military convoys of the Anglo-American expeditionary force (Operation Torch) that sailed from the U.K. and the U.S. beginning on 18 October and effected landings on 8 November in French Northwest Africa, at
Casablanca in Morocco, and at Oran and Algiers in Algeria. Only one of the 334 ships that participated was attacked by a U-boat, and it by accidental encounter. German records do not disclose a single sighting, even inkling, of that armada as such.
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