Black May (4 page)

Destined for Freetown, the convoy had originated on 26 April a short distance to the east-southeast, at Takoradi, on the Gold Coast (today’s Ghana). The run between those two ports had been made many times without losses: only eight ships sunk out of 743 sailing since September 1941. It was hoped by the British Admiralty’s Flag Officer Commanding West Africa, headquartered at Freetown, that RAF overflights along the route would be a sufficient supplement to the small Royal Navy (hereafter RN) surface escort to deter U-boat attacks. The aircraft available for that purpose were one Hudson (an American Lockheed passenger plane converted to bomber) squadron and two Sunderland flying boat squadrons operating from Bathurst (Banjul, Gambia), one Catalina squadron at Freetown, and a half-squadron of Wellington bombers at Takoradi, with detachments of Hudsons at Port-Étienne (Nouâdhibou, Mauritania) and Lagos, Nigeria.

There were two sea/air escort failures, however. An interception of a W/T (radio) transmission in Morse code from Henke’s boat was made by the Senior Officer, Escort, but that fact (not the message itself, which was unknown because it was encrypted) was not forwarded or relayed directly to Headquarters, Flag Officer, with the result that three destroyers at Freetown that might have been sent out at once to reinforce the escort did not sortie until it was too late. Furthermore, at
1820 GST (1620 GMT), which was two hours and fifty-one minutes before civil twilight in the area, the one aircraft assigned to dusk patrol over TS.37 ran into line squalls and electrical storms that forced it to leave the argosy and return to base. The continuing bad weather, combined with an absence of moonlight, caused the RAF to scratch a planned all-night escort. As a consequence, by nightfall Convoy TS.37 was near-naked to its enemy.
¹⁹

The night was black with flashing sheet lightning across the horizons. The sky was overcast with heavy rain squalls, but visibility was good. There was a moderate sea with swell and a light westerly wind, force 3–4 on the Beaufort scale. As Henke advanced to his work, a radar detection device on board (
Funkmessbeobachter [FuMB],
or “Metox,” after the name of the first French firm, based in Paris, to manufacture the equipment) sounded a high-pitched alert tone through the U-boat’s loudspeaker system. Metric radar pulses from one or more surface escorts not yet equipped with 10-centimeter radar (which was outside the FuMB’s frequency range) were searching for an enemy signature. Henke continued his advance regardless and, after two hours and fifty-four minutes, still on the surface, passed under the cover of a rain squall into the rear of the convoy columns.

When he had proceeded forward as far as the convoy center without having been sighted, and there took up a position, at steerageway (the minimum speed required for helm to have effect), canted northeast across the convoy’s base course, his First Watch Officer (I.W.O.) Oblt.z.S. Ernst Sauerberg brought up to the conning tower bridge the UZO (
U-boot-Zieloptik
), target-aiming binoculars with fourteen-inch barrels, and attached them to the rotating UZO post bracket. With these 7 X 50 lenses, reticle-etched for degrees of elevation and deflection, the I.W.O. obtained bearing, range, and angle-on-the-bow for a
Mehrfach,
or multiple launch, against two target ships in one of the port columns astern and transmitted the data to the Siemens-made deflection calculator (
Vorhaltrechner
) manned by the Second Watch Officer (II.W.O.), Leutnant Heinrich Niemeyer, in the tower below. Meanwhile, the aft torpedo room crew opened the exterior caps of Tubes V and VI, to flood them for launch.

When the aim-off heading had been established by the calculator
and transmitted to the guidance systems of the two stern torpedoes, and a depth of five meters, as decided by the I.W.O., had been hand-cranked into the eels by the torpedo room crew, Henke gave permission to launch. At 2256 GST the I.W.O. shouted
Los!
and hit the electromechanical launch button.
PISSSHH! PISSSHH!
Blasts of compressed air 1.2 seconds apart sent the two eels seaward and, 0.4 seconds after launch, the warheads activated and rudder vanes, directed by inboard gyro compasses, began to steer the warheads toward their targets. Simultaneously, Henke began counting the seconds from launch on his stopwatch; the aft torpedo room ratings vented the excess air inboard to prevent exterior surface bubbles; in the Control Room
(Zentrale),
the Chief Engineering Officer (
Leitender Ingenieur,
or L.I.) began taking water into the stern regulator tanks to compensate for the lost weight on board of the two eels; the sound man reported the torpedo runs as hot, straight, and normal; and the I.W.O. began setting up aiming triangles for four target ships forward in the convoy’s starboard columns. Henke’s war diary records:

One minute after the first launches, the I.W.O. and deflection calculator had a trigonometric solution for a torpedo in the bow tubes. Again, Henke’s KTB:

Within the next four minutes, the I.W.O. would have aiming triangles for three more ships:

White rockets signaling Hit By Torpedo went up in the dark night, to be joined by brilliant starshell illuminants fired by the convoy’s tiny escort in an attempt to sight the surfaced U-boat. In the same light Henke’s lookouts descried a small patrol vessel and a “destroyer” to port, and then, to starboard, another “destroyer” coming at them bows-on! Henke ordered an Alarm dive to 170 meters (562 feet). Depth charges dropped by what must have been the corvette
Bellwort
exploded a fair distance away. In the U-boat’s sound room the hydrophone operator heard the noises made by bursting bulkheads in the sinking ships. The torpedo crews reloaded three Etos.
²⁰

Henke erred in stating that he had scored six hits and had observed five sinkings. Both his stern shots missed, despite his observations. But the rapid fusillade from his boat did result in four starboard column ships being hit, all of which would sink. First to take a torpedo was the motor ship
Kota Tjandi,
a 7,295 GRT Dutch vessel in British service sailing from Haifa, Table Bay, and Takoradi for Freetown and the United Kingdom. Hit on the port side, as were the three victims to follow, this ship carried 7,453 tons of general cargo, including potash, rubber waste, and 1,000 tons of tea. Of her crew of 91 plus eight Navy and Army gunners, six men were lost.
²¹

The second vessel, struck on the starboard hand of
Kota Tjandi
, was the British freighter
Nagina,
6,551 GRT, carrying a general cargo of 4,886 tons that included 2,750 tons of pig iron. Her crew numbered 103,
including eight Navy and two Army gunners. Next hit was the British steamer
Bandar Shahpour,
5,236 GRT, sailing from Abadan, Mormugao, and Takoradi for Freetown and the U.K., with 6,768 tons of general cargo, including 3,000 tons of manganese ore, together with oil seeds, rubber, copra, and 2,002 bags of mail. Her crew, with four Navy and four Army gunners, numbered 62. She carried eight passengers: two women, one child, and five Merchant Navy officers. The last victim was the British motor ship
Corabella,
5,681 GRT, with a cargo of 8,035 tons of manganese ore. The crew, including six Navy and two Army gunners, who, like the gunners on the other torpedoed vessels, never got a shot off at their attacker, numbered forty-eight. The four ships were all hit within six and a half minutes, and all in or near the position 07°15'N, 13°49'W.
²²

From the Masters of
Nagina, Bandar Shahpour
, and
Corabella
we learn what happened to the crews on board those three vessels (there being no report found from the Master or crew of
Kota Tjandi).
Captain W. Bird stated that
Nagina
sighted a single torpedo approaching the ship from abeam on the port side. Its warhead exploded loudly but without a flash between Nos. 1 and 2 holds in the vicinity of the ‘tween decks and threw up a large column of water that, when it fell, crushed the fore part of the bridge. The No. 2 lifeboat and a raft were destroyed by the blast, but little other damage could be seen in the very dark night. Immediately, the ship listed about 10° to port and Captain Bird ordered engines stopped. Three minutes after the explosion, when the list increased, Bird ordered Abandon Ship. The five running lifeboats were lowered, one of which capsized. Three rafts were also launched, Bird joining the last of them.

Everyone was clear of the ship within seven minutes of being torpedoed, and from their boats and rafts they watched the holed
Nagina
go down, bow first, at 2113 GMT. Bird’s raft, with ten aboard, was overloaded, with the result that when three other men in the water grabbed hold of its sides, the raft capsized. The survivors managed to get purchase on the raft again, and a quarter-hour later, No. 6 lifeboat rowed over and took the thirteen on board. At 2230, H.M. Trawler
Birdlip,
part of the convoy escort, rescued the occupants of that boat and those of No. 5 boat. Five more survivors were found by a destroyer from Freetown
but not until 3 May, and No. 3 boat with its survivors was not found, by an aircraft and a motor launch, until 4 May. Notwithstanding the exposure suffered by these last two groups, casualties were light: the Second Wireless Operator was killed by the explosion and a Chinese carpenter was missing. To Admiralty authorities, Captain Bird complained: “I do not consider that this convoy was sufficiently protected. There were three destroyers lying in Freetown Harbour; the Naval authorities must have known that this convoy was passing through this dangerous area where submarines were known to be operating, yet these destroyers were not sent to our assistance.”
²³

Captain W. A. Chappell reported that the torpedo that struck his ship, S.S.
Bandar Shahpour,
was also sighted before it hit, by one of the gunners at his action station, but not in time to give a warning. The explosion, when it came, was dull and flashless, but it sent up a large column of water that then cascaded over the ship. Much of the 2,002 bags of mail, too, went skyward and came down like snowflakes over the deck and surrounding sea. Captain Chappell received reports that the mainmast had collapsed on the wireless room, destroying it and its equipment; that the engineers’ accommodation on the port side was destroyed; that the deck on the port side was twisted and fractured; and that the settling tanks in the engine room had burst, spewing oil and forcing the Fourth Engineer, who was on watch, to flee the engine room without stopping engines. Fortunately, because of the damage to the settling tanks, the engines gradually stopped on their own. Chappell fired white flares and transmitted an emergency message that was acknowledged by the Convoy Commodore. Then, deciding that the freighter’s condition was hopeless, he ordered Abandon Ship. Though the vessel was still slightly under way, three lifeboats sufficient to carry all the passengers and crew were successfully lowered; No. 4 boat became fouled and capsized on becoming waterborne. Chappell and the Chief Engineer, J. R. Black, were the last to leave, and, after a half-hour, all the survivors, with but one loss, were taken aboard
Birdlip,
making a total of 253 convoy survivors packed onto that small vessel. From the trawler’s gunwales the
Bandar Shahpour
party watched their ship go down at 2300 GMT.

When the trawler delivered her human cargo to Freetown at noon on
1 May, Chappell discovered that the dangers of being sunk were not all nautical. The accommodations provided his officers and his Goanese crew were appalling. The so-called Grand Hotel rooms assigned to his officers were so stinking and unhygienic, it was a wonder, he stated, that they did not all die from dysentery or typhoid; and the Sabars Hotel, which housed his native crew, was so foul that every man among them became sick. “They were simply wallowing in filth,” he reported, “and the food provided was uneatable; some were only given a piece of bread, with jam, after being without food for 36 hours.” No baths were available. It was worse, he said, than the boardinghouses in Bute Street, Cardiff.
²⁴

The last to be struck by one of U-515’s six torpedoes was the British motor ship
Corabella.
While steaming at 8½ knots on a course 295°, she was struck in No. 2 hold on the port side. “It was not a violent explosion, just a dull thud,” her Master, Captain P. Leggett, reported. In his cabin at the time, he found it difficult to make his way to the bridge because of piles of wreckage and debris in the corridor. On finally making the bridge, he found it in a collapsed state, with jagged cement and iron everywhere. Looking out, he saw that the foretop mast and wireless aerial were down; worse, that the cabin containing the emergency wireless had been stove in, making it impossible to send out an S.O.S. There was no sign on deck that any sea water had been thrown up by the explosion (indicating that a magnetic exploder had detonated beneath the hull).