The British-flagged Yorkmoor weighed 4,457 tons and was built by John Readhead & Sons Limited of South Shields, England, in 1925. Since then she had been owned by Walter Runciman and Company Limited, known as the Moor Line, of Newcastle-Upon-Tyne. Propelled by a single steam engine, Yorkmoor was registered to London.
On her final voyage the Yorkmoor loaded 6,700 tons of dense bauxite cargo in Saint Thomas, Virgin Islands. Her total crew of 45 included four Royal Navy gunners. The Master was Captain Thomas Harrison Matthews. The ship was armed with eight Hotchkiss and Marlin machine guns as well as the customary 4-inch gun along with rockets and kites. She was utilizing an experimental system called degaussing which was to detect the presence of torpedoes in the immediate vicinity of the ship and set off an alarm to alert the crew.
The ship left Saint Thomas on the 23rd of May 1942 and swung northeast to exit the Anegada Passage in daylight. Clearing the passage out of the Caribbean at dusk, the ship made a rhumb-line course for Cape Lookout in the Carolinas. The intention was then to utilize the coastal route north to her discharge port, New York.
On the 27thof May the gunners held a practice, firing four round out of the 4-inch gun. That evening at 9:05 p local time found the ship at 29.30N and 72.29W, northeast of Abaco Island, and roughly half way between there and Bermuda. The weather was settled, visibility very good, with only a light breeze. The moon was bright. Degaussing was activated at the time Yorkmoor was attacked by U-506 under Erich Wurdemann.
Captain Matthews was in the chart-room when he heard the whistle of shells passing over the bridge. He also heard the distinct sound of gunfire, like those from his owns guns that afternoon, only coming from further off. He immediately sounded the alarm, ordered an SSS sent and turned the ship so that its stern faced the offending gunfire and thus presented the smallest target. Unfortunately for the Yorkmoor, the first round of shells had penetrated the engine room and disabled on of the boilers, cutting the ship’s speed in half. Fortunately however none of the engine staff had been seriously injured.
The DEMS (Defensively-Equipped Merchant Ships) gunners, L. Hansford was manning the four-inch gun when a shell exploded beneath the gun platform, knocking him unconscious and throwing him from the gun emplacement. Within a few minutes he had regained his wits and managed to crawl back to his station however. Captain Harrison sent Chief Officer Charles C. Boylan aft to direct fire from the 4-inch gun.
One of the early hits from the submarine was an explosive shell which hit the forecastle head up forward, setting it on fire. After a few hits astern Wurdemann’s men focused on the machinery placed amidships on the Yorkmoor. At 10:15 pm Chief Engineer H. R. Hancock reported to the bridge that the engine room was flooding fast and had to be abandoned. Then the lights failed. With it clear that the ship, which was settling by the bow, was sinking quickly, with a very dense cargo, Captain Matthews gave the order to abandon ship. The engines and auxiliaries were then shut down and two lifeboats lowered in an orderly manner.
When the ship was abandoned the bauxite cargo was intermingling with the engine space. The Radio Operator had managed to rig an emergency aerial and send a number of distress messages. The gun crew, under the Chief Officer and the Gunl-layer G. Poley, managed to fire off some 19 rounds from the 4-inch gun. They were replying to between 50 and 60 high-explosive shells from the submarine, however, when the sub stopped firing it was difficult for the merchant gunners to find the target, as they were aiming for the muzzle flashes. Except for the fire on the forecastle, the gunners on the submarine also found aiming a challenge in the dark, despite the bright moon. Captain Matthews and the Chief Officer credited Poley with doing the work of two men, and for keeping the submarine at a safer distance away throughout the ordeal, thus prolonging the life of the ship and the men on it.
At 10:30 pm there was a terrific explosion, probably of the boilers exploding when the comparatively cold sea water reached them. The ship, which had a list to port of 45 degrees already, rolled over and sank. The port lifeboat had been damaged by shellfire, so all 45 men were taken onto Captain Matthew’s life boat until a more permanent situation could be arranged. Once Yorkmoor had sunk Wurdemann brought U-506 over to the lifeboat and inquired from Captain Matthews what ship, tonnage, cargo and destination, in German-accented English. Once he noted the replies the submarine headed southwards on the surface.
The port lifeboat had extensive and numerous (dozens of) small holes from shell fire. The Captain transferred the Chief Officer, Carpenter J. Cairns, and two men to repair it so that some 20 or more men could be transferred back to it. These repairs ended up taking a day and a half, until the evening of the 28thof May. At that point 17 men were added to the four men already in it to make 21 in the port boat and 24 in the starboard. Meanwhile the Captain managed to go amongst the wreckage and rafts and retrieve as much water and edible supplies as possible. This included a barrel of rum, the exact disposition of which is not given.
On the day after their attack the trade wind was characteristically blowing from the east and so both boats hoisted sail and headed westwards, towards the coast of the Carolinas, roughly 400 miles away. The captain rationed the available food and water, expecting a voyage of over a week. At 4:00 pm on the 30thof May Chief Officer Boyland told Captain Matthews that the port lifeboat was now fully fit for its voyage, and so Captain Matthews told them to go on independently. At 4:30 am on the morning of the 1st of June – two days later – the boat was sighted by the steam ship Laguna. They had attracted it with flares in position 32.00N and 75.46W. The men were landed in Charleston South Carolina the following day.
The same day found Captain Matthews and his 23 officers and men approaching the coast. They decided to use their emergency radio transmitter to send an SOS at 7:00 pm. At 10:00 am on the 4th of June they sighted to presumably Allied airplanes, one of which remained nearby, the other returning to shore to obtain assistance. At 11:30 that morning a US Coast Guard Cutter arrived and welcomed the British sailors on board. They then took the lifeboat in tow and motored to Morehead City, North Carolina. The crew were looked over by a Naval Medical Officer and aside from some severe sunburn declared to be in good health. As Captain Matthews proudly noted, “no one was hungry or thirsty when picked up.”