For the Seadogs: April 17th 1942. From:
SeaWaves Magazine
1942 - At 0523, the unescorted & unarmed Heinrich Von Riedemann was hit by one torpedo from U-66 on the port side in the way of #6 tank. The explosion wrecked the steering gear and the port diesel engine. The ship was pouring oil from the tank while steering circles until the other engine was stopped. 20 minutes after the hit, the ship was abandoned in three lifeboats. At 06.40 hours, another torpedo hit the ship setting her on fire, which went out after 25 minutes. At 0755, a third torpedo struck and set the ship on fire again. The tanker finally sank at 0905. The boat of the master containing 15 men landed at Blanquilla Island at 0100 on 18 April, the survivors were picked up on 20 April by the steam merchant Maricaibo and landed at Caracas two days later. 29 men in two lifeboats were picked up by the Karmt at 1330 on 17 April and landed at Trinidad one day later
1942 - U-123 spotted the unarmed and unescorted Alcoa Guide and pursued her for hours before Hardegen opened fire with the gun on parallel course at 0523 because he was out of torpedoes. The first shell struck the starboard side on the saloon deck. The master then ordered the helmsman to throw the wheel hard to starboard to try and ram the U-boat. Moments later a shell hit the bridge, fatally injuring the master and jamming the rudder. With the engines still running, the vessel began circling out of control and U-123 continued firing with the gun and the AA Armament. A damaged ammonia condenser kept men from reaching the engine room to stop the engines. Hardegen ceased fire and allowed the crew of eight officers and 26 men to get off the ship. Six officers (including the master, who died in the lifeboat) and 22 men left in two lifeboats, while the Alcoa Guide was still running at high speed. The U-123 continued the shelling and one hour later, after 25-30 rounds; the freighter sank about 300 miles east of Cape Hatteras. On 19 April, destroyer USS Broome picked up 27 survivors and landed them at Morehead City, North Carolina. Four other survivors got away on a raft and became separated from the boats. At 1600 on 16 May, the British steam merchant Hororata located the raft in 34.35N/71.08W, but only one man was still alive
1942 - Submarine USS Snook laid down
1942 - U-739 laid down
1942 - Submarines HMS Shalimar & Strongbow laid down
1942 - Minesweeper HMCS Kentville launched Port Arthur ON
1942 - Submarine HMS Sportsman launched
1942 - Soviet submarine SC-139 renamed from SC-423 (former SC-315)
1942 - In the Mediterranean, U-81 used her 88-mm gun to attack shore-based targets near Haifa