OPERATION “CAESAR”

On 5 December 1944 the Type IX long-range U-boat U-864 departed Kiel, northern Germany, for Penang, Indochina (modern Malaysia).  The Japanese coveted German jet aircraft technology and U-864’s mission was to transport Messerschmitt “Swallow” jet engine parts and two aeronautical engineers, Rolf von Chlingenspreg and Riclef Schmerus, to the Emperor.  This mission, Operation “Caesar,” was one of several U-boat shipments in the final months of WWII.  Two Japanese nautical engineers, Tadao Yamoto and Toshio Nakai, were on board hitching a ride home.  As well, 1857 flasks (65 tons) of the strategic metal mercury, used for explosive primers, were packed as ballast along the keel.

But U-864 had problems.  Avoiding the many British patrols of the North Sea required cruising submerged, running her diesel engines via a schnorkel breathing device.  Korvettenkapitän Ralf-Reimar Wolfram hugged the Norway coast, at least until he ran aground and had to put in at Bergen, Norway, for repairs.  While there, on 12 January, the Bergen submarine base was bombed by the British, damaging U-864 further.  Wolfram could not get underway again until 30 January, trying to make a 10 February rendezvous with an escort off the Hellisoy Light on Fedje Island, Norway.  But on this day the U-boat’s starboard engine began missing, a noisy problem that demanded a return to Bergen.

Little did Wolfram know that the British were aware of his movements.  Code breakers at Bletchly Park had deciphered the German “Enigma” encoder and were reading the message traffic to U-864.  The submarine HMS VENTURER had been dispatched to the Hellisoy Light where LT James S. Launders, RN, lay in wait, submerged.  His passive sonar now picked up a strange motor noise.  Turning his periscope in the direction of the noise he spotted the feather wake of a schnorkel.  For two hours he remained submerged, tracking the contact with passive sonar and plotting her movements.  Launders then took up a position along her expected path and at the calculated moment fired a spread of four torpedoes.

Wolfram knew his noisy engine would give away his position and was zig-zagging underwater back to Bergen.  For several hours he coursed invisibly–he thought.  But out of nowhere the sonarmen suddenly heard high-speed propeller noises.  The first, second, and third torpedoes passed into the distance, but the fourth struck U-864 amidships.  She broke in two and sank, taking all hands, in this first recorded duel between two submerged submarines.

The wreck of U-864 was located in 2003.  Though she is a war grave, the mercury aboard represents a serious environmental hazard, and clean-up efforts by the Norwegian government are ongoing.

Watch for more “Today in Naval History’  13 FEB 26

CAPT James Bloom, Ret.

Brasse, Marc, Christopher Rowley and Karl Vandenhole, Directors.  “U-864: Hitler’s Last Deadly Secret.”  Military Channel documentary (November 2012), Discovery Communications, 2007.

Tarrant, V.E.  The U-Boat Offensive 1914-1945.  Annapolis, MD: USNI Press, 1989, p. 137.

Wynn, Kenneth.  U-Boat Operations of the Second World War  Vol 2: Career Histories, U511-UIT25.  Annapolis, MD: USNI Press, 1998, pp. 177-78.

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