The U-boat war continued unabated. They were still mounting a serious threat to the Allied supply lines across the Atlantic. However, a process of attrition meant that more and more experienced U-boat crews were being lost – and the newly trained crews now putting to sea increasingly faced convoy escort ships that were refining their tactics and becoming ever more persistent.
Like the unfortunate U-335, lost on the 3rd August, U-210, commanded by Rudolf Lemcke was also on her first war patrol.
U-210 had succeeded in getting out into the Atlantic and was within range of convoy SC-94, sailing from Sydney, Nova Scotia, to the United Kingdom, when she was spotted in the fog by the Canadian destroyer HMCS Assiniboine under Lieutenant Commander Stubbs. The sequence of events was reconstructed from the interrogation of survivors:
At 2000 on August 6 the bridge watch was relieved aboard U-210, the following men coming on duty: quartermaster HOLST, coxswain KRUMM, MONBACH and MEETZ. MUELLER relieved MYCKE at the helm. MUELLER is believed to have been alone in the control room at this time. As none of the bridge watch survived the following action, accounts of the sinking of U-210 are limited to his statements and those of the men below decks.
According to MUELLER, fog closed round the U-boat as the watch was relieved and LEMCKE, thinking that U-210 was safely hidden came below to eat his supper. At 2020 MUELLER heard confused sounds of shouting and firing above, and LEMCKE and TAMM passed him on the way to the bridge. General alarm was sounded throughout the boat, by buzzers in the forward compartments and by flickering green and red lights in the engine rooms, as the crew were eating their evening meal.
During the morning of the same day ASSINIBOINE, on convoy escort duty together with DIANTHUS, had dropped two depth charge patterns at the spot where they had seen a U-boat submerge. At 1700 a signalman on ASSINIBOINE, then off duty, sighted the conning tower of U-210 at 1000 yards range.
According to the commanding officer, ASSINIBOINE gave chase, but the fog shut down. He turned to port, came out of the fog, and sighted the U-boat again, now at a distance of one-half mile. ASSINIBOINE put on full steam, intending to close and possibly ram, but the fog intervened once more. Then the U-boat emerged from the mists a third time, only “a stone’s throw away”. The destroyer closed to 200, yards, started firing and attempted vainly to ram her stern, the range now being so short that ASSINIBOINE could not depress her guns.
Aboard U-210 no effort was made to dive immediately nor could anyone reach the 8.8 cm. gun, but fire from ASSINIBOINE was returned by HOLST, manning the 2 cm. gun at a range of approximately 200 yards. Explosive bullets were used and started a second degree fire in ASSINIBOINE’s forecastle, spreading aft almost to the bridge.
LEMCKE was blamed posthumously by his men for not submerging at once, but the volume of smoke pouring from the destroyer apparently led him to believe that he had damaged her considerably, and encouraged him to prolong the action. Prisoners also stated that he felt he could escape on the surface through the protecting fog, if need be.
U-210′s bridge was first struck by machine gun bullets. HOLST was shot through the neck and killed outright, and KRUMM was badly wounded. An instant later ASSINIBOINE scored a direct hit with her 4.7 gun on the conning tower, the shell making a shambles of the bridge. A prisoner stated that LEMCKE was literally blown to pieces, and that KRUMM, lying wounded, was virtually decapitated. It is assumed that TAMM also suffered a violent death.
MUELLER believed that a body flung against the torpedo firing mechanism, releasing an unset torpedo. Between them prisoners counted three more direct hits: one through the forward torpedo tubes, another which carried away the deck covering between the 8.8 cm. gun and the forward torpedo hatch — neither causing leaks in the pressure hull — and one aft which smashed the screws, water entering the boat. The boat was down by the stern, and the electric motors had caught fire.
SORBER, the engineer officer, now attempted to dive U-210. As the boat submerged, she was rammed by ASSINIBOINE abaft the conning tower and over the galley hatch (Kombüsenluke). U-210 descended to a depth of 18 meters. Water was flooding into the boat through the Diesel air-intake, damaged in the shelling of the conning tower, and through the battered stern. The electric motors had failed and everything breakable within the boat had been shattered.
SORBER gave the order to blow tanks and abandon ship, under the misapprehension that GÖRLICH, who had received superficial cuts, was too badly injured to make the ultimate decision. SORBER later reproached himself for surfacing as he believed, upon subsequent reflection that he might have been able to escape submerged. ASSINIBOINE rammed again aft as U-210 surfaced, firing a shallow pattern of depth charges as she passed. The C.O. of the destroyer stated that the U-boat then sank by the head in 2 minutes.