Commissioned in to the German Kriegsmarine on December 12th 1943, U-867 was a Type IXC u-boat built by the Aktien-Gesellschaft, Weser company at their yard in Bremen. The new u-boat implemented many of the lessons that had been learned since the early days of the war such as the fitting of a snorkel that allowed the diesel engines to run underwater to limit the chances of detection. It also followed the growing trend of having the deck gun deleted since there were now fewer opportunities to use it given the strength of defences around allied convoys.
After working up to operational status through 1944, the u-boat began its first wartime patrol on September 1st 1944 out of Kiel under the command of 39-year old Kpt. Arved von Mühlendahl. Despite his relatively advanced age compared to most other u-boat commanders, U-867 was von Mühlendahl’s first u-boat command. After nearly two weeks at sea, morale aboard the u-boat was increasingly becoming drained by a mix of foul weather battering the sub whenever they surfaced and a lack of any kind of success against the allies.
On September 17th 1944, the u-boat’s diesel engines became disabled in heavy weather forcing von Mühlendahl to order the u-boat to head for the Norwegian coast and the protection of the Luftwaffe. The u-boat made slow progress having to run economically enough on the surface so as to not drain the batteries of the electric engines that were normally reserved to power the u-boat underwater before they met up with one of three other u-boats that had been dispatched to render assistance.
It was tense time for von Mühlendahl and his men. They were travelling slowly through waters that were swarming with allied aircraft patrolling overhead. Through the next day, the u-boat crew’s luck held out but then, just after 2100hrs on September 18th they found themselves attracting the attention of a Leigh Light equipped Liberator of RAF Coastal Command’s No.224 Squadron based at RAF Miltown. As the Liberator attacked, the anti-aircraft gunners on U-867 and the nose gunner in the Liberator exchanged fire until the gunners on the u-boat were silenced just as the RAF plane began to drop depth charges. Six depth charges were dropped by the Liberator which landed in a line on the starboard side of the u-boat causing additional damage to the already disabled diesel engines which saw them start leaking oil.
After the depth charge attack, the anti-aircraft gunners were able to return to their positions and start firing on the British aircraft again which was now circling overhead. The British and the Germans briefly exchanged gunfire before von Mühlendahl was forced to resort to the only option left open to him which was to dive the u-boat even though this would probably use up the last of the power in his batteries. Having slipped below the dark waves of the North Sea, the RAF plane lost sight of the u-boat but at the cost of the last of U-867’s battery power.
Three other u-boats had been dispatched to render assistance to the disabled U-867 namely U-218, U-858 and U-1228. In the waning hours of September 18th, U-1228 was illuminated on the surface by another Coastal Command Liberator from No.224 Squadron using its powerful Leigh Light. The Liberator attacked with a stick of depth charges as the u-boat attempted to dive to the safety of the depths below but one of the six depth charges the Liberator released inflicted damaged on the u-boat’s snorkel. Thus when U-1228 attempted to use its snorkel the u-boat quickly filled with choking carbon monoxide from the engines that eventually caused the death of one crew member and left the rest gasping for air until they could surface again and open the hatches. U-1228 was forced to give up on attempting to reach U-867 and so it turned around and headed for port.
The next day, on September 19th 1944, von Mühlendahl and his men began inflating dinghies and lashing them alongside the crippled U-867 as it bobbed up and down on the inhospitable North Sea. The oil leak from the attack the day before now glistened in a large pool on the surface surrounding the u-boat and the dinghies. Then at 1737hrs, their worst fears were realised when they heard the sound of yet another No.224 Squadron Liberator growling towards them flown by Flight Lieutenant H.J. Rayner. Rayner carried out another attack with depth charges but all six of them overshot their target leaving the Liberator to orbit overhead and report the u-boat’s position so another aircraft could attack.
This was the final straw for Kapt. von Mühlendahl. Watched by the RAF Liberator crew, he and his men climbed in to the dinghies after appearing to deliberately flood the u-boat and cut themselves free before U-867 slipped beneath the waves for the last time. The Liberator crew reported that there were at least 50 men in the dinghies indicating that the entire crew escaped the doomed submarine.
The crews of U-218 and U-858 were close enough to the area to hear the detonations of the depth charges. Fearing for their comrades, they raced to the scene but at 2010hrs, U-858 found itself attracting the attention of yet another RAF Liberator only this time from No.206 Squadron. The Liberator attacked but U-858 managed to escape any serious damage by first making an aggressive turn to port as the depth charges landed in the water and then crash diving.
With U-867 no longer a threat, the RAF Liberators left von Mühlendahl and his men in their dinghies to continue hunting for other u-boats in the area. Another Liberator overflew a group of dinghies whilst on its patrol and it was long presumed they were from a different u-boat that had been attacked while U-867 was limping home. It is now generally agreed that these dinghies were from U-867.
Despite being so close to where the final attack on U-867 occurred, the heavy RAF presence in the area coupled with bad weather meant neither U-218 or U-858 was able to locate von Mühlendahl or any of his men. On September 22nd, the Germans called off their search thus confining them to the pages of history.