14 Oct 19
Posted by: Richard Sharpe

What is it about German submarines of World War II vintage?  Having recently read about them in the context of end-of-war passages to South America, another one surfaces with the life story of U-1105. The U-boat is also pretty much in permanent attendance in the backwaters of television documentaries on lesser-known specialist channels. Das Boot is the best known. Visit a retired submarine in a naval museum or, better still, if you are a diver, when it is a wreck sitting on the seabed, and you sense the ‘other worldly’ atmosphere which is presumably the main attraction, but bear in mind that when the ship was in full commission she hummed with life much like any other nautical place of work.

The particular attraction of U-1105 seems to have been the early snort mast device, an external coating of rubberised material (Alberich) designed to reduce her sonar echoing area, and an improved passive sonar for the better detection of targets.  Of the three, only the snort became a universal submarine fitting, allowing diesel engines to be run without the need to surface.  Of the other improvements, the guaranteed adhesion of flexible sound absorbent surfaces in the demanding underwater environment remains a problem to this day.  Also, sonar technology improvements have advanced out of sight over the years but will always be constrained by the variable thermal conditions and background acoustics of the oceans.

The history of this submarine has been researched and written over a six-year period by Aaron Hamilton, an American maritime archaeologist and specialist in German U-boats.  It is an account of end of war trials and work-up in the North Sea and Baltic, followed by a single wartime patrol off Ireland and the sinking of an RN destroyer.  The patrol was terminated by the end of the war and orders to surrender, followed by internment on the River Foyle at Lisahally in Northern Ireland.

In total, the Allies had access to 125 surrendered U-boats post VE Day.  In spite of receiving the hull of U-1105 the Americans did no further testing on its Alberich covered surfaces and did not start to use external rubber coating technology until 1980. Once in American waters, the hull was subjected to a series of destructive tests, being sunk six times and recovered, before finally being laid to rest on the bottom at Piney Point in Chesapeake Bay at a depth of 90ft.  Only the upper deck and conning tower are above the bottom silt, and inspection of the wreck is closely controlled by the US authorities.