Further to your post on 12 July re U-953, I can offer you some further information about the history of U-953 after it surrendered in Trondheim on 9 May 1945.
It left Trondheim on 29 May and arrived in Scapa Flow on 31 May 1945.
It left Scapa Flow on 2 June and arrived in Loch Ryan on 3 June 1945.
It was allocated to the UK by the Tripartite Naval Commission on 10 October 1945.
It was transferred to Lisahally from Loch Ryan on 30 December 1945
It was never used for any experimental purposes by the Royal Navy, nor was it allocated an RN Pennant Number in the “N” or any other series.
In September 1946 it was one of 6 U-Boats (from the UK’s TNC allocation) earmarked by the Admiralty for use as target ships, though they were never used for this purpose.
It remained tied-up to the jetty at Lisahally until mid-1947, when it was moved further up Lough Foyle for berthing at Londonderry.
In July 1948 the Admiralty decided it no longer had a requirement for the 6 U-Boats as target ships.
In early 1949 it was authorised to be sold for scrap.
It remained at Londonderry until June 1949 when it was towed away to the shipbreakers, at which stage the story becomes very ‘interesting’.
U-953 was supposed to be moved to Dunston-on-Tyne, Newcastle on 30 May 1949, but it seems most likely that the U-Boat that arrived under tow at Dunston on 4 June 1947 was actually U-712.
Thus it is most likely that U-953 (rather than U-712) was the U-Boat towed to the ship-breakers at Hayle in Cornwall in June 1949, arriving there on 29 June 1949.
Finally, if you want to read more about what happened to U-953 (especially the events of June 1949) and the other U-Boats allocated to the Royal Navy by the TNC after the war, might I suggest that you look at the “uboat.net” website under the “Articles” heading, where you will find a copy (dated 9 October 2011) of my paper “U-Boats in the Royal Navy post-May 1945”.
I hope this helps.