|Ordered||6 Nov 1943|
|Laid down||20 Sep 1944||F Schichau GmbH, Danzig (werk 1665)|
|Launched||23 Nov 1944|
|Commissioned||12 Jan 1945||Kptlt. Sarto Ballert|
|Successes||No ships sunk or damaged|
Sunk 31 Jan, 1945 in the Baltic Sea north-east of Bülk, in position 54.28N, 10.12E, by mines. 85 dead (all hands lost).
Men lost from U-boats
Unlike many other U-boats, which during their service lost men due to accidents and various other causes, U-3520 did not suffer any casualties (we know of) until the time of her loss.