The German squadron did not detect the K-21 submarine's torpedo attack on 5 July 1942.
Notes on verification
Corroborated by multiple independent sources citing German documents and Soviet submarine reports, including a detailed account of Captain Lunin's own report and post-war investigations confirming the German squadron's failure to detect the attack.
Sources
- Attack on the battleship Tirpitz by submarine K-21 (en.wikipedia.org)
- https://warhistory.org/@msw/article/k-21-versus-bb-tirpitz (warhistory.org)
- https://www.octodaydispatch.com/column_posts/world_war_ii/germans-commission-kms-tirpitz/article_8dd6e070-7227-11eb-b83d-53c8c0957780.html (octodaydispatch.com)
- https://weaponsandwarfare.com/2015/03/02/k-21-versus-bb-tirpitz/ (weaponsandwarfare.com)
- https://en.topwar.ru/36127-ataka-na-tirpic-obstoyatelstva-podviga-k-21.html (en.topwar.ru)