There's sadly a lot of misinformation in what Justo posted.
Except for some plans, neither Pi-Mz nor Unterwasserzuender were used in BTs. The Pi-MZ was actually found inappropriate for the BT and could not be used at all, while the Uw.Z. was not even tested. Operational BT models used standard delayed action electrical bomb fuze, mounted on a fuselage side. Generally not hydrostatic, but time, distance and proximity fuzes were considered usable.
There's no physical possibility for a BT dropped from 200 m in a 20 degrees dive to cover 2800 m, especially that the underwater trajectory was only 50-100 m long - a BT dropped this way at 600 km/h would enter the water after after some 450 m of flight. BTs were to be dropped from a climb, not dive.
Only bigger BTs (1000+) were made from welded steel plates, smaller had cast warheads.
The BT 1000 RS did not actually reach 960 km/h, this value refers to max. velocity at which usual BT could be dropped.
I don't know if BT 1850s were used against Remagen bridge, but smaller BTs were to be used (and probably were indeed) by III./KG 200 against sea targets in northern Europe.
The last picture posted by kiradog shows an EB (Eintauchbombe), not BT (Bombentorpedo) - a similar projectile developed by Henschel, while BTs came from FGZ. These are really amazing photos!
Regards
Grzesio