The other explanation involved a shell passing right down the funnel and setting off the boilers.
... there is no way a shell could have entered the funnel. (This is an old subject, so may trigger a hefy response
). That is, unless the Germans adopted a shell that can consiously decide to change course in midair (say, 70 degrees)
Quite obviously, Foeth, you aren't familiar with the secret "magic shell" employed by the Germans at DS! It was a well-kept secret at the time, delivered to Bismarck's magazines prior to Rheinübüng. Its success was beyond all expectation at DS and, as a result, led to the development of a much smaller version for use by infantry riflemen.
Although there were no further quantities of this shell supplied to Tirpitz
, the principles were essentially identical. The development of the small-calibre version was initially intended as anti-landmine ordnance. However, its use was limited until 1943, when most of the production quantities were furnished to Italy.
Germany's field commanders quickly realized that the Italians were about to turn against them in favor of the Allies and, rather than having Italian troops use straight-shooting ammunition against the Wehrmacht, opted to furnish the Italians with bullets less likely to strike soldiers.
The Italians soon realized they had been duped, but by then, the British and Americans were already routing Germans from Italy, and the balance of power had shifted firmly in their favor. In any event, the remaining stocks of this special ammunition were squirrelled-away, not reappearing until after the war.
The majority of this ammunition was subsequently destroyed, but not before some had been developed for the old Mannlicher-Carcano carbines, which mysteriously disappeared until the early 1960's. The last
known instance of their use was at Dallas, TX in 1963, when one was randomly included in a pack of surplus cartridges purchased by Lee Harvey Oswald. It was, of course, famous as "The Magic Bullet"....