Regarding the explosions. Something I've pondered, occasionally, was the order in which the explosions occurred. Slight blast, followed almost immediately by second massive blast. Might the FIRST explosion- which survivors writing on the 8th described with trivial terms like 'door slamming' and 'glass breaking'- have been something along the lines of a steam pipe rupturing, and the SECOND explosion have been the torpedo?
That random thought came as I was analyzing accounts from May 8th- aka "The Honest Day" when people wrote from their hearts and not for effect- and almost uniformly one finds people attempting to describe the first explosion as a fair 'bump' and the immediate second explosion as a bone jarring crash. Later, as dramatic coloring sets in, both explosions are frequently described as severe but during the Golden 48 (first two days~ 48 hours) such was not the case. Even in the First Class dining room, which was slightly aft of, and of course above, the point of impact, people were initially in agreement that the initial concussion was a 'bump' a 'slight jar'.
Would it be possible, then, for there have been a small coal dust explosion as the torpedo penetrated the bunker, followed almost immediately by the detonation of the torpedo?