I know there are some older threads about this, but they've been inactive for a while and this is about a new theory. I watched
Horizon tonight and they're now saying that the accusation that the Kursk collided with an American sub has lost out to a new theory. Apparently, Russian torpedoes used a chemical called HTP as a oxidant for their torpedo engines. If a torpedo is accidentally started while inside the sub the engine over revs, pressure builds up and the pipes carrying HTP burst. On contact with certain metals HTP reacts to produce steam and oxygen. The pressure builds up inside the torpedo casing and finally bursts it.
They're putting this forward as the most likely explanation as British seismologists (sp?) say that the detected a much smaller explosion before the Kursk's torpedoes detonated. The first signal the picked up had a similar signature to the one caused by the torpedo's detonation, so they think it must have been an explosion, too.
The Russians have removed the HTP powered torpedoes from service and now say that they too think it was an explosion in the torpedo room that sank the Kursk. However;
The Russians are refusing to raise the front section of the Kursk (where the explosion happened) so it cannot be examined.
And there was an satellite image of what could be an American sub at a Norwegian base (close to where the sinking took place) taken by the Russians six days after the Kursk sank. An American naval analyst said there were two 'innocent' explanations for this: i) the sub was landing Norwegian intelligence officers who had been observing the Russian excersize or ii) it was landing computer tapes of elcectronic data obtained by the Americans. I think the second is unlikely as there is no reason for the sub to dock only to offload inforamtion.
The Russians used HTP in their torpedoes for 40 years without incident, although it is now being blamed for the sinking of the British sub 'Sidon' in the 1960s.