Let me guess, using the good old Clancy method (using unclassified data and making sense of it): the Otto Fuel is kept in a sealed container near an empty combustion chamber and the separation between both of them can be torn down by a simple mechanical process such as, say, a steel ball inside the fuel tank itself. When the torpedo is catapulted hard enough, the ball bearing tears through the separation, allowing the Otto Fuel to get vaporized thanks to the sudden drop in pressure. Of course, an additional safety would require to have the separation being a decent thermal insulator and the combustion chamber to be pre-heated so that the fuel vapour start igniting.

Or it could simply be an ullage issue, and the expulsion of the torpedo plays the same role as an ullage motor.

EDIT: this makes me wonder if a torpedo like the Black Shark, with an Al-AgO battery, could have a swim-out feature with 650 mm tubes. IIRC, it needs seawater to start the engine as a safety measure, so it would be hard to manage it from a 533 mm tube.

Nothing like that..

Fair enough.

Otto Fuel II has a very high flash point (130'C/266'F) and a very low vapor pressure.....

It's actually hard to get Otto Fuel to burn...

It also becomes addictive if you breathe enough of it. :doh:

There were lots of stories about guys from the weps shop smuggling out pints of Otto Fuel just before a long weekend. :timeout: