[PSUBS-MAILIST] enquiry - Surface Propulsion

[peter mckellar <mckellar@earthlink.net>]

Hi All,

how does everyone provide propulsion when on the surface with a fully autonomous submersible?

At this stage I'm entertaining all options, with maximum speed and range the preference (though no expectation that either could be adequately met with the limitations imposed below).  For safety's sake, i'm inclined to design with a pure electric engine for sub-marine propulsion and a separate surface engine to get to the dive location.  This leaves it pretty open (for surface anyway).

Something that works in both environments would be great, but I suspect is out of the question.

What sort of considerations would I need to make if i shut down the surface motor and expect it start again when i re-surface?

Some issues that the group may be able to clarify for me:

1.  Pressure proofing/ambient tolerance
2.  Electrical insulation
3.  Corrosion
4.  Temperature stress if submerging when the engine is hot
5.  Safe fuel storage, combustion issues etc

Does anyone make engines with these demands in mind?

thanks in advance
peter