A submarine thought...

[Litvyak]

Take a diesel submarine... take out the diesel engine. Replace with a hydrogen fuel cell. Add a section where seawater can be converted to hydrogen fuel.

Result: an alternative to SSNs for arctic operations?

[rickshaw]

Been done.  The Germans have been working on fuel cell technology for AIP (Air Independent oPeration) now for a long time.   The Swedes use a Stirling engine which converts heat to energy.   Both have proved troublesome and expensive.

The Italians have been toying with stored oxygen for submerged diesel operation for a long time as well.   Again, expensive and troublesome.

[Hobbes]

Add a section where seawater can be converted to hydrogen fuel.

Using what for power? You'd still need a primary power source for the electrolysis, and no, you can't use the fuel cell as that process would yield less hydrogen than the fuel cell uses.

[GTX]

Add a section where seawater can be converted to hydrogen fuel.

Using what for power? You'd still need a primary power source for the electrolysis, and no, you can't use the fuel cell as that process would yield less hydrogen than the fuel cell uses.

Exactly.

[Hobbes]

Been done.  The Germans have been working on fuel cell technology for AIP (Air Independent oPeration) now for a long time.   The Swedes use a Stirling engine which converts heat to energy.   Both have proved troublesome and expensive.

The Italians have been toying with stored oxygen for submerged diesel operation for a long time as well.   Again, expensive and troublesome.

The question is, is it more expensive than a nuclear powerplant?

[Litvyak]

I guess I didn't really think this through or did research... twas just a sudden thought.

If it were made to work reliably, though, then even if it cost the same as a nuc, I think long term it'd probably be worth it even if just for the clean factor...?

[Hobbes]

It could be worth it for nations that really don't want to go the nuclear route. A nuclear plant requires lots of specialized knowledge and an extensive infrastructure. Fuel cells are less complex (no need to mine and refine uranium, for example).

But however good fuel cells get, they're still limited by the amount of fuel you can put on board the sub. You can use a fuel cell to create a submarine that can stay underwater for a few weeks, so it's a big improvement over conventional diesel-electrics, but you'll never match the endurance of a nuclear sub.

[rickshaw]

It could be worth it for nations that really don't want to go the nuclear route. A nuclear plant requires lots of specialized knowledge and an extensive infrastructure. Fuel cells are less complex (no need to mine and refine uranium, for example).

But however good fuel cells get, they're still limited by the amount of fuel you can put on board the sub. You can use a fuel cell to create a submarine that can stay underwater for a few weeks, so it's a big improvement over conventional diesel-electrics, but you'll never match the endurance of a nuclear sub.

Nor its speed...

[scooter]

It could be worth it for nations that really don't want to go the nuclear route. A nuclear plant requires lots of specialized knowledge and an extensive infrastructure. Fuel cells are less complex (no need to mine and refine uranium, for example).

But however good fuel cells get, they're still limited by the amount of fuel you can put on board the sub. You can use a fuel cell to create a submarine that can stay underwater for a few weeks, so it's a big improvement over conventional diesel-electrics, but you'll never match the endurance of a nuclear sub.

Still, couple it with improved battery technology and new gen turbodiesels and shrouded props, you'll still get a quiet boat underwater and probably a decent boat above, especially with the right shape hull.  After all, diesel boats are supposed to be hard to detect passively, save by a trained operator.

<- would love to see the old Balao and Gato fleet boats come back into USN service