Type 212 sprint endurence?

[Hinrich Schwab]

Originally Posted by magicstix

I always find these debates amusing, as none of them have enough info to go on. The capabilities of both types of submarines are closely held secrets, so an internet argument will invariably come out wrong. :P

Agreed. The only thing debatable are those issues that are publicly known. Nuke boats make constant noise with certain cooling systems. Diesels make noise during a battery charge and AIP boats have very expensive fuel cells to replace.

[magicstix]

Originally Posted by Hinrich Schwab

Agreed. The only thing debatable are those issues that are publicly known. Nuke boats make constant noise with certain cooling systems. Diesels make noise during a battery charge and AIP boats have very expensive fuel cells to replace.

Just because a nuke has a reactor doesn't mean it needs a coolant pump, and just because it has a coolant pump doesn't mean you can hear said pump outside of the hull. ;P

[ikalugin]

Most modern (late 3rd and 4th generation) pressuriesed water-water reactors have the ability to operate under natural circulation when on low power.

In liquid metal reactors you could use magnetic pumps which do not have any moving parts, thus the only noise you make is the flow noise (which is more or less constant in this case and can be actively cancelled out).

Another means of reducing the noise of a nuclear submarine is to detach the turbines from the propulsor, for example by using electric transmission. Partially this is done on the pr.885 for example - when on low speed it would travel under the electric motor.