4 ms·

I see you've posted this approximate figure and its comparison to a car three times already, but the Kia figure is irrelevant. The relevant comparision is the r

by clort 7y ago

I see you've posted this approximate figure and its comparison to a car three times already, but the Kia figure is irrelevant. The relevant comparision is the required power to push the USS Seawolf forward and what speed can you get with 84kW? I myself can push a 6500Kg boat although not as fast as the built-in 10kW engine, admittedly. Don't forget that it is a sub and silent running is likely way more valuable than fast running (nobody is saying they can't have two methods of propulsion) Also, I don't know anything about this USS Seawolf - is it a nuclear sub? IIRC the problem with them is that the pumps cooling the atomic core can't be shut down, meaning there is always detectable sound. Would a hose with this material on the inside be able to pump cooling water silently? Don't forget that the 'pump' in that case could be almost the entire length of the sub..

masklinn 7y ago
> I see you've posted this approximate figure and its comparison to a car three times already, but the Kia figure is irrelevant. It's very relevant as it gives a sense of scale of the issue and how little power is actually produced. > The relevant comparision is the required power to push the USS Seawolf forward and what speed can you get with 84kW Since you're apparently checking all my comments you've likely seen Gotland's 2x75kW AIP gives it a top speed of 5kn. These 85kW would be a smidge above half that on a submarine about 6 times the weight. The relationship is probably somewhat non-linear but I'd say the result would be around "geriatric pacing". > Don't forget that it is a sub and silent running is likely way more valuable than fast running (nobody is saying they can't have two methods of propulsion) You could get about the same effect by just shutting down propulsion entirely. > Also, I don't know anything about this USS Seawolf - is it a nuclear sub? IIRC the problem with them is that the pumps cooling the atomic core can't be shut down, meaning there is always detectable sound. That doesn't seem to have any relevance to my point that this tech doesn't seem able to actually provide propulsion for a sub'. > Would a hose with this material on the inside be able to pump cooling water silently? Don't forget that the 'pump' in that case could be almost the entire length of the sub.. You do realise there's other shit in a sub than just reactor cooling systems right?
dogma1138 7y ago
The reactor on the Seawolf has a shaft horsepower output of 45,000 shp or 34 MW. So yeah 80KW won’t be enough to power the lights.
jabl 7y ago
> Also, I don't know anything about this USS Seawolf See https://en.wikipedia.org/wiki/USS_Seawolf https://en.wikipedia.org/wiki/USS_Seawolf , presumably we're talking about the fourth (and current one). Yes, it's nuclear powered. > IIRC the problem with them is that the pumps cooling the atomic core can't be shut down, meaning there is always detectable sound. AFAIK current generation US and Russian (and presumably other navies operating nuclear subs too) nuclear subs can shut down the primary coolant pumps and rely on convection at low power. As long as they're cruising along at low speed they can be very quiet.

by clort 7y ago

masklinn 7y ago

> I see you've posted this approximate figure and its comparison to a car three times already, but the Kia figure is irrelevant. It's very relevant as it gives a sense of scale of the issue and how little power is actually produced. > The relevant comparision is the required power to push the USS Seawolf forward and what speed can you get with 84kW Since you're apparently checking all my comments you've likely seen Gotland's 2x75kW AIP gives it a top speed of 5kn. These 85kW would be a smidge above half that on a submarine about 6 times the weight. The relationship is probably somewhat non-linear but I'd say the result would be around "geriatric pacing". > Don't forget that it is a sub and silent running is likely way more valuable than fast running (nobody is saying they can't have two methods of propulsion) You could get about the same effect by just shutting down propulsion entirely. > Also, I don't know anything about this USS Seawolf - is it a nuclear sub? IIRC the problem with them is that the pumps cooling the atomic core can't be shut down, meaning there is always detectable sound. That doesn't seem to have any relevance to my point that this tech doesn't seem able to actually provide propulsion for a sub'. > Would a hose with this material on the inside be able to pump cooling water silently? Don't forget that the 'pump' in that case could be almost the entire length of the sub.. You do realise there's other shit in a sub than just reactor cooling systems right?

dogma1138 7y ago

The reactor on the Seawolf has a shaft horsepower output of 45,000 shp or 34 MW. So yeah 80KW won’t be enough to power the lights.

jabl 7y ago

> Also, I don't know anything about this USS Seawolf See https://en.wikipedia.org/wiki/USS_Seawolf https://en.wikipedia.org/wiki/USS_Seawolf , presumably we're talking about the fourth (and current one). Yes, it's nuclear powered. > IIRC the problem with them is that the pumps cooling the atomic core can't be shut down, meaning there is always detectable sound. AFAIK current generation US and Russian (and presumably other navies operating nuclear subs too) nuclear subs can shut down the primary coolant pumps and rely on convection at low power. As long as they're cruising along at low speed they can be very quiet.