Wouldn’t the waste heat from the sub melt the ice a small distance around them? I’d expect that they could move (albeit very slowly) through the ice by nuzzling up against one ice-wall, melting it, and moving on.
There probably isn’t enough waste heat. In fact, there is probably a risk of the sub letting crushed in the ice.
Lets take the S9G reactor (the biggest I could find) that generates about 30MW of shaft power. Lets assume 20% efficiency overall (best case scenario for melting ice) - so the heat dissipated is 150MW.
Water latent heat of fusion is 334 kJ/kg or 334 MJ/MT (MT = metric ton). So the 150MW of heat (lets assume all of it goes into latent heat and not sensible) will melt about half a metric ton of water per second. The displacement of a Virginia class submarine is about 8000 metric tons. So theoretically if the melting is all concentrated at the front of the submarine, the submarine can move at 0.0000625 of its length/sec or 0.2 of its length in an hour. And thats a best case scenario.
In reality, the heat dissipation system will fail since there is sea water to discharge the waste heat to.
Hey–
A zombie to call attention to this Old School Zombie, If the Sun winked out tomorrow
And just think, OP was only four months old (SD Calendar) at the time. Now he’s such an old f- dodderer he can’t even remember when he thought aloud about this in childlike awe.