... forall we know! Serious geezers & geezrices, or what! ... definitely no scope for mucking-about if one be under the Arctic ice-cap in a nuclear submarine!

Image from

https://www.popularmechanics.com/military/navy-ships/a19681544/how-a-submarine-surfaces-through-ice/

.

Also a qupte fræ

this

article on Quora-contraption.

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So to answer your question, yes. It’s a very hazardous environment. The ice is uneven. You think of it as a flat surface on top, but it’s more like a bunch of icebergs frozen together, with big chunks of ice extending downward, and thin areas in between. You can use special sonar to avoid the big chunks and find the weak places in the ice where it is safe to surface. The submarine is especially vulnerable under ice because if a casualty occurs (like a fire or an engine room casualty) you can’t just emergency blow to the surface, you actually have to keep track of safe surfacing locations as you transit, so that if a casualty does occur you can drive there as fast as possible.

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