Q&A: The joke about Soviet icebreaker submarines

Icebreaker submarines?

The phrase was a joke about some Soviet submarines with strengthened bows for surface ice. In the recollection, they still needed tug support.

The phrase "icebreaker submarines" comes from a naval-architectural joke recalled from Dr. Clarke's father. It refers to strengthened bows on some Soviet submarines that were intended to cope with ice during surface movement. In this recollection, toughening the bow did not make that approach work satisfactorily, so large tugs remained necessary. The retained strength is tentatively explained as a precaution for extreme circumstances.