[moscowexile]

Here's a submarine thing I've always wondered about: When I was a kid over half a century ago, I saw a picture of a WWII sub and asked my dad what the sawtoothed contraption on its prow was for. He told me that it was for cutting cables on anti-submarine nets.

Was he correct, I wonder? And if the thing was intended to cut cables, how effective was it? I can hardly imagine it being of any use whatsoever in such a function.

Modern subs don't have them, nor do immediate post-WWII ones.

Were they only installed in the hopes that they would be able to cut through a steel cable? Were they only ornamentation furnished as a result of wishful thinking?