The Alfa-Class Submarine Was Built with Titanium and Was Remarkable

Meet The Alfa-class – Russia's  Fast Attack Submarine That NATO Feared: Between 1968 and 1981, the Soviet Union produced a total of seven Project 705 Lira (NATO reporting name Alfa) nuclear-powered attack submarines.

The boats were cutting edge when they were produced, and in addition to the then-revolutionary use of titanium for the hull, each of the subs utilized a powerful lead-bismuth cooled fast reactor (OK-550 or BM-40A, 155-MWt) as its power source.

That greatly reduced the size of the reactor...