Alfa class

The second Soviet titanium-hulled submarine design, the Project 705 Lira, known in the West as the Alfa class, came to light in December 1971, when the first unit was commissioned. Five more followed in 1972-82.

The Alfa class was the world's fastest and deepest diving submarines as of their time. An extensive automation allowed to reduce crew to only 30 men. These advanced submarines had their crews completed from officers and warrant-officers only. It also featured an advanced low drag configuration and was extremely maneuverable. The Alfa class submarines were significantly smaller than contemporary attack submarines.

A single reactor and turbine plant drive the boat at the phenomenal 42 knots under water. Reactor's power could be rapidly increased, as well as submarines speed. However what was not realized at the time was that there was a serious flaw in the lead-bismuth system of the Alfa's 40 000 hp reactor cooling system. The plant was very unreliable, and the cost led to the Lira/Alfa being nicknamed the 'Golden Fish'.

It is worth mentioning that Alfas had sophisticated crew rescue system. It provided safe exit for entire crew from maximum depth.

When British and American submariners first encountered the Alfa they were astounded. The result that NATO navies allocated massive R&D funding to the development of deep-running torpedoes.

By this time all Alfa class boats have been decommissioned or remain in reserve, however their current state is likely to be poor.

Entered service	1971
Crew	31 men
Diving depth (operational)	?
Diving depth (maximum)	750 m
Sea endurance	50 days (stores)
Dimensions and displacement
Length	81 m
Beam	9.5 m
Draught	8 m
Surfaced displacement	2 800 tons
Submerged displacement	3 680 tons
Propulsion and speed
Surfaced speed	20 knots
Submerged speed	42 knots
Nuclear reactors	1 x 155 MW
Steam turbines	2 x ?
Armament
Torpedoes	6 x 533-mm torpedo tubes for conventional or nuclear torpedoes
Other	up to 36 mines in place of torpedoes

Source: Military Today