Kasatka class submarine

Russian submarine Kasatka
Class overview
Name:	Kasatka class
Builders:	Baltic works
Operators:	Imperial Russian Navy
Preceded by:	Som class
In commission:	1904–1922
Completed:	6
Lost:	2
Retired:	4
General characteristics
Type:	Submarine
Displacement:	140 tons surfaced 177 tons submerged
Length:	33.5 m (109 ft 11 in)
Beam:	3.5 m (11 ft 6 in)
Draught:	3.4 m (11 ft 2 in)
Propulsion:	1 shaft petrol / electric (later diesel electric) 150 kW (200 hp) / 75 kW (100 hp)
Speed:	8.5 knots (15.7 km/h; 9.8 mph) surfaced 5.5 knots (10.2 km/h; 6.3 mph) submerged
Complement:	24
Armament:	4 external torpedoes in drop collars 1 machine gun (later 1 × 47mm gun)

The Kasatka class was a class of submarines built for the Imperial Russian Navy. The six boats were built between 1904 and 1905. They were designed by I. G. Bubnov and were based on the Russian submarine Delfin. The first boat, Kasatka, experienced significant problems with stability on trials and had to have extra flotation added. The boats were re-built around 1910 with diesel engines added (89 kW (120 hp)) and new conning towers replacing the older structure.

All six boats were built by Baltic works St. Petersburg and launched in 1904