Holland 602 type submarine

USS H-3 served as the prototype for the class
Class overview
Builders:	Vickers Canada
Operators:	United States Navy  Chilean Navy  Royal Navy  Imperial Russian Navy Ukrainian State Navy  Soviet Navy  Regia Marina  Royal Canadian Navy  Royal Netherlands Navy
In service:	1915
In commission:	- 1950
General characteristics
Displacement:	390 tons surfaced 520 tons submerged
Length:	46 m (151 ft)
Beam:	4.9 m (16 ft)
Draught:	3.8 m (12 ft)
Speed:	surface - 14.5 knots (26.9 km/h) submerged - 10.5 knots (19.4 km/h)
Complement:	32
Sensors and processing systems:	Fessenden transducer
Armament:	4 × bow torpedo tubes (8 torpedoes) 1 × 45 mm semi-automatic gun (200 rounds) or 1 × 47 mm gun 1 × machine gun

The Holland 602 type submarine, also known as the H class submarine was one of the most numerous submarines of the First World War. The type was designed by the Electric Boat Co. of the United States but most of the boats were built abroad: in Canada by the subsidiary of the British Vickers company and in British shipyards.

Operators included the United States Navy, the Chilean Navy, the Royal Navy (33 submarines), the Imperial Russian Navy, the Soviet Navy, the Italian Regia Marina, the Royal Canadian Navy, the Royal Dutch Navy and the navy of the short-lived Ukrainian State.

The predecessor for this class were two submarines ordered in 1911 for the Chilean Navy, to the John Philip Holland design 19-E and design 19-B. These eventually became the CC class submarines of the Royal Canadian Navy.

Three prototypes were then built to an improved design 30, with an increased displacement of 358/434 tons. These became the United States H class submarines and were designated H-1, H-2 and H-3.

In October 1914, after the start of World War I, the British Admiralty ordered ten submarines to design 602E, to be built by Canadian Vickers in Montreal, Quebec. These would become the British H class submarines. Another ten submarines were secretly constructed at Fore River Yard at Quincy, Massachusetts, in the then neutral United States. This group was impounded by the United States government and ended up in the Chilean Navy and the Royal Canadian Navy after the American declaration of war. A third group, of twenty-five British H class subs, was constructed in 1917-1919 in Britain, many of them serving in World War II.