The ''Rainbow''-class submarine or R class was a quartet of

patrol submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely ...

s built for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...

in the early 1930s.

Design and description

The ''Rainbow''-class submarines were designed as improved versions of the ''Parthian'' class and were intended for long-range operations in the

Far East The ''Far East'' was a European term to refer to the geographical regions that includes East and Southeast Asia as well as the Russian Far East to a lesser extent. South Asia is sometimes also included for economic and cultural reasons. The te ...

. The submarines had a length of

overall Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers". Overalls were ...

, a

beam Beam may refer to: Streams of particles or energy * Light beam, or beam of light, a directional projection of light energy ** Laser beam * Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized g ...

of and a mean

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a ves ...

of . They

displaced Displaced may refer to: * Forced displacement Forced displacement (also forced migration) is an involuntary or coerced movement of a person or people away from their home or home region. The United Nations High Commissioner for Refugees, UNH ...

on the surface and submerged. The ''Rainbow''-class submarines had a crew of 56 officers and ratings. They had a diving depth of .Bagnasco, pp. 106–07 For surface running, the boats were powered by two

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...

. When submerged each propeller was driven by a

electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate forc ...

. They could reach on the surface and underwater. On the surface, the boats had a range of at and at submerged. The boats were armed with six 21-inch

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed abo ...

s in the bow and two more in the stern. They carried six reload torpedoes for a grand total of fourteen torpedoes. They were also armed with a QF 4.7-inch (120 mm) Mark IX

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose ...

.Chesneau, p. 49

Boats

Six boats were planned, but economic considerations resulted in the cancellation of the projected boats HMS ''Royalist'' and HMS ''Rupert''. It is often stated that the sank HMS ''Rainbow''. However, the submarine ''Enrico Toti'' sank was .

Design and description

Boats

Notes

References

External links