Three Janus-class torpedo-boat destroyers (TBDs) served with the Royal Navy. Janus, Lightning and Porcupine were ordered under the 1893-94 Programme, all laid down on 28 March 1894 at Palmer's shipyard at Jarrow and launched during 1895. They displaced 275 tons (light), were 204 feet 6 inches (62.33 m) long and produced 3,900 hp (2,900 kW) from their Reed water tube boilers which gave them a top speed of 27 knots (50 km/h; 31 mph).

Class overview
Name	Janus class
Builders	Palmers Shipbuilding and Iron Company, Jarrow
Operators	Royal Navy
Preceded by	Hardy class
Succeeded by	Salmon class
Built	1895
In commission	1895–1920
Completed	3
Lost	1
Retired	2
General characteristics
Type	Torpedo Boat Destroyer
Displacement	275 long tons (279 t)
Length	204 ft 6 in (62.33 m) overall, 200 ft (61 m) pp
Beam	19 feet 9 inches (6.02 m)
Draught	8 feet (2.4 m)
Propulsion	Reed boilers, 3,900 hp (2,908 kW)
Speed	27 knots (50 km/h; 31 mph)

These vessels belonged to the "27-knotter" type of early TBD, of which thirty were built under this Programme; those that survived until 1913 (including all three Janus-class vessels) were re-classed as the 'A' Class at that date.

Bibliography

• Chesneau, Roger & Kolesnik, Eugene M., eds. (1979). Conway's All The World's Fighting Ships 1860–1905. London: Conway Maritime Press. ISBN 0-85177-133-5.
• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• Friedman, Norman (2009). British Destroyers: From Earliest Days to the Second World War. Barnsley, UK: Seaforth Publishing. ISBN 978-1-84832-049-9.
• Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All The World's Fighting Ships 1906–1921. London: Conway Maritime Press. ISBN 0-85177-245-5.
• Lyon, David (2001) [1996]. The First Destroyers. London: Caxton Editions. ISBN 1-84067-364-8.
• Manning, T. D. (1961). The British Destroyer. Putnam & Co. OCLC 6470051.
• March, Edgar J. (1966). British Destroyers: A History of Development, 1892–1953; Drawn by Admiralty Permission From Official Records & Returns, Ships' Covers & Building Plans. London: Seeley Service. OCLC 164893555.