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)

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).

Under the 1893–1894 Naval Estimates, the British Admiralty placed orders for 36 torpedo-boat destroyers, all to be capable of 27 knots (50 km/h; 31 mph), the "27-knotters", as a follow-on to the six prototype "26-knotters" ordered in the previous 1892–1893 Estimates. As was typical for torpedo craft at the time, the Admiralty left detailed design to the builders, laying down only broad requirements.^[1][2]

In September 1913 the Admiralty re-classed all the remaining 27-knotter destroyers, including all three Janus-class vessels, as A Class destroyers.

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