Agamemnon-class ship of the line

The Agamemnon-class (sometimes known as the James Watt-class) steam battleships, or steam ships of the line, were a class of five 91-gun steam second rates of the Royal Navy. The original design was produced by John Edye in 1847, as a response to the French Le Napoléon, which was rumoured to be under development.

HMS James Watt
Class overview
Name	Agamemnon
Operators	Royal Navy
Preceded by	Princess Royal class
Succeeded by	Renown class
In service	August 1852 — 1904
Completed	5
General characteristics
Type	Steam Ship of the line
Displacement	4614 long tons
Tons burthen	3085 bm
Length	239 ft 3 in (72.92 m) (overall) 193 ft 3 in (58.90 m) (keel)
Beam	55 ft 4 in (16.87 m)
Draught	23 ft 1 in (7.04 m)
Propulsion	Sails & 600nhp steam engine with single screw
Sail plan	Full-rigged ship
Speed	11.9 knots (steaming)
Complement	860 officers and men
Armament	91 guns: Gundeck: 34 × 8 in shell guns (65cwt) Main deck: 34 × 32-pounders (56cwt) Upper deck: 22 × 32-pounders (45cwt) + 1 × 68-pounder (95cwt)

The first ship of the class, Agamemnon, was originally designed as a two decker, 80 gun sailing ship of the line. But was re-ordered as the first purpose built steam screw ship for the British Navy.[1]