HMS Gorgon was the first ship commissioned of the four Cyclops-class breastwork monitors built for the Royal Navy during the 1870s.

The engines produced a total of 1,670 indicated horsepower (1,250 kW) during the ship's sea trials which gave her a maximum speed of 11 knots (20 km/h; 13 mph).

They carried 250 long tons (250 t) of coal,[3] enough to steam 3,000 nautical miles (5,600 km; 3,500 mi) at 10 knots (19 km/h; 12 mph).

[4] The ships mounted four 10-inch rifled muzzle-loading guns in twin-gun turrets fore and aft of the superstructure.

The superstructure and conning tower was fully armoured, the reason it was called a breastwork, with 8–9 inches (203–229 mm) of wrought iron.