Built at the cost of 125,000 pounds (of which the British Government donated 100,000 pounds). She was laid down in 1867, completed in 1870 and delivered (after a perilous journey) the following year. She was ordered to protect Melbourne, one of the Empire's richest colonies at the time due to the gold rush, from the Russian threat. Not an inconsequential threat it turns out, as Russia was allied to the United States during the civil war and the Russian Pacific Fleet commander had sealed orders to bombard Sydney, Melbourne and Hobart should hostilities break out between the US and Great Britain.
The monitor was the first British armoured ship to fully dispense with sail and be powered purely by steam. She was also first vessel with a central superstructure with gun turrets at the ends, and the first design to have breastwork protection and low freeboard. She had two sister ships, Abyssinia and Magdala, built for service in India though they were completed later.
HMS Devastation (1871), built 3 years after Cerberus, incorporated many lessons learnt from Cerberus can rightly claim credit as being the first ocean going modern battleship. (Whereas Cerberus was specifically designed for Harbour defence)
"Indeed Devastation itself was an enlarged version of the coast defence Breastwork Monitor Cerberus, whose construction marked the beginning of practical turret ship design" Birth of the Battleship, John Beeler, US Naval Institute Press, 2001
"Between the harbour defence ship and the sea-going battleship was a matter of degree - the Devastation was to develop out of Cerberus in due course." British Battleships, Oscar Parkes, Seeley Service & Co., London, 1957
She was a powerful warship equipped with two twin 10 inch gun turrets (muzzle loading, rifled Armstrong guns), 4 quad barreled Nordenfeldt machine guns and 2 six pounder guns (added in 1892/93). Armour plate ranged from 6 inches on the sides to 10 inches on the turrets. She was not initially provided with any protection against torpedoes, but outriggers and nets were later fitted for this purpose.
The local press commented upon her arrival that "Victorians can sleep peacefully upon their pillows, with the consciousness that Cerberus is in every way fit to fight their battles and to fight them in modern style".
Cerberus enjoyed a period of 53 years service in which she never fired a shot in anger. Ironic then that her guns caused such general collateral damage to windows that public protest effectively negated the conduct of firing practices close to shore!
A free 1/250 scale card model of Cerberus as she appeared in the 1890s (with mast modification and torpedo booms fitted) is available here:
In the meantime, I'm working on my lovely 1/1200 scale Cerberus from Brigade Models: pics soon!