During the Crimean war of 1854-1856 both the French and British navies built armoured vessels for shore bombardment. These were better at surviving gunfire, especially the molten metal incendiary rounds designed to set fire to wooden warships. France decided to build sea going 'ironclads' with iron armour on top of the wooden hull. The French hoped this would give them a technological edge over the Royal Navy.

Even as their first French ironclad, Gloire, was under construction Britain built an answer, the impressive HMS Warrior, half as big again and with an iron hull. She can still be seen today at Portsmouth where she is preserved.

Commissioned in 1861, HMS Warrior brought together a series of technological innovations which highlighted Britain's industrial power and her determination to remain in complete command of the sea; she was built completely of iron, her steam engines produced a speed of 14.5 knots and she was armed with new breech-loading type guns. Britain had shown she could out-build any potential rival and the French naval challenge soon collapsed.

Warrior had a relatively uneventful career and served in home waters as the only dry dock large enough to take her was in Britain. Since the aim of her construction was to deter the French, however, she completely succeeded in her role. A French decision to build only ironclads in the future led to a similar decision in London and ironclads soon replaced wooden ships as the major fleet units in the Royal Navy.

Further reading: Non-RN HMS Warrior Website

Notes: Breech-loading weapons were easier to operate as the loading took place at the rear, through the breech, rather than at the front end of the barrel. Rifling, grooves around the inside of the barrel, was designed to improve range and accuracy. The armour belt was the protection along the sides of a ship's hull.