HMS Warrior

France's launch of the steam-powered ship of the line Napoléon in 1850 opened a decade-long arms race with Britain. The destruction of a wooden Ottoman fleet by Russian explosive shells at Sinop, and of Russian coastal fortifications by French armoured floating batteries at Kinburn, made the case for iron plate. When France launched the first ocean-going ironclad, the wooden-hulled Gloire, in 1859, it neutralised Britain's investment in wooden ships of the line and set off an invasion scare; Queen Victoria asked the Admiralty whether the navy was adequate for what it might have to do. Warrior and her sister Black Prince were ordered in response.

She was ordered on 11 May 1859 from the Thames Ironworks and Shipbuilding Company at Blackwall and laid down on the West Ham side of Bow Creek, the slipway reinforced to carry her weight. Admiralty indecision and repeated design changes caused delays that nearly bankrupted her builders before a grant of £50,000 kept them solvent. Her launch on 29 December 1860 fell in the coldest winter for fifty years: she froze to the slipway and had to be freed with hydraulic rams, extra tugs, and dockworkers running side to side on the upper deck to rock her.

She was completed on 24 October 1861 for £377,292, almost twice the cost of a contemporary wooden ship of the line. Warrior and Black Prince were the first armour-plated, iron-hulled warships. The Admiralty stopped building wooden ships of the line and ordered another eleven ironclads over the following years. Jacky Fisher, her gunnery lieutenant in 1863–64, later wrote that few realised at the time that "this, our first armourclad ship of war, would cause a fundamental change in what had been in vogue for something like a thousand years".

The Chief Constructor Isaac Watts and Chief Engineer Thomas Lloyd designed her, and to minimise risk they copied the hull of the large wooden frigate HMS Mersey, modified for iron construction and for an armoured box, or citadel, amidships along the single gun deck. Most of her individual technologies — iron hull, marine steam engine, screw propeller — were already proven; only her wrought-iron armour was a major advance. The naval architect and historian David K. Brown put it that what made her novel "was the way in which these individual aspects were blended together, making her the biggest and most powerful warship in the world".

The armour was 4.5 inches of wrought iron backed by 18 inches of teak, laid in two nine-inch layers at right angles to damp the shock of shell impacts that would otherwise shear the bolts holding the plate to the hull. The 3 by 12 ft plates interlocked by tongue and groove and, unlike most later ship armour, were made by hammering rather than rolling. The belt covered the middle 213 ft of the ship, 16 ft above the waterline and 6 ft below. The ends were unarmoured — subdivided into watertight compartments, but leaving the steering gear and rudder vulnerable.

Her armament as built mixed 68-pounder smoothbore muzzle-loaders with ten Armstrong 110-pounder rifled breech loaders and four 40-pounders. The breech loaders disappointed: after a 110-pounder's vent piece blew out aboard HMS Euryalus in 1863 they were used only with reduced charges, which left them ineffective against ironclads. Her 1864–67 refit replaced the lot with 24 seven-inch and four eight-inch rifled muzzle-loaders, the larger of which could pierce 9.6 inches of wrought iron at the muzzle.

A two-cylinder trunk engine by John Penn and Sons, fed by ten rectangular boilers, gave 5,772 indicated horsepower and 14.08 knots on her trials of 1 April 1868. She was ship rigged with 48,400 square feet of sail and made 13 knots under canvas alone. Her hoisting propeller — the largest ever made, at 26 long tons — could be raised into the ship by 600 men to cut drag under sail, and both funnels telescoped down. Under sail and steam together she once reached 17.5 knots against the tide running from Portsmouth to Plymouth.

She joined the Channel Squadron under Captain Arthur Cochrane. In March 1863 she escorted the royal yacht bringing Princess Alexandra of Denmark to Britain to marry the Prince of Wales; the princess sent word that she was much pleased with the conduct of the crew, and Cochrane had the message engraved on a brass plate fitted to the ship's wheel. That summer the Channel Fleet toured British ports for twelve weeks and Warrior received 300,000 visitors, as many as 13,000 in a day. In September she rescued the survivors of the Mersey flat Mary Agnes, sunk in a collision off Liverpool.

At the end of 1867 she was sent to Osborne Bay to guard Queen Victoria at Osborne House, the Fenian Rising then under way and intelligence suggesting the Queen might be in danger; the Queen paid her an informal visit. In August 1868, cruising to Scotland, she collided with HMS Royal Oak, losing her figurehead and jib boom; Captain Boys was court-martialled and acquitted. In July 1869 she, Black Prince and the paddle frigate Terrible towed a floating drydock big enough for ironclads 2,700 nautical miles across the Atlantic from Madeira to Bermuda.

The rapid evolution of warship design that she had helped set off made her obsolescent within about ten years of her launch. The Royal Navy's first mastless capital ship, HMS Devastation, freed the main armament from the broadside and let it traverse from a higher position. Warrior refitted from 1871 to 1875, then served as a guardship at Portland and later on the Clyde. Mobilised during the Russo-Turkish War of 1877–78 against the possibility of a Russian move on Constantinople, she cruised to Bantry Bay instead. Two masts were found rotten in May 1883 and, with no replacements available, she was decommissioned.

She was reclassified twice without alteration, struck off the effective list in March 1900, and used as a storage hulk before becoming a destroyer depot ship. In March 1904 she was assigned to the Portsmouth torpedo school Vernon and renamed Vernon III to free her name for a new armoured cruiser, her upper deck roofed over for radio classrooms and new boilers and generators fitted to supply the neighbouring hulks. Declared redundant in 1924, she found no scrap buyer and was converted from 1927 into a mooring jetty, towed to Pembroke Dock in 1929 and moored off an oil depot at Llanion Cove for the next fifty years, where she refuelled 5,000 ships.

Restoration was discussed from the early 1960s but only became real when the Royal Navy announced the Llanion depot would close. The Maritime Trust had been established in 1969 to save her and other historic ships, and with the promise of financial support the Navy donated her to the trust in 1979. That August she began an 800-mile journey to Hartlepool for a £9 million restoration, largely funded by the Manifold Trust, aimed at returning her to her 1862 condition. The first two years went on removing later additions, including 200 long tons of concrete decking.

Research was intensive: official records, the papers of men who had served aboard, bolt-holes and ridges in the paint, and the sketch plans of Midshipman Henry Murray found in Captain Cochrane's letter book, which showed where the armament, moveable fittings and stores had gone. Lower masts were made of cut and welded steel tube rather than wood. Engines and boilers were judged too expensive to rebuild and were replicated in sheet steel, the replica engines turning slowly on electrical power for visitors. Original 68-pounders and a 110-pounder lent by the Woolwich Rotunda and the States of Jersey served as moulds for fibreglass guns.

She left Hartlepool on 12 June 1987 and was towed 390 miles to the Solent in four days. Entering Portsmouth Harbour she was met by thousands of people lining the town walls and shore and by over 90 boats and ships, and she opened as a museum on 27 July. Renamed HMS Warrior (1860) to avoid confusion with the Northwood headquarters commissioned as HMS Warrior in 1963, she is part of the National Historic Fleet and lies in Portsmouth Historic Dockyard alongside Victory, Mary Rose and the monitor M33. The National Museum of the Royal Navy took over her trust in 2017.