SS Great Britain

The Great Western Steamship Company gathered materials for a sister to SS Great Western, and the same team — Isambard Kingdom Brunel, Thomas Guppy, Christopher Claxton and William Patterson — reassembled, with Brunel now asserting overall control of the design. Two chance visits to Bristol changed the ship. In late 1838 John Laird's iron Channel packet Rainbow called; Claxton and Patterson made a return voyage to Antwerp in her and came back converts. Brunel scrapped his plans for a wooden ship and persuaded the directors to build in iron.

Iron was getting cheaper as timber grew dear, and it was proof against dry rot and woodworm. The decisive advantage was strength. A wooden hull can be built to about 300 feet before hogging — the flexing of the hull as waves pass beneath it — becomes intolerable; an iron hull is far less subject to it. With each successive draft the design grew bolder, until by the fifth she stood at 3,400 long tons, over 1,000 tons larger than any ship then in existence.

In early 1840 the screw steamer SS Archimedes arrived at Bristol. Francis Pettit Smith lent her to Brunel, who tested propellers on her over several months and settled on Smith's four-bladed design. Brunel then argued the company out of its half-built paddle engines: screw machinery was lighter and cheaper, sat lower in the hull for stability, freed cargo space, cut resistance and stayed fully submerged at all times. The directors agreed in December 1840, at the cost of another nine months.

Completed in 1845, she was 322 feet long with a beam of 50 ft 6 in, four decks, a crew of 120 and accommodation for 360 passengers, plus 1,200 tons of cargo and 1,200 tons of coal. Brunel made the hull massively redundant in strength against hogging: ten longitudinal iron girders along the keel, inch-thick keel plates, hull seams lapped and double-riveted in many places, a double bottom and five watertight iron bulkheads. The iron in hull and machinery came to 1,500 tons.

Two direct-acting engines weighing 340 tons together, built to a modified patent of Brunel's father Marc, rose through three decks; their twin 88-inch bore cylinders were inclined upward at 60 degrees and developed 1,000 horsepower at 18 rpm, fed by three "square" saltwater boilers at 5 psi. With no precedent for the gearing, and the spur-and-pinion arrangement in Archimedes too noisy for a passenger ship, Brunel used four massive inverted-tooth chains — the first commercial use of silent chain, and probably the largest ever built.

The main propeller shaft, from the Mersey Iron Works, was her largest single piece of machinery: 68 feet long and 28 inches in diameter, bored with a 10-inch hole to save weight and let cooling water through. Sail power was kept — one square-rigged and five schooner-rigged masts, of iron, hinged so they could be lowered against a headwind, with iron cable in place of hemp rigging. Instead of heavy bulwarks, a light iron railing let shipped water run straight back to sea.

The float-out came on 19 July 1843, a public holiday in Bristol, the processional route decorated with flags, banners and ribbons. Prince Albert arrived at the Great Western Railway terminus at ten, on a royal train Brunel had conducted from London in two hours and forty minutes. Clarissa Miles swung the christening bottle, but the steam packet Avon had already begun towing the ship away and it fell about ten feet short; the Prince hurled a second bottle against the iron hull.

Then she sat. The harbour authorities had not made the necessary lock modifications, and the ship had been widened for the propeller engines and given a deeper draught by the late decision to fit them before launch. Only the Board of Trade's intervention moved the Bristol Dock Board. She jammed in the second lock in December 1844 and was saved by Captain Claxton's seamanship; workmen under Brunel then stripped coping stones and gate platforms so the tug Samson could pull her into the Avon at midnight.

Construction had taken six years and £117,000, against an original projection of £70,000. She left Liverpool for New York on 26 July 1845 under Captain James Hosken with 45 passengers, crossing in 14 days and 21 hours — the first iron steamer to cross the Atlantic, though nearly a knot and a half off the prevailing record. Propeller blades broke on the following crossings, she rolled badly in calm weather, and bilge keels and conventional rigging had to be fitted.

On 22 September 1846, on her third passage of the season, a series of navigational errors ran her hard aground in Dundrum Bay on the north-east coast of Ireland; Helen Doe has suggested the captain, lacking updated charts, mistook the new St John's light for the Calf light on the Isle of Man. Brunel and James Bremner protected her through nearly a year ashore. Floating her free on 25 August 1847 cost £34,000 and exhausted the company's reserves; she was sold to Gibbs, Bright & Co. for £25,000.

Her new owners rebuilt her. The keel was renewed over 150 feet, ten new keelsons run its length, bow and stern strengthened with heavy double angle iron. The original engines gave way to smaller oscillating engines by John Penn & Sons of Greenwich; the chain drive was replaced by cog gearing, and three boilers by six working at twice the pressure. Cargo capacity nearly doubled to 2,200 tons. A third refit for the Australia trade raised passenger accommodation to 730 and gave her a liftable propeller.

She reached Melbourne first in 1852 with 630 emigrants, and 4,000 people paid a shilling each to inspect her. She worked the England–Australia route for almost thirty years, interrupted only by two spells as a troopship in the Crimean War and the Indian Mutiny, and became known as the most reliable of the emigrant ships. In 1861 she carried the first English cricket team to tour Australia — the same voyage took 544 passengers, a cow, 36 sheep, 140 pigs, 96 goats and over a thousand birds.

Her longest-serving master, the Scot John Gray, held command from 1852 until he went missing overnight on a return voyage from Melbourne in November 1872. Anthony Trollope sailed in her to Melbourne in 1871 and wrote Lady Anna on the way; George Everest crossed to New York in her in 1845, and Fanny Duberly travelled from Cork to Mumbai in 1857. Passengers watched a total solar eclipse off the Brazilian coast in 1865, seeing stars in daylight. She carried over 33,000 people in all.

Converted to sail in 1882 for the bulk coal trade, she left Penarth Dock for San Francisco on 8 February 1886, caught fire on passage and reached Port Stanley damaged beyond economic repair. The Falkland Islands Company used her afloat as a coal hulk until 1937, when she was towed to Sparrow Cove, scuttled and abandoned. As a bunker she had coaled the South Atlantic fleet that beat von Spee at the Falklands in 1914; in the next war her iron was scavenged to repair HMS Exeter.

In 1970, after 33 years abandoned, Sir Jack Hayward paid to have her raised. Ewan Corlett surveyed her and reported she could be refloated; a submersible pontoon and a German tug were chartered, and "Voyage 47" left Port Stanley on 24 April, reaching Barry Docks on 22 June. On 5 July she was towed up the River Avon, under Brunel's Clifton Suspension Bridge, and back into the Great Western Dockyard dry dock where she had been built 127 years earlier.

A 1998 survey found the hull still corroding in the damp of the dock and gave her about 25 years. A glass plate was laid across the dry dock at her waterline with two dehumidifiers holding the space beneath at 20% relative humidity, and she was "re-launched" in July 2005. She won the Gulbenkian Prize in 2006, and in 2015 was chosen for the Iconic Innovations page of the British passport. Part of the National Historic Fleet, she drew 131,056 visitors in 2025.