SS Great Britain (1843): Brunel's Iron Screw Steamship

The SS Great Britain is the iron-hulled, propeller-driven passenger steamship designed by Isambard Kingdom Brunel and launched in Bristol on 19 July 1843. At the time it was the largest ship in the world, and in 1845 it became the first iron, screw-propelled ship to cross the Atlantic. Its long working life, its abandonment in the Falkland Islands and its return to Bristol in 1970 make it one of the best-known historic ships in the world.

Background: Brunel and the Atlantic

In the 1830s steamships were wooden vessels driven by paddle wheels. Brunel, already engineer of the Great Western Railway from London to Bristol, argued that the line could be extended across the ocean by steamship. The Great Western Steamship Company built his first ship, the wooden paddle steamer Great Western, which began a regular service between Bristol and New York in 1838.

Encouraged by its success, the company ordered a second and larger ship. Brunel and his colleagues soon decided that it should be built of iron rather than wood. Iron allowed a longer, stronger hull, and a wooden ship of the size Brunel wanted would have needed so much timber that it would have been weak and heavy.

Design: iron hull and screw propeller

The ship was first planned as a paddle steamer. In 1840 the experimental screw steamer Archimedes, built to demonstrate Francis Pettit Smith’s propeller, called at Bristol. Brunel studied it, ran trials and persuaded the company to switch to a screw propeller, even though the engines for paddle wheels had already been designed. A propeller sat low in the water, was less affected by the ship’s rolling and left the sides of the hull free.

The finished ship was about 98 metres (322 feet) long, far longer than any vessel then afloat. The hull was built from wrought-iron plates riveted together and divided by watertight bulkheads. Its engines had four large inclined cylinders and drove the propeller shaft through chains, giving roughly 1,000 horsepower. The original six-bladed propeller was about 4.7 metres (15.5 feet) across. Masts and sails were also fitted, as all ocean steamers of the time relied partly on wind.

The launch of 19 July 1843

The hull was built in a specially dug dry dock, now called the Great Western Dock, in Bristol’s Floating Harbour. Construction began in 1839. Because the ship was built in a dock, the “launch” on 19 July 1843 was a floating out: water was let in until the hull floated.

The event was a public celebration. Prince Albert travelled from London on the Great Western Railway to attend, and the ship was formally named during the ceremony. Large crowds gathered along the harbour.

The ship then became trapped. It was too wide to pass through the locks that led out of the Floating Harbour into the River Avon, so the company had to wait while masonry was removed. The Great Britain finally left Bristol in December 1844, more than a year after the launch.

Atlantic career and the Dundrum Bay stranding

The Great Britain sailed on its maiden voyage from Liverpool to New York on 26 July 1845, arriving after about 14 days. Passenger numbers on early voyages were disappointing, and the propeller and engines needed repairs and modifications.

On 22 September 1846, after a navigational error, the ship ran aground at Dundrum Bay on the coast of County Down, Ireland. It stayed there for almost a year. The strength of the iron hull, which survived winter storms on the beach, impressed engineers. The ship was refloated in August 1847, but the cost of the salvage helped push the Great Western Steamship Company into financial collapse.

The Australia years

In 1850 the ship was sold to Gibbs, Bright and Company of Liverpool. It was refitted with new, smaller engines, a different rig and much larger passenger accommodation. From 1852 it sailed between Liverpool and Melbourne, carrying emigrants drawn partly by the Victorian gold rush.

For around three decades the Great Britain made regular voyages to Australia, usually completing the outward passage in about two months. It is commonly estimated that it carried around 15,000 to 16,000 emigrants in that time. The ship also served the British government as a troopship, taking soldiers to the Crimean War in 1855 and to India during the rebellion of 1857.

Decline in the Falklands and rescue

In 1882 the ship’s engines were removed and it was converted into a sailing cargo ship. In 1886, on a voyage carrying coal, it was badly damaged by storms off Cape Horn and took refuge at Port Stanley in the Falkland Islands. Repairs were judged too expensive.

The Falkland Islands Company bought the ship and used it as a floating warehouse for wool and coal. In 1937 the hull, now leaking, was towed to Sparrow Cove near Stanley and deliberately run aground and holed so that it settled in shallow water.

In the 1960s the naval architect Ewan Corlett drew attention to the ship’s historical importance. A salvage project followed, funded largely by the businessman Jack Hayward. In 1970 the cracked hull was patched, floated onto a submersible pontoon and towed about 8,000 miles across the Atlantic.

After a final passage up the Avon, the Great Britain re-entered the Great Western Dock on 19 July 1970, 127 years to the day after its launch. Restoration took decades. Since 2005 the dock has been sealed at waterline level by a glass plate, and the lower hull sits in dehumidified air to slow the corrosion of its iron.

Legacy in ship design

The Great Britain was not a commercial success for its first owners, but its technical lessons spread quickly. Its survival on the Irish beach in 1846–1847 was widely cited as proof that iron hulls were stronger than wooden ones. The Royal Navy and commercial shipowners adopted the screw propeller during the following decade, and by the 1860s iron, propeller-driven ships dominated new construction for ocean trade. Brunel went on to design the far larger Great Eastern, launched in 1858, which used both paddles and a propeller.

Key people

• Isambard Kingdom Brunel (1806–1859): chief engineer, also responsible for the Great Western Railway, the Clifton Suspension Bridge and the giant Great Eastern.
• Thomas Guppy and Christopher Claxton: members of the company’s building committee who worked closely with Brunel.
• William Patterson: Bristol shipbuilder who oversaw construction.
• Francis Pettit Smith: promoter of the Archimedes, whose propeller trials influenced the design.
• Ewan Corlett: naval architect whose campaign led to the ship’s return in 1970.

Timeline

• 1838: The Great Western, Brunel’s first steamship, begins Atlantic crossings.
• 1839, July: Construction of the new iron ship begins in Bristol.
• 1843, 19 July: The SS Great Britain is floated out in the presence of Prince Albert.
• 1844, December: The ship finally passes out of the Floating Harbour.
• 1845, 26 July: Maiden voyage from Liverpool to New York begins.
• 1846, 22 September: The ship runs aground at Dundrum Bay, Ireland.
• 1852: First voyage to Melbourne under new owners.
• 1886: Storm damage off Cape Horn; the ship stays in the Falklands as a hulk.
• 1970, 19 July: The ship returns to its Bristol dock.

Why it matters

The SS Great Britain showed that a large ship could be built of iron and driven by a propeller across the open ocean, the combination that later defined steamships and ocean liners. It belongs to the same burst of Brunel engineering as the Thames Tunnel, which opened in the same year. Its survival offers a rare, physical record of how Victorian engineers and emigrants crossed the world.