SS Great Britain

Bristol MMB 43 SS Great Britain.jpg
S.S. Great Britain in dry dock at Bristol in 2005, preserved for exhibit as a museum ship
History
Name:S.S. Great Britain
Owner:Great Western Steamship Company
Builder:William Patterson
Cost:
  • Projected: £70,000 pounds sterling
  • Actual: £117,000 pounds sterling
Laid down:July 1839
Launched:19 July 1843
Completed:1845
Maiden voyage:26 July 1845
In service:1845–1886
Homeport:Bristol, England
Status:Museum ship
General characteristics
Type:Passenger steamship
Displacement:3,674 tons load draught
Length:322 ft (98 m)
Beam:50 ft 6 in (15.39 m)
Draught:16 ft (4.9 m)[1]
Installed power:2 × twin 88-inch (220 cm) cylinder, 6 ft (1.8 m) stroke, 500 hp (370 kW), 18 rpm inclined direct-acting steam engines
Propulsion:Single screw propeller
Sail plan:
Speed:10 to 11 knots (19 to 20 km/h; 12 to 13 mph)
Capacity:
  • 360 passengers, later increased to 730
  • 1,200 tons of cargo
Complement:130 officers and crew (as completed)

SS Great Britain is a museum ship and former passenger steamship, which was advanced for her time. She was the longest passenger ship in the world from 1845 to 1854. She was designed by Isambard Kingdom Brunel (1806-1859), for the Great Western Steamship Company's transatlantic service between Bristol and New York. While other ships had been built of iron or equipped with a screw propeller, the Great Britain was the first to combine these features in a large ocean-going ship. She was the first iron steamer to cross the Atlantic, which she did in 1845, in the time of 14 days.

The ship is 322 ft (98 m) in length and has a 3,400-ton displacement. She was powered by two inclined 2 cylinder engines of the direct-acting type, with twin 88 in (220 cm) bore, 6-foot (1.8 m) stroke cylinders. She was also provided with secondary masts for sail power. The four decks provided accommodation for a crew of 120, plus 360 passengers who were provided with cabins, dining, and promenade saloons.

When launched in 1843, Great Britain was by far the largest vessel afloat at that time. However, her protracted construction time of six years (1839-1845) and high cost had left her owners in a difficult financial position, and they were forced out of business in 1846 having spent all their remaining funds re-floating the ship after she was run aground at Dundrum Bay in County Down near Newcastle in Northern Ireland, after a navigational error. In 1852 she was sold for salvage and repaired. Great Britain later carried thousands of immigrants to Australia from 1852 until being converted to all-sail in 1881. Three years later, she was retired to the Falkland Islands where she was used as a warehouse, quarantine ship and coal hulk until scuttled and sunk in 1937, 98 years since being laid down and construction began.[2]

In 1970, after lying underwater and abandoned for 33 years half a world away, following a cash donation by Sir Jack Arnold Hayward, O.B.E. (1923-2015) a prominent businessman, developer, philanthropist and owner of the English football club Wolverhampton Wanderers F.C. that paid for the vessel to be raised, repaired enough to be towed north through the Atlantic back to the United Kingdom, and the Great Britain was returned to the Bristol dry dock where she had been built 127 years earlier. Now listed as part of the National Historic Fleet, she is an award-winning visitor attraction and museum ship in Bristol Harbour, with between 150,000 and 200,000 visitors annually.

Development

The SS Great Western on her maiden voyage

After the initial success of its first liner, SS Great Western of 1838, the Great Western Steamship Company collected materials for a sister ship, tentatively named City of New York.[2] The same engineering team that had collaborated so successfully on Great WesternIsambard Brunel, Thomas Guppy, Christopher Claxton and William Patterson—was again assembled. This time however, Brunel, whose reputation was at its height, came to assert overall control over design of the ship—a state of affairs that would have far-reaching consequences for the company. Construction was carried out in a specially adapted dry dock in Bristol, England.[3]

Adoption of iron hull

Two chance encounters were to profoundly affect the design of Great Britain. In late 1838, John Laird's 213-foot (65 m) English Channel packet ship Rainbow—the largest iron-hulled ship then in service—made a stop at Bristol. Brunel despatched his associates Christopher Claxton and William Patterson to make a return voyage to Antwerp on Rainbow to assess the utility of the new building material. Both men returned as converts to iron-hulled technology, and Brunel scrapped his plans to build a wooden ship and persuaded the company directors to build an iron-hulled ship.[4]

Great Britain's builders recognised a number of advantages of iron over the traditional wooden hull. Wood was becoming more expensive, while iron was getting cheaper. Iron hulls were not subject to dry rot or woodworm, and they were also lighter in weight and less bulky. The chief advantage of the iron hull was its much greater structural strength. The practical limit on the length of a wooden-hulled ship is about 300 feet, after which hogging—the flexing of the hull as waves pass beneath it—becomes too great. Iron hulls are far less subject to hogging, so that the potential size of an iron-hulled ship is much greater.[5] The ship's designers, led by Brunel, were initially cautious in the adaptation of their plans to iron hulled-technology. With each successive draft however, the ship grew ever larger and bolder in conception. By the fifth draft, the vessel had grown to 3,400 tons, over 1,000 tons larger than any ship then in existence.[6]

Adoption of screw propulsion

Artist's impression of SS Archimedes
Replica of Great Britain's original six-bladed propeller on the museum ship. This propeller proved totally unsatisfactory in service and was quickly replaced with a four-bladed model.

In early 1840, a second chance encounter occurred, the arrival of the revolutionary SS Archimedes at Bristol, the first screw-propelled steamship, completed only a few months before by F. P. Smith's Propeller Steamship Company. Brunel had been looking into methods of improving the performance of Great Britain's paddlewheels, and took an immediate interest in the new technology. Smith, sensing a prestigious new customer for his own company, agreed to lend Archimedes to Brunel for extended tests.[6] Over several months, Smith and Brunel tested a number of different propellers on Archimedes to find the most efficient design, a four-bladed model submitted by Smith.[7]

Having satisfied himself as to the advantages of screw propulsion, Brunel wrote to the company directors to persuade them to embark on a second major design change, abandoning the paddlewheel engines—already half constructed—for completely new engines suitable for powering a propeller.

Brunel listed the advantages of the screw propeller over the paddlewheel as follows:

  • Screw propulsion machinery was lighter in weight, thus improving fuel economy;
  • Screw propulsion machinery could be kept lower in the hull, lowering the ship's centre of gravity and making it more stable in heavy seas;
  • By taking up less room, propeller engines would allow more cargo to be carried;
  • Elimination of bulky paddle-boxes would lessen resistance through the water, and also allow the ship to manoeuvre more easily in confined waterways;
  • The depth of a paddlewheel is constantly changing, depending on the ship's cargo and the movement of waves, while a propeller stays fully submerged and at full efficiency at all times;
  • Screw propulsion machinery was cheaper.[8]

Brunel's arguments proved persuasive, and in December 1840, the company agreed to adopt the new technology. The decision became a costly one, setting the ship's completion back by nine months.[8]

Reporting on the ship's arrival in New York, in its first issue Scientific American opined, "If there is any thing objectionable in the construction or machinery of this noble ship, it is the mode of propelling her by the screw propeller; and we should not be surprised if it should be, ere long, superseded by paddle wheels at the sides."[9]

Other Languages
Deutsch: Great Britain
français: Great Britain
Gàidhlig: SS Great Britain
português: SS Great Britain
српски / srpski: СС Грејт Бритен
srpskohrvatski / српскохрватски: SS Great Britain