Sir Marc Isambard Brunel

views updated

Sir Marc Isambard Brunel

1769-1849

Engineer

Underwater Tunneling One of the major engineering achievements of the nineteenth century was the development of the technology to construct tunnels under rivers. People had been building land tunnels since ancient times, but efforts to tunnel through ground under water failed because the soft, water–bearing strata tended to collapse. Marc Brunei solved the problem by inventing the tunneling shield (patented in 1818) and went on to build the first underwater tunnel in the world under the River Thames in London (1825-1843).

Early Life The son of a prosperous farmer, Marc Isambard Brunei was born in Hacqueville, a small village in northern France, and demonstrated his talent for mathematics, mechanics, and drawing at an early age. By the time he was eleven, he had expressed his desire to become an engineer, but his father wanted his son to become a priest and enrolled the boy at a seminary in Rouen. The head of the seminary helped Brunei to acquire training elsewhere in preparation for a career as a naval engineer. Brunei served in the French navy for six years, returning to France in 1793. His Royalist sympathies soon came to the attention of the French Revolutionary government, and he fled to the United States.

Chief Engineer For the next several years Brunei worked as an architect and civil engineer in New York City and was eventually appointed chief engineer for the city. He also won the competition for designing the Capitol building in Washington, D.C., but another design was used because Brunei’ was considered too expensive. During this time he perfected a machine to make pulleys for ships mechanically, instead of by hand, and in 1799 he went to England to submit his plans to the British government.

Engineering in England The British government had Brunei install forty–three of his machines at the Portsmouth dockyard, where he created one of the first completely mechanized production processes in the world. When complete, his system could be run by ten men and could produce pulleys better and faster than more than one hundred men making them by hand. During the early nineteenth century Brunel designed the first floating landing piers, which were build in Liverpool.

Financial Failures During his early years in England, Brunei also invented boot–making and knitting machines, an improved printing press, and devices to saw and bend timber, but his attempts to capitalize on these innovations were unsuccessful. His sawmills at Battersea in southwest London were badly damaged by fire in 1814, and the business soon went bankrupt. His army–boot factory, which supplied British troops with strong, comfortable boots during the Napoleonic Wars, went out of business after the war ended in 1815, and the government stopped buying his boots. In 1821 Brunei spent several months in debtors’ prison. By then, however, he had patented an invention that ensured his financial stability.

The Tunneling Shield By the time Brunei turned his attention to the problem of tunneling through water–bearing ground, two attempts to tunnel under the Thames, in 1801 and 1807, had failed when excavators hit quicksand. Around 1818, Brunei noticed how the shipworm bored through wood while its shell plates pushed the sawdust behind it and was inspired to build a large protective iron casing that screw jacks pushed through soft ground while miners inside it dug through shutters that could be opened and closed.

The Thames Tunnel Brunei’s shield was tested for the first time on the tunnel he designed to pass under the Thames between Rotherhithe and Wapping on the east side of London. Construction began in 1825 and, after several major delays, was finally completed in 1843. Partway through the project, Brunel replaced his first tunneling shield with a much larger one. Neither shield failed at any point in the project, demonstrating the safety of Brunel’s invention. The tunnel started out as a pedestrian tunnel, and within four months of its completion more than a million people passed through it. It was converted to a railroad tunnel during the 1860s and became part of the London Underground (subway) system in 1913. In recognition of his achievement, Brunei was knighted in 1841. His only son, Isambard Kingdom Brunei (1806–1859), began his career as resident engineer for the Thames Tunnel and went on to design bridges and railroads, as well as the first transatlantic steamships in regular service.