Sir Marc Isambard Brunel (Ĭz´əmbärd´ brōōnĕl´), 1769–1849, British engineer and inventor. Born in France, he came to the United States in 1793 as a royalist refugee. He became chief engineer of New York City, and his projects included building the old Bowery theater (burned in 1821) and constructing a canal between Lake Champlain and the Hudson. In 1799 he went to England, where he patented machinery for making ships' blocks and later invented many other mechanical labor-saving devices. In 1825, Brunel began the construction of the Thames Tunnel (the first in which a shield was used; see tunnel). In 1841 he was knighted. In the work on the tunnel Sir Marc was assisted by his son, Isambard Kingdom Brunel, 1806–59, British civil engineer and an authority on railway traction and steam navigation, b. Portsmouth. He was chief engineer of the Great Western Railway, building bridges and docks. Later he constructed railways in Italy and was a consulting engineer in Australia and India. He is best known, however, for his designing and construction of three oceangoing steamships: the Great Western (1838), which was the first transatlantic steam vessel, the Great Britain (1845), the first ocean screw steamship, and the Great Eastern (1858), the largest steam vessel of its time.

See biography of M. I. Brunel by P. Clements (1970); study by P. Hay (1973); biographies of I. K. Brunel by his son, I. Brunel (1870, repr. 1972), and L. T. Rolt (1959); C. B. Noble, The Brunels: Father and Son (1938); S. Fox, Transatlantic: Samuel Cunard, Isambard Brunel, and the Great Atlantic Steamships (2003).