French-born civil engineer.
Brunel was originally destined for a career in the church, but nothing could induce the nascent engineer to take an interest in his literary studies. As a last resort he entered the Navy. Already he showed a pronounced mechanical aptitude: he was able to make himself a quadrant, after seeing one briefly for the first time, that served him until he left the forces in 1792.
Post-war, as a loyalist, he found himself in great danger in France. He fled to the United States the following year, finding employment as an engineer and architect. He designed New York's first theatre - described as a masterpiece - which later burned down. He soon rose to the position of chief engineer of that city, but in 1799 left for England, partly for professional reasons and partly to pursue a Miss Sophie Kingdom, whom he had met in Rouen much earlier. They married at the end of that year.
After a long struggle, his system for the construction of ships' blocks was put into service at Portsmouth in 1808. This was a pioneering achievement of mass production, reducing the number of men required by the process to a fraction of the previous number.
In the following years Brunel worked on an enormous number of ingenious projects, including a suspension bridge, a series of (ultimately impracticable) compressed air engines, and the first double-acting marine steam engine. Sadly he lacked a commercial intelligence commensurate with his professional skill and in 1821, after various losses, he was imprisoned for his debts. Redeemed by a grant from his friends, he began his last and greatest work, the construction of a tunnel under the Thames, which was completed in 1843, almost 20 years after a company was first formed for its execution.