John Rennie the Elder

He married Martha Ann, daughter of E. Mackintosh, in 1790. The couple had seven children, two of whom George and John, became notable engineers in their own rights.

John Rennie was a very hard working man devoted to his profession. It is believed that the incessant labour and pressures of his work shortened his life. He died after a short illness on 4 October 1821.

John Rennie was born on 7 June 1761 in East Lothian, Scotland. He was the fourth son of a prosperous farmer.

From a young age he displayed an interest in mechanics and was naturally skilled in this field. He often skipped school to visit the workshop of Andrew Meikle, the local millwright. Meikle was himself a famed person, popular as the inventor of the threshing machine.

John had built working models of a windmill, a steam engine, and a pile engine by the time he was ten and he started working in Meikle’s workshop on his vacations when he was 12.

He received his primary education at the parish school of Prestonkirk Parish Church before moving on to the burgh school at Dunbar.

In 1777, the schoolmaster at Dunbar left to take up another job and Rennie was offered this post. He declined the offer and instead chose to continue working with Meikle. Rennie built a number of corn mills and flour mills near Dundee even before he was 18.

He began his career as a millwright, and in 1783, took up a job as an engineer at Boulton & Watt, a partnership between the English manufacturer Matthew Boulton and the celebrated Scottish engineer James Watt.

He left for London in 1784 to work on a project for Boulton & Watt. He was made in-charge of the works at the Albion Flour Mills and he designed all of their machinery. Rennie made use of iron instead of wood for the shafting and framing--an innovative concept at that time.

He started his own business in 1791 and expanded into civil engineering as well. He developed a particular interest in the construction of canals and waterways and some of his early projects were Lancaster Canal (started in 1792), the Chelmer and Blackwater Navigation (started in 1793), the Crinan Canal (started in 1794).

One of the major canal projects he undertook was the Kennet and Avon Canal which included the Dundas Aqueduct, Caen Hill Locks and Crofton Pumping Station. The work, started in 1794 was completed in 1810.

John Rennie also proved himself to be a brilliant architect blessed with an innate sense of aesthetics. Along with canals he also built a number of bridges and introduced several innovative techniques in bridge building. The Leeds Bridge and the Waterloo Bridge were among the beautiful bridges he built.

John Rennie is credited to have constructed several structurally sound and aesthetically appealing bridges, but the Waterloo Bridge was considered his masterpiece. The granite bridge which had nine arches, each of 120 feet (36.6 m) span, separated by double Doric stone columns, and was 2,456 feet (748.6 m) long was built across the River Thames in London.