John Rennie / Engineers
- Name : Rennie
- Born : 1761
- Died : 1821
- Category : Engineers
- Finest Moment : Construction of a bridge at Kelso (1799-1803), his favourite.
Born the son of a prosperous farmer at Phantassie, East Lothian on 7 June 1761, Rennie would have been immersed in farm machinery and, more critically, milling technology, from an early age. He worked during his youth with a millwright, before studying at Edinburgh University.
Some of us have laboured in factories during summer vacation periods; Rennie undertook contracts as a millwright, the first apparently involving the instalment of a threshing machine on his family's estate. No supper if it didn't work presumably!
He left University in 1783, touring various prominent engineering workshops, before returning to build his first bridge, over the Water of Leith in Edinburgh. Bridges were to be a constant theme in his work over the following decades, and in designing and building them he applied scientific theory rather than just make carbon copies of earlier, traditional designs. One common method, for example, was to build a hump-backed bridge, which was of course self-limiting in the distance it could safely span. It was also inconvenient for heavy traffic. Rennie preferred to build his roads over a flat span.
Major contracts Rennie became renowned for include the Crinan Canal (1793-1801), the Plymouth Breakwater (started 1812), and three London bridges; Waterloo (1811-17), Southwark (1814-19), and New London Bridge (1831). The latter now resides, somewhat bizarrely, in Arizona, USA, having been dismantled and shipped out, stone by stone, some 130 years after it was built.
He supervised work on Stevenson's Bell Rock Lighthouse, worked on canal constructions, fen drainage, dock improvements, and kept an eye on technological advances being made in other areas, such as steel manufacture. His two sons continued the business after his death in London, on 4 October 1821. He is buried in Westminster Abbey.