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John Rennie

John Rennie

Civil engineer, 1761-1821


Bridges, Water


United Kingdom
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Famous for his Thames bridges – Waterloo Bridge, Southwark Bridge, and the new London Bridge

Jointly designer, with Robert Stevenson, of the Bell Rock Lighthouse

First university-educated engineer

Why you might have heard of John Rennie

John Rennie was a leading civil engineer in the United Kingdom during the first part of the 19th century.

Originally Rennie trained as a millwright, maintaining, repairing, and reassembling machinery.

He set up his own business in London, where he was involved with surveying and planning canals and later, improvements to dockyards and harbours.

However, he is possibly most famous for his work on bridges, using stone and cast iron to produce bridges with daringly wide arches.

Many of his largest projects were for naval and maritime clients, creating or improving several major docks and harbours.

These included the London docks, East India Docks and West India Docks on the Thames, and the massive rebuilding of the Sheerness Dockyard.

Work was with him not only a pleasure – it was almost a passion - Samuel Smiles, John Rennie's biographer


In 1779, Rennie set up in business on his own as a millwright in Scotland.

On a recommendation from his university professor John Robison to his close friend James Watt, in 1784, Rennie began to work for engineering and manufacturing firm, Boulton & Watt, in Birmingham.

Rennie eventually moved to London to improve the design of and supervise the engines for Boulton & Watt’s project at the Albion Flour Mills in London. While working in London, it was agreed that Rennie could undertake work for other clients. At first, his commissions came from flour mills, breweries and distilleries, and later sugar mills for the West Indies.

Rennie had moved to London armed with several letters of introduction, including one to John Smeaton, often regarded as the ‘father of civil engineering’. Smeaton invited Rennie to join the Society of Engineers, later the Smeatonian Society and a forerunner of ICE.

Rennie was commissioned to make a survey of the Basingstoke Canal for William Jessop, which subsequently led on to his involvement in the Ipswich & Stowmarket Navigation.

In the 1790s, Rennie began working on the Kennet and Avon Canal in Wiltshire. Rennie was responsible for designing and project managing several more canals, including the Lancaster Canal and the Crinian Canal in Scotland.

In 1800, he was appointed engineer to the London docks and in 1803, engineer to the East India Docks. For the royal dockyards, Rennie was very involved in introducing steam-driven machinery to speed up the repair of ships.

He moved on to become involved in designing road bridges, becoming famous for his bridges over the Thames - Waterloo Bridge, Southwark Bridge and London Bridge as well as others across the country, including Kelso, Scotland.

Waterloo Bridge
Waterloo Bridge

We asked John…

Personal life

Rennie was born on 7 June 1761, near East Linton, 20 miles east of Edinburgh, the ninth child of a tenant farmer.

In 1790, Rennie he married Martha Ann Mackintosh (d.1806), daughter of E. Mackintosh. They had seven children.

John Rennie 'the elder' was an imposing figure, 6ft 4in tall, and 15 stone, but suffered badly from rheumatism.

By contemporary accounts, Rennie lived to work, and had few other interests. His biographer, Samuel Smiles said: “Work was with him not only a pleasure – it was almost a passion.”

Rennie was a book collector. He would commission any friends visiting Paris to purchase rare texts for his collection. The only holiday that it is known Rennie took was with James Watt to France in 1816, the year after the Battle of Waterloo. They spent much time inspecting the dock and harbour works commissioned by Napoleon.

Rennie died, after a short illness, at his house in Stamford Street, London, on 4 October 1821, and was buried in the crypt at St. Paul's Cathedral.

Two of his sons, George and John, became notable engineers, George as a mechanical engineer, John as a civil engineer. Both sons were responsible for completing several of their father’s projects after his death. His son, Sir John Rennie became the third president of the ICE in 1845.


While still at the local parish school, Rennie loved to visit Andrew Meikle, the local millwright and inventor of the threshing machine.

He began to work for him when he was 12, for two years while continuing his education.

After a further two years of education at Dunbar High School, Rennie returned to work for Meikle.

Rennie studied at Edinburgh University from 1780 – 1783.

He was the first professional engineer to have a university education.

Membership of other bodies and committees

Elected Fellow of the Royal Society of Edinburgh, 28 January 1788

Member of the Committee of Managers of the London Institution

Elected Fellow of the Royal Society in 1798

ICE positions

Rennie was invited by John Smeaton to join the Society of Engineers, later the Smeatonian Society, which was a forerunner of ICE.

He became treasurer of the society in 1811.

The granite face work and parapets of the old London Bridge were sold to McCulloch Properties, Inc, of California, and was rebuilt on a new bridge structure at Lake Havasu City, Arizona.

Rennie was the first to use a steam engine to drive piles in cofferdams for the London docks and Humber Dock, Hull.

Rennie also gave advice on novel maritime structures, such as steam-powered dredgers used to deepen rivers and docks and diving bells, which gave engineers safe access to underwater engineering projects, such as the building of Ramsgate harbour.