Thomas Telford (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotland, as well as harbours and tunnels. Such was his reputation as a prolific designer of highways and related bridges, he was dubbed the 'Colossus of Roads' (a pun on the Colossus of Rhodes), and, reflecting his command of all types of civil engineering in the early 19th century, he was elected as the first president of the Institution of Civil Engineers, a post he held for 14 years until his death. The town of Telford in Shropshire was named after him.
Telford was born on 9 August 1757, at Glendinning, a hill farm three miles (five kilometres) east of Eskdalemuir Kirk, in the rural parish of Westerkirk, in Eskdale, Dumfriesshire. His father John Telford, a shepherd, died soon after Thomas was born. Thomas was raised in poverty by his mother Janet Jackson (died 1794).
At the age of 14, he was apprenticed to a stonemason, and some of his earliest work can still be seen on the bridge across the River Esk in Langholm in Dumfries and Galloway. He worked for a time in Edinburgh and in 1782 he moved to London where, after meeting architects Robert Adam and Sir William Chambers, he was involved in building additions to Somerset House there. Two years later he found work at Portsmouth dockyard and – although still largely self-taught – was extending his talents to the specification, design and management of building projects.
In 1787, through his wealthy patron William Pulteney, he became Surveyor of Public Works in Shropshire. His projects included renovation of Shrewsbury Castle, the town's prison (during the planning of which he met leading prison reformer John Howard), the Church of St Mary Magdalene, Bridgnorth and another church, St Michael's, in Madeley. Called in to advise on a leaking roof at St Chad's Church, Shrewsbury in 1788, he warned the church was in imminent danger of collapse; his reputation was made locally when it collapsed three days later, but he was not the architect for its replacement.
As the Shropshire county surveyor, Telford was also responsible for bridges. In 1790 he designed Montford Bridge carrying the London–Holyhead road over the River Severn at Montford, the first of some 40 bridges he built in Shropshire, including major crossings of the Severn at Buildwas, and Bridgnorth. The bridge at Buildwas was Telford's first iron bridge. He was influenced by Abraham Darby's bridge at Ironbridge, and observed that it was grossly over-designed for its function, and many of the component parts were poorly cast. By contrast, his bridge was 30 ft (9 m) wider in span and half the weight, although it now no longer exists. He was one of the first engineers to test his materials thoroughly before construction. As his engineering prowess grew, Telford was to return to this material repeatedly.
In 1795, the bridge at Bewdley in Worcestershire was swept away in the winter floods and Telford was responsible for the design of its replacement. The same winter floods saw the bridge at Tenbury also swept away. This bridge across the River Teme was the joint responsibility of both Worcestershire and Shropshire and the bridge has a bend where the two counties meet. Telford was responsible for the repair to the northern (Shropshire) end of the bridge.
Telford's reputation in Shropshire led to his appointment in 1793 to manage the detailed design and construction of the Ellesmere Canal, linking the ironworks and collieries of Wrexham via the north-west Shropshire town of Ellesmere, with Chester, utilising the existing Chester Canal, and then the River Mersey.
Among other structures, this involved the spectacular Pontcysyllte Aqueduct over the River Dee in the Vale of Llangollen, where Telford used a new method of construction consisting of troughs made from cast iron plates and fixed in masonry. Extending for over 1,000 feet (300 metres) with a height of 126 ft (38 m) above the valley floor, the Pontcysyllte Aqueduct consists of nineteen arches, each with a 45 ft (14 m) span. Being a pioneer in the use of cast-iron for large scaled structures, Telford had to invent new techniques, such as using boiling sugar and lead as a sealant on the iron connections. Canal engineer William Jessop oversaw the project but left the detailed execution of the project in Telford's hands. The aqueduct was designated a UNESCO World Heritage Site in 2009.
The same period also saw Telford involved in the design and construction of the Shrewsbury Canal. When the original engineer, Josiah Clowes, died in 1795, Telford succeeded him. One of Telford's achievements on this project was the design of Longdon-on-Tern Aqueduct, the cast-iron aqueduct at Longdon-on-Tern, pre-dating that at Pontcysyllte, and substantially bigger than the UK's first cast-iron aqueduct, built by Benjamin Outram on the Derby Canal just months earlier. The aqueduct is no longer in use, but is preserved as a distinctive piece of canal engineering.
The Ellesmere Canal was left uncompleted in 1805 because it failed to generate the revenues needed to finance the connecting sections to Chester and Shrewsbury. However, alongside his canal responsibilities, Telford's reputation as a civil engineer meant he was constantly consulted on numerous other projects. These included water supply works for Liverpool, improvements to London's docklands and the rebuilding of London Bridge (c. 1800).
Most notably (and again William Pulteney was influential), in 1801 Telford devised a master plan to improve communications in the Highlands of Scotland, a massive project that was to last some 20 years. It included the building of the Caledonian Canal along the Great Glen and redesign of sections of the Crinan Canal, some 920 miles (1,480 km) of new roads, over a thousand new bridges (including the Craigellachie Bridge), numerous harbour improvements (including works at Aberdeen, Dundee, Peterhead, Wick, Portmahomack and Banff), and 32 new churches.
Telford also undertook highway works in the Scottish Lowlands, including 184 miles (296 km) of new roads and numerous bridges, ranging from a 112 ft (34 m) span stone bridge across the Dee at Tongueland in Kirkcudbright (1805–06) to the 129 ft (39 m) tall Cartland Crags bridge near Lanark (1822).
In 1809, Telford was tasked with improving the Howth Road in Dublin, to connect the new harbour at Howth to the city of Dublin as part of wider plan to improve communication between Dublin and London. The milestones that are a feature of this route from Howth to the GPO on O'Connell Street still mark the route. He also drafted the first design of the Ulster Canal. Irish engineer, William Dargan, was trained by Telford.
Telford was consulted in 1806 by the King of Sweden about the construction of a canal between Gothenburg and Stockholm. His plans were adopted and construction of the Göta Canal began in 1810. Telford travelled to Sweden at that time to oversee some of the more important initial excavations.
Many of Telford's projects were undertaken due to his role as a member of the Exchequer Bill Loan Commission, an organ set up under the Public Works Loans Act 1817 (57 Geo. 3. c. 34), to help finance public work projects that would generate employment.
During his later years, Telford was responsible for rebuilding sections of the London to Holyhead road, a task completed by his assistant of ten years, John MacNeill; today, much of the route is the A5 trunk road, although the Holyhead Road diverted off the A5 along what is now parts of A45, A41 and A464 through the cities of Coventry, Birmingham and Wolverhampton. Between London and Shrewsbury, most of the work amounted to improvements. Beyond Shrewsbury, and especially beyond Llangollen, the work often involved building a highway from scratch. Notable features of this section of the route include the
Waterloo Bridge across the River Conwy at Betws-y-Coed, the ascent from there to Capel Curig and then the descent from the pass of Nant Ffrancon towards Bangor. Between Capel Curig and Bethesda, in the Ogwen Valley, Telford deviated from the original road, built by Romans during their occupation of this area.