Robert Stephenson FRS (16 October 1803 – 12 October 1859) was an English civil engineer. He was the only son of George Stephenson, the famed locomotive builder and railway engineer; many of the achievements popularly credited to his father were actually the joint efforts of father and son.

Early life
After his education at the Bruce Academy, an apprenticeship to Nicolas Wood, the manager of Killingworth Colliery, and a period at the University of Edinburgh, Robert went to work with his father on his railway projects, the first being the Stockton and Darlington Railway. In 1823, when he was 20, Robert set up a company in partnership with his father, Michael Longridge and Edward Pease to build railway locomotives. The firm, Robert Stephenson and Company, was situated in South Street, off Forth Street in Newcastle. The works, known as the Forth Street Works, were the first locomotive works in the world, and it was here that the locomotives for the Stockton and Darlington Railway were built. The first locomotives produced there were, Locomotion, Hope, Diligence and Black Diamond The Forth Street works continued to build locomotives until the mid-twentieth century, and the original factory building still exists, at Forth Street in Newcastle, as the Robert Stephenson Centre. George used Locomotion in 1825 for the opening of the Stockton and Darlington line, which Robert had helped to survey.
In 1824, a year before the Stockton and Darlington line opened, Robert went off to South America for three years, to work as an engineer in the Colombian gold mines. His decision seems unusual, and there have been suggestions that it was caused by a rift with his father, but there is no evidence of this. When he returned in 1827, his father was building the Liverpool and Manchester Railway. George was living in Liverpool directing proceedings, so Robert took charge at the Forth Street Works and worked on the development of a locomotive to compete in the forthcoming Rainhill Trials, intended to choose a locomotive design to be used on the new railway. The result was the Rocket, which had a multi-tubular boiler to obtain maximum steam pressure from the exhaust gases. Rocket competed successfully in the Rainhill Trials, none of its competitors completing the trial. The Liverpool and Manchester Railway opened in 1830 with a procession of eight trains setting out from Liverpool. George led the parade driving the Northumbrian, Robert drove the Phoenix and Joseph Locke drove the Rocket. Following its success, the company built locomotives for other newly-established railways, including the Leicester and Swannington Railway. It became necessary to extend the Forth Street Works to accommodate the increased work.
On 17 June 1829, Robert married Frances Sanderson in London. The couple went to live at 5 Greenfield Place, off Westgate Road in Newcastle. Unfortunately they were not married long. In 1842, Robert's wife, Fanny as she was known, died. They had no children and Robert never re-married.
In 1830 Robert designed Planet, a much more advanced locomotive than Rocket. Stephenson's company was experiencing stiff competition from other locomotive manufacturers. Up until then, locomotives had their cylinders placed outside the wheels, as this was the easiest arrangement. It was thought that, placing the cylinders inside the wheels was a more efficient arrangement and this was done on Planet. However there was thought to be an increased risk of broken crank axles. There was friction between Robert and his father over this question. The locomotive, when completed, was found to produce much more power than previous designs. It was used on the Camden and Amboy Railway in the USA.
In 1833 Robert was given the post of Chief Engineer for the London and Birmingham Railway, the first main-line railway to enter London, and the initial section of the West Coast Main Line. That same year Robert and Frances moved to London to live. The new line posed a number of difficult civil engineering challenges, most notably Kilsby Tunnel, and was completed in 1838. Stephenson was directly responsible for the tunnel under Primrose Hill, which required excavation by shafts. Early locomotives could not manage the climb from Euston Station to Chalk Farm, requiring Stephenson to devise a system that would be draw them up the hill by chains using a steam engine near The Roundhouse. This impressive structure remains in use today as an Arts Centre. The London and Birmingham Railway was completed at an enormous cost of £5.5 million, compared with the cost of £900,000 for the Liverpool and Manchester Railway.

Locomotive designer
Robert constructed a number of well-known bridges to carry the new railway lines. In 1850 the railway from London to Scotland via Newcastle was completed. This required new bridges for both the Tyne and the Tweed and Robert designed them both. He designed the High Level Bridge, at Newcastle upon Tyne as a two-deck bridge supported on tall stone columns. Rail traffic was carried on the upper deck and road traffic on the lower deck. Queen Victoria opened the bridge in 1849. Robert also designed the Royal Border Bridge over the Tweed for the same line. It was an imposing viaduct of 28 arches and was opened by Queen Victoria in 1850. At last the railway ran all the way from London to Edinburgh. In the same year Robert's, Britannia Bridge across the Menai Strait, was opened. This bridge had the novel design of wrought-iron box-section tubes to carry railway line inside them, because a tubular design using wrought-iron gave the greatest strength and flexibility. The Conwy railway bridge between Llandudno Junction and Conwy was built in 1848 using a similar design. The Conway and Britannia bridges were such a success that Robert applied the design to other bridges, two in Egypt, and the 6,588 feet long Victoria Bridge over the St Lawrence River at Montreal in Canada. This was built as one long tube made up of 25 sections. Other bridges include, Arnside Viaduct in Cumbria, and a joint road and rail bridge in 1850 over the River Nene, at Sutton Bridge in Lincolnshire.
One of Stephenson's few failures was his design of the Dee bridge, which collapsed under a train. Five people were killed. He was heavily criticized for the design, even before the collapse, particularly for the poor choice of materials, which included cast iron. In fact, he had used cast iron for bridge designs before, as had Brunel, but in this case it is thought that he used longer girders (98 feet) than used previously and that this may have contributed to the failure. Robert had to give evidence at the inquest and this proved to be a harrowing experience. Fellow engineers such as Joseph Locke and Brunel refused to criticise Stephenson, even though they rarely used cast iron themselves.

Bridge builder
He served as Conservative Member of Parliament for Whitby from 1847 until his death. Paradoxically, given his background, he was a right-wing Tory, hostile to free trade, and anxious to avoid change in almost any form. He was a commissioner of the short-lived London Metropolitan Commission of Sewers from 1848. He was President of the Institution of Civil Engineers, for two years from 1855.
Robert's father George died in 1848 aged 67. Robert died on October 12 1859 at his London home aged 55. Brunel had died one month earlier on 15 September 1859. Robert was buried in Westminster Abbey next to Thomas Telford. Queen Victoria gave special permission for the cortege to pass through Hyde Park and 3,000 tickets were sold to spectators. In his eulogy, he was called 'the greatest engineer of the present century'. In his will he left nearly £400.000.
Stephenson was well respected by his engineering peers and had a lifetime friendship with Joseph Locke, a rival engineer during his career. In fact, Locke was a pallbearer at his funeral. Another such friendship was with Isambard Kingdom Brunel, who often helped Stephenson on various projects. One major topic, on which the two were very much opposed, was Brunel's advocacy of 'atmospheric' railways; railways on which locomotives were driven by compressed air in sealed tubes. Stephenson was convinced that the idea would not work, and although it was tried out on a small scale in a few places, Stephenson was right.
The Stephenson Railway Museum in North Shields is named after George and Robert Stephenson.

Trivia

Rolt, L.T.C. (1960) George and Robert Stephenson: The Railway Revolution, London: Penguin, ISBN 0-14-007646-8
Robbins, Michael (1981) George and Robert Stephenson, London: Her majesty's Stationery Office, ISBN 0-11-290342-8
Haworth, Victoria (2004) Robert Stephenson: Engineer and Scientist, Newcastle-upon-Tyne: The Rocket Press, ISBN 0-9535-1621-0
Smith, Ken (2003) Stephenson Power: The Story of George and Robert Stephenson, Newcastle upon Tyne: Tyne Bridge Publishing, ISBN 1857951867
Dugan, Sally (2003) Men of Iron, London: Channel Four Books, ISBN 1-4050-3426-2