The world's first public railway to use steam locomotives,[1] its first line connected collieries near Shildon with Darlington and Stockton in County Durham, and was officially opened on 27 September 1825.

It suffered severe financial difficulties at the end of the 1840s and was nearly taken over by the York, Newcastle and Berwick Railway, before the discovery of iron ore in Cleveland and the subsequent increase in revenue meant it could pay its debts.

[2][3] The harbour of Stockton-on-Tees invested considerably during the early 19th century in straightening the Tees in order to improve navigation on the river downstream of the town and was subsequently looking for ways to increase trade to recoup those costs.

The Scottish engineer Robert Stevenson was said to favour the railway, and the Quaker Edward Pease supported it at a public meeting in Darlington on 13 November 1818, promising a five per cent return on investment.

[11] Overton surveyed a new line that avoided Darlington's estate and agreement was reached with Eldon, but another application was deferred early in 1820, as the death of King George III had made it unlikely a bill would pass that parliamentary year.

4. c. xliv), which received royal assent on 19 April 1821, allowed for a railway that could be used by anyone with suitably built vehicles on payment of a toll, that was closed at night, and with which land owners within 5 miles (8 km) could build branches and make junctions;[13][14] no mention was made of steam locomotives.

The committee designed a seal, showing waggons being pulled by a horse, and adopted the Latin motto Periculum privatum utilitas publica ("At private risk for public service").

[21][note 5] Stephenson was assisted by his 18-year-old son Robert during the survey,[23] and by the end of 1821 had reported that a usable line could be built within the bounds of the act of Parliament, but another route would be shorter by 3 miles (5 km) and avoid deep cuttings and tunnels.

[25] On 23 May 1822 a ceremony in Stockton celebrated the laying of the first track at St John's Well, the rails 4 ft 8 in (1,422 mm) apart,[note 6] the same gauge used by Stephenson on his Killingworth Railway.

[29] A new bill was presented, requesting Stephenson's deviations from the original route and the use of "loco-motives or moveable engines", and this received royal assent on 23 May 1823 as the Stockton and Darlington Railway Act 1823 (4 Geo.

Approaching Stockton, running alongside the turnpike as it skirted the western edge of Preston Park, it gained speed and reached 15 mph (24 km/h) again, before a man clinging to the outside of a waggon fell off and his foot was crushed by the following vehicle.

As work on the final section of track to Stockton's quayside was still ongoing, the train halted at the temporary passenger terminus at St John's Well 3 hours, 7 minutes after leaving Darlington.

[50] The 1821 act of Parliament had received opposition from the owners of collieries on the River Wear who supplied London and feared competition, and it had been necessary to restrict the rate for transporting coal destined for ships to 1⁄2d per ton per mile, which had been assumed would make the business uneconomic.

[67][68] The Tees Navigation Company was about to improve the river and proposed that the railway delay application to Parliament, but, despite opposition, at a meeting in January 1828 it was decided to proceed.

[81][82] For the opening ceremony on 27 December 1830, "Globe", a new locomotive designed by Hackworth for passenger trains, hauled people in carriages and waggons fitted with seats across the bridge to the staiths at Port Darlington, which had berths for six ships.

[84] Before May 1829, Thomas Richardson had bought about 500 acres (200 ha) near Port Darlington, and with Joseph and Edward Pease and others he formed the Owners of the Middlesbrough Estate to develop it.

[98] Representatives of the Y&NMR and S&DR met two weeks later and formed the Great North of England Railway (GNER),[99] a line from York to Newcastle that used the route of the 1+1⁄2-mile (2.4 km) Croft branch at Darlington.

Pease specified a formation wide enough for four tracks, so freight could be carried at 30 miles per hour (48 km/h) and passengers at 60 mph (97 km/h), and George Stephenson had drawn up detailed plans by November.

In August a general meeting decided to start work on the southern section, but construction was delayed, and after several bridges collapsed the engineer Thomas Storey was replaced by Robert Stephenson.

[123] By this time, Port Darlington had become overwhelmed by the volume of imports and exports and work started in 1839 on Middlesbrough Dock, which had been laid out by William Cubitt, capable of holding 150 ships, and built by resident civil engineer George Turnbull.

[138] The Weardale Extension Railway ran from Waskerley on the Wear & Derwent to Crook on the BA&WR and included the Sunniside Incline worked by a stationary engine.

[143] A deviation replacing Nanny's Mayor's Incline, as well as a curve that allowed trains from Crook direct access to Rowley, was opened for freight on 23 May 1859 and for passenger traffic on 4 July 1859.

This required a payment of £47,000 each year, exceeding the SD&R's net revenue;[149] traffic from the Derwent Iron Company was reduced during a period of financial difficulty and the Black Boy colliery switched to sending its coal to Hartlepool.

They opened a mine, laid a branch line to the Middlesbrough & Redcar Railway and started hauling ironstone over the S&DR to their blast furnaces west of Bishop Auckland.

By 1851, Derwent Iron had opened a mine in the area and began moving ironstone 54 miles (87 km) to Consett,[154] and the S&DR had paid the arrears on its debt and was able to pay a dividend the following year, albeit only 4 per cent; between 1849 and 1853 the traffic more than doubled.

[159] An application to Parliament for a jetty in the following year was unsuccessful,[160] but in 1860 the Upsall, Normanby & Ormesby Railway received permission for a line with access to the river, the S&DR claim of exclusive rights to the foreshore having been rejected.

[171] Two 4-4-0 locomotives with enclosed cabs had been built for the line in 1860 by Stephenson and Co,[172] and the S&DR worked traffic from the start: two return services a day were provided for passengers.

The Sunniside Incline was replaced by a deviation, albeit with gradients of 1 in 51 and 1 in 52, which opened for mineral traffic on 10 April 1867 and for passengers on 2 March 1868;[189] after 1868 trains on this line were extended to serve Benfieldside station (later known as Blackhill and then Consett).

[218] Fifty years later centenary celebrations were held in July to allow guests from foreign countries visiting the International Railway Congress to take part.

An exhibition of rolling stock at the new Faverdale Wagon Works in Darlington was opened by the Duke and Duchess of York (later King George VI and the Queen Mother).