History

The Great Western Railway originated from the desire of Bristol merchants to maintain the position of their city as the second port in the country and the chief one for American trade. The increase in the size of ships and the gradual silting of the River Avon made Liverpool an increasingly attractive port, and with its rail connection with London developing in the 1830s it threatened Bristol's status. The answer for Bristol was, with the co-operation of London interests, to build a line of their own, a railway built to unprecedented standards of excellence to outperform the other lines being constructed to the north-west. and was incorporated by Act of Parliament in 1835. Isambard Kingdom Brunel was appointed as engineer. This was by far his largest contract to date, and he made two controversial decisions: to use a broad gauge of seven feet (actually 7 ft 0¼ in (2,140 mm) for the track, potentially to allow large wheels outside the bodies of the rolling stock thus providing smoother running at high speeds; and to take a route which passed north of the Marlborough Downs, an area with no significant towns, though it did offer potential connections to Oxford and Gloucester and then to follow the Thames Valley into London. He surveyed the entire length of the route between London and Bristol himself.

G. T. Clark played an important role as an engineer on the project, reputedly taking the management of two divisions of the route including bridges over the River Thames at Upper Basildon and Moulsford, and Paddington Station. Involvement in major earth-moving works seems to have fed Clark's interest in geology and archaeology and he, anonymously, authored two guidebooks on the railway, one was illustrated with lithographs by John Cooke Bourne, the other was a critique of Brunel's methods and the broad gauge.

The initial group of locomotives ordered by Brunel to his own specifications proved unsatisfactory. 20-year-old Daniel Gooch was appointed as Locomotive Superintendent and set to establishing a reliable fleet. He bought two locomotives from Robert Stephenson and Company which proved more successful, and then designed a series of standardised locomotives which, from 1846, could be built at the newly established railway workshops. Brunel and Gooch had chosen to locate these close to the village of Swindon, at the point where the gradual ascent eastwards from London turned into the steeper route towards the Avon. The GWR also championed other technological advances, for instance commissioning the world's first commercial telegraph line. This ran for 13 miles (21 km) from Paddington to West Drayton and came into operation on 9 April 1839.

The first stretch of line, 22.5 miles (36 km) from London Paddington to Maidenhead Bridge station, had opened on 4 June 1838. Once the Maidenhead Railway Bridge was ready, the line was extended to Twyford on 1 July 1839, and then through the deep Sonning Cutting into Reading on 30 March 1840. The next section, from Reading to Steventon crossed the Thames twice but was ready to open for traffic on 1 June 1840 although a further 7.25 miles (12 km) extension moved the end of the line to Faringdon Road from 20 July 1840.

Meanwhile work had also started at the Bristol end of the line, where the 11.5 miles (19 km) opened to Bath on 31 August 1840. On 17 December 1840 the London section of the line was extended to a temporary terminus at Hay Lane, west of Swindon and 80.25 miles (129 km) from Paddington. 31 May 1841 saw the main line extended from Hay Lane to Chippenham, but also the opening of Swindon Junction and the Cheltenham and Great Western Union Railway (C&GWUR) to Cirencester railway station. This was an independent line worked by the GWR, as was the Bristol and Exeter Railway (B&ER), the first section of which from Temple Meads to Bridgwater was opened on 14 June 1841. At this time the GWR main line was still incomplete due to the lengthy Box Tunnel, which was finally ready to receive trains on 30 June 1840, from which time through trains ran the 152 miles (245 km) from Paddington to Bridgwater. In 1846 the GWR took over the running of the Kennet and Avon Canal, which offered a competitive route from London via Reading and Bath to Bristol.

The GWR was closely involved with both the C&GWUR and the B&ER, as it was with several other broad gauge railways. The South Devon Railway (which for a time was operated by the “atmospheric” system of propulsion rather than locomotives) was completed in 1849, extending the broad gauge to Plymouth, from where the Cornwall Railway took it over the Royal Albert Bridge and into Cornwall in 1859, reaching Penzance over the West Cornwall Railway by 1867, although this last stretch of line had been built originally using the 4 ft 8½ in (1,435 mm) standard gauge, or 'narrow gauge' as it was known at the time. The South Wales Railway had opened in 1850 and was connected to the GWR via Brunel's Chepstow Bridge in 1852, and was completed to Neyland railway station in 1856.