He designed several different 7 ft 1⁄4 in (2,140 mm) broad gauge types for the growing railway, such as the Firefly and later Iron Duke Class.

In 1864 Gooch was succeeded by Joseph Armstrong who brought his standard gauge experience to the workshops at Swindon.

Joseph Armstrong's early death in 1877 meant that the next phase of motive power design was the responsibility of William Dean, his assistant and successor.

Dean went on to develop express 4-4-0 types, but the familiar 4-6-0s of later years were initially introduced by the next engineer, George Jackson Churchward.

He was also responsible for the introduction of self-propelled Steam Rail Motors for suburban and light branch line passenger trains.

Next came Charles Collett in 1921; he standardised the many types of locomotives then in service, producing the iconic Castle and Kings.

[7] In order to meet his demands some novel ideas were tried such as the Haigh Foundry's geared locomotives and TE Harrison's Hurricane and Thunderer which had the engine and boiler on separate chassis.

[8] The two Star class locomotives were not designed to meet Brunel's specifications – they were bought from Stephenson's surplus stock after another railway had been unable to pay for them.

The most familiar from this period are the Iron Duke Class with their 8-foot (2.44 m) driving wheels, a type that operated express trains right up to the end of the broad gauge in 1892.

[8][10] With the acquisition of the northern standard gauge lines in 1854 came 56 locomotives, a second workshop at Wolverhampton, and Joseph Armstrong.

At the same time some 69 class passenger locomotives were built by Beyer, Peacock and Company in Manchester so were able to be transported on their own wheels.

By the time that Armstrong replaced Gooch at Swindon in 1864 many more locomotives had been acquired with the Birkenhead and West Midland Railways.

[12] Broad gauge Standard gauge After his brother was promoted to Swindon, George Armstrong took his place at Wolverhampton and for the next 33 years continued to repair, rebuild and build standard-gauge locomotives in a spirit of independence from Swindon, just as Joseph had done during his own ten years at Wolverhampton.

Joseph Armstrong's early death in 1877 meant that the final phase of broad gauge motive power was the responsibility of William Dean.

He continued the Iron Duke renewal programme and added more convertibles, including some of Armstrong's 388 class goods locomotives.

[15] After his appointment as Locomotive Superintendent in 1902 he developed a series of standard locomotive types with flat-topped Belpaire fireboxes, tapered boilers, long smokeboxes, boiler top feeds, long-lap long-travel valve gear, and many standardised parts such as wheels, cylinders and connecting rods.

[16] Experiments had already been made for a 4-6-0 design while Dean was still in charge, and these continued under Churchward; the first 4-6-0, number 100, appeared in 1902 as the initial prototype of what became the Saint class.

These experiments moved the GWR towards using four cylinders and they even tried a 4-6-2, 111 The Great Bear which was the first locomotive of this type in the United Kingdom.

[18] Other innovations during Churchward's office included the introduction of self-propelled Steam Rail Motors for suburban and light branch line passenger trains.

[20] He also remodelled Swindon Works, building the 1.4 acres (0.57 ha) boiler-erecting shops and the first static locomotive-testing plant in the United Kingdom.

Collett further developed the 4-6-0 type as the ideal GWR express locomotive, extending the Stars into Castles in 1923, and then producing the largest of them all, the four-cylinder King class, in 1927.

Some were configured for long distance express services with buffet counters, others for branch line or parcels work, and some were designed as two-car sets.

Opened on 6 March 1865, the line was worked by the contractor Waring Bros until 1869 when the company was left to make its own arrangements.

GWR experimental 4-4-0ST number 13 was also regularly used on the line, at first hired to the Liskeard and Caradon, but it continued to be used after the Great Western Railway took over operations.

Re number 1361 – An extant photo exists in the SLS Stanford Jacobs Collection showing 1361 to be Pembroke.)

Withdrawal of ex-GWR locomotives took place earlier than for the other 'Big Four' companies as the Western Region took the decision to be the first to end steam traction.

[23] More than 140 Great Western locomotives (including some designed by the GWR but built by British Railways) have been preserved.

Nine pre-grouping locomotives that were absorbed into the GWR in 1923 are known to survive: Three locomotives of 1 ft 11+3⁄4 in (603 mm) gauge were acquired from the Vale of Rheidol Railway as part of the Cambrian Railways at the grouping, but only one survived to be privatised from British Rail in 1989: Two more, similar to no.

[36] More recently, a number of other GWR engine classes have been or are being reconstructed, often taking advantage of the strong standardisation of the Swindon designs to use spare parts from other types.

93 is included as 'new build steam', as the power bogie was constructed from scratch; however, the remainder of the coachwork was an original railcar, preserved as noted above.