The Great Western Railway Super Saloons were eight railway carriages developed to service the boat train traffic from London to Plymouth. Built to the maximum loading gauge to be more opulent than the rival Pullman Company coaches offered by rival railway companies, and all named after members of the British Royal Family, their success was short-lived due to the onset of the Great Depression of the 1930s. Taken out of service by British Rail in 1967, today five of the original carriages survive in preservation.^[1]

The original backers of the GWR had adopted Isambard Kingdom Brunel's plan to speed trans-Atlantic Ocean passage for both passengers and freight by providing a direct route from London westwards to the connecting ports located in the West Country and Wales. However, many of the financial backers were based in Bristol, itself a major port, and so although the company eventually developed Brunel's plan, the only major high-speed railway connection was eventually developed to Plymouth.^[1]

Post-World War I and with the United States now economically booming, new developments in Ocean Liner design and construction brought about new, faster ships with more luxury capacity. These nouveau-riche first-class passengers were used to speed, quality and service; mixing with commuters and third class passengers, let alone mail and freight, was not what they wanted. What the new passengers required were high-speed dedicated boat train services.^[1]

As a result, from the mid-1920s a new race to attract the Ocean Liners and hence these passengers began between the Southern Railway and the GWR. Although the GWR had access to Southampton Docks via a circuitous route, the company decided to instead focus on developing services from Plymouth. Effectively, this would save ocean liners 6 hours of steaming in the crowded English Channel, and reduce the overall travel time by 4 hours.^[1] By 1930, 684 liners had landed 38,472 passengers at Plymouth, with the vast majority being trans-Atlantic customers who then needed transport to London.^[2]

In 1929, under the auspicies of Chief Mechanical Engineer Charles Collett, the GWR board agreed development from 1929 of a new, bigger carriage for the Ocean trains. Due to the GWR's original adoption of broad gauge, its loading gauge using standard gauge track was larger than any other mainland UK railway. This allowed the company to develop a larger bespoke carriage to its own dimensions, which would be wider than the Pullman saloons then in operation on both the Great Western and Southern Railways.^[1][4]

Collett made full use of the loading gauge advantage, designing a basic carriage shape that was 61 feet 4.5 inches (18.707 m) in length and 9 feet 7 inches (2.92 m) wide—a full 7 inches (180 mm) wider than a standard British loading gauge carriage.^[1][4] The result was that the Swindon Works designated "Super Saloons"—which also became known as "Ocean Saloons" and "Cunarders" in service operation—were restricted to the mainline of the GWR that had been originally developed as broad gauge.^[1][4] Hence, each carriage had painted on its end plate:^[1][4][5]

Not to run over the Eastern and Western Valleys, North of Saltney Junction or between Littlemill Junction and Maindee Junction.

Collett had also designed-in a clearance insurance policy, by designing the carriages with inset end doors which were angled at 30 degrees to the exterior body panels.^[1][4]

All Super Saloons were built within Swindon Works Lot No. 1471,^[1][4][6] the first two carriages fitted out by specialist contractor Trollope & Co. under Diagram G.60 in 1931,^[1][4] whilst the remaining six were all fitted out by the Swindon Works Saloon Gang under Diagram G.61 in 1932.^[1][4] Initially the windows were of a wind-down Beclawat type, but these were replaced in 1935 by fixed windows of more modern type with sliding vents.^[1][4] Once the exterior was completed, each of the carriages was fitted-out with fine French-polished light-coloured walnut, with book-matched burr veneer panels on the interior sliding doors and fold-down tables, outlined with gold-leaf hairlines.^[1][4][6] Each carriage was then equipped with 30 loose (but heavy, to prevent them from moving during the journey) wing-back chairs: 26 in saloon; 4 in coupé.^[1][4] The complete run of eight carriages, all named after members of the British Royal Family were as opulent as the Pullmans they replaced, and had an unladen weight of 35 long tons (36 t).^[1][4][7]

With the Super Saloons now fully available for traffic, the lease on the seven Pullman cars was terminated at the end of 1931, and these were transferred to the Southern Railway, joining the SR's Western Section carriage pool at Clapham Junction.^[3] The legacy of the Super Saloons included Collett's 1935 development of the new "Centenary" carriages built for the Cornish Riviera Express, which again made full use of the wider loading gauge on that route.^[4]

Introduced in 1931, the Ocean Liner Express ran non-stop in each direction between London Paddington and Plymouth Millbay. Passengers were charged a full first-class fare as appropriate for their journey, plus a one-way tariff of 10 shillings to use the carriages.^[1][4][5]

Due to their weight, commonly only five Super Saloons were operated in one train at any one time, together with two passenger brake vans to accommodate passengers' luggage.^[1][4] Often, the trains were reduced to three Super Saloons and two passenger brake vans, allowing the train to run at higher speed.^[1][4] The Ocean Liner Express was always banked both ways over the Devon and Wellington Banks.^[1][4]

Five of the eight Super Saloons have survived into preservation: