Civil Engineering August 2021 | Vol 29 No 7

50 August 2021 Civil Engineering achievements were an experimental line in Uganda (48 km, from 1923 to 1927); a military line in Morocco (80 km, from 1922 to 1926); and an industrial line at a distillery in Scotland (5 km, 1922 to 1928 or earlier). It is likely that Dutton, far away in South Africa, had little to do with these international endeavours. The economic slump in South Africa after 1918, as previously referred to, was part of a worldwide phenomenon. In 1922 a decision was made in England to host a British Empire Exhibition in 1924 at Wembley in London “as a means of devel- oping the resources and the trade of the Empire” after a “long-drawn-out period of depression and distress”. The South Africa Committee of the British Empire Exhibition had its first meeting on 12 January 1923 where the committee was briefed by Prime Minister Jan Smuts. SAR&H General Manager Sir William Hoy was appointed by Smuts as the chairman of the committee “because he had pushed South African advertisement and propaganda more than any man that he knew of”. Additional to its coordinating du- ties, the SAR&H had its own exhibit at Wembley. In an exterior area there was one of the new electrical locomotives on order for the Pietermaritzburg-Glencoe electri- fication scheme, a new 46-seat dining car which was used as a popular restaurant throughout the exhibition, a first-class main line passenger coach, and a grain wagon. In the interior section there was a full-size model of a Class 12A locomotive in the mouth of the Langsnek tunnel between Volksrust and Newcastle, as well as models of a Class 15C locomotive, a Garratt locomotive, a 100 000 lb hopper wagon and a 100 000 lb bogie wagon. The British Empire Exhibition, with visi- tors and exhibitors from all over the world, offered a great marketing opportunity to Roadrails Ltd. They first built a single line in 1922 winding through the exhibition area which was used as a construction line. This was eventually broken up and replaced with an eye-catching demonstration loop in a new position which would carry thousands of passengers – reputedly including the British king and queen – past the South Africa Pavilion during the exhibition itself. The loop was slightly longer than 1 000 m and had a turning circle on each end with a radius of 48 m. Dutton was granted four months leave of absence from April 1924 to proceed to England to oversee the preparation and initial running of the dem- onstration line. A London journal carried this description: Increased attention is being focussed on the Dutton road-rail, which is proving a unique feature of the transport facilities of the Exhibition. The track half-circles the Exhibition grounds, with a halt at the South African Pavilion. The rails are laid over the natural unprepared surface, and consequently the curves and gradients – the steepest of the latter is 1 in 18 – constitute a severe test of efficiency. The tractors at present are for freight purposes, but are pulling from five to seven passenger coaches, carrying 30 to 50 passengers each. Several different tractors were used at the Wembley roadrail, powered by either steam or petrol engines and mostly supplied by William Beardmore and Company (who had acquired a controlling interest in Roadrails Ltd in 1921); an ex- ample is shown in Figure 11. The roadrail schedule allowed for departures every six to ten minutes and was reported to have carried 350 000 people during the 21-week 1924 season. Originally, the exhibition was intended to run during 1924 only, but its success led to a second season in 1925. For reasons unknown, the roadrail loop did not reopen for the 1925 season. At the time of the British Empire Exhibition, the SAR&H was already plan- ning to build its first experimental roadrail line, 34 km long, from Naboomspruit to Singlewood to serve an underdeveloped ag- ricultural area. The Singlewood Experiment will be the focus of a second paper to follow. ABOUT FRANK DUTTON Frank H Dutton was born in 1872 in Worcester, England, the son of Samuel Telford Dutton who is remembered as a pioneering railway signal engineer. Samuel founded a business, Dutton & Co Ltd, for the invention and manufacture of railway signalling equipment for British and export markets. As a schoolboy, Frank spent much time there observing the making and testing of the equipment. On growing up, he served as pupil engineer in his father’s business where he worked in the workshop and drawing office, as well as gaining clerical and construction experience. At the age of 25, Frank left for India and Ceylon where he supervised the installa- tion of signalling gear on various railways. During this time, he sailed by boat to the Maldives (then largely untouched by the outside world) of which he published an entertaining account a decade later in the South African Railways Magazine . At the turn of the century, Dutton & Co amal- gamated with Saxby & Farmer. Dutton moved to South Africa in 1902 at the time of the Anglo-Boer War to join the Imperial Military Railways. After the hostilities of the war ceased, Frank was ap- pointed in June 1903 by Sir Percy Girouard, the railway commissioner, as signal engi- neer of the Central South African Railways (CSAR). From 1907, Dutton was responsible Figure 11 Roadrail tractor with passenger wagons at the British Empire Exhibition at Wembley (Credit: THL N90074_41)