Civil Engineering August 2021 | Vol 29 No 7

Civil Engineering August 2021 45 H i story and her i tage A round 1915, an unusual idea was proposed by Frank Dutton, an engi- neer of the South African Railways and Harbours Administration (SAR&H): a hybrid system of running a conventional train on narrow, light tracks but being drawn by a rubber-tyred tractor instead of a steam locomotive. Such “roadrail” lines, he suggested, could stimulate agricultural de- velopment in rural areas by linking them to the main railway lines. Moreover, they could be cheap enough to be operated profitably in areas where conventional branch lines would be making a loss. This first paper tracks the initial de- velopment and demonstration of roadrail from the first proposals up to the 1924 British Empire Exhibition in London. The second paper will deal with the first and only full-scale roadrail experiment performed on South African soil. EARLY TRANSPORT DIFFICULTIES IN SOUTH AFRICA After a slow, tentative start in 1860, South African railways took great leaps after the establishment of two mining develop- ments in its deep interior, far away from the coastal cities. After the discovery of diamonds in 1876, the first railway lines rapidly converged on Kimberley from the harbours at Cape Town, Port Elizabeth and East London. When the discovery of gold at the Witwatersrand followed in 1886, the harbours at Lourenco Marques and Durban joined them in the fray for the “Race to the Rand”. As a result, the major parts of the early railway network were essentially long- distance bulk freight lines built to meet the needs of the mining industry. Naturally, smaller communities and farmers within reasonable distance of the railway routes soon lobbied for con- nections to the railways. Their political pressure, along with government’s desire to diversify the mostly mining-driven economy to include agricultural and industrial development, resulted in the construction of numerous branch lines. Branch line construction followed a typical pattern. A town with its sur- rounding farming community would peti- tion for a line with optimistic estimates of agricultural produce that would follow the construction of the line. However, after construction of the line the projected freight volumes failed to materialise. Moreover, agricultural production being highly seasonal, farmers reverted to using their own animal transport instead of the railway during the idle season. In the words of an observer around 1920: The glowing accounts of the produc- tiveness of the district, and the enor- mous amount of traffic promised if only a railway is built, in many cases seem to vanish into the air as soon as the line is built . The financial losses incurred on most branch lines sustained a debate which raged for years. Should the government, in addition to long-distance lines with standard gauge, provide lighter narrow- gauge, or even standard gauge lines for pre- dominantly agricultural transport with low volumes? While the “battle of the gauges” was ongoing, numerous branch lines were constructed all over South Africa. The approval of further narrow-gauge lines was eventually withdrawn in the interest of uniformity and to eliminate transshipping at points where the different gauges met. But even these lighter, cheaper lines often did not live up to expectations and mostly failed to turn a profit. Herbert Frankel, one of the leading development economists of the 20 th century and pro- fessor at Oxford University from 1946 to 1971, published his doctoral dissertation in 1928 on “The Railway Policy of South Africa”. It included a scathing analysis of 14 branch lines in operation in 1926 and showed that only one line turned a small profit, while the other 13 lines suffered heavy nett losses. He blamed the problem firstly on the estimates presented to Parliament, which were “couched in the vaguest possible terms, and containing astoundingly inaccurate estimates”. Secondly, the parliamentary debating “… has become a matter of annual com- petition … for the favours of a Minister cajoled and threatened by large numbers of politicians, each clamouring for a line in his own constituency…”. Frankel’s analysis of branch lines was only a small part of South Africa’s overall railway policy. At the same time, railway engineer Frank Dutton dug deeper into the economics of branch lines specifically. He analysed numerous branch lines as well as main lines and noted that the operating cost per tonne-mile on branch lines was in some cases sixteen times as much as the cost per tonne-mile on the heavily trafficked lines. To ensure profit- able operation, Dutton eventually devel- oped the following guideline in terms of the tonnage of freight carried: Q Q Up to 600 tonne/month: These low freight volumes did not warrant rail transport in any form. For heavy, bulky objects, animal transport would suffice; smaller parcels and passengers could be moved with smaller road vehicles. Q Q 600 to 4 000 tonne/month: Railway branch lines could be profitable, but only if their construction cost could be drastically reduced to less than £1 000/mile. Historical roadrail: from idea to international demonstration This article forms Part 1 of a two-part series which explores the history of roadrail, from its rise and early successes to its eventual demise. Part 2 will be published in a later issue of Civil Engineering .