Civil Engineering October 2021 | Vol 29 No 9

48 October 2021 Civil Engineering by Britannia Engineering Works, with two views shown in Figure 12. As construction winded down, the daily operation of the Singlewood line had to be transferred to another department. Who should be put in charge? For regular railway lines, operations would default to the relevant SAR&H division. The operations of the SAR&H had been decentralised into eight divisions since its inception, each operating with a great degree of autonomy. A case could therefore be made that the Singlewood line, given its partly commercial nature, should be operated by the Pretoria Division. But the line was also experimental in nature, which logically suggested that its developer, Dutton, should be closely involved with its operation, monitoring and on-site modifi- cations if necessary. Ultimately, Hoy tasked the district superintendent of the Pretoria Division to take full charge of operating the line. This was a fateful decision, one that was later admitted by two senior railway officers to be a mistake: [It is suggested that] the working of the line for first twelve months should be organised upon an entirely different system to that under which the Naboomspruit experiment was conducted. Lines of this nature form a departure from orthodox railway working and it would probably be better to treat same as an ordinary transport feeder to the main line until such time as conditions became normal, and the whole then handed over to the Divisional Officer. From the available information, it appears that there was an uneasy relationship be- tween Dutton and the district superinten- dent. Dutton later wrote that he received a letter from the district superintendent with an antagonistic request: … that I should have nothing more to do with the roadrail as it was on his [Pretoria] Division. Since then I have accordingly only dealt with any correspondence on the matter that has been referred to me and I may say this has been remarkably little and even so in most cases I find my recommendations were not adopted. After the Pretoria Division took over, matters took a turn for the worse. There seemed to be no attempt to keep the trac- tors in good working order. The tractors were not in proper mechanical order when the line was opened and their planned overhaul before being placed in regular service never happened. Furthermore, RR1155 was considered to be the only one “of real value for open line working” due to its reversibility. This alarming state of affairs prompted Dutton to act, as he recalled a few months later: I foresaw there would be shortage of engine power and in December 1924 I then recommended the purchase of an additional tractor, and also that the two old tractors that had done 18 months rough work on construction should be brought in and thoroughly overhauled before the maize season started. Neither of these recommendations were acted upon and today with the rush season on them, there is only one tractor run- ning (and that the least useful one).… The lack of maintenance finally came home to roost and RR973 had to be sent to the Germiston locomotive workshop for major overhaul on 18 February 1925. It was re- turned six weeks later on 30 March. Three weeks later, on 27 April, RR1155 followed to the workshop and was only returned to site 13 weeks later on 27 July 1925. It was not explicitly stated why these overhauls took so long. It might indicate the severity of the wear and tear of the tractors, but still seems inordinately long for a well-equipped workshop with spares on hand. The provision of passenger service, part of the original plan, also ran into me- chanical difficulties, but through no fault of the Pretoria Division. The regular road- rail schedule ran at an average of 10 km/h, not much more than walking speed. Passenger service needed to be faster and thus self-propelled, and for this Dutton had a red bus body fitted to an FWD lorry adapted to run on the roadrail line. Part of the Singlewood experiment was to compare gas with paraffin as its propel- lant. To this end, a Parker gas production plant, producing gas from charcoal, was fitted to the paraffin-propelled “Scarlet Pimpernel” to allow the use of either. The gas plant initially seemed to work well and economically – on its trip of 240 km by road from Johannesburg to Naboomspruit, it consumed only three bags of charcoal costing six shillings.Once on site, however, the gas option disappointed. It was blamed on a driver not experienced in working the gas production plant, which was too small anyway, and required a large load of charcoal to be taken on board. Paraffin was more successful with a round trip to Singlewood completed in 3 hours 37 minutes of running time at an average speed of almost 20 km/h. After two further mechanical failures (fractured crankshaft and trouble with big end bearings), the passenger bus experi- ment came to an end, its function taken over by regular roadrail wagons which had meanwhile been converted for pas- senger travel. Passenger transport, with no statistics found up to now, was unlikely to have been an important part of the roadrail operation. By the end of May 1925, the shortage of hauling power became critical. RR973, the only tractor running while RR1155 was in the shops, could only haul a load of about 60 tonnes. Any failure on its part would cause a complete breakdown in service. Both tractors would have to be on site, working continuously, to clear the projected maize production for the up- coming harvesting season of 932 tonnes/ month in June; 2 238 in July; 2 484 in August and 1 232 in October. But with RR1155 away and RR973 so difficult to shunt, “… it was decided to strengthen the track and utilise a Lawley steam locomo- tive that formerly worked the Pankop line instead of working the tractors.” Although not explicitly stated, the likely modifica- tions to the roadrail track were: Q Q The radius of the turnout curve at the Naboomspruit station, which was built with a radius of 15 m, was referred to in a subsequent report to have a radius of 46 m. Q Q Extra sleepers were added to the line to compensate for the heavier locomo- tive. Why would the recovered Pankop rail sets, which carried the same locomotive successfully on the Pankop line, not be considered adequate on the Singlewood line? Mention was made earlier of a difficult 10 km “black turf” section, which might have been the section where the extra sleepers were added as a precaution. Q Q The causeway over the Nyl River, which was left partially incomplete due to lack of funds, was completed. Dutton wryly commented that “once the line was put