Development of Mk 2 HVS
Van Vuuren and his team provided the impetus for this innovation. By 1970 a prototype mobile HVS had been planned, supported by the SA Department of Transport ( DoT ), and was under construction. This machine, dubbed the Mark II, was commissioned towards the end of 1970 and began accelerated testing on road S12 between Johannesburg and Witbank in March 1971. The prototype machine completed 24 tests during the first five year operational period, and some 1.8 million load repetitions (corresponding to approximately 12 million equivalent standard axle loads) were applied in the first year of operation alone. Even prior to this five year review, the benefits arising from the HVS were clearly regarded as significant: motivations for the manufacture of three new production machines of improved design were made in 1972. machines of improved design were made in 1972.
These were funded respectively by the SADoT , the then Transvaal Provincial Administration or TPA (now the Gauteng Department of Transport and Public Works) and the NIRR. Part of the motivation for obtaining the TPA HVS Mk III machine was to investigate the poor performance of the relatively new route S12 which links Johannesburg to the Mpumalanga coal fields. This made the TPA the first provincial road authority in the world to own a mobile, full-scale APT machine