The transportation of large dimension and heavy loads which cannot be moved by rail has generated a requirement for acceptable hauling methods and vehicle specifications. Regulations affecting weight and load distribution have influenced the design of specialized trailers and vehicles for abnormal load hauling. Restriction on the loading of the hauling vehicle's drive axles limits the tractive effort and the ability to move the load, which necessitates the requirement for multiple hauling tractors. Tractor and trailer combinations utilising as many as four hauling vehicles are featured in the requirements for the transportation of up to 400 ton loads.THE DESIGN OF VEHICLES for the movement of abnormal loads will be confined to the requirements of the South African Railways (S.A.R.) for operation throughout the Provinces of South Africa: Cape Province, Natal, The Orange Free State, Transvaal, and South West Africa. The administration of these provinces, in recognition of the requirements for the transportation of indivisible heavy loads over public highways, has collectively established recommendations for the conveyance of abnormal loads. Equipment such as electrical transformers weighing up to 400 tons and reactors for chemical plants measuring over 6 metres (20 ft.) in diameter and over 50 metres (160 ft.) in length are being contracted for movement to inland installations as the development of these provinces increases. For each load to be transported, separate exemption permits are issued by each province through which the vehicle will proceed. The administration recommends that before any abnormal load vehicle is purchased, imported or constructed, prior permission is to be obtained to ensure that any such abnormal vehicle will be granted authority to operate on public roads. Although the safety of the public along the route and through villages and cities is of great concern, and requires careful policing and planning for travelling when traffic is least congested, the text of these regulations for the conveyance of abnormal loads will apply principally to weight and load distribution.