1 This British Standard specifies clearance dimensions and the positions and heights of fifth wheel attachments fitted to the tractive units of articulated vehicles for the purpose of coupling semi-trailers. It relates to towing vehicles with single rear axles not exceeding 2·5 metres width and to semi-trailers fitted with king pins complying with BS AU 1.
2 The standard applies to vehicles in normal road use and excludes vehicles used under cross-country conditions.
note:*BS AU 1, 'Dimensions of 2 —23/8 in diameter fifth wheel king pin for use with semi-trailer.
BS AU 3:1970 history
0000 BS AU 3:1970(1999)
1970BS AU 3:1970 Specification for clearance dimensions and fifth wheel positions for tractors and semi-trailers