Section 255 in The West Bengal Motor Vehicles Rules, 1989
255. Special rules applicable to trailers.
(1)in order to prevent a goods vehicle from running backward on slopes, or otherwise to render it immobile. every such vehicle, not being a light motor vehicle, shall be equipped with two wedge-shaped rigid chocks, each measuring 30 centimeters in length, 30 centimeters in breadth and 254 millimeters in height, with one of its sides having a slope making an angle of 45 degree at the end. The plane surface of the sloped side of each chock shall be rendered concave so as to fit the outer circumference of the tyres normally fitted to the rear wheels of the vehicle.(2)Notwithstanding anything contained in sub-rule (1) where such vehicle is fitted with single rear wheel the breadth of each such chock may be less than 30 centimeters but not less than 15 centimeters.(3)Each such chock shall have a hook and be kept, -(a)in a bracket fitted on the outer skirt of the tail-board of the vehicle; or(b)where the vehicle has no tail-board, in a metal carrier fitted between the frame side members, underneath the body nearest to the rear wheel on either side. The tail-board of the vehicle and where the vehicle has no tail-board, the wooden planks above the frame side members shall also have a hook in the centre.(4)Each such chock shall be linked with the tail-board or, where the vehicle has no tail-board, with the wooden planks above the frame side members, by means of a metal chain or steel wire rope of sufficient length and strength, fastened to the hook in the chock and to the hook in the tail-board or the wooden planks, as the case may be.(5)No person shall use any boulder or any substance of similar nature in lieu of wooden chocks on slopes or otherwise to prevent the goods vehicle other than, light motor vehicle, from running backward on slopes to render it immobile otherwise.(6)Notwithstanding anything, contained in this rule, the State Government may, by notification in the Official Gazette, exempt from the provisions of this rule, any goods vehicle or class of such vehicles which in its opinion are not likely to slip backward on slopes.
