145General coupling requirements

145 General coupling requirements (1) A fifth wheel coupling, the mating parts of a coupling, a kingpin or a towbar must not be used for a load that exceeds the load rating specified by the manufacturer. (2) A kingpin must be used only with a fifth wheel coupling that has a corresponding jaw size. An adaptor must not to be used to fit a kingpin to a fifth wheel coupling. (3) The mating parts of a coupling used to connect a semi-trailer to a towing vehicle must not allow the semi-trailer to roll to an extent that makes the towing vehicle unstable. 146 Drawbar couplings (1) A coupling for attaching a trailer, except a semi‑trailer or pole‑type trailer, to a towing vehicle must be built and fitted so— (a) the coupling is equipped with a positive locking mechanism; and (b) the positive locking mechanism can be released regardless of the angle of the trailer to the towing vehicle. (2) If the trailer is in a combination and is not fitted with breakaway brakes in accordance with clause 127(2) of this Schedule, it must be connected to the towing vehicle by at least one chain, cable or other flexible device, as well as the coupling required by subclause (1). (3) The connection must be built and fitted so— (a) the trailer is kept in tow if the coupling breaks or accidentally detaches; and (b) normal angular movement of the coupling is permitted without unnecessary slack. (4) If practicable, the connection must be built and fitted so the drawbar of the trailer is prevented from hitting the ground if the coupling accidentally detaches. (5) For the purposes of subclauses (3) and (4), a connection between a trailer and a towing vehicle includes anything which connects the trailer and the towing vehicle. Examples of a connection between a trailer and the towing vehicle include— (a) chains; or (b) cables; or (c) a thing fixed to a trailer or a towing vehicle to which a chain is attached; or (d) shackles.