Motor vehicles

Almost nobody in this country assembles cars. What this line of business actually is, here, is bodybuilding: taking a bare chassis and turning it into a tipper, a tanker, a lowbed or a bus, which is steel fabrication with three things bolted on that ordinary fabrication has not got. The first is that a vehicle has to be LEGAL — not merely to specification, but legal on a public road with a policeman entitled to stop it. Gross weight is one number and every axle has its own, and a load placed too far back overloads the rear while the weighbridge total still reads fine; that is the commonest fault in the trade and it is why the weights here are computed by taking moments rather than by adding up a bill of materials. Each axle is judged against the lower of two limits, the law's and the axle maker's, and which one binds is named. The second is that every kilogram of body is a kilogram of payload for the life of the vehicle: a hundred kilos of unnecessary bracing on a tipper doing two loads a day for ten years is six hundred tonnes the customer never hauls, and a bodybuilder who cannot say what his body weighs is selling something he has not measured. The third is that the options on a build sheet are not independent — a tail lift needs overhang to hang from and takes more payload than it weighs because of where it hangs — so the rules are checked at the quotation rather than argued about at the handover. And the whole thing is tested against a weighbridge ticket, because a shop that calculates and never weighs has an opinion rather than a design.