Semi-trailer truck
Regional configurations
Most UK trailers are 45 ft (13.7 m) long and, dependent on the position of the fifth wheel and kingpin, a coupled tractor unit and trailer will have a combined length of between 50 and 55 ft (15.25 and 16.75 m). Although the Construction and Use Regulations allow a maximum rigid length of 60 ft (18.2 m), this, combined with a shallow kingpin and fifth wheel set close to the rear of the tractor unit, can give an overall length of around 75 ft (22.
Semi-trailer truck-18