Safety when working on heavy vehicles

Everything on a heavy vehicle is bigger than on a passenger car: the wheels are heavier, the springs stronger, the pressures higher and the parts so large that they can crush or pinch. This means that a safety lapse does not result in a scratch, but in a serious personal injury. Safety when working on heavy vehicles is therefore not an appendix to the trade — it is a prerequisite for being able to practise it for the rest of your working life.

§Heavy parts you lift and support correctly

Wheels, gearboxes, axles and engine parts on a heavy vehicle can weigh many times more than a person can lift. Use appropriate lifting equipment — car jack, overhead crane, transmission lift — and always mechanically support a lifted part or a lifted vehicle with approved stands. A vehicle or part that only rests on a hydraulic lift must never be worked under: if a valve or hose fails, the load falls.

§Compressed air and hydraulics are relieved before separation

Heavy vehicles are full of stored energy in the form of pressure. The compressed air system for brakes and high-pressure hydraulics for tipping, cranes and lifts contain pressure that can blow parts out or spray fluid with great force. Always depressurize the system in the prescribed way before separating anything. A thin stream of hydraulic oil under pressure can penetrate the skin and cause serious injury — never feel for a leak with your fingers, use e.g. a piece of cardboard.

Fixed security principles.

• 01Always mechanically support lifted vehicles and parts with approved stands.
• 02Empty compressed air and hydraulics of pressure before separating parts.
• 03Never separate a spring brake without proper tools and procedure.
• 04Secure the vehicle against rolling with wedges and parking brake.
• 05Use appropriate lifting equipment for heavy parts — don't lift with your back, and have more than one person for the heavy items.
• 06Keep the floor tidy so hoses, tools and spills don't become a fall hazard.

§Wheels and tires on heavy vehicles

A truck wheel is heavy and contains air under high pressure. When assembling and inflating you must use correct equipment and procedure and you must tighten the wheel bolts to the manufacturer's torque after short driving — loose wheel bolts on a heavy vehicle are life-threatening to everyone on the road. Pay special attention to rims and locking rings which can fail if not handled according to regulations.

§Load handling and cooperation

Much work on heavy vehicles requires multiple people or clear communication when lifting and moving large parts. Agree on who does what, keep others out of the danger zone, and use protective equipment according to the task. Safety in a heavy workshop is a team sport: one person's inattention can affect another, so you look out for each other as much as for the vehicle.