Safety equipment, checks and vehicle condition
What this domain tests
The exam tests daily inspection, trailer-specific equipment, and your ability to identify a defect that makes the combination unroadworthy. A defect on the trailer is just as serious as one on the lorry.
Daily walk-around
Check tyres, lights, mirrors, number plates, brake lines, coupling, breakaway cable, jockey wheel, and load securing. Look for cuts, bulges, and objects trapped between twin tyres. Test brake lights, indicators, and hazard lights with a helper or reflection. Check that the trailer handbrake releases fully and that the wheels turn freely.
Tyres and brakes
- Minimum tyre tread depth is 1.6 mm across the central three-quarters of the tread for the vehicle and trailer.
- Check tyre pressures cold; incorrect pressure affects stability and fuel use.
- Listen for air leaks on air-braked trailers and check that the brake system reaches operating pressure.
- An ABS warning light that stays on indicates a fault; do not ignore it.
Equipment and documents
Carry a warning triangle and place it according to the situation. Know where the first-aid kit and fire extinguisher are if your operator supplies them. Keep registration, insurance, and tachograph records available. The trailer must have its own registration and plate.
Worked example
During the walk-around, a trailer tyre measures 1.5 mm tread on the central tread. The driver reasons that the lorry tyres are fine and the trailer is only lightly loaded. Correct answer: the trailer tyre is below the 1.6 mm minimum and the combination is illegal. The trailer must not be used until the tyre is replaced, regardless of load.
Traps that cost marks
- Checking the lorry but not the trailer.
- Forgetting the breakaway cable and electrical connection.
- Ignoring an ABS warning light.
- Accepting a tyre at 1.5 mm because it is on the trailer.
- Not checking that the coupling locking indicator is engaged.
- Loading the trailer before checking lights and brakes.