Defects found during the depot walk-around
At 05:10 in a Riyadh depot, a driver starts the walk-around inspection of a 6x4 tractor unit before hooking up a loaded trailer. He finds: the near-side steer tyre has a bulge the size of a fist on the sidewall and a 40 mm cut; a soapy-water test on a rear brake chamber shows bubbles at the diaphragm joint; the ABS warning lamp stays on after the self-test; and air pressure builds from 0 to cut-out in 6 minutes, while the workshop spec says within 4 minutes. The defect book contains an earlier entry for the same tyre marked 'monitor'. The dispatcher says the load must leave in 20 minutes and the workshop is not open until 07:00.
1. For each finding, state whether it is a reason not to dispatch, and explain why.
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Steer tyre with a fist-sized bulge and a 40 mm cut: no dispatch. A bulge means the sidewall cords have separated, and a steer tyre failure at highway speed can take away steering control. The earlier 'monitor' entry does not make it acceptable; it shows the defect has been known and left.
Brake chamber bubbling at the diaphragm joint: no dispatch. Air is escaping, so the system will not hold pressure, and that wheel brake may be weak or dragging. Combined with the slow build-up, this is a clear fail.
ABS lamp staying on after self-test: not roadworthy until diagnosed. The basic service brakes still work, but ABS is disabled, so wheel-lock and jackknife risk rise on a slippery or unladen surface.
6 minutes from 0 to cut-out against a 4-minute spec: the compressor, governor or a leak is out of specification. On its own this warrants investigation; with the chamber leak it confirms the vehicle should not leave the yard.
2. What should the driver do, in what order, and what should be recorded?
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Order of actions: stop the inspection, do not sign the vehicle as roadworthy, and record every defect in the defect book with the tyre position, the chamber location, the ABS lamp and the measured build-up time. Photograph each one. Then report to the dispatcher and transport manager, book the unit into the workshop for 07:00 or call out a fitter, and ask for a spare unit or a delayed departure.
The vehicle stays parked - a vehicle-off-road defect - and he should not hook up the loaded trailer. After repair, re-inspect: new steer tyre, chamber replaced, ABS fault cleared, and a build-up test within 4 minutes. Only then sign the inspection sheet. The record matters because it shows the defect was found before the journey, which protects the driver and puts the decision on the company.
3. The dispatcher says to take it anyway and 'just drive slowly'. How should the driver respond?
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He should refuse and explain the specific defects: a separated sidewall on a steer tyre can burst at any speed, and slowing down does not repair it; an air leak can worsen and the spring brakes may apply without warning; a disabled ABS reduces control under braking. Slow driving reduces but does not remove these risks, and it does not make the vehicle legal.
He should ask for the instruction in writing if the dispatcher persists, then escalate to the transport manager or fleet engineer. The driver has a legal duty not to operate an unroadworthy vehicle, and refusing is the protected course. He should note the time, the name of the person giving the instruction and his refusal in the defect record. If no replacement unit is available, the load waits until the tractor is repaired and re-inspected.