Pre-use check defects and a concrete pour deadline
You begin your shift at 07:00 and carry out the pre-use check on a 1-tonne site dumper you have not operated before. You find three defects. The footbrake pedal feels soft and travels almost to the floor before it bites. The parking brake holds on level ground but the machine creeps when parked on the 1-in-8 ramp by the compound. There is a 40 mm deep cut in the sidewall of a front tyre, and the seat belt has a frayed section about 25 mm long with the fibres showing. The supervisor says the concrete pour starts at 08:00, there is no spare machine, and the defects have probably been there for weeks. The defect book has no entries for the last two weeks.
1. Which of these defects prevent the machine being used, and why?
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All three do.
The brake fault is the most serious: a pedal that goes nearly to the floor means air, a leak or worn components in the system, and braking under load on a slope cannot be relied on. A parking brake that will not hold the machine on a 1-in-8 ramp is a failure – it must hold the machine with its rated load on the specified gradient. A 40 mm sidewall cut is structural: sidewalls flex, and a cut of that depth can lead to a blowout, particularly with a load on rough ground. The frayed seat belt has already lost strength and may fail in a rollover.
None of these is cosmetic and none can be managed by driving carefully. The machine is out of service until each is repaired by a competent person and re-checked.
2. What is the correct defect and isolation procedure?
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Park the machine safely, out of the traffic route and on firm level ground. Lower the skip, apply the parking brake, select neutral, stop the engine and remove the key.
Attach a do-not-use tag naming you, the date and the defects, and make the machine safe so it cannot be started – key out and, where the site uses it, a lock-off. Record all three defects in the defect book or reporting system with enough detail to be actioned. Report to the supervisor and the plant owner in person, not just by note. The machine stays out of service until a competent person has repaired or assessed it, and there is a recorded re-inspection before it returns to work.
Reporting a defect is not permission to use the machine; only a clearance is.
3. The supervisor tells you to take it out and keep the speed down. How do you respond?
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Refuse, politely but clearly, and explain the specific defects and the consequence: the brakes may not stop a loaded dumper on a slope and the tyre may fail. State that the machine is tagged and recorded as out of service and that you are not authorised to remove that.
Offer practical alternatives – a spare machine, a hire, moving the pour, or a different machine for the task – so the refusal comes with a solution. If the pressure continues, escalate to the site manager and the health and safety adviser and use the site procedure for refusing unsafe work. Keep a record of the instruction and your refusal.
The duty not to use unsafe plant sits with you, and a supervisor's instruction does not transfer that duty or provide a defence.