Defect Found at the Pre-Start, Pressure to Keep Working
At the start of the shift you complete the pre-start inspection. You find: (1) the left rear tyre has a deep sidewall cut about 40 mm long, with the cord not visibly exposed but the cut is open; (2) the boom lift cylinder has a light film of oil around the gland, with no drips on the ground; (3) the reverse alarm sounds intermittently when you test it, working about seven times out of ten; (4) the load chart placard in the cab is faded but the figures are still legible. The machine is needed for a hot-shot container movement in 30 minutes and the supervisor says 'the tyre's fine, it's not flat - just get it done and we'll look at it tonight.'
1. Classify each defect and state whether it is a stop-work item, and why.
Read the worked answer
1. Tyre sidewall cut (40 mm, open, cord not exposed). Sidewall cuts are a stop-work item until assessed. The sidewall flexes under load and a cut is a stress raiser; at 9.5 kg/cm² contact pressure and 48 t machine mass, a sidewall failure under a loaded front axle can cause loss of control or a tip. 'Not flat' is not the test - structural integrity is. The tyre must be inspected by a competent tyre person and either passed in writing or replaced.
2. Boom cylinder gland oil film, no drips. This is a monitor-and-report item, not automatically a stop. A light film can be normal weeping, but it can also be the start of a seal failure. It must be recorded, the level checked, and the area cleaned and re-checked at intervals. If it becomes drips or the boom drifts under load, it becomes a stop item.
3. Intermittent reverse alarm. Stop-work item. A reverse alarm that works 7 times in 10 is a failed alarm. Pedestrian safety in this yard depends on the alarm; an intermittent alarm gives a false sense of security and is worse than none because people rely on it. It must be repaired before reversing operations.
4. Faded load chart placard, legible. Report and rectify, not a stop - provided the figures are genuinely legible and match the machine's configuration. If there is any doubt about legibility or that it is the correct chart for the attachment, it becomes a stop item, because the chart is the basis of every lift decision.
2. The supervisor's instruction is to work and fix it tonight. What do you do, and how do you record it?
Read the worked answer
I do not operate. Two of the four items - the tyre and the reverse alarm - are stop-work items, and the supervisor's 'it's not flat' reasoning addresses the wrong failure mode. A sidewall cut does not need to be leaking to fail; the alarm failure is a direct pedestrian risk in a yard where people walk behind machines.
What I do:
- Isolate the machine - park it safely, apply the park brake, lower the attachment, and tag it as out of service with the defects listed.
- Report in writing - complete the defect report with each item, the classification, and the reason. Give a copy to the supervisor and the maintenance planner.
- Offer a path forward - the hot-shot movement can be done by another machine, or the tyre and alarm can be assessed/repaired now. A 30-minute delay is cheaper than a sidewall blowout or a pedestrian struck by a reversing machine.
- Escalate if directed to operate - if the supervisor insists, I record the instruction, my objection and the reasons, and refer it to the site safety contact. I do not operate a machine with a failed reverse alarm in a yard with pedestrian traffic.
- Clear the tag only when the defects are rectified and signed off, and record the clearance.