Dozer Daily Check After a Dusty Night Shift
At 06:00, a crawler dozer returns from a 10-hour night shift on a dusty earthworks site in Kuwait. The operator's daily walk-around finds: engine oil at the LOW mark; coolant below the cold line; the air-filter restriction indicator locked in the red zone; the left track sags 40 mm more than the right; the tilt-cylinder hose has a damp patch and one frayed wire; the brake pedal travels about 60 mm before resistance; the park brake holds on a slope; the horn does not sound; the seat-belt webbing is frayed through 15 mm; the fire extinguisher gauge needle is in the red; and the last three daily inspection sheets are unsigned. The machine is booked for a 07:00 compaction start. The supervisor says, 'Top up the oil and run it; we will fix everything at the weekend.'
1. Sort the findings into stop-work/out-of-service, rectify-before-shift, and monitor. Justify each decision.
Read the worked answer
Out of service until repaired:
- Air-filter restriction indicator in the red: the engine is being starved of air or dust is passing the filter. Running it risks piston and ring damage; the filter must be serviced and the indicator reset.
- Tilt-cylinder hose damp with a frayed wire: a pressurised hose can burst, dropping the blade or spraying hot oil. Replace before operation.
- Brake pedal 60 mm travel: excessive travel suggests air, wear or a linkage fault. The brake must be tested and repaired; a dozer that will not stop is not fit for work.
- Horn inoperative: it is a required warning device on a machine with poor operator visibility.
- Seat belt frayed through 15 mm: the restraint may fail in a rollover. Replace.
- Fire extinguisher gauge in the red: the extinguisher is not serviceable.
Rectify before shift: engine oil and coolant below limits. Top up only after checking for leaks, because low oil may indicate a leak or burning. Left track 40 mm slacker: adjust and inspect idler, sprocket and pins. Park brake holding on a slope is acceptable, but record the test.
Monitor: none of the above should simply be monitored. The unsigned sheets are a documentation nonconformance, not a machine defect, but operation should not begin until a competent person signs the inspection.
2. How should you respond to the supervisor's instruction, and what defect-reporting process should be followed?
Read the worked answer
I would refuse to operate and explain the specific reasons: the air filter, hose, brakes, horn, seat belt and extinguisher are safety-related defects. 'Top up the oil and run it' treats a symptom and leaves the machine unsafe. Topping up can also hide a leak or excessive consumption, and the air-filter indicator will not clear itself.
The process is: stop the machine, isolate it, and attach a clear 'DO NOT OPERATE' tag with the date and your name. Record every defect on the daily checklist, including the location and severity, and hand the sheet to the supervisor and maintenance. Raise a job card for each stop-work item and keep a copy. The machine is released only when maintenance signs off the repairs and a competent person completes a fresh inspection.
If the supervisor insists, I would escalate to the site HSE officer or manager. Refusing to operate an unsafe machine is a legitimate stop-work action, not disobedience. I would not sign a clean inspection sheet or backdate the three missing sheets; that would falsify records and remove the evidence trail if an incident occurs.
3. Explain how the three unsigned inspection sheets affect the site's legal and safety position, and what records you would complete now.
Read the worked answer
Unsigned sheets mean the site cannot show that the machine was inspected by a competent person before those shifts. If an incident occurred, the missing records would weaken the defence and suggest the daily-check system was not being followed. They also break the handover chain: the next operator cannot see what was found or repaired.
I would not backfill the missing sheets or copy today's findings into yesterday's records. Instead, I would record the gap honestly: note that the sheets are unsigned, state what can be verified from the operator's memory and maintenance records, and report the nonconformance to the supervisor and HSE. I would complete today's inspection in full, with time, machine hours, defects, and my signature, and open a defect log for each item. Maintenance should sign off each repair, and a competent person should sign the release. The site should then review why the sheets were missed, tighten the handover procedure, and audit a sample of daily checks. A daily check that is not recorded is difficult to prove and easy to skip.