Inspection, maintenance, and troubleshooting
Domain 4: Inspection, maintenance, and troubleshooting
This domain tests inspection intervals and criteria, wire-rope and brake checks, functional tests, lockout, and fault diagnosis. Questions often describe a defect and ask whether to operate, derate, repair, or remove from service.
Core rules
- Pre-operational check each shift: visual condition, fluid levels, leaks, wire rope spooling, hook and latch, brake feel, limit switches, anemometer, fire extinguisher, signage, manual in the cab, and communication equipment.
- Frequent and periodic inspections: follow CSA Z248, the manufacturer, and the jurisdiction. Frequent inspections are typically monthly; periodic inspections are typically annual and may require a competent person or engineer. Inspect after modification, after a severe wind or lightning event, after an incident, and after long idle periods.
- Wire rope: know the removal criteria. Common criteria include 6 randomly distributed broken wires in one lay, 3 broken wires in one strand in one lay, diameter reduction beyond the manual's limit, kinks, birdcaging, corrosion, heat damage, and broken end fittings. When in doubt, remove and tag it.
- Brakes: test holding and control brakes each shift. A crane that drifts with the controller in neutral is out of service until corrected.
- Safety devices: never bypass a limit switch, moment limiter, anti-collision system, or anemometer. Troubleshoot by the manual, lock out and tag out, and use qualified persons.
- Records: write defects, repairs, and tests in the log with time, name, and action.
Worked example
An operator finds four broken wires in one strand within one lay of the hoist rope. The manual's criterion is three broken wires in one strand in one lay. Reasoning: the rope has exceeded a removal criterion even though the crane still hoists. The correct action is to stop use, tag the crane, record the finding, and have the rope replaced by a qualified person; then inspect the sheaves and drum for the cause. Continuing because it still works is a fail.
Traps that cost marks
- Greasing over broken wires or cracks and calling it maintenance.
- Resetting a limit switch without finding why it tripped.
- Using a rope with a kink or birdcage because the diameter looks okay.
- Skipping the post-incident inspection.
- Recording OK without actually testing the brake or anemometer.