Pre-Use Checks After a Night of Rain
You are the operator for the day shift. Overnight there was 25 mm of rain. The 180° excavator has been parked on a gravel pad with the boom lowered and the bucket on the ground. During your walk-around you find: the left track has a visible flat spot and the track tension looks slack; the hydraulic oil sight glass shows the level at the minimum mark; there is water in the fuel/water separator bowl; the horn works but the travel alarm does not sound; and the greasing points on the boom foot have not been greased for two shifts. The machine starts and runs. The site is due to begin a concrete pour in 30 minutes and the supervisor wants you working immediately.
1. Sort these findings into 'do not operate until rectified', 'operate with monitoring', and 'record and continue', giving your reasoning.
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Do not operate until rectified: water in the fuel/water separator (drain it - water in the injection system can cause running faults and damage); non-functioning travel alarm (it is a safety device for people on foot and must work before travelling); slack track tension with a flat spot (risk of derailment, especially on soft rain-soaked ground). Operate with monitoring: hydraulic oil at minimum - top up to the specified level before work and watch for leaks; low oil can indicate a leak and can cause overheating. Record and continue: overdue greasing on the boom foot - schedule it, but it does not by itself stop work. The point is that each defect is judged on whether it affects safe control, machine integrity, or the safety of others; the pour deadline is not a reason to operate with a safety device failed.
2. The supervisor says the travel alarm 'doesn't matter, the banksman will watch'. How do you handle this, and what does the law/practice require?
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The travel alarm is part of the machine's safety equipment and must be functional before the machine is used for travelling. A banksman supplementing the alarm is good practice but does not replace a required audible warning, especially where pedestrians, other plant, or poor visibility exist. The correct action is to report the defect, have it repaired or the machine isolated/tagged out, and not travel until it is working. If the machine must be moved, it should be under a controlled procedure with the area cleared and a competent person directing - but the default is repair before use. The pour schedule does not override this.
3. What pre-use checks would you add specifically because of the overnight rain?
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Check the gravel pad and travel route for soft spots, rutting, and slope stability; check for water ingress into the fuel system (drain the separator); check hydraulic oil level and look for leaks that rain may have masked; check the air filter/water indication if fitted; check the tracks for mud packing and correct tension; check the bucket and quick-hitch for security; test the horn, travel alarm, and all controls; check the parking brake holds on the wet pad; and check the windows/wipers/mirrors for visibility. Rain changes ground bearing capacity and visibility, so the checks should reflect the changed conditions, not just the standard list.