Safety Watch – March 2009

The accident: A contractor was removing tree stumps on a road project and processing the stumps and other wood debris in a tub grinder. An excavator loaded the grinder, operated remotely by a worker on the ground. The excavator operator started to dump a log into the grinder when a scream was heard. The operator discovered that he had run over his co-worker, and had to reverse to get off him. The worker’s left leg and lower abdomen were crushed and he died later of his injuries. The operator said he had made eye contact with the worker and gave him a hand signal, one that may have been misinterpreted by the other man.

The bottom line: Before starting to dig, set up safety barriers to the sides and rear areas of your swing pattern to prevent anyone from walking into the working area.

Make sure the area is clear of all people before you start operating. Never enter or allow anyone else to enter the excavator swing pivot area. Also be sure there is sufficient clearance for the machine’s tail swing. Never lift, move or swing a load over anyone, or the cab of a truck or another machine. Understand all hand, flag, horn, whistle, siren and bell signals used on the jobsite.

Other excavator precautions: Extreme caution is required when working at the edge of an excavation. Keep the machine well back and avoid undercutting. Do not dig under the machine or stabilizers – a cave in could happen, resulting in the machine falling into the excavation. Also avoid the edge of an overhang or stockpile and use extreme caution when working along the top of banks or slopes.

When operating an excavator on a slope, if possible swing to the uphill side to dump the load. If downhill dumping needs to be done, swing only as far as required to dump the bucket. If possible, place the undercarriage up or down a slope – rather than across the slope – for maximum stability.

When lifting with an excavator, make sure you are within the safe load and work radius limitations of your machine and are on solid, level ground. Position the machine so that lowering is done over the end of the machine rather than either side. Always lower the stabilizers to the ground before lifting. If the ground is soft, place pads or timbers under each stabilizer.