It was December 21st, 2009; and the whole crew was looking forward to taking a few days off to celebrate Christmas. A feller buncher operator was starting to cut the boundary on a new block. Just above the road a few trees dotted a short steep pitch of frozen ground that was covered with a light skiff of snow. The existing ice lugs on the buncher’s tracks were getting worn down and didn’t really have enough depth to dig in through the duff. The operator considered leaving the few trees for a hand faller, or coming back later once the welder was able to “cork up” his machine.

Both alternatives would hold things up so the operator decided to go ahead. Just as he finished cutting one of the trees, the buncher lost traction and started sliding backwards. The machine pivoted sideways to the slope and then toppled over the bank onto the road below, landing on top of the cab. The operator was able to turn the machine off, but the cab had twisted and he couldn’t get out of either the main door or the roof hatch. He then tried to remove the front windshield but couldn’t pop it either. Efforts to contact the crew on the adjacent block by radio didn’t work until he was able to move the antenna into a different position in the cab. Within fifteen minutes, several crew members arrived with extra fire extinguishers, first aid supplies, crow bars, and wrenches. In a short period of time they were able to release him through the front window escape hatch. Other than a few bumps and scrapes, the operator was unharmed. The machine was out of service for a few month and repairs totalled over $80,000. Lost time and productivity ended up costing the company much more than that amount.

The machine didn’t have adequate ice lugs for traction. That’s the simple answer; but if you dig a bit deeper you can see how the human factor plays into this. The crew was possibly distracted and rushing due to the impending Christmas break. The operator, the crew’s most experienced on steep slopes, had concerns about the slope, but didn’t want to slow down the operation. He wanted to do the right thing for the company, but it ultimately turned out wrong. There was the issue that the welder hadn’t already been called in to work on the tracks before the operation got into steeper frozen ground.

There also hadn’t been an adequate site hazard assessment. The operator didn’t realize there was a seep that left an icy patch right under the working surface. Although the operator was following normal safe operating procedures for steep slopes; there was no site-specific risk assessment or working plan that had been developed and agreed to by the supervisor and the operator.