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Timber Harvester Operator Killed Following a Chain Shot Incident

Washington Case Report: 10WA048
Release Date: February 24, 2014

The following report is the product of our Cooperative State partner and is presented here in its original unedited form from the state. The findings and conclusions in this report are those of the individual Cooperative State partner and do not necessarily reflect the views or policy of the National Institute for Occupational Safety and Health.


On August 12, 2010, a 47-year-old timber harvester operator (employed by a logging company) was fatally injured when he was struck in the neck by a broken saw chain link while processing a Douglas-fir tree and the cutting chain experienced chain shot. Chain shot is the high velocity separation and ejection of a piece or pieces of cutting chain from the end of a broken chain.[1] The operator was using a Timberjack harvester equipped with a Timberjack cutting head to thin a stand of trees. Prior to the chain shot incident, the operator used the harvester to cut the Douglas-fir stem and move it to the left side of the operator’s station for processing. When the operator started the cut-off saw to cut the tree into shorter lengths, the chain broke. It is believed by the employer and DOSH inspector, that when a portion of the broken chain hit a snow hole on the cutting head, chain shot occurred. Three pieces from the chain struck the operator’s cab. One of the pieces penetrated the 12 millimeter (approximately 1/2 inch) polycarbonate window made by Lexan and struck the operator in the neck. The injured operator contacted a co-worker in the area, who contacted emergency responders and the employer. The harvester operator was pronounced dead on the scene.

Timber Harvester Operator Killed Following a Chain Shot Incident [PDF 3.36 MB]