Safety Bulletins

Chain-shot Hazard...Reducing the Risk!

What is chain shot? Chain shot is essentially a bullet (high-speed ejection) of cutting chain from the end of a broken chain in mechanised harvesting. Like a bullet, it poses a serious injury risk to machine operators and bystanders alike. Chain shot typically occurs at the drive-end of the cutting system and far more often than you may think! Research indicates that 1 in 50 broken chains had parts missing that may have been the result of a chain shot event.

Our own experience is that chain shot occurs often enough to make this matter our concern. In a very recent incident (October 2015), a saw-chain broke during processing, sending pieces of the chain into the machine's front window. Fortunately, the crew's chain-shot plan had fully isolated the machine from ground-workers and the polycarbonate front screen, 22mm thick, protected the operator.

The key components of a chain-shot plan!

  • Establish a chain-shot exclusion zone using marker cones or a goal-post system. Draw a plan of the exclusion zone and absolutely prohibit all people and machines from entry.

  • Use signage to alert everyone to this hazard, the exclusion zone, and to stay clear.

  • Install 19mm polycarbonate/acrylic as front screen protection. This is a minimum thickness and mandatory for all mechanised harvesters whether they process or fell.

  • If any other machine must (even temporarily) operate within a chain-shot exclusion zone, then either plan for harvester to pause or ensure that machine is protected.

  • Preventative maintenance reduce the likelihood of the chain breaking in the first place.

  • Install, inspect and maintain a purpose built chain catcher (deflector).

View this article in Health & Safety Bulletin 96