Updated - September 2026

This Technical Note has been revised to redefine the chainshot risk/exclusion zone from a flat 70m minimum to the greater of 90m, the manufacturer's risk zone, or two tree lengths plus boom length, with slope now an explicit factor.

The FISA Risk Zone campaign will address the ever-growing problem of public and operative encroachment into active forestry work areas.

It is estimated that 1 in 50 chain break occurrences will result in some level of chain shot release. While the rate of instance is very low, the consequences can be serious. The person most at risk is the machine operator.

Key learning following a Serious Incident Review.

V7 update - 23 April 2021 - The machine should also have visible or audible overload warning (loads over 1 tonne), check valves, be marked with SWL and be subject to LOLER thorough examination (if operator not protected by FOPS/OPS/ROPS or if there is a risk that loads may be lifted over or close to people).

Thanks go to the FISA Plant & Equipment Tree Shears/Grapple Saws Sub-Group, chaired by Sean Reilly for pulling this safety alert together so quickly in support of the industry. 

Forestry and Timber News article - August 2020

FISA Safety Bulletin - updated May 2020