A new joint guide from FISA and the AA
Simon Richmond, Senior Technical Officer
The Association has been working with FISA to produce a new safety guide on the use of tree shears and grapple saws. The FISA working group has put many hours of work into this important guide, which sets out the considerations and potential hazards associated with the use of these mechanised attachments, and it is now available to download.
We have observed an increasing prevalence to mechanisation in tree work – the majority of forestry felling operations moved onto harvesters and forwarders many years ago, and MEWPs are an obvious example of mechanical technology providing solutions for arboriculture. The advantages are usually clear: these machines are time- and labour-saving, and they also take the human operator away from the hazard, therefore reducing the risk of operator injury.
The same is true with tree shears and grapple saws, particularly given the large amount of ash dieback we have – and will have in the coming years. With the correct combination and configuration of carrier vehicle (base machine) and attachment for the task, trees can be cut, dismantled and removed, all from the safety of a protected cab.
However, there are also circumstances where new risks can be introduced, with potentially catastrophic consequences. There are many different types and sizes of attachment, from a simple tree shear designed to work only at ground level to complex rotating grab-and-cut grapple saw heads using high-speed chains, capable of managing large-diameter timber at height. These attachments can be fitted on a wide range of carrier vehicles and the potential for overloading carrier vehicles and overturning them when they are dynamically loaded is a serious risk.
Grapple saws can also produce chain shot – the high-velocity separation and ejection of one or more pieces of cutting chain from the end of a broken chain, exposing both operators and bystanders to risk of serious injury or death. Currently, not all manufacturers have fully tested their grapple saws to recognised test standards, and this is causing some confusion for dealers and contractors considering the best machine to purchase. The Health and Safety Executive is working with the manufacturers to resolve this, and it is hoped that all machines available for sale in the UK will have been appropriately tested soon.
As with any large machinery, there are all the usual hazards – soft ground, slopes, infrastructure, services and overhead power lines, the general public, especially in urban areas – and so individual site-specific risk assessment is crucial, including the establishment of adequate exclusion zones and identified risk zones within the working area. Operator competence is essential and that includes not only machine operator competence but also knowledge and experience of tree felling and different timber characteristics.
FISA 608 captures all these points and many more; it sets out in a logical structure the considerations and legal requirements for anyone planning to use this machinery for tree work and the operational dos and don’ts. Copies are will be free to download from the AA (www.trees.org.uk) and FISA (www.ukfisa.com/).
Download the Guide
FISA 608 article
This article was taken from Issue 195 Winter 2021 of the ARB Magazine, which is available to view free to members by simply logging in to the website and viewing your profile area.