Down to Earth
In this series of articles staff, students and graduates of Burnley College
share their views with Global Garden readers on a range of topical horticultural
issues. Burnley College is
part of the University of Melbourne’s Institute of Land and Food Resources and
enjoys an esteemed reputation as one of Australia’s premier horticultural
institutions. Click
here for a list of other articles in the series.
Safety Issues in Arboriculture
In 1992, Philip Smallman
was one of Australia’s leading tree surgeons. On a routine
job in December 1992, the karabiner on Philip’s harness was
subject to rollout as he was moving to a different part of a tall
tree. Philip plunged 14m to the ground, breaking his legs,
smashing his vertebrae and damaging his spinal cord. The result
was paraplegia. As a part of Philip’s attempt to rebuild his
life, he is working to warn others about the dangers, not only of
imperfect equipment, but of the belief that "It will never
happen to me." We spoke to Philip about the issues raised by
his accident.
What is rollout?
Rollout is a phenomenon that is basically a function of poor design. If a karabiner is twisted against another piece of hardware that is incompatible, or even karabiner on karabiner will do it, a cross between a lateral force and a direct force is exerted on the gate and, if the locking mechanism has inadvertently come undone through eg vibration, rubbing, etc., the gate opens.
You have said that it is your opinion that no karabiners currently on the market are sufficiently safe. Why not?
There is a big debate raging at the moment about the relative merits of using alloy or steel karabiners. Alloy is light, while steel is stronger. There is a need to establish a minimum standard regarding the quality of the equipment. Currently one does not exist. However, in my opinion they are barking up the wrong tree entirely. To my knowledge, no equipment failure occurring in the tree climbing industry has ever been due to failure of materials. The problem is in the gating design.
Manufacturers are aware of the problem, but they have
failed to do anything to change the design to suit arborists. 
Karabiners were originally
developed for military use, and they are widely used by rescue
crews and police and also for recreational purposes such as
abseiling and mountaineering, but arborists use the equipment all
day, every day, not just occasionally. The karabiners arborists
use are subject to vibration from chainsaws, their use is
complicated by interaction with branches, ropes, twigs and
sticks. There is a great need for lateral thinking on the part of
designers to overcome these problems and it’s just not
happening.
Is there anything that can be done with existing equipment that can significantly protect arborists from this kind of accident?
Nothing is 100% safe, however it is highly recommended that a backup system is used which will abate the inherent risks, but not eliminate them.
Has any research been done into increasing the safety of karabiners?
No scientific research has been done. Resources need to be directed to forming a hypothesis to prove exactly what happens with rollout so that funding can be allocated to research a solution. Pressure needs to be brought to bear on the manufacturers by national and international arboricultural representative bodies such as the International Society of Arboriculture to force them out of their complacency.
Apart from equipment failure, what other factors contribute to this kind of accident?
A whole range of things. Attitude is a major factor - arrogance, complacency and the "It can’t happen to me" syndrome all contribute. There are other elements too. Fatigue, hypothermia and the effects of medication can contribute to a lapse in concentration or lack of attention to detail. Lack of training is also a big factor. Work pressure too is dangerous. In situations where workers are put under pressure to get so much done per day, they are less likely to take the extra time to use a dual system. Both the supervisors and the workers have to understand that it is simply not worth the risk.
Philip Smallman lectures in arboriculture at Burnley College. He is also a consultant to WorkCover Safety and conducts lectures to the industry on horticultural safety issues. Philip can be contacted on 0418 312 499.
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