The Limitations of MEWPS
by Rob Forrester

Access platforms are relative newcomers to British arboriculture.

Although many contractors are already using them for day to day work, it will be a long time until enough experience will be accumulated to add up to a comprehensive evaluation of their strengths and weaknesses. There are lots of factors which have to be considered when deciding whether to carry out a job using a MEWP, or to stick with climbing. Most arborists have moments of clarity when it comes to assessing a tree. Only the foolhardy macho types will attempt to climb and say, dismantle a tree which is beyond their capabilities. Unfortunately, if a lovely big cherry-picker is languishing back at the yard, the tempted arborist may decide to go for glory and find himself (or herself) out of his depth….The primary limitation when looking for the safest method of work is the skill, experience and capability of the operative.

The limitations imposed by the site are usually fairly self evident. A huge tree half way up a slope is not going to be accessable to even a tracked platform if the gradient is too steep. To take a narrow access MEWP to work on a back garden tree with access solely through the house, is also out of the question (in theory it could be done but you would have to be out of your mind..)

The best and most practicable arena for using cherry-pickers is undoubtedly that of the highways, streets and open public spaces belonging to our Local Authorities, and it is here that contractors have most to lose by not capitalising on the efficiencies which MEWPS can bring.

At the risk of stating the obvious, and in the desperate hope that I am not accused of producing a ‘bluffers guide’ to using a mewp, I think some useful comment can be made as to the suitability and practicality of using a platform for common pruning operations.

Crown Lifting – Ideal and easy work for mewps, working from branch tips back to pruning points. Often carried out over highways and involving numerous trees- which would be laborious to climb

Crown Reduction – Again well suited to mewps, fast movement around the outer crown, saving a lot of tricky branch walking and rope snagging. The usual problem is the top of a tree with any significant crown spread will often be out of reach. For these situations why not use a climber to work the top of the tree while handling the sides with a platform?

Crown Thinning – not easy from a mewp, it is often difficult to get a basket into the crown without causing damage to the tree. Best left to the climbers.

Traditional deadwooding – again difficulties penetrating a dense crown to get at the deadwood. Varies with species, location and extent of deadwood.

Conservation Deadwooding – Often involves coronet cuts and work in stag-headed and veteran trees which may be dangerous to climb. A platform can provide a safe means for ecologically sound management of such trees.

Repollarding – poorly attached pollard growth can be weak and risky to anchor to, again a mewp offers a safe means to work on the tree.

Dismantling – The golden rule is to work well within your capabilities. The machine will not leap out of the way of that half-ton swinging limb when it inexplicably comes right at you. As a climber you have your wits and reflexes and adrenalin to help you out of a jam, but as a mewp operative you will have no chance to get out of the way. If you are going to take down large trees from a platform you had better be very very good with your rigging and your cuts! Smaller trees are clearly not as dangerous, and can be carefully dismantled without too much risk to the operative/arborist.

It seems to me that when we are dismantling trees or removing large and heavy sections, it is important to build into a risk assessment a greater margin for error for the use of a mewp than would be allowed for a climber. The arborist using a platform is more vunerable simply because his lifeline is ground based, and unplanned descents of tree sections have the potential to crash onto the booms or base of the platform.

The most annoying truth about using a platform for treework is that to work SAFELY you need a bigger machine in reality than you do in theory. It is nearly always the outreach of a mewp which lets you down- usually when you need both height and outreach to get at the central top section of the crown. One solution is glaringly simple. Put a climber into the top of the crown, and work the sides of the tree from the platform – a perfect working relationship and a sensible way to harness the strengths of both man and machine.

Although platforms cannot replace a climber for many tree work operations, they can do much of the work of a climber, often quicker, and save much of the sheer hard graft of getting around trees. Why not experiment a bit? Hire in a mewp occasionally to work with your climbing team and see how it can usefully take on some of the donkey work. The real climbers can get on with the special stuff only climbers can do, and let the mewp take care of the rest.


Rob is a Tech.Cert.Arbor.A. and runs a contracting and hire business in Gloucestershire.