Special Feature: Wood Chippers

publication date: Apr 30, 2008

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author/source: Alex Ball

Alex Ball of Timberwolf tells us what to look out for...

A major trend in tree surgery, has been the move towards hiring wood chippers. These are an essential piece of kit and whilst almost every tree surgeon owns from one to a whole fleet of them, hiring wood chippers gives you the flexibility to respond to almost any job at short notice, without committing to the financial burden of owning every type of chipper for every job. It also solves the long-term problem of storage and lessens insurance costs.

The choice of brand and type of chipper available in the UK is higher now than it has ever been, with an overwhelming assortment of size, type and configuration.

There are two main types of chipper – hydraulic feed and gravity feed. Gravity feed machines are usually restricted in capacity to around 100mm (4”) and are ideally suited to smaller jobs or clearing up after a big chipper has been used. They are attractive to those starting out in business because of the low capital outlay and can be transported behind a small vehicle or in the back of a van. Many tree surgeons who started with this type of chipper, tend to keep them even when they can afford a larger machine, as they can prove to be indispensable.

The majority of chippers fall into the hydraulic feed category and there are three main types –
roadtow, tracked and PTO. The most common is roadtow, as this type is able to cope with the majority of tree surgery work in the UK. Sizes go from 100mm (4”) to 300mm (12”) and above. The most common size is 150mm (6”); this will cope with most jobs, is manoeuvrable and capital outlay is reasonable. Before choosing a chipper, you need to be satisfied that it fulfils essential criteria:

Is it manufactured by a reputable firm that has been trading for a number of years?

This is an essential work tool on which the professional depends. Look around and see which brands other tree surgeons favour – some are better than others. If one brand stands out more than others, it is safe to assume that it provides efficient and reliable service.

Is it supported by the manufacturer, or their authorised dealer?

Bargain price chippers are tempting, but what happens when they go wrong? Ideally, you need a 12-month warranty (new machine), a comprehensive owner’s manual and access to an authorised dealer with personnel trained by the manufacturer, within comfortable reach.

Does it comply with CE and Health and Safety
requirements?

All new chippers must comply and display a current CE plate, with a copy of the CE certificate enclosed with the manual. The law is stringent with chippers and even used chippers must comply with Health and Safety law. Safety kits should be available from the manufacturer to bring older machines up to current requirements, but the cost may be prohibitive when compared to the value of the machine.

Is it the right weight and size for you?

Not all drivers are qualified to tow chippers weighing in excess of 750 kg. If you buy a chipper that is claimed to be under 750 kg in weight, then make sure this is the case. If the weight is stated as exactly 750 kg, then you should seek to verify this as it is quite difficult and improbable to hit exactly that figure. (The manufacturer’s identification plate may confirm the true weight.) Ignorance will not going be accepted by the traffic officer who has just directed you to the weighbridge! In terms of capacity, make sure you have enough to competently handle the work you intend to pursue and the number of people feeding the chipper. An overworked under capacity chipper will struggle, but by the same token, a powerful, large capacity chipper will be under utilised if there are insufficient people feeding it.

What security measures are available to help prevent theft?

As any piece of equipment, chippers can be vulnerable to theft. Make sure that antitheft devices such as satellite trackers and security markings can be installed at the factory, or by the dealer. Theft insurance should also be available as a package from the dealer. The third type of hydraulic chipper is the PTO (power take off). If you have a tractor available as a power plant, then this is a possible option. PTO chippers vary in size from those suited to compact tractors, through medium size utility tractors to the monstrous agricultural tractors which can produce up to around 500 hp. The drawback is that you can only move these chippers on the tractor, but the advantages are less outlay (no engine) and off road ability.

Another rapidly growing market in this sector is for shredders. Tree surgeons, landscapers and contractors are finding that they need a shredder to process green waste such as leaves, prunings and rootballs that a chipper will struggle to process. Further, a chipper is vulnerable to damage by soil, stones and many other tough objects and material that may be contaminated in this way should only be processed by a shredder. A shredder will process bulky green waste with little or no wood content far more quickly and efficiently than a chipper with minimal blockages.

Being multi purpose machines, shredders are becoming essential for many uses across many industries. The government is under pressure to reduce landfill and to stop the burning of waste, so recycling and volume reduction become
very important. In addition to green waste, shredders can process pallets, contaminated timber, plastics, cardboard and packaging materials. Some of these materials can be recycled, but all of them can be greatly reduced in volume, saving on skip and transport costs and removing volume from landfill.