A Guide to Chainsaws

Chainsaws have long been an essential tool for arborists and tree surgeons but now many homeowners are also purchasing them to carry out tasks such as garden clearance and pruning. There are plenty of chainsaws available and it can be hard to make the right decision on what to buy. Here is a quick guide to help you select the right model.

Here are three factors to consider when choosing and using your next chainsaw.

Engine Power and Type

Chainsaws can be powered by petrol, mains electricity or battery. Petrol chainsaws are the workhorses of tree management and are the usual choice for the kind of heavy-duty tasks, such as tree felling, associated with arboriculture and tree surgery. They are often powerful, can be used in remote locations with only the need for fuel and oil; the downside is that they are heavy and noisy. 

The two most popular brands of saw in the UK are Stihl and Husqvarna. Both brands offer a range of models from lesser-duty homeowner models through to the highly powerful professional saws for the most demanding tasks. 

Battery-operated chainsaws are an attractive alternative and also have the advantage of not requiring a power source. However, the batteries only have a limited life so you may need to purchase and carry spares with you if you are undertaking a lengthy task. Stihl have a very up to date range of battery powered chainsaws that are very quiet to use and hence highly appropriate for noise-sensitive areas. Added to this, the absence of emissions makes them a very environmentally friendly choice – and backed up by Stihl’s extensive experience and modern technology, some battery saws offer surprisingly good performance and are finding a place with professionals.

The power of the engine is important because it affects the size of wood you are able to tackle. If the engine is not powerful enough for your work, it will cause fatigue which can lead to accidents. Similarly, engines that are too powerful are not the safest option. You will see that petrol chainsaws have a cc (cubic centimetre) value which corresponds to the size of the engine in the same fashion as other petrol powered tools and devices.

Battery chainsaws and electric chainsaws have their power expressed in volts. The higher the figure, the more powerful the chainsaw. Chain speed also affects how fast the chainsaw cuts but chainsaws with faster speeds are inherently more dangerous so it is important to have the correct protective clothing for the type of saw you are using (more on this in a a bit).

One other factor to bear in mind is repairs and spares. Whilst chains and bars can usually be obtained for most saws purchased in the UK, spare parts can be difficult or impossible to come by for own-brand or obscure brand saws. If you intend to use your saw a lot, you may wish to stick with a Stihl or Husqvarna branded saw as spare parts are usually easy to get, even for older models. 

Guide bar length

The guide bar length is the distance from the tip of the chain to where it meets the housing of the chainsaw. This is the active cutting area of the chainsaw and indicates the largest diameter of wood that the chainsaw can cut in a single pass. For arborists who are using a chainsaw all day, this is important because the fewer passes you have to make, the better. As a general rule, the bar length should be two inches longer than the largest pieces of wood you want to cut, so you need to think about the type of work that you may need to carry out.

For medium duty jobs, you may want a bar length of 16 inches to 20 inches. A professional arborist will almost certainly undertake jobs that will need a bar length of 22 inches to 36 inches. 

Bigger saws are normally only available in battery operated or petrol versions, and are inherently more challenging to handle. The chainsaw is more likely to become unbalanced and fatigue is more likely to become an issue. They should only be used by trained and qualified personnel.

Another challenge longer length guide bars is kickback. If the guide bar is too long, it’s more likely to hit an object or to become pinched in the wood and kickback towards the operator. For felling a small tree, around 12 to 14 inches is appropriate but for cutting a felled tree into logs (bucking) 18 inches would be needed.

Chainsaw safety

A chainsaw is a potentially lethal piece of equipment and you have a responsibility to protect yourself when you are using it. If you are an employer and you require your employees to use a chainsaw, you must provide them with the necessary training and personal protective equipment.

You have a legal responsibility to protect your own safety and that of anyone else who could be affected by your work involving a chainsaw. The Health and Safety at Work etc Act 1974 is the umbrella law that applies to all workplaces and imposes the following general duty of care including “the provision and maintenance of plant and systems of work that are, so far as is reasonably practicable, safe and without risks to health.”

Anyone using a chainsaw as part of their job must receive appropriate training and must have sufficient experience. This is required by The Management of Health and Safety at Work Regulations 1999.

Employees must be assessed under the Provision and Use of Work Equipment Regulations 1998 (PUWER 98) and have a “relevant certificate of competence or national competence award, unless they are undergoing such training and are adequately supervised.”

There is detailed guidance available from the Health and Safety Executive as to how to carry out a risk assessment for chainsaw work. It will require hazard identification, listing everyone at risk, assessing the risk of the hazard occurring, putting measures in place to control the risk and recording the assessment.

Personal protective equipment is vital for chainsaw work and the equipment must be suitable for the particular employee, maintained correctly and employees must receive instruction and training on how to use it. There are some specific items of PPE, like chainsaw trousers, that are appropriate for chainsaw work. Also important are head protection, hand protection, eye protection, body protection and hearing protection.