In certain areas of forestry I believe we are pushing forest machinery beyond their intended limits.
Pushing the limits-Modern forest machines have significantly greater capabilities compared to those from 20–30 years ago. These advancements allow them to operate in environments that might have previously been deemed unsuitable for older machines. For instance, a modern harvester is designed to climb, reach, process, and extract timber in challenging conditions. However, this enhanced technical capability does not inherently imply that operation in such environments is economically or environmentally appropriate.
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That’s a remarkable amount of work hours for a single machine, the Norcar 600 owned by Erkki Rinne is taken well care of, it even has the original Diesel engine.
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Kieran Anders is a forestry contractor working in the lake district. His work involves hand cutting and extracting timber using a skidder and tractor-trailer forwarder.
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It is not possible to eliminate chain shot, but there are simple steps that can be taken to reduce the risk.
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Arwel takes great pride in the fact that the mill has no waste whatsoever, “the peelings are used for children’s playgrounds, gardens and for farm animals in barns in the winter and the sawdust has multiple uses in gardens and farms as well.
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Timber hauliers need to encourage young blood in, and also look after the hauliers we have, we need make the sector a safe and positive place to work.
FIND US ON
The bigger issue is often the operating environment and production expectations, rather than simply machine size.
Where the pressure is greatest
* Bigger payloads: Forwarders are carrying increasingly large loads, sometimes on ground and roads that haven’t improved to match.
* Poorer ground conditions: Wet winters and harvesting during marginal conditions can put enormous stresses on tracks, bogies, frames, transmission and hydraulics — as well as causing soil damage.
* Steeper terrain: Purpose-built machines are being expected to work on slopes where cable extraction or winch assistance may be a more appropriate system.
* High utilisation: Machines costing hundreds of thousands of pounds have to work long hours to pay for themselves. That encourages operators to keep working when conditions aren’t ideal.
* Higher productivity expectations: Modern harvesters can process timber incredibly quickly, but the rest of the system — forwarding, extraction, roads and haulage — doesn’t always have the capacity to keep up.
* Machine weight: More power, larger cranes and greater payloads inevitably mean heavier machines. That can become a vicious circle: more machine → more capacity → more weight → greater ground pressure → need for better extraction infrastructure.
The interesting contradiction
Modern forest machines are far more capable than machines of 20–30 years ago, but we’re also asking them to work in places where older machines might simply have stopped.
A modern harvester can climb, reach, process and extract timber in conditions that would have been considered unsuitable previously. That doesn’t necessarily mean it should.
The danger is when technical capability gets confused with economic or environmental suitability.
For example, a forwarder may physically be capable of carrying 20 tonnes through a wet site. But if doing so causes rutting, damages the machine and requires expensive remedial work, the fact that it can do it doesn’t mean it was the right decision.
I think the industry needs to look at the whole system, rather than continually asking:
“What is the biggest machine we can put on this site?”
We should perhaps be asking:
“What is the most appropriate harvesting system for this site?”
That could mean a conventional harvester/forwarder system on good ground, but winch-assisted machines, cable systems, smaller machines, skidders or alternative extraction systems may make much more sense elsewhere.
And there’s another issue that I think is particularly important for UK forestry: we sometimes expect machines to compensate for inadequate infrastructure — poor forest roads, insufficient turning areas, difficult access and unsuitable extraction routes.
Here is a strong argument that some modern forest machines are becoming too heavy for some areas of the UK, but I wouldn’t say that modern machines are universally “too heavy.” The real issue is machine weight relative to soil bearing capacity, weather, extraction distance and site infrastructure.
The numbers tell an interesting story
A modern Ponsse Scorpion starts at around 21.7 tonnes, rising to 23 tonnes for the Scorpion Giant.
Modern forwarders are even more striking (empty weights):
Ponsse Wisent 16.3 t
Ponsse Elk 8W 17.7 t
Ponsse Buffalo 8W 18.6 t
Ponsse Buffalo King 20.6 t
Ponsse Elephant 22.0 t
Ponsse Elephant King 22.9 t
Ponsse Mammoth 27.5 t
Large forwarders will be operating at well over 40 tonnes gross weight when fully loaded.
Compare that with the older philosophy
There’s a fascinating example in Ponsse’s own history.
The company’s S15 forwarder from the early 1980s weighed approximately 10 tonnes while carrying 12 tonnes. Ponsse specifically describes its low weight as allowing harvesting on poor-bearing soils.
That’s quite a contrast:
1980s S15: 10 t machine + 12 t payload = ~22 t loaded
Modern large forwarder: ~22–27.5 t empty + ~15–20+ t payload = potentially 37–47+ t loaded
Of course, modern machines have better productivity, traction, stability, ergonomics and load distribution. So simply comparing tonnes isn’t fair.
But it does highlight the fundamental question:
Have we increased machine capacity faster than the UK’s forest soils and infrastructure have improved?
This is where I think the argument becomes particularly strong.
The Forestry Commission’s UK Forestry Standard explicitly warns that heavy harvesting and forwarding machinery can cause soil compaction and rutting. Peaty and clayey soils are particularly vulnerable, especially where machines make repeated passes. Damage below about 20 cm depth can also be considerably harder to rectify.
But here’s the important bit
Machine weight isn’t the same thing as ground pressure.
A 25-tonne machine with a long wheelbase, eight wheels, wide tyres/tracks and good load distribution can potentially cause less surface pressure than a much lighter machine concentrated over a smaller footprint.
Manufacturers have clearly recognised this. Ponsse, for example, specifically markets weight distribution and low surface pressure as characteristics of its forwarders, while the Scorpion has been developed with low surface pressure as one of its design objectives.
So the question shouldn’t simply be:
“Is a 25-tonne machine too heavy?”
It should be:
“What is the ground pressure and total soil loading on this particular site?”
Where I think the UK has a problem
I’d divide UK harvesting sites roughly into three categories:
🟢 Good ground
Large modern machines make enormous sense. Higher productivity and payloads can actually reduce the number of machine passes required per cubic metre.
🟠 Marginal ground
This is where machine selection becomes critical. Tyre pressures, bogie configuration, tracks, load size, extraction routes and weather can make the difference between a productive operation and a damaged site.
🔴 Very soft/wet ground
This is where simply putting a bigger machine on the site becomes questionable.
A 25-tonne machine with 20 tonnes of timber doesn’t become a good machine for peat simply because it has enough horsepower to get through it.
That’s where smaller forwarders, low-ground-pressure systems, winch assistance, cable extraction or carefully designed extraction routes can become much more appropriate.
And there’s another problem: the productivity race
I believe this aspect might be more critical than just focusing on the machine’s weight alone. A modern harvester is capable of generating substantial output, which naturally leads to the use of a larger forwarder to keep pace. As a result, the forwarder must be designed to handle increased loads. This, in turn, requires forest roads to be built to support higher production levels, and lorries must adapt to transport more timber efficiently. Essentially, the entire system gets streamlined around maximizing tonnes per hour. However, British forestry doesn’t always benefit from the ideal conditions found in Scandinavian plantations, such as perfect terrain, soils, and infrastructure. The risk lies in tailoring the harvesting system to fit the machine rather than creating a machine that suits the unique needs of the forest.
My Opinion
I wouldn’t recommend simply reverting to smaller machines.
Modern machinery has brought significant advantages in terms of operator safety, productivity, precision, and reduced labour needs.
However, I believe the UK industry should place greater emphasis on factors such as machine weight, ground pressure, soil type, weather conditions, extraction distance, and road infrastructure, instead of focusing solely on tonnes per hour.
There’s an intriguing question to consider:
Would a 12–15 tonne forwarder making two trips actually result in less damage—and be more cost-effective overall—compared to a 25-tonne forwarder attempting to haul everything in one go?
This comparison could provide valuable insights for the UK forestry industry, as the answer isn’t as straightforward as you would think.
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