Nisula N6: Next Generation Thinning Harvester

Nisula N6 Harvester

Redesigned to better meet the needs of thinning

How often when looking at the layout of the inside of a cab or skinning your knuckles trying to remove an awkwardly situated engine filter, have you thought “I wish this machine was made by someone who has used one.”

One Company that fits this bill is Finnish manufacturer Nisula Forest OY. Brothers Seppo and Ali Nisula, the founders of the company, started out as timber harvesting contractors. In 1978 they made the decision to design and manufacture their first forwarder as they continually searched for new ways to help improve their business and increase productivity. The brothers had a Valmet 702 tractor on the family farm which they thought would be ideal for the plans they had. The tractor chassis was reinforced, the front wheels were removed and a noise reducing cab was fitted. The centre joint and rear frame were built from scratch with a MAN truck mid lift centre axle used for the rear bogies and a Cranab 4010 crane was fitted for loading timber. The forwarder was never given a name or number but none the less it was dependable and increased their productivity. Looking to capitalise on their success, the duo moved forward and manufactured a bed processor based on a Valmet 870CK.

1984 saw the introduction of the Nisula Brothers first grapple mounted processor which led to two of their own processors and their forwarder working effectively on their own harvesting sites. The processing head was further modified so that it could tip upright for felling trees. Unfortunately, the design of the processor wasn’t ideal, so it was back to the drawing board to find an alternative design. This prompted Ali to retire from the day to day running of the forestry contracting business to concentrate solely on the engineering division.

Seppo and Ali went to see a Ponsse S20 in Vieremä which they thought would be the ideal base for a harvester. On their second visit the brothers met with Ponsse owner Einari Vidgren and revealed their design for a new type of crane they had been working on. This was the start of a successful co-operation between the two companies. 1987 was a decisive step in terms of machine sales with the arrival of the new model S15 Ponsse and the Nisula HN 125 harvester crane. Further improvements were made in 1988 as the cabin was repositioned, and the fuel and oil tanks moved to increase operators’ visibility. Nisula developed the H53 harvesting heads that were presented at the Elmia Wood exhibition in Sweden. The demonstrations at Elmia were phenomenally successful and discussions took place to manufacture a larger H73 harvesting head.

A new idea was formed in 1998 to manufacture a combi-machine (Harwarder). This time a Valmet 838 was selected as an ideal base machine. Valmet was owned by Partek, and a deal was signed to manufacture the combi machines based on Nisula’s prototype. In 2001 the Valmet 801 Combi was born and put into serial production. This partnership continued for some time with the 330 series harvesting heads made for Valmet harvesters and the 400 series of heads were sold under the Valtra brand.


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Nisula have continued to evolve ever since, and the company has created many new products which are exported to over 24 countries; half of their turnover comes from export sales.

I first saw Nisula’s harvesting heads and the N5 4WD thinnings harvester at FinnMetko in 2016. The design was unlike any harvester base I had seen before, it was narrow and compact and ideally suited for working in single line thinnings also it is easily manoeuvred in selective thinnings.

I saw Nisula again at Elmia Wood in Sweden in 2017. On display were a selection of harvesting heads, the N5 harvester, extension dipper booms for excavators and the clever FLEX-14 System, which allows excavator tracks to pivot, like a forwarder bogie. Although the FLEX -14 system has since been shelved for now – the different fittings for each make and model of excavator meant each one was a custom and expensive build – it showed just how forward thinking the Nisula family are.

I was pleased to hear that SB Forestry Ltd are the UK and Irish distributers for all of Nisula Oy’s products. I have known Scott Burton for several years and have witnessed his enthusiasm for conducting proper thinnings and his stance on the importance of using the correct equipment. Scott has spent many years harvesting and extracting on his own contracts using his own equipment prior to starting up SB Forestry Ltd, so he is ideally placed to offer good sound advice to potential customers.

When Scott first mentioned joining him on a trip to Finland to attend the dealers launch presentation of the N6 and N6E harvesters, along with the new 755 harvesting head, I was both excited and slightly apprehensive as this was my first overseas trip since Covid 19 landed. Flying is not as easy as in pre Covid days, you need a Covid test beforehand, proof of Covid injection status and passenger locator forms for every country you are travelling to. On the plus side, airports are no where near as busy as they used to be and there was more room to stretch out, due to empty seats, on the planes we travelled on.

The hotel where we met the other dealers from France, Germany, and Poland on the first evening was about a three-hour drive from Helsinki airport. It was around -15°, with a great deal of snow on the roads. This is a dry cold leaving the roads nowhere near as slippery for driving as back home.

The following morning after an early night – Covid rules in Finland requires restaurants and bars to be vacated and closed by 9pm – we set off to the Nisula factory which was about an hour’s drive away. I was surprised at just how large the factory was. A multimillion Euro investment has increased the size of the facility to an area of 6000m³ with a workforce of 39 and will significantly increase production. Two new 17m high Modula automated spare parts delivery systems have been installed which will speed up Nisula’s production and customer delivery times.

Kalle Mattson, sales and marketing, and Timo Savornin, sales director, were awaiting our arrival and took us into the huge workshop where the new N6 and N6E harvesters stood along with a selection of Nisula harvesting and energy heads. The two harvesters were an impressive sight and after a coffee Kalle started his presentation on the N6E.

N6 loaded and ready to start the demo tour of Finland.

The development of the N6‘s started two and a half years ago, the N5 was a successful thinnings harvester but the Nisula family were looking to improve and build on its achievements. After speaking to owners of earlier N5 series models they were able to get good honest feedback that they incorporated into their newest harvester.

Both models have the same base units and cabs, the difference between the two are in the cranes and applications for use. The machines are four-wheel drive on 600 tyres with two extra non-driven smaller wheels on the front for lower ground pressure. Bandtracks can be fitted to the driven and non-driven wheels to further reduce ground pressure and increase traction. Both non-driven wheels can be raised and lowered independently using hydraulics. The N6 is designed and intended to be used as a thinning harvester – although quite capable in premature clearfell – so weight and size were critical factors in the design.

Nisula use a four-cylinder engine made by SISU to keep the weight down, and by using a heavier flywheel they have managed to increase the power to 190hp. The harvester weighs under 16 tonnes and is 2.7m wide. It has a new sub-frame design which has increased ground clearance and a larger diesel tank which allows 30-35 hours of harvesting. A good proportion of the parts used in the N6 are manufactured “in house” and others like the SISU engine, ZF axles and Danfoss Hydraulics are easy to get replacement parts for.

The N6E is classed as an Energy Wood Cutting Machine and is fitted with a Palfinger Epsilon S110F crane with a tilting kingpost. The main boom is made for Nisula by Palfinger as it is shorter than the standard boom and improves the ability to work closer to the machine. Both crane mountings have a tilting base of +/-14°.

It is a multifunction machine, ideal for multi-tasking, with quick release hydraulic couplings and a single pin for a fast switchover of attachments. This model had three attachments laid out:

  • Nisula 285E Accumulating Energy Wood Head, which is ideal for felling, bunching, and loading small trees and for clearing roadsides, paths, parks and power lines of trees and overgrown bushes.
  • Nisula 500H (other sizes are also available) harvesting head. This is a lightweight (640kg) but strong and powerful head with a 500mm cutting diameter and five moving and one fixed delimbing knives for stronger grip and enhanced productivity.
  • Kronos Predator 1700H boom mounted chain mulcher attachment. This is a hydraulically driven 1.7 m wide mulcher with the wearing surfaces made from HARDOX 500 steel for maximum service life.

The N6 has a maximum road speed of 40km/hr so can drive reasonable distances between jobs under its own steam and has a road package with steering wheel and lights for conducting work or driving on the highway.

Access for servicing and maintenance is first-class with the power assisted bonnet opening well out of the way. The power assisted cab tilts and the front engine panel opens right down to the ground with steps fitted inside the cover for sure footed access to radiators, batteries, and the front of the engine. There is plenty of storage for hydraulic hoses and other bits and pieces. Illuminated tool storage trays are secured inside the engine compartment where the refuelling points are located, along with the useful recoiling airline which will power air tools and can be used for cleaning. All the cooling radiators for water, oils and air conditioning are at the front of the engine and the cooling fan can be reversed for blowing out debris and dust.

Front grill on the Nisula N6 doubles up as a stepladder to access the front of the engine compartment.
Front grill doubles up as a stepladder to access the front of the engine compartment.
Nisula N6 with 555H harvesting Head.
Nisula N6 with 555H harvesting Head.

The cabin is spacious, comfortable, and quiet with good vision. The differential locks are mechanical, and the Epsilon crane has a hydraulic parallel function for easier, accurate working.

The second N6 harvester was fitted with Nisula’s own 10m parallel crane and 555h harvesting head. This model was fitted with wheel chains and bandtracks. A ring bolted onto the rim of the rear wheels with short chains attached to the outer rim of the wheel chains, prevents the wheel chains from running off the tyres. This was a problem when using chains in the past. The bandtracks had short chains running between the outer links and over the tyres at a slight angle. This was so the small wheels get 100% traction, and also the chainsare cleaning the inside of the tracks brands when the snow is packing, especially with flotation tracks, These chains are available for all track and machine models. The hose layout down the crane was skilfully thought out, it was routed to avoid any chaffing and rubbing but was still easy to get access to if a hose needed replacing.

Fixing chains to keep the wheel-chains in place.
Fixing chains to keep the wheel-chains in place.
Refuelling point on the Nisula N6, with tool/spares storage trays and air line.
Refuelling point with tool/spares storage trays and air line.

Harvester Heads

The 555H is one of a new generation of thinning heads, it offers a 550mm cutting diameter and weighs between 810 and 840kg depending on options. The grip force is adjusted to the size of the stem it is processing and it has five moving, and one fixed knife. The head has the patented Nisula Goldfinger guillotine cut function and not only runs with Nisula’s own operating systems but is compatible with Technion, Dasa Forester, Valmet/Komatsu maxi, Motomit IT and JD/Warratah Timberrite. This head is suitable for using along with 14-18 tonne excavators.

Finally, we were introduced to their newest harvesting head, the larger 755X designed for final thinnings and clearfelling operations. This head is for using with 18 tonne and over harvester bases and with excavators in the 16-23 tonne class. It weighs between 1,380 and 1,420 kg and will cut up to 750mm stems in a single cut, there are four moving and one fixed de-limbing knives. The grip force of the feed rollers and de-limbing knives are proportionally controlled so that the heaviest stems are held firmly in place.

Although I am no harvester head expert when inspecting this head, you can’t help but notice how easy it is to work on. The saw, feed motors, hydraulic rams and measuring wheel are all so accessible and all the greasing points are user-friendly. A point worth noting is that many of the hydraulic cylinders are the same size, the only difference is the interchangeable hydraulic fittings.

As with all Nisula products the head is built to last with a high strength frame and strong
de-limbing knives using the best HARDOX steel.

An owner of TMO Forest – distributor for Nisula Forest in Brazil – Mr. Robson Ferroni Olsen, sadly passed away prematurely. To commemorate him Nisula have made a dedicated model for the Brazilian market, the “Robson Special Edition.”

Nisula’s largest felling head the 755X “Robson Special”.
Nisula’s largest felling head the 755X “Robson Special”.
Nisula N6 E fitted with the 285E accumulating energy wood head, alongside a variety of quick fitting interchangeable attachments, including the 500H harvesting head and Kronos Predator chain mulcher.
N6 E fitted with the 285E accumulating energy wood head, alongside a variety of quick fitting interchangeable attachments, including the 500H harvesting head and Kronos Predator chain mulcher.


Nisula has their own forest at the rear of the factory, and a demonstration was arranged of the N6 with the 555H head. Although temperatures outside were heading for -20° it wasn’t as cold as you would imagine. As said before, this is a dry cold, wading through knee high powdery snow just brushes off with your hand, your clothes don’t get wet.

It was good to see an experienced operator at the helm on the N6 and the harvester was impressive to watch thinning the block of mixed Birch and Scots Pine. The timber was straight and finely branched, compared to the hairy Sitka Spruce that we work with, but nonetheless you could see that this was a fast head with an exact measuring system. There were several double stems in the crop which it managed with ease.

Looking around the group there were plenty of smiles and nodding of heads, it appeared to me that they would be going home safe in the knowledge that they had some great new products to market.

After the Demo we had a final tour of the factory and saw a new 555H head partly assembled, Scott smiled and let me know that he had bought this head and once finished it would be shipped to the UK, fitted onto an excavator base and available for demonstrations.

Nisula’s list of products is much larger than I imagined; there are two versions of the new N6 harvester, eight sizes of harvesting heads, four types of energy wood heads, three types of accumulating energy wood heads, two types of parallel cranes, extension booms for excavators, wheel chain holders, swing dampers, hose swivels, track tensioners and timber grapples.

From what I saw Nisula are a ground-breaking and forward-thinking family, striving to be the best at what they do. They are helped on this journey by an enthusiastic workforce who take immense pride in their work. The family values which Nisula was founded on continue as Ali’s son Esa has followed in his father’s footsteps and is an integral part of the research and development department.

The rest of the group headed back to Tampere for dinner and an overnight stay but as Scott and I had an exceedingly early flight home via Amsterdam the following morning, we thought it best to drive the three hours back to Helsinki airport for a few hours’ sleep.

A big thumbs up from the dealers from France, Germany, Poland and the UK on the new Nisula N6.
A big thumbs up from the dealers from France, Germany, Poland and the UK on the new Nisula N6.

Forest Machine Magazine is written and edited by a forest professional with over 40 years hands on experience. We are dedicated to keeping you informed with all the latest news, views and reviews from our industry.

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