11 minute read
MARKET REVIEW
The 425 is the newest head in the line-up, a facelifted version of the 415, with many improvements over its predecessor.
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MAKING THE CUT
The range of OEM and third-party felling and processing heads is massive, so for this issue’s Market Review Ken Topham looked at units in the 500 to 700mm+ sector, which still left us with plenty to go at. Naturally, the Nordic countries provide the lion’s share of third-party heads, as well as OEM attachments
IMAGES MANUFACTURERS
If you’re in the harvesting game and run a dedicated harvester, then chances are you’ll run an OEM head. However, for excavators or special builds, there is a whole world of choice for harvesting and processing attachments. The UK and Ireland harvesting and thinning sector will find most of their work can be done with a mid-range head that can handle around 700mm trunks. But as with any attachment, there is no cure-all solution, and gains in the maximum capacity will affect the other end of harvesting versatility.
There are differences between heads – drive wheel count and knifes being the most obvious. Here, we look at seven heads of a similar class, size and weight. The carrier machines will largely dictate the choice of head – dedicated harvesters will tend to have a massive oil flow to get the most from the head, whereas an excavator may limit the choices without additional hydraulic capacity.
JOHN DEERE
The John Deere 425 is a fresh head from the Swedish branch of John Deere. Launched this year, the head is a reworked version of the 415 head, with
expander pins to take up wear in the upper tilt cylinder, feed motor arms, and lower de-limbing knives fitted as standard in high frequency moving components. Pipe routing has been improved, but the headline for the 425 is a new chain tensioner. The SuperCut 100S should improve the stability of the tension when under load. The 425 is predominately found in an OEM SPECIFICATIONS application, suited to the larger end of the harvester range on
Make John Deere Model 425 Weight 1,360kg the 1270G and 1470G carriers. The feed is four-wheel drive,
Most efficient harvesting range which when fitted to John 50-630mm Deere’s own harvester can bring
Max cut diaMeter 710mm Multispeed in 425HD iteration. ideal for… Final and other fellings where the tree diameter at chest height is There are four mobile knives and one stationary, which have 250-500 mm an optimum efficiency range of feeding force 27kN 50mm, up to 630mm. Maximum feeding speed 2.9-7.0m/s oil requireMent Na cut is 710mm, which may involve a step cut in none uniform trunks. The 425 head is also available to third party carriers with an easy to integrate control system, which is compatible with third party control systems. Weighing in at 1,360kg the 425 is at the lighter end of the scale, replacing one of John Deere’s most popular harvesting and processing heads.
SPECIFICATIONS
Make Komatsu Model C144 Weight 1,410kg
Most efficient harvesting range 200-580mm
Max cut diaMeter 710/750mm, bar dependent ideal for… Final felling and thinning Max feed force 23.7-29.6kN motor depending
feeding speed 0-5m/s oil requireMent 320L/min
Above: The Komatsu C144 has been around since 2014, the finished article is a solid performer for felling and thinning.
KOMATSU
Komatsu C114 has been in the line-up of harvest and processing heads for Komatsu for eight years now. The C144 has been refined since launch, to a well trusted member of the harvesting head range, typically found on OEM host carriers like the 931 and upwards, the head can be attached to thirdparty carriers if required. The Komatsu head is one of the marques most common heads found on the frontline in harvesting, but versatile enough to work in thinnings. The C144 has four hydraulic de-limbing knives, with the two forward knives providing more efficient de-limbing of challenging trees, and four-wheel drive feed, with the backplate wheels in a vertical layout.
The Komatsu head has an ideal working range of 200-580mm for greatest efficiency, but it can cut smaller and the knives open to 660mm, with a maximum cut diameter of 710mm, which increases to 750mm with the optional 900mm bar.
There are multiple options for the C144, The Eco-GLS lubrication system reduces lubricant consumption and eliminates oil mist. Multi-tree handling is an additional feature to further enhance production capacity in thinning, where extra retention arms can hold smaller material, allowing the knives to re-open for the next cut.
PONSSE
Ponsse’s H8 is another top selling OEM head, widely seen on the company’s larger harvesters. Like those heads of other OEMs, the H8 can be used on other harvesting carriers, and like the others will see a slight reduction in functionality when connected to third-party hosts, largely in terms of oil requirement, an excavator package is available. The H8 is a three-wheel drive head, with four hydraulic and two stationary de-limbing knives. The H8 is aimed more at felling, with its maximum cut at 800mm.
The H8 is a high-capacity head, but modest in weight, at 1,250kg gives a favourable head to capacity ratio, but it requires a 20- to 30-tonne tracked carrier. The knives open to 740 and 780mm, with the standard bar at 820mm there is a 900mm option if you’re working at the upper end of the the H8’s capability. On a full OEM system, the Ponsse head can deliver stepless knife and roller pressure with intelligent saw control relating to the stem diameter, said to prolong the service life of the saw. The H8 harvester head is also ideal for multi-stemming. The geometry of the rollers and de-limbing knives is also excellent for collecting and cutting larger diameter trees.
SPECIFICATIONS
Make Ponsse
Model H8 Weight 1,250kg (without rotator)
Most efficient harvesting range Up to 720mm
Max cut diaMeter 800mm (with 900mm bar) ideal for… Felling
Max feed force 36kN feeding speed 5m/s
Ponsse’s H8 head is aimed more at felling and processing, and suited to the company’s larger wheeled harvesters such as the Ergo and Bear.
SPECIFICATIONS
Make Kesla Model 29RH-II
Weight 1,540kg (without rotator)
Most efficient harvesting range Up to 720mm
Max cut diaMeter 780mm ideal for… Felling, and de-limbing difficult hardwoods
Max feed force 20-32kN, oil flow depending feeding speed Variable, oil flow depending
oil requireMent 175-260L/min
KESLA
On to third-party heads and Kesla’s offering in the bracket – the 29RH-II. Kesla offers a wide range of head sizes and tailored solutions for customers. The 29RH-II is near the top end of the range, with only one model above it. The Kesla can be fitted to wheeled harvesters, but it’s likely that buyers will be fitting it to an excavator, which will need to be in the 20- to 30-tonne class. Weight is in line with the OEMs; at 1,530kg, with a 780mm max cut diameter, the 29RH-II is less complex than the units already mentioned, a tip toward the typical carriers lower oil flow compared to a dedicated harvester.
Kesla’s 29RH-II is a two-wheel drive head, that will communicate with other control and measurement systems. Kesla itself offers different versions of the proLOG-system. The head features a three hydraulic and one stationary de-limbing knives. The feeding rollers are mounted on a linkage, which allows them to carry more weight on larger stems, increasing their grip on the trunk. The 29RH-II harvester head is ideal for felling crooked and branched hardwoods due to its compact dimensions. Kesla can also supply and fit extender booms to increase reach, but this will naturally impact the carrier size requirement.
AFM FOREST
Another head out of Finland, AFM Forest offers the AFM 65, which sits as our class choice for this feature. The AFM 65 is a three-wheel drive head but with four drive motors and, like rivals, will fit either an excavator or wheeled harvester. Featuring an easy-to-integrate measuring system, the AFM is similar in feature set to the OEM heads, with four hydraulic knives and as such needs plenty of oil to get the maximum output from it. Excavator requirement is a little more modest compared with what we’ve looked at already, at 20 to 25 tonnes, and the same weight for a wheeled harvester, which will put it at the large end of carrier.
A common feature of the heads we’re looking at is automatic management of proportional hydraulics, drive wheel and knife pressure, and the AFM harvester head doesn’t disappoint in this regard. The company says the 65 is suited to felling and big thinnings, but also promotes its versatility in handling storm damaged woods and its ability to work from stockpiles. It’s slightly heavier than an OEM at 1,620kg, but has speed and power that are certainly
The AFM is very similar in design and capability to the OEM heads, but in a standalone package.
Left: Third-party heads are popular for excavator users and Kesla’s wide range of heads are aimed at smaller carriers, with the 29RH-II near the top of its series.
SPECIFICATIONS
Make AFM Forest Model AFM 65 Weight 1,620kg (without rotator)
Most efficient harvesting range 300-500mm
Max cut diaMeter 860mm ideal for… Felling and storm damaged wood Max feed force 35kN, oil flow depending
feeding speed 0-5.5m/s oil requireMent 300L/min
SPECIFICATIONS
Make Keto Forest Model 500HD Weight 1,450kg (without rotator)
Most efficient harvesting range Up to 600mm
Max cut diaMeter 600mm ideal for… Felling and thinning Max feed force 30kN, oil flow depending
feeding speed 3.8m/s oil requireMent 300L/min
Above: The rugged Keto 500HD stands out from the crowd with its caterpillar track feeding system, ideal in inconsistent stems.
competitive with those heads. The optimum working tree diameter is 300 to 500mm, but max cut is a 860mm with the longest sawbar installed.
KETO
Another from the felling Fins. Keto specialises in harvester heads and they stand out somewhat because of their track drive, which is claimed to reduce stem damage, with a much increased contact point with the wood. The 500HD sits at the lower end of the sector, in terms of max cutting diameter, but midway in terms of weight at 1,450kg. The 500HD will communicate with a number of measuring systems. Keto doesn’t specify a carrier weight, but with the mass of the harvesting head plus tree, it’s likely to be in the 20- to 30-tonne class of excavator. Keto’s 500HD has four hydraulic de-limbing knives, and one stationary. The tilt ram and rotator are built into the connecting arm, which should provide good protection of these components. The feeder drive chains are mounted on a parallel linkage to maintain consistent grip on stems of varying diameter. The feeding speed of the Keto is a little slower than others in this list, but with so much more purchase on the log, the difference in real world use may be less noticeable, as the 500HD may be able to use its 30kN to more effect.
LOG MAX
Log Max is frequently used by Tigercat when a smaller felling/processing head is required over its own large- capacity heads. The 7000 Twin has a pendulum action for the feed wheels compared to the opposing grab of the others. It also runs with no back plate wheels, as the two large diameter drive wheels do the work, pulling stems through the four hydraulic de-limbing knives. The Log Max also differs in the top knife department, with a floating knife, which aims to reduce limbs flattening on none uniform logs, as well as saving fuel with reduced friction when possible.
The 7000 Twin has a max cut of 750mm but the highest productivity range is 160 to 500mm. The heaviest in this class at 1,889kg, you’ll need a 21- to 30-tonne tracked machine to hang it off, or a large wheeled harvester, in the 18- to 25-tonne range. The control and measuring system can run either through the carrier machine’s system, or a Log Mate 510 can be used for measuring, control and reporting of harvested logs.
There is a plethora of options for the Log Max, the Hultdins SuperCut 100 saw unit being an attractive addition. The drive wheels cab can also be specced to your requirement, suiting the timer mostly harvested.
SPECIFICATIONS
Make Log Max Model 7000 Twin Weight 1,889kg
Most efficient harvesting range 160-500mm
Max cut diaMeter 750mm ideal for… Felling Max feed force 35.9kN, on standard configuration feeding speed 3.9m/s, on standard configuration
The Log Max’s design is quite different to the rest of the line-up, a floating top knife and two large feeder wheels headline features.
