The stock is totally in the bucket. Wide stripes in the spruce forest glow reddish, and the needles trickle softly. The bark beetle has been at home in this forest near the village of Kalletal south of Porta Westfalica in North Rhine-Westphalia for months. Dennis Batzer will abort the inventory in some areas. The 32-year-old does not climb into a harvester, however, but a Welte W130M. A Log Max 4000T dangles from the outrigger of the skider. In Austria, combinations of forestry tractors and aggregates are common. Small forest areas squeezed between rock walls often do not give enough harvest to a harvester. In Germany, on the other hand, this pairing is rather rare. Two entrepreneurs from Kalletal bought exactly this solution.

It gets lighter
Batzer first needs to have a clear view. He fetches a spray bottle with glass cleaner from the world and foams the domed rear window of the combination machine with it. Today is the first glorious autumn day of the year, and the sun shines from the sky, but also deep from the front. With a spotty pane, Batzer would hardly be able to tell where to start the unit. After the little autumn cleaning, the trained forester and tree gardener swings into the pilot's seat and starts the engine. The four-cylinder from Volvo Penta wakes up under the hood. Then its 190 hp push the skidder backwards out of its parking position in order to pull it up a small climb. After a first open space covered with trunks, Batzer circles the world in the dense, dark spruce forest. But it will soon be brighter here. Countless trees are marked, many noticeably let the branches hang or are simply dry. A classic pure spruce stock of medium size - worth a gold a year ago, soon to be cleared.
The crane, an Epsilon S110 with a reach of 8.60 meters, extends. The Log Max head swings to the first spruce trunk, the rail whirls into the tree and fountains of sawdust glitter to the ground in the sunlight. The tree has little of all this harvest romance. He falls to the ground and is quickly delimbed, cut up and stripped of his crown. A hacker waits for them later. And now it's the next candidate for spruce. Harvesting is a short process. The hydraulics of the Welte always pump enough oil into the lines and oil motors for the small Log Max 4000T. The pump performance of the Welte is naturally sufficient. However, the entrepreneurs preferred the option "Harvester preparation with control block extension". This installation of an additional valve offers Welte exactly for the use of a reprocessing head - costs around 2,000 euros. With up to 170 liters at 1.00 revolutions per minute, the oil supply rotates through the system of the world. "We even have reserves and could increase the pressure even more," assures Batzer. With the current setting, the head reaches a feed speed of four and a half to five meters per second. This corresponds to the manufacturer's specifications. There is a 670 rail on the Log Max. "A 55-foot stem can still be cut with it," explains Batzer. However, at over 830 kilograms, the compact Log Max 4000T plus rotator is still a real chunk. "The S110 is the largest forwarding crane available for the 130." Nevertheless, Batzer has to admit: "On the long arm you can just get the unit raised." But the overall package that Welte put together and delivered to the company in June is working. How did it come about that Batzer ordered a Skidder aggregate combination from the machine manufacturer in the Black Forest?

Above all impact
As I said, Batzer is, among other things, a trained forester. His neighbour's name is Lars Sprenger, also a forester and a one-man business for many years. Even before his apprenticeship, Batzer helped his neighbour in the forest. Later he also worked as a self-employed forester. Because the two of them worked together more and more often in the forest, they eventually asked themselves the question: "Why don't we make a company out of it," Batzer says. So the younger and the somewhat older 46-year-old Lars Sprenger founded the forestry and tree felling service as a GbR. That was in 2016 and the company now has three employees
The tasks of the troop, which consists of two other foresters and a farmer: "First and foremost, we do motor-manual felling. We get to almost nothing else," explains Batzer. The team is divided into two routs, each with one world at its side. The motor-manual beechwood felling in particular is on the agenda. because the guys with the saws are completely booked out, the Welte came into focus. "We're absolutely out of motor-manuals." One of their thoughts was to buy a harvester. But there was a lot to be said against it: The times are very bad for that right now. In view of the high demand for machines throughout Europe, delivery times are rather long and the market for used machines is empty. In addition, the motor-manual cutting group would have become a harvester company. That would have meant completely restructuring the company. What is important to them, on the other hand, is the flexibility of a combination machine with a harvesting head without the financial outlay for a harvester and forwarder that they would have needed.

There were many arguments in favour of the Welte head solution. One important one: The company already owns a Welte, a W130K. So the two know about the quality of the Black Forest Skidder. In addition: "With the W130K you can go 40 speeds. and you can hear everything." Meaning that not only is the Welte faster than a cut-to-length machine, but it also fits all the equipment on it. Because the 130M was purchased with the two-piece combi basket. This provides them with a stake basket and a folding clamping bench, which can also serve as a loading stool. When they go into action, the basket with clamping bench is assembled, the grab is bolted to the crane and the processing head is clamped between the stakes. "That way a man can work completely independently," says Batzer happily, and you hear that the Juns from Kalletal are simply combination fans. They need a machine that can do many things. Not to forget: "We can put the unit in the corner. Not the harvester." Nevertheless, the two of them know about the performance of the Welte: With 16,000 hectares of forest area, the Lippe regional association is a large municipal forest owner and the largest client for the company. Besides there are however some forest owners in Kalletal, who have to harvest straight once 50 solid cubic meters. Batzer and Sprenger want to fulfil these orders equally. With the Welte all this is possible because the machine allows for quick repositioning and handles all forestry tasks.

The Log-Max unit, which the forestry company bought new, was assembled by Welte. The technicians laid a hose package that extends from the control block at the base of the crane to the beginning of the luffing jib. The hoses end in a coupling protected by a steel plate. From here the remaining supply lines run to the Log Max. These are suspended via two sleeves at the tip of the telescopic boom. Here the lines are neatly tidied up, so they can also be dismantled quickly. When the head is dismantled, the sleeves are also pinned. Dismantling the head only takes about half an hour, because the hoses are practically falling towards you. The conversion from the packing tongs to the unit takes up to 40 minutes. The main hose package, on the other hand, always remains on the crane, but could also be completely dismantled. This is an advantage if the world is used exclusively for the back for a long time and the hoses are to be protected from damage. In addition, a dismantled machine is easier to sell again.
The screen as well as the control unit in the Welte cabin are from Log Max. Incidentally, Dennis Batzer chose the product range on the left-hand side, the power unit functions on the right-hand side. Finally, a Log Max service partner took over the final adjustment of the head.

Too thick remains standing
In the spruce stand near Kalletal, Batzer cuts as much wood as possible with the W130M. Whatever is too thick or inaccessible for the crane stops. At one o'clock in the afternoon Batzer switches off the engine - but only briefly. Because it is shift change and employee Tim Lürsen gets on the machine. In fact, the Welte is working at full capacity from five in the morning to nine in the evening. While Lürsen now controls the machine, Dennis Batzer reaches for the chainsaw and cuts the remaining trees, which he or his employee delimbs with the Welte and cuts into assortments. For very thick trees, the forestry service provider also uses a pull-through sensor. However, wherever the strongest timber is felled, the second cutting team and the W130 K are also regularly on the road. "Two to two-and-a-half-foot trees are no problem for him."
The Log Max does its job to the full satisfaction of the entrepreneurs: "On one day, after working with the unit for several weeks, I cut a good 160 solid cubic metres in one shift," reports Batzer. But he admits: "That was also top quality wood." In order to make the best possible use of the combination machine in other respects as well, the entrepreneurs make use of the strengths of the team: the problem with combination machines with a reconditioning head is often the poor time to performance ratio. a skidder hardly ever achieves the cutting performance required to be able to finance the machine. At the same time, it cannot be used for the back during the time it is carrying the unit, which is the real king disciple of such a machine. In addition, time is lost due to the conversion from gripper to unit and back. In order for the combi to make sense, however, it must be used in strokes where it can play to its strengths". These include rather smaller, scattered areas, which are often the case with the forestry service from Kalletal. According to the manufacturer, the Log Max 4000T packs diameters up to a maximum of 58 centimetres. Anything thicker is processed manually by motor. This means that anyone who equips a skidder with a head also needs a manual team to cut down trees that are too thick, too heavy and too knotty for the head. In addition, the men with the chainsaws sometimes have to cut trees that the crane with its reach of 8.60 metres cannot reach. It is important to let the combination machine loose only on those trees that can be managed without much cinnabar, i.e. which do not reduce the performance. The coordination between the motor-manual crew and the machinist must also be smooth. Finally, no trees must be forgotten that the Welte driver had to leave standing. Once every log has been processed, the W130M is converted to the grapple and fitted with the two-part combi basket or just the clamping bench. Then it goes to the back. When the felling team cuts four to five-metre logs, even a back carriage is coupled to the Welte if the terrain permits. The Welte with basket and back carriage can then accommodate up to 15 solid cubic metres.
Today, three meter chipboard, five meter sections and the currently common container wood are produced on site. Once the stock has been thinned or cleared and moved, the work of the Welte-Log-Max team is done. The final step will be the mulcher of a friend of mine, who will leave the area ready for planting: entrepreneurs Dennis Batzer and Lars Sprenger have put together a machine that can do almost everything that harvesting timber requires. The concept of a tractor with a processing head works, if used correctly, not only in Austria but also in Germany. It is possible that a trend is emerging here, fired by thousands of hectares of damaged wood that urgently need to be processed.

The complete article was published in the magazine "Forstmaschinen Profi", issue no. 12 December 2019