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The short strong one

Welte introduces the new Skidder W190 four-wheeler.

In heavy timber harvesting, an entrepreneur wants a strong machine. But it doesn't have to be oversized. A suitable offer now comes from Breisgau.

In 2018 Welte presented the W190 six-wheeler. This model consists of two construction classes. This is because the machine manufacturer Welte took the front end of the four-cylinder series and connected it to the rear end of the six-cylinder series. This new model type was initially built as a six-wheel skidder. Now the first W190 four-wheeler went to a customer.
Emile Lucht is a fortunate entrepreneur from the Eifel and owner of the new W190. His company is located in Kall, 60 kilometers south of Cologne. He and his wife Stephanie are both trained foresters and got to know each other during their training. They founded the company in 2004, since then Emile has been controlling the machines and Stephanie has been swinging the chainsaw.
The Eifel is known for its steep slopes. In the partly rugged valleys there are often thick Douglas firs. Thick wood requires a powerful machine. The fact that it is only four-wheeled is part of the plan: "To regularly move very thick wood, but also five solid cubic meters or less, I don't need a six-wheeled machine," explains Emile Lucht. What is important to him is the compactness of the machine in combination with power.

Made for a heavy crane
The machine has power: because the rear end of the W190, including the centre joint, corresponds to the six-cylinder class. The two larger axles of the four-wheel skidder are also installed in the W230. This means more stability: The six-cylinder rear frame, for example, is about ten percent wider, ten percent higher and also a little heavier in cross-section than the rear frame of the W130. The swivel joint of the large centre joint is 35 percent larger in diameter than on the W130. "The cylinders for locking the twist are located further out, so they have more power due to the leverage effect," explains Joscha Nühnen, managing partner at Welte, and adds: "Both centre joints also have two joints, one vertically above the other, for the articulated movement. The distance between these two joints is greater in the case of the six-cylinder center joint, making the joint more stable overall". In addition, larger steering cylinders provide more steering power.
At the same time, however, the machine appears as compact as the W130, especially as it carries its smaller cab. However, the strong rear frame offers one advantage: it can carry a correspondingly heavier crane. For example, the largest possible rear crane from Epsilon would be conceivable for the 190: the X150. The four-cylinder machines from Welte, on the other hand, are fitted with the crane manufacturer's S-Class at most. So the powerful four-wheeler W190 also promises a powerful crane. In this case, however, the customer opted for an X130, more precisely an X130R72. This is similar to its big brother in the components main and luffing jib as well as telescope and "is strong enough for my purpose", explains entrepreneur Lucht. There is also a reason why the crane only reaches 7.20 metres for the logs, not eight metres, which Epsilon also offers. The 7.20-metre Epsilon luffs a little more at short distances, because the difference between the eight-metre version of the X130 and the 7.20-metre version is solved via the respective length of the main arm. The main arm of the X130R72 is therefore shorter. When the luffing jib hangs down vertically from the main arm, the crane has the most power. On the X130R72, the grab can be guided 80 centimetres closer to the machine and in this case it provides more lifting power at certain points than the longer version. Especially when the wood is particularly thick and takes the crane to the limits of its capacity, such reserves of power are worth their weight in gold - or rather, wood.
This little bit more lifting power is necessary. Because the massive Douglas firs that were felled here in Stephanie Lucht's stand now have to be moved from the slope down to the removal path. The ground is soft. Although the Welte carries the grippy Tianli tyres Super Logger SL 1 of the dimensions 28L-26 with rough cleats and steep shoulders. Nevertheless, Lucht fights his way up the slope in his W190 with chain-lined tyres. Arriving at the beginning of the back road, the 36-year-old entrepreneur quickly realises that a second uphill drive with the machine will probably not be possible. The ground is already too greasy and Lucht does not want to ruin the alley. So he resorts to a trick: First, Lucht uses the winch to bring the trees outside the reach of the crane. On the Welte double-drum winch, he had a highly compressed 13-millimeter steel cable on the left side and a 16-millimeter Dyneema plastic cable on the right. Once all the logs have been packed with the crane, Lucht always places them a little further down the aisle, continues with the machine and then moves the logs back behind. At the same time he has more logs in the rope. In this way he manages to avoid another trip into the alley, but to get all the wood out of the slope. The assembled Epsilon X130R72 truck-mounted crane does a good job in this. After all, it has a gross lifting moment of 156 kilonewton metres and, with a jib length of three metres, still lifts 4.2 tonnes. This is also necessary in this department. Because the logs on this slope impress with an average log content of 4.5 solid metres. That demands a lot from the driver and the machine.

Torque of 820 Newton metres
The W190 can take such strains: So two hearts beat within, that is, two traction motors. Both engines plus the complete drive train of a six-cylinder engine bring its torque of 820 Newton metres to the forest floor at 1200 revolutions of the diesel engine. The four-cylinder engine comes from Volvo Penta, which still complies with the Tier 4 final emissions standard. It delivers a lush 217 hp and allows working in second gear. The transmission has a good ratio and the engine has enough reserves to deliver power in second gear. This allows the operator to drive faster without any loss of power. However, because of the two traction motors, the maximum travel speed is reduced to 38 kilometers per hour instead of the familiar 40. The large Welte double-drum winch pulls ten tonnes. The rear blade also has the optional height-adjustable cable infeed. The special feature: two "windows" that give the driver a good view of the aisle even from the cab when the rear blade is raised. This is particularly useful on unclear paths where trees lie crosswise or roots protrude into the roadway. Such obstacles can be detected more quickly thanks to the recesses. "Some people will say, I never needed this. But anyone who has it will be happy to see trunks that are directly behind the sign," says Frank Hellekes, sales consultant at Welte and contact person for Lucht. 

Deflector made of steel tubes
At the end of the back lane, on the path that is once again fixed, Lucht opens the ropes and drives each log individually to the polter. Here the logs are cut into the different lengths, ordered by quality, by his wife with a saw.
At the end of this procedure it is again Emile Lucht's turn: he used to work with skidders without a crane. So he polishes the logs with the front shield. Frank Hellekes about this technique: "Since the introduction of the rear cranes, it is rarely done this way, the polishing is mostly done with the crane". Lights don't touch that: It's not for nothing that he ordered a front bulldozer from Welte for an extra tough job. This shield is also used on the large W200 eight-wheeler. It is suspended lower, namely at the level of the front axle on the frame, and is therefore fitted with cylinders at the top, which thus provide more force for pushing. "The two-metre wide French sign is even slightly lighter than the narrower 1.80-metre wide standard front lift arm," says Nühnen. Because it is specially designed for pushing. This version is widely used in France, which is why Welte internally calls it the "French Shield". The reason: In France, entrepreneurs regularly have to push back roads into the forest, as forests there are sometimes poorly developed. The articulation of the padding shield thus favours the pushing away of earth masses. Stowage boxes welded to the side make it additionally stable for lateral forces. In Germany, on the other hand, fewer and fewer customers are ordering a front polarizer shield, explains Joscha Nühnen. After all, he says, the polishing of logs with a crane is now the norm. Because Welte sells its machines with a front blade as standard, customers receive a credit note. Welte also offers a version of the deflector, which is mainly ordered by French customers. Emile Lucht, for example, ordered the tubular steel deflectors from Hellekes instead of the standard wire ropes. The rod deflectors can be tilted to the side using a swivel joint. The hinges are located on the roof rails. The rod deflectors are disengaged at the front of the vehicle. A chrome-colored swivel joint holds the two steel tubes together. If the deflectors are opened at this point and swung to the side, the cab can be tipped without having to remove the steel tubes. The bonnet, on the other hand, can always be opened, as it swivels through the closed deflectors. For Emile Lucht, these steel cab guards are the icing on the cake on a machine that has two main capabilities: Steam in the power train and a strong crane. Frank Hellekes describes it like this: "This is how we get the delicate look of the four-cylinder front end and the brute working characteristics of the six-cylinder."

The complete article was published in the magazine "Forstmaschinen Profi", issue no. 6 June 2020