Dec Jan 2004/2005 - The Logging and Sawmilling Journal
The Swedish Beast in the forest
A new harvesting system called the Beast and her Messengers—involving three machines, but only two operators—is showing the Scandinavian spirit of forest equipment innovation is still alive and well.
By Dieter Biernath
The fabled Scandinavian spirit of invention is not dead, though it’s been suspiciously quiet for some time. There has been little recent innovation in harvester and forwarder technology from the lands where mechanized harvesting originated. But now that silence has been broken. Near Vislanda, in southern Småland, Sweden, a revolutionary timber harvesting system has been undergoing testing for a year.
The men behind this world-first are contractors Christer Lennartsson and Jan Carlsson from Vislanda. They are well known in forest machinery circles. For example they invented the Fiberpak, the brash bundler which is now part of the Timberjack range. The new system is known as “Besten & Kuriren”, which literally translated means the Beast and her Messengers. Under this system, two forwarder drivers take turns to operate a harvester while still at the controls of their forwarders. The system reduces both the harvesting logistics and costs. The harvester has no cab or other frills. So, two operators, three machines, and all of them operating all the time… How exactly can that happen? The “Beast” is actually a remote-controlled harvester.
Without a cab, it consists simply of a chassis with six wheels and a crane fitted with a harvester head; that’s all. The chassis is constructed of steel, up to 40 mm thick, in which an engine is fitted—a 6.8 litre John Deere turbo intercooler which produces 225 hp. Transmission is via a Rexroth hydrostatic pump, with Rexroth components for other hydraulic functions. The Beast moves on six wheels, three 600-26.5s either side. The wheels, mounted individually on swinging arms, can be hydraulically raised or lowered. The machine is leveled automatically while working, but each wheel can also be manually controlled. Additionally the wheels were fitted with Olofsfors Eco-trac bandtracks. The flat, 18-tonne machine is steered like a tracked machine by braking the wheels on one side. On the forward part of the machine is a Mowi EGS A7 crane with a reach of 8.7 metres and a lifting capacity of 20 tonne metres.
The crane is notable for its wide slewing circle, and is moved by two hydraulic motors. The slewing force is 4.5 tonne metres. On the end of the crane is a Votec 850 harvester head with a felling diameter of 85 cm and a delimbing diameter of 60 cm. The machine carries 400 litres of oil and 600 litres of fuel. The Beast is controlled from the forwarder. Christer Lennartsson drives a Rottne Rapid SMV which has been specially converted for this purpose. All harvesting operations are conducted from its cab, in which the harvester’s computer is located. At present this is a Dasa 4. The operator manoeuvres his forwarder into position, swings the forwarder crane to one side.
He moves a lever, enabling him to operate the harvester crane via the forwarder’s crane control system. It is not possible to operate both cranes simultaneously. Apart from that, the keypad is just the same as in a harvester. The operator cuts timber directly onto the forwarder’s load bay. To make this easier, the operator rotates the load bay 90 degrees and folds back the pins, which can be tilted outwards 30 degrees. Then he starts harvesting. The load area on the forwarder is not only rotatable through 360 degrees, but it can also be tilted plus or minus 10 degrees. Thus it is always possible to keep it in the optimal position for the harvester crane. It’s quite eerie being in the forwarder cab as the operator does the felling and delimbing: no working movements are felt, nothing in fact, as he operates the harvester.
The forwarder engine ticks over in neutral, and all is quiet—a pleasant workplace. Only the first, thick logs falling into the bunks make the machine shake a little. Once the vehicle has been filled, the operator drives to the unloading area. If he has to pass through narrow racks or tracks on the way, the pins are drawn into the upright position. The system is intended for use with two forwarders, which take turns to serve the Beast. Of course, both operators have to master not just their forwarders, but must be equally adept with the harvester. Once the first forwarder has set off to the unloading area, the second forwarder driver cuts himself a load. Changeover occurs immediately when a forwarder returns from unloading.
The communication between forwarder and harvester is conducted via a radio link. Both inventors remain silent about this at the moment. The manner in which so many functions can be controlled simultaneously is quite new. The system is particularly suited to clearcutting as carried out in Scandinavia. It seems unsuitable for other harvesting methods. Nevertheless, this system marks a new era in harvesting technology. Jan Carlsson and Christer Lennartsson have clearly shown that the classic Scandinavian spirit of invention is not dead.
The harvester is transported on a simple low loader behind the forwarder. The harvester drives over the two bars on the low loader, and raises its wheels so that its chassis sinks onto them. The chassis is then attached by means of chain. The wheels are then lowered, raising the chassis until the eye on the drawbar is positioned correctly for the hitch on the forwarder. This is then attached, the wheels are raised again, and off it goes—it’s as simple as that. A cheap but effective solution, suitable at least for transport on Swedish roads.
This article was originally published in Forstmaschinen-Profi magazine earlier this year.
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