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Previewing Ponsse’s Scorpion harvester

Ponsse recently put on a tour of its facilities in Finland—including a demo of its brand new Scorpion harvester, which will soon be hitting North America—and Logging and Sawmilling Journal has the full report on this new concept harvester.

By George Fullerton

The late Einari Vidgren, founder of the Ponsse line of forestry equipment, had a simple message for engineers when they began to envision a new concept harvester, according to his son Juha, the current Chairman of the Board. He essentially said: “Don’t copy, don’t compromise. If we can’t make a new concept harvester, then don’t bother.”

Well, they have made a new concept harvester and the culmination of that exercise, the Scorpion harvester, was launched at the 2013 Elmia Forestry show, and it profoundly sets a new standard for innovation.

Ponsse invited the North American forestry media to their home base in Vierema, Finland for a double celebration in early October. First on the agenda was the celebration of the 9000th Ponsse forestry machine, an Elephant king forwarder, rolling off the assembly line. The Quebec customer for this special machine was Lemieux and Girard Inc., represented by Rejean Girard and his sons, Christopher and Andy. The second celebration was the presentation of the revolutionary new Scorpion harvester. Although it was introduced at Elmia, only photos and video of Scorpion have so far made it to North America.

Ponsse delivered excellent hospitality, with beautiful late autumn weather, and the company presented a detailed overview of their business and development history, their current business strategy, an in-depth look at their production facilities—and one of the highlights, the Scorpion in action on a eastern Finland woodlot.

Visually, the eight-wheel Scorpion is eye-catching, sporting a cab with so much glass it resembles a fish bowl rather than the command centre of a high production tree harvester. Cabs have certainly come a long way from the years when protection grilles and large cab frame posts obstructed the operator’s view of the work site, to this high visibility cab that comes equipped with roof to floor screens to control heat and the sun glare.

Visually, the eight-wheel Scorpion is eye-catching, sporting a cab with plenty of glass. The cab offers operators an optimum view of the machine path and the operating site. The cab not only provides excellent forward and side views; a sizeable back window and an angled top window provide view of tree tops, a critical need for controlled felling and silviculture decisions.

The Scorpion cab offers operators an optimum view of the machine path and the operating site. The cab not only provides excellent forward and side views; a sizeable back window and an angled top window provide view of tree tops, a critical need for controlled felling and silviculture decisions.

The second most intriguing visual feature is the crane system which anchors to a cast foundation, which is also the base for the cab. It extends in a wishbone fashion over the top of the cab and connects together and supports the new C50 parallel boom crane.

The cab and crane foundation are centred directly over the cab/crane base slewing ring, so the cab and loader rotate in precisely the same turning point and the harvester head is continually in front of the operator’s forward vision. There is no crane post and hose bundle to obscure the operator’s vision of harvester head travel or operation. The operator will have a lot less need to stretch or twist in the seat to view either the head or ground and stand conditions.

Since the operator seat sits directly on top of the cab turning point, there is no merry-go-round effect that the excavator-type harvesters possess. That translates into less of the operator’s energy directed to maintaining balance while traveling and operating, which translates into higher overall productivity.

The third unique feature of the Scorpion becomes apparent when observing the machine travelling. Rather than the conventional two-frame design, the Scorpion has three separate frames, with the cab and crane mounted on the centre frame. As the machine travels, the front and rear frames rotate independent of the centre frame, which remains leveled by a combination of sensitive positioning sensors and leveling cylinders.

In addition to the three-frame concept offering advanced cab levelling function, the Scorpion also sports a unique stabilization system that senses load lift on the crane and hydraulically transfers that lift resistance to the rear frame and engine mass. This load transfer mechanism dramatically balances out the lift, pull and twist forces faced in harvesting processes, as well as actively smoothing out travelling.

While the Scorpion might appear long, its overall length at 316” compares to the 317” of the 8-wheel Ponsse Ergo, and it is significantly shorter than the 8-wheel Ponsse Bear at 350”. The Scorpion’s crane lift torque is spec’d at 252 KN, which compares with 255 KN for the Bear and 230 KN on the Ergo.

In the harvesting demo, it was somewhat dramatic to observe the Scorpion’s operator and observer/passenger’s lack of body and head movement while travelling or harvesting, compared to the bracing and twisting movements that are typical in conventional harvesters. The Scorpion operator appeared very relaxed and comfortable, with attention focused on the harvest head.

Ponsse marketing manager Antti Rasanen (above) points out features of the Scorpion harvester. The Scorpion is designed for ready access for servicing; it features a tall engine cowling to contain the Tier IV Mercedes Benz engine.

The Scorpion’s stabilization system definitely sets a standard in regards to operator comfort. Additionally, the stabilization system operates while the machine is both stationary and travelling. The system will stop travel if the stabilization system is taken beyond a safety threshold.

While cab and crane configuration are the primary eye catching elements, the engine cowling on the rear frame is a new look for Ponsse. The Scorpion’s cowling appears significantly higher than other Ponsse harvesters. Antti Rasanen, Ponsse’s marketing manager, explained the expanded cowling was necessary to house extra pollution control equipment that comes with six cylinder Mercedes Benz Tier 4 engines. The new (European market) engine rated at 286 horsepower sports both SCR (Selective Catalytic Reduction) and EGR (Exhaust Gas Recirculation) pollution control systems. While Tier Four will be used in European markets, it is expected that North America will initially receive Scorpions with Tier III engines.

In addition to the unconventional structure of the harvester crane, construction is a bit unusual in that both the mounting base and the structural members arching over the cab are cast units, rather than fabricated steel structures.

While Ponsse engineers have confidence in the performance of the forged components, the Scorpion’s base and crane system are subjected to extensive destructive testing at facilities at their manufacturing centre in Vierema. To base-line the testing, stress loads affecting the Scorpion`s cab and crane base and crane system were measured and recorded in an in-woods production application.

In the test facility the Scorpion base and crane system functions (lift and swing) go against resistance provided by a series of anchored hydraulic cylinders. The controlled testing insures that forces exerted on the base and crane system correspond equally to the recorded stress levels collected in the live woods harvesting. Testing will continue, at least, to an equivalent of a minimum of 10,000 hours of service duty.

The Scorpion cab appears smaller than the cabs on other Ponsse machines, but despite the compact look, there still remains room for an observer to squeeze in behind the operator’s seat—with still further room for a picnic basket and stowing a suit of insulated coveralls for those brisk winter days. The cab features the most up-to-date Ponsse comfort controls and effectively designed machine controls and screens.

Access points for service and maintenance are well thought out. Another comfort feature is the placement of a tool box on top of the hydraulic tank, which translates into warm, dry storage of bars, chains, hoses and other consumable necessities through those cold winter months.

The Scorpion harvester was accompanied in the Ponsse demo by the company’s Ergo harvester and Elephant forwarder. Quality control is a big focus for Ponsse; all machines are tested in a harvest operation before being shipped to customers.

The C50 Crane is a four chamber design which ties the extension travel to lift cylinders, to balance crane geometry and lift capacity. Crane reach is 34 feet on the standard Scorpion.

In addition to the basic Scorpion model, Ponsse will also offer a Scorpion King model which provides two hydraulic pump systems (145 and 190 cubic centimetre) compared to the single 210 cubic centimetre pump on the basic Scorpion model. The King also has a little extra reach and tires are 710/45-26.5 compared to 600/55-26.5 on the standard model.

While the basic Scorpion is marketed with either the Ponsse H5 or H6 processing head, the Scorpion King comes equipped with an H7 head, which offers significantly more diameter capacity and cutting and feeding power.

In October, the Finnish Society of Automation and Meesukeskus awarded Ponsse the Viva Automation prize in recognition of the design innovations of the Scorpion’s stabilization and leveling systems. The Viva Automation award recognizes innovative product solutions in the field of automation and is awarded every two years. The announcement recognized that Ponsse utilized exemplary automation technology in the design of a new type of machine.

Jean Trottier, sales director with Quebec-based Hydromec Inc.—and a long time Ponsse salesman—says the Scorpion sets a new bar for forest harvesting, offering five new patented technologies. Hydromec expects to take delivery of the first Canadian machine in October 2014. The first Scorpion in North America will arrive in Rhinelander, Wisconsin in June 2014 and will go into a live demo.

Trottier said that the Scorpion is so impressive that it pretty well sells itself.

“I attended the Elmia launch of the Scorpion with a group of Quebec-based contractors. Among the group was Bertrand Tremblay and he was especially impressed with the Scorpion. Bertrand is a very successful contractor, and is very good with technical issues including electronics and hydraulics. Bertrand’s wife and two sons also work in the family business. His wife recognized Bertrand’s enthusiasm for the Scorpion, and proceeded to place the order with Ponsse right there at the Elmia Show, commenting, ‘my husband would love to have one!’.”

The Ponsse tour included an in-depth look at the Ponsse production facilities, but one of the highlights was the new Scorpion harvester in action on an eastern Finland woodlot.