Pocket Power Pack
The Forcat goes diesel. In May this year Forestry Journal carried an enthusiastic report by Ed Robinson on the Forcat skidder who considered it well able to fulfil the Canadian manufacturer’s claims, and offer the buyer a costeffective lightweight machine, with exceptional manoeuvrability and pulling power. Likewise, the Forcat UK agent, Forest Machine Services (FMS), has had very positive feedback from customers, including one who had fitted a three-point linkage to carry a drilling head used for taking soil samples in connection with site investigations.

In this application the user was delighted with the machine’s performance in that it could access areas impassable to other machines. However, FMS were aware that in the UK many potential customers would prefer to avoid petrol engines, so they contacted the manufacturers and explained that a diesel option might be worth considering. FMS were greatly encouraged when the manufacturers, Équipements Tremzac Inc, eagerly agreed to do
so, in spite of the petrol-engined version having been so successful in Canada for the past 15 years. They were further encouraged when the first diesel-engined machine arrived in the UK.

The new version had been fitted with the Perkins 404C15, but Tremzac had not just swapped the petrol engine with a ‘will-fit’ diesel. They had gone to a lot of trouble to ensure the additional weight was well forward so as to improve balance and traction, in order to make full use of the additional pulling power from the engine. Since the physical size and weight of
this engine are substantially greater, and the engine needs more cooling capacity, the final machine looks considerably bigger than its predecessor. Designated the Forcat 36D, and weighing in at under 1.9 tonnes, but sharing the same fourfoot width of its petrol driven stablemate, manoeuvrability off road and transportation on road are not a problem.

Since the engine is commonly used in the UK, as are the hydraulic pumps, valves, winch and controls, all spare parts will be readily available through the dealer, so ensuring that the machine will require low maintenance. According to experience already gained, track wear is
not likely to take place other than on the grouser bars, and these can easily be changed. New rubber tracks, should they be needed, can be located in the UK. Changing tracks and other maintenance duties are made easy since the machine can lift itself clear of the ground
by using the front blade and the butt plate, but for safety reasons it should always be remembered that lifting a machine by means of its hydraulics should only be done to enable suitable stands to be placed under the machine prior to any work commencing.

Initial user feedback indicates that the Forcat can do a day’s work on approximately 20 litres of red diesel. The engine is also designed to accept bio-diesel. The operator’s workstation is
fully compliant with the necessary regulations, demonstrated by the applied CE mark. Other safety features include the transmission locking brake, which is automatically applied when the weight of the operator is removed from the seat, thus not only ensuring that the parking brake is applied when the machine is unattended, but also, should the operator fall from the
seat, the machine will not take off.

Operators will also appreciate the simplicity of the controls and the easy access to the operating position – a feature which is most important when skidding work is being tackled as a one-man job. To increase the versatility of the Forcat, a trailer is available from the same manufacturer, and this can be used to forward up to 5-tonne payloads. Also, an auxiliary hydraulic control facility, a rear mounted three-point linkage system, and a higher flow pump, which increases the flow from the standard 9 gallons a minute to 18 gallons a minute, makes possible the fitting of a toolbar in place of the front blade, allowing a wide range of tools to
be fitted.

To introduce the new Forcat 36D to the UK, Forest Machine Services had invited interested parties to a demonstration in Perthshire with the object of putting the Forcat through its paces on two extreme sites. One was an SSSI site at Drumcastle Farm near Loch Rannoch, where a wetland area was being cleared of unwanted scrub and ground damage had to be avoided at all costs.

The other was a steep Commission site in Craigvinean forest where top quality Douglas fir logs had to be skidded from a continuous canopy area without damaging the standing crop. Two very tall orders for a lightweight skidder, since zero ground damage is seldom possible
with a tracked machine, and heavy logs are not usually extracted from a steep site with a skidder weighing a mere 1.9 tonnes. At the first site the ‘wetland’ turned out to be almost totally submerged, and to make matters worse, a short but heavy snowfall had covered the area sufficiently to hide the few dry patches which were presumably there somewhere.

When approaching the scrubwood that was to be skidded off, the Forcat’s only disturbance was to the snow cover. This was no surprise since it was not pulling anything. What was surprising was that when a turn of scrub wood, some of which had stems of around 40cm diameter and were heavily branched, was attached via the 8,000 lbs linepull hydraulic winch, the Forcat again travelled off without tearing the ground-cover vegetation.

Even when pushing the material into piles with the 48” front blade, a task entailing multiple direction changes, damage to the ground was inconsequential. Exceptional manoeuvrability is achieved by the Sundstrand variable flow hydraulic 2-speed transmission which allows one track to be reversed, while the other maintains forward rotation. The lack of ground damage is due not only to the 3.4 psi ground pressure, but to track assemblies that have more in common with a military ‘Bren Gun carrier’ system than they have with civil engineering
excavators or bulldozers in that they have a system of floating jockeys instead of fixed rollers running on the back of the track.

Also, like the Bren Gun carriers, the track drive sprocket is at the leading end of the track assembly which allows the weight of the machine to be applied more evenly over the ground contact area, giving more positive traction. When the scrub was collected into piles and the observers were content that the ground damage was virtually non-existent, the ‘circus’ moved off to the next site.

On the Craigvinean site the Forcat negotiated the roadside ditch and climbed up the steep roadside banking into the forest without any great drama. When the Forcat is on a steep slope it becomes obvious that the manufacturers have got the engine position right, in that
it is vertically above the centre of the track’s contact area with the ground. As the Forcat negotiated its way across the obstacle-strewn forest floor, it became clear to the onlookers that its other features, such as a low centre of gravity, good ground clearance, and the smooth belly-plate, all played an important part in helping the machine to move around unimpeded.

The logs that were to be extracted commonly weighed over half the weight of the Forcat, had been lying a while and were fairly well bedded into the forest floor, making them
difficult not only to choker but also to move. However, by judicious use of the winch and butt-plate, which had a convenient lip sufficient to take the weight of the log, they
were soon secured to the Forcat and on their way to the roadside. On the steep decent approaching the forest road, the Forcat’s hydrostatic transmission’s ability to prevent the logs taking charge and pushing the skidder downhill became evident. In the same circumstances much heavier machines with conventional transmissions and braking systems would demand high levels of skill and courage from their operators.

Thanks to the hydrostatic transmission on the Forcat, minor slides encountered as a result of traversing patches of the forest floor offering low traction did not escalate into dramatic
situations demanding heroic remedial actions by the operator. On this site amongst the impressively lofty Douglas fir, the Forcat again was able to impressively demonstrate its
ability to work competently. Considering that the cost of the machine is only £5,000 more than a bottom-of-the-range four-wheel drive estate car, it is impossible to argue that the Forcat does not offer impressive value for money. What also was impressive was the reaction
amongst the onlookers at both demonstrations, in that, as well as the approval of the machine’s performance as a skidder, they generated a continual barrage of ideas for other uses for the Forcat.
Forest Machine Services
01434 230852
Jim Christie