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--  Equipment Report  --

The Mid-Size Option

The Cat 550 mid-size harvester proves its stuff in a field trial for J D Irving in New Brunswick.

By Harold Hatheway

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J D Irving’s woodlands group selected the remote Black Brook operation in remote northwestern New Brunswick for the Cat 550 harvester trial. The overall reaction to the machine has been positive, with comments about the harvester possessing lots of power, it being able to handle everything it ran into and offering good maintenance access. Experienced operators also felt the machine could cope well with snow.

The bright yellow, mid-size Caterpillar 550 sits solidly by a blue Rottne mini-harvester. The Cat’s twice as big and rugged, clearly a different type of machine. Comparing them is apples and oranges—but unavoidable under the circumstances. The machines sit on a New Brunswick road which neatly divides the terrain and stands of trees where the work is under way, revealing the difficulty of developing a "universal" harvesting machine.

The steep, downhill slope is a naturally-regenerated mixed softwood stand, while uphill the slope is gentle, with a planted stand of spaced, same-age spruce. The smaller, agile Rottne has been patch clearcutting on the steep slope, where larger stems can give it occasional problems. The bigger Cat 550 has been thinning on the plantation, where its greater capacity and power means higher production. Reverse the locations and neither machine will do as well.

When mechanical harvesters came on the scene they quickly became big enough to handle the largest stems and crawl over everything except the worst gullies and rocks. They were also big enough to raise questions from the environmentalists—and some woods workers too—concerned about the possible impact on forest soil and regeneration and the replacement of chainsaw operators. In essence, their size adds another factor to consider when choosing the type of equipment to use in a particular terrain.

But nothing in forestry is simple, and it gradually became clear that while the big machines were certainly cost-efficient where clear-cutting was the accepted treatment, there were circumstances where their size was a disadvantage—and of course the investment and maintenance costs meant expensive down time.

Eventually the Scandinavians developed "mini-harvesters" which were seen as the ultimate solution. In the last 10 years, the pendulum has swung back and mini-harvesters are increasingly rare in Scandinavia, replaced by sophisticated full-size machines like the Timberjack 1270B and Valmet 921 as well as mid-size harvesters built by a number of manufacturers.

In North America, the full-size machines are still very much in use, but the shift from clearcutting natural-regeneration stands to steadily expanding "planned" stands— plantations with pre-commercial, first and second commercial thinnings and semi-permanent road systems—makes equipment changes inevitable. Major North American manufacturers have become involved, with Caterpillar taking control of equipment manufacturer Skogsjan.

This development has been of special interest in the Maritime provinces where extensive cut-to-length was pioneered. Stems are comparatively smaller and con-tractors need equipment which can per-form well throughout much of the year in the widely-differing conditions between the seacoasts and the interior. Machines which are not versatile work fewer weeks and aren’t cost-effective.

It is no surprise that J D Irving Ltd., a major player with owned and leased operations throughout the region, is actively looking for equipment which will be operationally, financially and environmentally viable in the planned stands of the future. The reason is simply that Irving is already there. Founder K C Irving began producing genetically-selected greenhouse stock and establishing massive plantations well before most companies. There is now an urgent need for harvesting equipment which is "soft-on-the-earth" but rugged enough to handle larger stems in less-manicured stands and work during heavy snowfall.

That’s a big order and Irving, with a reputation for wanting to know exactly what it is buying, has invited manufacturers to demonstrate their wares under real conditions. This has led to trials of two machines. Last fall, the Partek’s Valmet 901C (Valmet 945 head on a Cranab 690 parallel crane) was tested by Irving staff in southwestern Nova Scotia with favourable comments and now the Caterpillar 550 is having its turn at Irving’s Black Brook operation in north-western New Brunswick.

The Cat 550—still in the work up stages—is powered by a 3126 DITA Caterpillar engine, has an 1800 extendible stick boom, front and rear frame short pendulum arms, a HH45 harvesting head, DASA 380X computer head control and 700/55-34 14PR (4) T Trelleborg tires. Operator comfort is ensured by a BEGE air-ventilated mechanical suspension seat, Marguard green windows, plus air conditioning and a radio/cassette package.

Caterpillar puts its prototypes through preliminary testing, makes any design and functional changes and then carries out in- depth, real-life trials called "field follows". Caterpillar provides parts (based on trials and European experience), manuals and maintenance information and close involvement by Cat staff in a carefully selected, low-profile location, making Irving’s isolated Black Brook operation ideal.

Irving approached Caterpillar about trying out the Cat 550 in the remote north-western New Brunswick location. The unit and the backup package was provided through the local Caterpillar dealer, Atlantic Tractors and Equipment Ltd., of Fredericton, New Brunswick. The machine is operated by a contractor working for J D Irving Ltd. All problems, other than simple routine maintenance, must be reported to a Caterpillar representative, who either pro-vides instructions by phone or, if there are complications, comes on site himself. Everything is carefully documented for future reference.

This makes the contractor’s situation a bit of a gamble—if there are few problems and little down time, and if operators can get up to speed quickly, the absence of payments on a machine means a good profit. But serious downtime or lengthy operator familiarization, combined with ongoing expenses, could quickly put a contractor in the red.

In this case, contractor Marc Beaulieu has several things going for him: experience, a good relationship with Irving and ownership and operation of a machine shop in nearby St. Quentin, specializing in logging equipment. As an Irving staffer working with him on the project put it, "Marc’s shop has worked on just about every piece of logging equipment used in this area. In fact, he could pretty well build just about any of them."

Nevertheless, the 550 had some start-up problems. One was in the electrical wiring while the other was more persistent and challenging—the head simply wasn’t measuring properly, with inaccurate lengths the result. Both problems meant waiting for the Caterpillar rep to come on site. Once located, the wiring problem was quickly eliminated, but the head problem was only solved after a number of experimental wheel changes to eliminate slipping and jamming. The lesson learned here was that different seasons of the year produce different bark conditions, which in turn require different wheels.

The overall reaction to the 550, however, has been good—lots of power in a solid machine that could handle everything it ran into, good maintenance access and, while mid-summer is no time to assess snow capability, experienced operators feel the machine would cope well with it.

The Cat 554 forwarder making up the package had its share of problems too: the front-located muffler took a beating from trees and limbs—a problem easily solved by re-location; and the bed was just a bit too short to accommodate two ranks of eight-foot wood, meaning half-empty trips. But discovering such things are what trials are all about.

Danny Levesque, the Irving employee responsible for overseeing the thinning operations at Black Brook, explained most plantations get a first thinning at about 25 years, when they have a volume of about 160 cubic metres/hectare. The site chosen for the Cat 550/554 trial had been left for 33 years to increase the volume a con-tractor could expect to get and offsetting difficult working conditions. The trials would reduce the 2,800 stems/hectare to 900-1,000, and the volume from 210 to 120 cubic metres, yielding 90 to100 cubic metres per hectare.

Levesque explained the close spacing left after the first thinning requires a narrow-track machine, raising some concerns about the width of the Cat 550. But the Cat was highly manoeuvrable and had no difficulty in meeting the objectives. He agreed, however, that the much steeper slopes would pose a challenge to the mid-size unit.

Black Brook manager Gaetan Pelletier stressed that the unit had only been on site for four weeks and the "de-bugging" process meant that there had only been about 2 1 / 2 weeks of real productivity.

Nevertheless, both he and Michael Beaulieu, brother of Marc, felt that the machine had performed well. It appeared to have the capacity to work under most of the conditions of stand, terrain and weather expected and the time required for operators to get up to speed appeared to be well within expectations. In fact, the only half-serious criticism was that once operators had experienced the Cat 550’s ease of operation, they would be reluctant to move back to a mini-harvester.


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This page last modified on Tuesday, February 17, 2004