New Life for Old Iron
St Anne Nackawic gives new life to Koehring equipment with an injection of Komatsu iron.
By Harold Hatheway
Hugh Hambly watches as a tractor trailer-one of the 170 to 200 each day hauls 32 to 20 tons of the foot round wood alongside the huge hybrid log loader in the St. Anne Nackawic millyard. In the ten minutes it takes to move every stick to the top of the 30-foot high pile, his smile grows at the father watching his son scoring a winning goal. The company isn't so farfetched because Hambly, equipment maintenance manager at the hard wood pulp mill in Nackawic, New Brunswick, is unquestionably the man responsible for dreaming up and then developing this piece of equipment.
Specifically it was his idea to marry the bottom half of a retired Koehring feller buncher to this specially adapted, upper half of the new Komatsu backhoe. Four of these monsters (17 feet wide, 44 feet long, with a 40 foot high boom) represent St. Anne's solution to the waiting trucks and costly down time which threaten when trucks roll in to build up log inventory. The investment of $2.4 million in the equipment is seen his money well spent, guaranteeing some 12 to 15 years of solid, dependable performance.
So why not develop a relatively straightforward adaptation of the original machine-an upper section which could turn 360 degrees and an adapted boom with a simple grapple replacing the original combination cutting head and grip, plus a carrying bunk in back. With the decreasing demand for units in traditional woods applications, convincing Koehring to consider a log loader variation wasn't too difficult. It worked, and in the years following 1986, St Anne Nackawic purchased four of the Koehring log loaders. They were mobile, tough, had a reasonable reach and a thoroughly tested technology, minimizing down time and delays. However, Koehring was in trouble.
Orders for feller bunchers were drying up and, because orders for the millyard adaptations were limited-almost "one of a kind", the price soared towards $1 million. The end was in sight. By the late 1980s, Hambly advised St Anne Nackawic management that decisions had to be made about replacement of their existing Koehring millyard machines. Choices were limited: revert to smaller units which would not stand up to the workload, commit to the very expensive, and somewhat limited, portal cranes or try something different, something to which he had given a great deal of thought. Hambly knew that the Koehring bottom unit was an ideal base, mobile, stable and "bulletproof". Most old Koehring units had run 50,000 or more hours, but he was confident that this posed no problems, in part because he believes metal fatigue is exaggerated. "I haven't seen it many times in my long career."
His earlier efforts to interest manufacturers of upper units weren't successful, but he felt the growing demand had changed things. The breakthrough came when he realized that the tough and tested workhorse of the construction industry, the backhoe, had the potential to be adapted to his needs. He went back to meeting with manufacturers, finally making contact with Komatsu, whose Japanese built, thoroughly proven units, with then 1995 state of the art hydraulic technology, actually delivered a 30 per cent drop in fuel consumption. The prospects of selling four units to St Anne Nackawic-with obvious potential for demonstrating what they could do in this new field-convinced Komatsu and Lounsbury Industrial Limited, Komatsu's Fredericton representative.
St Anne management made the big dollar decision to accept Hambly's recommendation- he stresses the absolute importance of the steady support he has received-and he began the major challenge of turning concept into reality. He also emphasizes that while maintenance supervisors from the "school of experience" don't always agree with engineers, he was fortunate and happy to enlist Dave Hoar of Motion Design, a small Fredericton engineering design company, as a partner. The major challenge was to design and fabricate the pedestal between the two units, not just to fit everything together accurately. The combined units needed to be precisely placed and counterweighted to eliminate tipping forces inevitable when loads of up to five tonnes were moved at the end of a long boom.
Because the motor and hydraulic system built into the Komatsu upper unit would be used, only 30 per cent of the power had to be transferred through the pedestal-the opposite of the original Koehring system. Once designed, production of the 54inch diameter, 43inch high, 1inch thick cylinder was turned over to a specialist company. On arrival, complete with welding but tresses, it was welded permanently in place. While highlighting the challenging engineering required to ensure the stability and balance of the unit, Hambly notes that even after all the calculations, there were some practical adjustments to be made-like changing the tires. The original big 18 pounds per square inch pressure pillows, designed to "flow" over rocks, meant the new unit swayed when a load was picked up. The answer: substitute tires with hard sidewalls, 90 pounds pressure and loaded with water and calcium, resulting in a unit steady as a rock. With the exception of the massive pedestal, the mechanical and fitting work was done inhouse.
The old Koehring uppers became "traders" or spare parts, while the lowers went through a process Hambly has dubbed "relifeing". First, they were stripped to the bone, everything that was worn-especially hydraulics-was replaced, the framework was painted, made like new. In fact the units were even refinanced and renumbered, to provide complete control and comparisons over the life of the project. The Komatsu units required relatively little adaptation. The essential "34 feet under the grapple" was achieved by simply lengthening the boom cylinder and by substituting a suitable grapple for the bucket (which can quickly be restored in a pinch if necessary). The advanced hydraulics mean that the units are equal to or better than most machines currently in use.
Hambly has a crack team of mechanics, both able and enthusiastic about proving they can successfully tackle almost anything, but because of the size of the massive machines he had to add a new, higher section to the maintenance shop. But this is not just an assembly line for the four units. As each was completed, with changes and improvements learned from building and working its successors, the earlier machines were brought back for complete upgrading. So all four machines are identical, with practical implications for maintenance, parts stores and operator training and a life expectancy of 12 to 15 years. Last, but hardly least, all four came in under projected costs.
Nevertheless, Hambly recalls some sleepless nights and lots of worry. "You don't do something of this sort without being very concerned. After all, it was a multimillion dollar investment on the part of my employer." But it all came off and Hambly is a happy man these days. "How many people can approach retirement with the satisfaction of having successfully pulled off a lifetime dream?"
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