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Spotlight

Tips from the experts

Industry experts offered many useful tips on improving log quality at recent workshops held in British Columbia and Alberta.

By Jim Stirling

Commitment and communication sound like words a politician might use. The two "C" words are, however, key ingredients in the drive to improve log quality.


Among the recommendations made at the log quality workshops was that log accuracy checks-checking three to five logs twice a shift-should be made a daily operating procedure.

They are necessary to ensure everyone involved-from those marketing lumber to the loggers in the bush-are on the same technology transfer page.
The recurring themes and contexts of commitment and communication were evident in a recent series of workshops designed to improve log quality.

The workshops, held in Grande Prairie, Alberta and Kelowna and Prince George, British Columbia, were hosted by the western division of the Forest Engineering Research Institute of Canada (FERIC), in co-ordination with the Forestry Continuing Studies Network. FERIC is taking more of its practical workshops into the regions to spread the message closer to the action. In this case, logging contractors, operators and front line supervisors. The approach proved successful with the workshops attracting more than 300 people.
Derek Goudie set the scene, pointing out the importance of sawmills receiving good quality, on-target lengths from log harvesting operations. Fibre amounts to about 80 per cent of manufacturing costs, says the representative of research organization Forintek Canada Corp.

Inaccurate log lengths compromise recovery, value, yield and volume. "The cut-off saw is the place where the job loggers do has the biggest impact on the sawmill," explains Goudie. A bad bucking decision can't be reversed. The multi-combination of log lengths, especially with the lower ranked bucking solutions, can be the difference between profit and loss for a sawmill, he adds.
He illustrated how simulations using Optitek software showed the effects on the value of fibre to a mill with log lengths on and off target. He says every sawmill is unique, but the point is accurate stem lengths and cut-to-length logs are important and the potential for value gains to the sawmill is enormous.


Equipment maintenance and routine equipment inspections can also deliver benefits in log quality.

On a different tack, Bob Harrison describes a good log as one that meets or exceeds the standards set by the consuming mill. Harrison is in a good position to know, being the retired woodlands manager for Riverside Forest Products in Kelowna. He, too, emphasizes that delivering log lengths within the specified tolerances is important to the mill, allowing it to maximize lumber recovery and grade out-turn.
Natural defects complicate good log production. Characteristics like rot, crook, sweep, cat faces and roughness have implications on several fronts including truck payload, safety issues, mill equipment maintenance costs and production impacts. Harrison recommends training, supervision and monitoring to buck off defects and leave them in the bush.

Explaining the ways in which machines damage logs, he pointed to lifting before the cut is completed at the felling stage, during bucking and by dull saw use.
Reducing log breakage frequently comes down to having good operators and machine maintenance programs, two factors that can also reduce log damage during skidding. Logs can be damaged during the loading process through slabbing from the grapple and pressure caused by different diameter logs. The mill yard is a tough place for logs during unloading, stacking, reclaiming and mill deck feeding. Harrison says four to five per cent breakage is common here. Additional log handling during sorts risks further log damage.
Through the last couple of years Bjorn Andersson, a senior researcher for FERIC, has looked at log measuring accuracy under as-is field conditions on 103 processors, harvesters and delimbers operating in BC and Alberta. He discovered considerable variations between lengths displayed by the measuring systems compared with actual lengths.

Andersson explains there are non-controllable and controllable factors at play. The former category includes stand, tree characteristics, species, the upper and lower parts of the stem and to a lesser degree weather and seasons. Controllable factors include varying standards between companies (from plus or minus 2.5 centimetre tolerances to 7.5 centimetres); computer settings and calibration; knowledge of measuring system; condition of equipment; and commitment to log measuring accuracy.
Andersson says the opportunities exist to improve the performance of the systems and contribute to increases in recovery.
Marv Clark, FERIC's research director, summarizes some of those opportunities. He cites: Commitment by supervisors and operators to better log measuring accuracy.

Communication of required log specifications, either metric or Imperial (don't try converting), and auditing results.
Realistic log specs vis-a-vis butt logs versus tops.
Log accuracy checks, at three to five logs twice a shift, as a daily operating procedure.

Knowledge of the system for operators and supervisors so they can access, modify and troubleshoot.
Equipment maintenance, routine regular inspections (keeping delimber knives sharp came in for particular mention).
Sharing the gain, the need to recognize that improved measuring accuracy can increase logging costs.

That point was also touched upon by Dave Blackmore from Denharco who notes technology continues to change rapidly and the more complex it becomes, the less productive systems can be. Blackmore provided a detailed breakdown of log measuring systems and their accompanying components. He says most errors relate to how systems are managed. And he had some sound advice for contractors buying measuring systems; "Go to the manufacturers, dig in their brains about what the machines can actually do."

Ismo Makkonen listed systemic and occasional sources of length and diameter log measuring errors. The senior researcher from FERIC's Montreal office passed on some useful tips to contractors. He notes larger measuring wheels with longer trailing arms tend to make smaller errors. He also recommends keeping them in good shape with no loose bearings and free of sap and dirt. And when it comes to measuring log diameters, two delimbing knives are more accurate.
FERIC has completed a series of case studies into log damage during harvesting and handling operations. Useful insights resulted, although in some cases more research is required.

Not surprisingly, considerably more breakage occurs to logs sitting around a mill yard for a year than in fresh wood. Log damage during saw type feller bunching can be due to stem tension during the cut and in accumulating smaller stems; making incomplete cuts; using dull cutting teeth and more than optimum saw speed during the cut.
Corey Bedard, procurement manager for Tembec's Cranbrook, BC operations, shared pertinent pointers in setting up a log quality program. Create clear and defined objectives and communicate them to both wood products and woodlands so that everyone understands how the targets can be achieved. He advises customizing wood specifications, using explanatory log quality manuals and bucking cards and ensuring a regular review and monitoring of the process. And, he adds, don't forget to recognize the good log-don't just criticize the bad logs.

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