By Jim Stirling

It’s wryly dubbed the ‘hemlock surprise’.

What appears to be a perfectly sound log externally too often turns out on the inside to be riddled with pockets of rot and other fibre-damaging and value-reducing defects. In the bush, best guesses surrounding internal wood quality are typically made by probing the log and the buckerman’s experience in assessing what he sees and finds.

Skeena Sawmills is trying to turn the odds more in its favour by investigating the application of emerging technology to reduce the element and numbers of nasty surprises in the hemlock and other species occupying its wood basket in northwestern British Columbia. The particular technology undergoing analysis could result in installation of a new log scanner at Skeena Sawmills’ Terrace operation.

The scanning system would provide a three dimensional re-construction of all the inner features in each log. The information provided would be used to indicate the optimum cutting patterns for the sawmill’s log breakdown machines, with the objective of maximizing the value of all boards cut from each log.

The scanning system is part of a broad-based analysis of the mill’s operation and stem utilization designed to get the most from the unco-operative and challenging characteristics inherent with Skeena’s wood supply. Up to 50 per cent of the company’s standing wood volume under licence is comprised of grade 4 pulp quality logs. That’s an astonishing statistic. Most sawmills processing a diet of interior B.C. spruce-pine-fir fibre, for example, experience a single digit percentage of that classification of pulp quality logs.

Other factors impact sawmill operation in the Terrace region. There is no longer a pulp mill within economic transportation distance of Terrace. Logging and road building costs are high in the region partly because of the mountainous terrain and the fact that the easier accessed and quality valley bottom forest land has long since been creamed. The good news, as a longer term aside, is commercial thinning in so-called second growth stands in the region is showing promise.

In the meantime, Skeena Sawmills must face the realities of sawmilling in the region. “The traditional sawmilling model hasn’t worked here,” understates Roger Keery, vice-president of operations for Skeena Sawmills. “We’re looking at technology advances as the tools to help with our issues here.”

Under the closest scrutiny is a CT log scanner manufactured by Springer-Microtec Inc. It’s designed to help identify knots, cracks and rot pocket locations in lower quality hemlock and balsam stems. FPInnovations are also partners in the project, providing assistance in scanning and sawing the logs. In turn, Springer Microtec have been adapting their software algorithms to detect the unique internal defect present in Skeena’s logs, and meticulously analyzing the optimized data to determine the potential benefits.

“You can’t just scan the geometry. The problems with our wood aren’t external. They’re internal,” points out Keery.

Skeena and its partners believe the scanner looks promising. “If there’s an opportunity for better utilization of our fibre, it could be a game changer in this area,” adds Keery.

Skeena has also been busy on other fronts examining options to improve the utilization of and value from its wood fibre: innovations that work on an industrial scale. For example, notes Keery, exporting wood chips might produce a significantly higher payback than domestic opportunities. “We must have a home for and a value from our residuals,” he continues. It’s why Skeena Sawmills is following up on a feasibility study from CWA Engineers Inc., to install a small wood pellet manufacturing plant using the sawmill’s sawdust, shavings and bark as furnish. “We have not made a final decision on the pelletizing equipment. There are two potential suppliers that have quoted the project and Skeena will select one of those,” explains Keery “Prodesa has been selected to supply the critical element of the dryer system.”

The pellet plant will have a capacity output of about 80,000 tonnes/year and it will be constructed adjacent to the existing sawmill.

The decisions have been made for the first major improvement project at Skeena Sawmills. Work is expected to begin this fall/winter with the approximately $10 million installation of an Optimil small log canter line with a quad re-saw capability and in-line gang. Keery says the line will be capable of operating at speeds up to 450 FPM and be able to process logs from 16 inches in diameter down to four-inch diameters.

The ability to accurately process small diameter wood will mark new ground and a significant ‘first’ for Skeena Sawmills. The company’s sawmill is a solidly constructed structure, but it’s old and designed to process a much different log profile. In its original incarnation, it was rarely asked to process logs less than 10 inches in diameter. Now that’s all changed. The latest regional timber supply analysis is expected to confirm the smaller diameter trend as increasing volumes of ‘second’ growth stands become available for harvest. The new small log line installation will poise Skeena Sawmills to better process its complete timber supply spectrum.

The lumber recovery process for Skeena Sawmills doesn’t begin when loaders deliver logs to the mill’s infeed decks (top photo). It starts much earlier back in the bush, with the harvesting including log analysis and sorting processes, says Greg DeMille (left), Skeena Sawmills woodlands manager.