April 2002 - Logging and Sawmilling Journal -

The new small log line at Canfor's Chetwynd operation is delivering improved lumber recovery, as promised.

Canfor has been part of Chetwynd's log harvesting and sawmilling traditions since 1964. That was the year the company purchased a sawmill in the small community near the Rocky Mountain foothills of British Columbia's Peace River country. Both community and company have benefited significantly from the relationship.

Canfor's Barry Porter, project manager for the new $9-million small log line and associated improvements at the Chetwynd mill.

The evolution of Canfor's Chetwynd operations reflects the enormous changes that have revolutionized the BC Interior forest industry during the last 38 years. Precious little has stayed the same. The forest resource is viewed and treated in an
entirely different manner. As a result, harvesting strategies and machines are radically altered.

The microchip has ushered in a new era of lumber manufacturing sophistication. Precision and control are key elements in wood processing systems. Utilizing maximum fibre and extracting premium values from each log is an industry mantra.

Processing logs down to four-inch tops was unattainable a lot less than 38 years ago. Now the fast, accurate processing of wood down to three-inch tops is the most recent major challenge, successfully tackled by Canfor Chetwynd's management team and production staff.

It came about at a time when Canfor was assessing and co-ordinating upgrading options at its other sawmills and planers in central and northern BC. After much detailed consideration and analysis of present and projected fibre expectations, Canfor Chetwynd decided to incorporate a curve sawing capability into a new small log line. It had sought improved lumber recovery and throughput.

A raft of changes had to be made to maintain an efficient and cohesive product flow within the reconfigured mill.

The primary breakdown units selected were a Comact canter backed by a CAE/Newnes/McGeehee gang sawing system. The installation of the new small log line and associated improvements cost an estimated $9 million.

The new line replaced a Chip N Saw processing system that had proven to be a good servant to the mill for years and had undergone several modifications and improvements.
The new Comact line takes over after debarking with an auto rotation conveyor equipped with Porter Engineering true shape scanning, explains Barry Porter, Canfor's project manager for the small log line installation. A four-roll log turner prepares logs for progress along the double length infeed which features Porter scanning and multi hold-downs to provide the control and ability to slew and skew, lift and tilt. The system offers a full range of linear positions and the canter has two disc type side heads, he adds.
A six-foot C-Tec twin band saw has a high-speed automatic wheel tilt tracking system to help prevent the saws deviating from the selected positions, says Porter.

Side boards are dropped to meet the existing flow to the mill's number one edger. There's an ability to make flitches and a horizontal re-sawing capability.

Downstream, cants are rotated at 90 degrees for passage through the gang. A Newnes/McGeehee angle roll case moves cants to one side of a precision belt. There, a Newnes true shape scanning system scans the cants determining their positions. They then pass through the CAE/Newnes/McGeehee single arbor six inch shape sawing gang saw, says Porter. The system can handle three, four and six inch cants.

It's rarely an easy task to position and integrate a new log line into a mill's product flow pattern. In Canfor Chetwynd's case, considerable ground work was necessary, including short length pile driving and concrete pouring.

Sub-grade conditions were tough and uncompromising, ranging from rock to swamp. A solid foundation under the full canter and gang line was essential. Without it, the integrity and performance of the scanning, setworks and processing equipment would be compromised. "It was quite a challenge," recalls Porter.

A raft of changes had to be made to maintain an efficient and cohesive product flow within the reconfigured mill. A building extension was required to fully accommodate the new line. Some chip blow lines had to be re-located and the lumber line was extended. Changes were made to the sort station, including the addition of unscramblers, and the flow from the edgers needed to be altered. One of the added unscramblers allows re-sorting ahead of the trimmer. A new lug loader was also installed. The trimmer and sorter are at different elevations and a transfer was added cutting the angle of incline at both top and bottom.

Out in the mill yard, a new Salton kiln was added to complement the four older lumber drying facilities.
Sawmill superintendent Stephen Gilles oversees day-to-day running of the new small log line within the context of the overall mill operation. "I think it does what we expected," he says. "I would like to increase the log count and reduce gaps." The canter line runs about 550 fpm and gaps between pieces are around 13.6 feet, depending on wood diet.

"We're always striving in-house to make more logs available for the machine," adds Gilles. And therein lies the crux of success: Constantly seeking ways of doing things better. And that-as much as anything else-explains why the Canfor Chetwynd tradition has thrived for nearly 40 years.

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