From The Archives:100 Mile House Mill Off To A Smooth Start

Aug 26, 2024 - one year ago

This article first appeared 40 years ago, in the September 1984 issue.

The new sawmill at 100 Mile House started up May 7, and after two months of operation, it had achieved a production rate of 350,000 board feet a day - 58 percent of its rated capacity of 600,000 fbm.

From The Archives: 100 Mile House Mill Off To A Smooth Start

While mill manager Abe Friesen is proud of the chart which shows daily production levels moving upwards in almost a straight line, he doesn’t expect to hit 100 percent for at least a year.

“Getting a sawmill up to its rated capacity is comparable to an athlete breaking an Olympic record: he reaches a certain point then it can take years more of training to get that little bit extra,” he says.

“ln the case of our mill, the equipment will need adjustments and fine tuning, and we expect that we will proceed to full capacity in a series of plateaus.”

“Any time you build a new mill there are kinks and bottlenecks,” says maintenance foreman Orville Shpak. “Everywhere you look there is something to finish and additional work to be done.”

Although the start-up has by and large been a smooth one, it has not been entirely without its frustrations. “I’ve wondered how a so-called highly automated mill could be so manual at times,” says Abe.

But he hastens to add: “We are very pleased at our achievement so far particularly when you consider that almost our entire operating crew are new to their jobs, and the equipment is new to the maintenance people.”

From The Archives: 100 Mile House Mill Off To A Smooth Start — *Jack Viegas and Tony Costa at the trim saw.*

Weldwood’s sawmill at 100 Mile House is the newest mill in British Columbia: a state-of-the-art facility which utilizes computers, electronic scanners, laser beams and other sophisticated technology to recover the maximum amount of lumber from a large volume of logs.

The 100 Mile mill was specifically designed and engineered to accommodate its wood supply. Logs from the 100 Mile House Timber Supply Area (TSA) vary greatly in size, averaging 12 inches at the butt but ranging from 6 to 28 inches. As each log passes through the mill, it is electronically measured at every stage and routed through the ‑appropriate saws for its size. All the saws are controlled by a central computer which can be programmed to recover either the maximum quantity or highest quality of lumber. Saws also have the thinnest available kerf to minimize the wood lost to sawdust.

The mill produces random length dimension lumber in widths from 2 x 4 to 2 x 10 inches and lengths from 8 to 20 feet. Its capacity is 150 million board feet a year — enough to build more than 15,000 three-bedroom houses.

Although the mill is highly automated, in the final analysis it is the calibre of its people which determines the quality of the end product. At 100 Mile, a stable experienced work force ensures that the highest production standards are maintained. About 150 people work at the mill itself, and logging contractors employ another 100 in the woods.

The 100 Mile House mill consumes approximately 600,000 cubic metres of wood a year. The species mix is about evenly divided among Douglas fir, spruce and pine, with a small proportion of balsam and other species. The primary source of wood for the mill is the 100 Mile House TSA, a forest of nearly 1 million hectares (2.4 million acres) which surrounds the mill. The forest encompasses three distinct climatic zones through which the harvest moves with the seasons. In summer, logging is concentrated in the dry belt and as the temperature drops, the loggers move through the transition zone into the wet belt, where winter frosts help stabilize the road base for the movement of heavy logging equipment.

Weldwood contractors build more kilometres of roads every year. Most of the logging is done by fallers, particularly in the dry belt, but mechanical logging accounts for about 40 percent of the total harvest. One of the more common machines is the feller buncher, which shears off trees at the base and stacks them in “bunches” to be skidded out to the road.

The company conducts a comprehensive reforestation program, planting more than 600,000 seedlings a year in the 100 Mile TSA. On sites like those growing belt Douglas fir, which are best left to regenerate naturally, selective to length on computerized lines.

They are then automatically routed to one of three debarkers, each of which is designed to handle different log diameters.

After their bark is removed, the logs are again routed according to size to either the small-log Chip-N-Saw or the large log canter.

The Chip-N-Saw produces lumber and chips in one pass. (Chips are shipped to Cariboo Pulp & Paper in Quesnel to be made into pulp.)

The canter does the job of an old-fashioned head rig, but in a single operation. With electronic sensors to scan the log and saws set by computer, the canter removes four slabs to square off the log.

Again the routing is flexible. Cants of 10 inches and less are sent through the circular gang saw while larger cants go first to the twin bandmill. Cants may be passed through the bandmill more than once, with two-inch Sideboards being removed from one or both sides each time until the can measures 10 inches square. The cants are all sent through the gang saw.

Meanwhile, the Sideboards are routed through a three-saw edger. Here, too, the saws are computer set to cut the width of lumber that will yield either maximum recovery or highest grade.

At the trim saw, the mill will have trimmer optimizers using laser beams to “inspect” each piece of lumber before it is cut to length, although these are not yet in place. The optimizers determine the optimum length for either grade or recovery, and identify any pieces that need re-edging to remove wane or other defects. Defective pieces are routed through a twosaw edger to be remanufactured.

Finished lumber is sent through a 60-bin sorter where it is sorted according to its dimensions.

More than two-thirds of the mill’s production is kiln dried SPF (spruce, pine and fir species other than Douglas fir). Only Douglas fir is sold green.

Once lumber is dry, it is taken from the kilns to the planer mill where it is dressed to give it smooth surfaces and rounded edges. Three graders give it a final visual inspection before it is strapped, wrapped and shipped to market.

Kiln dried lumber is wrapped in heavy plasticized paper which keeps the wood dry and ensures that it arrives at its destination in the same condition it left the mill.

The kilns at 100 Mile have the capacity to dry the mill’s entire 600,000 board foot output every day, using planer shavings from one load to provide the heat to dry the next.

Like everything else at the mill, the kilns’ heating system is the last word in advanced technology. This is a hot oil system in which the oil is heated in two fireboxes (which in turn are heated by planer shavings) and circulates through the kilns and back for reheating.

“We’re completely energy self-sufficient,” says Herman Dutchak, supervisor of the heating plant and kilns. Each fire box consumes about two tons of planer shavings every hour to keep the oil at the steady 240°F required to dry the wood. Shavings are stored in a nine-storey silo and automatically metered into the fireboxes.

There are 6,700 gallons of oil in the pipes, constantly circulating through a closed system. Herman says the first system of this type was installed in B.C. about six years ago, and neither it nor any of those installed subsequently has ever needed an oil change.

Given the high and unreliable cost of oil, and the fact that planer chips are free, he says the mill should achieve considerable savings in energy. The system is also used to heat the planer and saw mills. The old mills had electric heat and the kilns were fired by a combination of natural gas and shavings.

In the kilns themselves, electronic sensors measure moisture content and transmit data to a computer in the heating plant which adjusts the drying time. The lumber is dried to a moisture content of 19 percent, and depending on the species and the climate in which the tree grew, it can take anywhere from a day to a day and a half in the kilns.

This article first appeared 40 years ago, in the September 1984 issue of Supply Post Newspaper.