May 2002 - Logging and Sawmilling Journal -

Hit by a fire, Manitoba's Garth Riehl replaced his small sawmill operation in less than a year with a more efficient mill using new twin dogger technology, powered by a diesel generator.

A better product that is produced faster and with a lower per unit cost is coming out of a small private sawmill that's 1,800 feet high and camouflaged in the northwest corner of Manitoba's Duck Mountains. Garth Riehl, owner of Riehl's Lumber & Logging of Durban, Manitoba, says today's increased production is a result of a million-dollar investment by Riehl and his sons after a 1997 fire devastated the original family mill on the site. "I think our production is just about twice as fast today," he says.

Riehl's lumber is sawing more accurately and has a higher recovery rate, following the rebuild. fir its power requirements, they opted for a Cat 3406E generator system, rated at 400kW, rather than a costly transmission line linking it to the grid.

About half the investment is in the mill itself; the remainder is in the mill's power source, a big Caterpillar engine and generator. Thin-kerf blades and log rotating, twin-dogger technology are making major differences in terms of production and quality. The mill today saws more accurately and has a higher recovery rate, Riehl says. A few new markets have opened up, too.

Most production is sold in Winnipeg to export brokers and pallet manufacturers. A portion becomes the green planks used for shoring at excavation sites. With more than 30 years in the logging business, and with a line of logging equipment ready to go back into the provincial forest by November, it didn't take long to decide what the family would do when the fire struck.

"We cleaned it up and built a new 30x120-foot pad on the old site that fall," Riehl says. By Christmas, they were ready to order a new headrig from Dika Industries Ltd of Rycroft, Alberta. Other equipment was ordered or modified. The Riehls spent two months welding to put everything in place for the milling season. The Dika one-operator, twin sawmill features an overhead carriage that is side-mounted for full visibility.

Garth Riehl: "I think our production is about twice as fast today."

Maximum log length is 16 feet. The manufacturer describes it as "high accuracy, high production, high recovery, particularly suitable for sawing maximum size cants from small to medium-size logs, or for salvaging fire-kill timber." It operates twin 48-inch diameter saws on separate mandrels.

The saws have settings from 22-inches to 1 3/4-inch. Logs are carried past the twin saws, held from above and between the dogs. It can produce dimension lumber, cants, ties and timbers to 20 inches square. It will also handle flared butts. A standard live deck with reversible chains feeds single logs to the machine. Log centralisers callipers ensure each log is dead centre, while a log turner positions the log for best recovery. The automatic carriage lets the operator position the next log while a last cut is being made on the previous log.

It can turn out 60,000 board feet a day with a single operator using two hydrostatic joysticks, foot controls and switches in a comfortable control room beside the rig. "We wanted it built so we could rotate the log on the dogs and he built it that way for us," says Riehl. "Dika's other mills can saw two-inch lumber, but there's no rotating dogs-the teeth just grab the log. We wanted it this way so we could sell big timber.

It works, too. We sell a lot of timber for a lot of homes. "It operates nearly the same as a carriage delimber," he adds. "There's saws in there, instead of limbers." The twin 48-inch blades handle stock from five inches to 26 inches in diameter. The 9/32-inch blades use "Dominator" carbide 5/16-inch teeth that are "very hard and slash through that bark pretty quick." It can also take off one-inch slabs simultaneously from each side of a log.

The smallest piece it can produce is a 4x4. Logs roll off the infeed deck onto the headrig's receiving side and are automatically centred by a caliper. "The caliper sizes up the log, then raises it. A proximity switch stops it when it centres." The carriage has a high-speed return, along with twin cutting, to achieve the high 125-board feet per minute output on 102-inch logs. Electronic options also let the operator drop a log at the end of the line after taking off just the two outside slabs.

The operator can over-ride the system, too, if a crooked log needs special treatment. After the first cut, rough-cut wood can go in several directions in the mill. Larger pieces go through a 7 1/2-inch Mainland bull edger that the Riehls remodeled for thin kerf blades. Shafts, blades and rollers were changed. "We changed the saws to laser-cut blades that are 0.165 kerf (under 1/4-inch)," he says. It sizes down material to a range from 1x6 boards to 4x6 cants. Each piece is hand-fed into the bull edger.

Upper rollers lift as each piece is cleared and re-apply pressure when the next is entered. A timer, guided by a sensor, delays the application of pressure until each piece is positioned. Hardwood supply has always been a problem for the little mill on the mountain, Riehl admits. Until this year, if they had the supply, they didn't have the milling capability to get maximum value.

For 2001, Riehl installed a new three-head Kent band saw for re-manufacturing. "It's a good investment if you've got the wood supply," he says. "It works really well and we're set up now so we can re-man the hardwood to get good money for it. That's what we have to do to make a profit." Finer hardwood from the Dika twin-dogger now goes through the new band saw. "We can mill our wood down to almost anything with this," he says. "For instance, we can re-saw the aspen down to one inch if we want."

It can produce boards up to eight inches by 3/8 of an inch thick. The band saw uses 0.032-inch thin kerf blades. Coming out of the band saw, material is laser-guided through an edger for final sizing. The edger also enables Riehl to salvage a certain amount of material that would be odd-sized and discarded.

After the fire, Riehl investigated whether to replace his old generator with a three-phase power transmission line. He learned it would require a five-mile service extension and a commitment to monthly consumption, year-round, even though the mill operates only four months a year. Instead, they opted for a new Caterpillar 3406E diesel-powered generator system, which was installed in a 40-foot van behind the new mill.

The generator engine is rated at 400 kW (enough to power about 400 homes) and produces 587 hp. Its six-cylinder engine nominally operates at 1,800 rpm. It is relatively light (7,180-lb) and easy on fuel, burning about 60 gallons a day. It can produce 30 per cent more power than the rated 400 kW for a short period when heavy motors start. "We learned we could buy the generator for the price they wanted to extend hydro lines up here," Riehl says.

Their annual cost for diesel for the generator approximately equals the minimum annual cost for the hydro service. "This is our fourth year with this generator and we've had no trouble with it. Three of Riehl's sons are partners as well as operators in the mill. Al operates the head rig; Lonny operates the loader and sharpens blades; Rick runs the trimmer. A fourth son, Kevin, is an engineer with Kenn Boreck Air in Calgary. He helped remodel the bull edger.

The mill has about 10 other operators, who work April through July. The crew harvests around 13,500 cubic metres for the mill from the nearby mixed forest between September and March. Their timber supply includes trembling aspen, balsam fir and black spruce. Some tamarack is also available. Another 26,000 cubic metres is hauled to the Louisiana-Pacific OSB mill at Minitonas.

Approximately 25,000 cubic metres of spruce is hauled to Spruce Products at Swan River. Both are less than an hour's drive from the cutting sites. About 8,000 cubic metres of spruce chips are hauled about 700 miles southeast to Pine Falls. In the bush, Riehl operates two bunchers, a slasher and four skidders. The newest skidder is a Deere 648G. In the mill yard, it operates two skidders and two Prentice XE410 loaders.

The new Deere 648G proved itself in the 2000-2001 winter. "It was tough," Riehl says. "We had 5 1/2 feet of snow that winter, after a lot of late fall rain. The ground didn't freeze underneath the snow, but the Deere was still able to move around." Garth and his wife Betty started in the bush in the 1960s "with a couple old Cats and a truck." The plan is to have their sons take over the new mill in a few years. "It's never been an easy business, but at least they'll have a better set-up than we did," Riehl concludes.

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