March-April 2008

Mission Critical? - Mission Possible

The full backup power generator installation at a Wisconsin lumber processing company is a key element in its utilization of lean-manufacturing processes.

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By Don Talend

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A prime example of the impact of competitive forces on manufacturing of all kinds—and technological and management solutions that address that impact—can be found at Wolf River Lumber in New London, WI. One might be inclined to think that this company, which provides premium materials for North American cabinetmakers from its production facility in a semirural region of northeast Wisconsin, as some kind of Old World artisan outfit. The reality is as far from that inclination as possible; Wolf River Lumber operates a state-of-the-art facility and has embraced lean-manufacturing techniques. The company has also taken major steps to guarantee customers its own continuity of operation, and its own backup power supply is the key element of this strategy.

Photo: Generac Power Systems
Wolf River Lumber in New London, WI is a highly automated, lean-manufacturing operation that management recently decided to safeguard with a total backup generation system.

In early 2007, the company installed a comprehensive 3-MW backup power system consisting of four 750-kW Generac Gemini Twin Pack gensets, each of which has a pair of 375-kW diesel generators mounted side-by-side in a single enclosure. The gensets also use onboard paralleling technology to combine their output. Mark Christopher, Wolf River Lumber general manager, explains why installing the system was so important to the company’s strategy. “With our industry and our business, it’s essential that we’re up and running,” he says. “We’re pretty much a next-day supplier—we’re kind of a supermarket for the hardwood industry, specifically the cabinet people. With lean process becoming more prevalent in manufacturing today, people want next-day delivery. Well, in hardwood lumber, you have to have a large volume of inventory and then the specs with the cabinet manufacturers may change the next week, the next day.”

Company is a One-Stop Shop
The company’s 335,000-square-foot main building, which houses the corporate offices, production facility, and a large warehouse, was built in 2001. On the exterior of the building are 40 steam-heated kilns in which raw lumber is inventoried and dried. The kilns are heated by three 600-horsepower, natural-gas-fired boilers that are backed up with liquid propane; one of the boilers can run on biomass material or coal.

Every day, Wolf River Lumber receives deliveries of varieties of lumber such as oak, maple, birch, walnut, butternut, cherry, and ash from area mills. The lumber arrives in random lengths and is put on a conveyor. Certified lumber grading specialists sample the lumber and mark the grade. Following the inspection and grading process, the lumber goes through a scanner that records the dimensions of each board and tallies the total number of board feet of each grade. Then, the boards are sorted and stacked by grade in the kilns.

The aluminum/stainless-steel kilns are equipped with large sliding doors for forklift access, steam pipes that dispense heat ranging from 90°F –160°F, and fans for evenly distributing the heat throughout the lumber. The large number of kilns is necessary, given the number of wood varieties and their varying temperature and drying time requirements.

“We have 2 million feet of kiln capacity in our 40 dry kilns, with each one holding a little more than 55,000 board feet,” notes Christopher. “All of our power comes from our boilers; we use steam to heat the coils and we actually add live steam into the process to relieve the stress in the lumber.”

The production facility has four service areas in which wood processing and finishing take place. After the lumber is dried in the kilns, it is moved into production. First, each board receives a smooth or rough finish from one of two planers. Precise dimensioning of each board occurs next, as computerized saws cut each board to a standard or custom length. This precise dimensioning is another reason why Wolf River Lumber can position itself as a one-stop shop to customers who do not have to do their own dimensioning.

Photo: Generac Power Systems
The company has positioned itself as a “hardwood supermarket” and has invested significant capital in
kilns to dry out lumber, and in machines for sorting and dimensioning the product.

The facility’s intricate mass-customization capabilities and strategic positioning as a just-in-time supplier places even more importance on keeping processes running than in a typical manufacturing operation. “If we ever went down in the dead of winter, when it was, say, 20 [degrees F] below [zero], 30 below, and if our pipes ever froze, it would take us forever and a day to rebuild,” says Christopher. However, he indicates pulling off lean manufacturing with a foolproof backup power supply might cause customers to depend on Wolf River Lumber for most or all of their finished wood supply. With construction of the new facility, the company already had the facility and the process; all it needed was reliable power backup.

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Full Power Backup Chosen
At first, Christopher points out that the company considered partial power backup compared with its total consumption. “All of us put our heads together—[company owner and president] Gary [Ort], myself, our maintenance manager Michael Harder and Cal Lehman of Master Electrical Services, the electrical contractor, to figure out the best strategy,” Christopher reports. “We looked at fully backing up our dry kilns, which would be putting two of these units in and then maybe giving ourselves enough power to keep some heat on in our building. We figured that, given our facility’s 335,000 square feet filled with 12–14 million feet of lumber, it was going to take a long time for that to cool down and everything where it would be detrimental to our sprinkler system.”

Consulting with the local utility, New London Utilities, convinced the team that full power backup would make economic sense. “We finally brought in our power supply people,” says Christopher. “We’ve got a local utility here in town: New London Utilities, which is part of Wisconsin Public Power, and we started getting them involved in the process. We found that they would be willing to work with us to have this backup power generation. As we learned more and more about that, we decided that if we’re going to do this, why not have full backup for the full operation? We figured that, as we grow, we could go [to our insurance company and we would] get a full guarantee for customers and our employees that we would be up and functional no matter what would happen.” Next Page >

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