Target: Yard Fibre Loss
Target: Yard Fibre Loss
Summary: At Merritt, Weyerhaeuser experiments with different log-handling systems to reduce fibre loss through stem breakage - and add to mill recovery.
By L. Ward Johnson
A visit to the log yard at the Weyerhaeuser mill in Merritt, BC these days will reveal a bright orange loader boom bobbing and dipping among the log decks. The boom belongs to a new Hitachi Ex300LL butt-n-top loader, which, for the past few months, has been part of an experiment conducted by Log Yard Supervisor George Rauch and his crew. The test was initiated to see if log yard waste and breakage could be reduced by employing a different log-handling system. So far, not only has there been a significant reduction in log yard losses, some additional benefits have also been realized which no one expected when the trials were started.
Located in the southern interior of the province, the Merritt sawmill operates on a diet of SPF and Douglas fir. The operation has only about 60- percent of its requirements in quota, the other 40 percent is gleaned from surrounding small business timber sales and private holdings.
About 75 loads a day come into the Merritt mill log yard. The loads are built in the woods, with butts on both ends and shorts spliced into the middle. This not only enables the logging operations to send in short wood, the resulting level loads also maximize load volumes and weight distribution on the axles. At present 61' or multiples thereof, is the longest log the operation handles. The company is contemplating reducing maximum allowable log length to 40' however to further reduce log yard waste and breakage when the load is lifted by the stacker.
Waste and breakage can represent a significant volume in log-handling operations - a commonly accepted figure in the industry is four percent of total volume. While this figure varies significantly with each operation, as do to the methods used to handle the logs, these waste losses led the Merritt log yard to think about ways to reduce the problem.
The log-handling system at the Merritt mill is like many throughout the industry. Full truck loads are lifted off the trailers by a stacker, which moves them to the log yard for storage. Loads are decked in the same configuration as when they were built in the woods - in this case, mixed tops and butts with shorts spliced in the middle, and the full gamut of species.
To move the logs to the sawmill, front-end loaders move into the log decks and pull out enough logs to fill the grapples. With logs intertwined and mixed within the decks, front-end loaders can break the odd stem here and there during this operation. Three can be also be occasional spillage as the loader attempts to placed the mixed tops and butts on the mill infeed deck, which can also account for some waste and breakage.
As with most operations using this log storage and retrieval method, the Merritt operation accepted the inevitable breakage, but also fall, George Rauch decided there had to be a better way. He was convinced the front-end loaders were doing the best job they could, so the only way to reduce the problem was to approach it from a different angle.
Rauch felt the answer was a butt-n-top loader. He was convinced that if the logs could be sorted and oriented butt-ahead before they were stacked, there would be less waste and breakage when the 966s broke open the decks to move the logs to the mill. Rauch also believed there could be an additional benefit to the mill from butt-ahead entry. If proven right, he knew there would be no problem justifying a new butt-n-top loader for the log yard.
The first step was to establish a mill study to determine what impact butt-ahead entry would have on mill productivity. Rauch and his crew ran a number of loads through the mill bush run, then an equivalent number of loads that were turned for butt-ahead entry. They quickly determined that just by turning the logs, there was a one percent improvement in lumber recovery in the mill and productivity went up as well. With the favorable study results in hand, Rauch got approval to add a butt-n-top loader to the log yard for a six-month trial.
The machine Rauch chose to try first was a Hitachi EX300LL. This is an 87,000-lb. machine with a 208-hp Isuzusix-cylinder diesel engine and a maximum reach of 38'. The unit has a wide car body with a Wajax rear-entry forestry cab. Ergo-nomically placed joy stick controls facil-itate easy, natural operation, and for operator comfort there is air conditioning and a stereo system. The EX300LL has heavy-duty guarding, an extra fuel tank and anadditional 7,000 lbs. of counterweight.
The business end of the unit is a Weldco Beales model 600 butt-n-top grapple, mounted on a boom modified for increased lifting capacity and improved visibility. After barely two months of operation, the machine has reduced waste and break-age, and Rauch says there are some other benefits.
One thing we discovered rightaway was that we could do species sorts without any trouble. At times during the year, we get a lot of balsam coming into this yard and since balsam is quite wet, it has special drying problems.
With the butt-n-top, wes o rt out the balsam and accumulate it until we have enough to make a run through the mill. Once its milled, we stack it in the yard to air dry instead of running it through the dry kilns. That eliminates ourdrying problem with balsam.
Rauch adds they canalso sort out other species, such as Douglas fir, which gives the mill more flexibility in maximizing the products it produces and sells. We also get a few sticks of yellow pinein this area and we sort those out as well, Rauch says.
Both the log yard and the mill are working more smoothly, Rauch says, now that the new system is in place. We are getting less waste in our log yard operations, which means material that used to becomewaste is now going into the mill t o bet u rned into lumber. In addition to that though, it is simpler to work the log decks, which means its easier on the loaders; andwith reduced spillage at the mill, its easier on the in feed decks as well.
Rauch says they have also reduced the doubling up that used to occur when feeding mixed top and butt ahead into the mill. With all butt-ahead infeeding, the logs flow naturally into the mill and there isntthe doubling up there was with the mixed-entry system.
That means mill flow is a lot smoother. The Chip-N-Saw is also having a much easier time of it, according to Rauch . With the sorting capability we now have, we can separate out the shorts for the Chip-N-Saw and put them into a re-entry deck. That makes things a lot easier for the whole sawmill.
The Merritt sawmill operates two shiftsper day. The 10-hour day shift produces 275,000 board feet from the headrig lineand the Chip-N-Saw line. The eight-hour afternoon shift runs with only the Chip-N-Saw line, but it still produces an additional 130,000 board feet per day. One Wagner stacker unloads the trucks and decks the loads, while two 966s keep themill in logs during the two shifts. There are seven fork lifts moving lumber and feeding the kiln and planer. A 950 and adump truck keep the mill yard clean and dispose of the yard waste. Operator on the new butt-n-op loader is Clarence Rauch.
Although he is an experienced equipment operator, he had no experience with this type of machine until mid-April when it arrived onsite. Its definitely an easy machine to oper-ate, says Clarence. It took me a day or two to get the hang of it, but after that it was easy. We are doing a lot of sorting now, he says, including sorting for length, species, size and Chip-N-Sawlogs. We also sort out house logs, sincewe sell to the log home builders in the area.
Im handling 25 to 30 loads a dayand its no problem doing that. The machine is fast and there is good visibility. I havent found anything to complain about so far. Summing up the benefits of the move, George Rauch adds: Its cut back considerably on our volume of yard debris andreduced our disposal problems as well andits certainly better to make lumber out ofthe wood than to burn it or burry it.
With the increasing scarcity of logs in this area, to say nothing of the increasing price, youhave to utilize every scrap of wood you get, and we think improving our sorting capability has really helped us achieve thatobjective. The next step will be to reviewour loading and hauling system in thewoods, and we are already working on that. When we figure out what we want to dothere, this operation will have a pretty efficient log-handling system.
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