INDOOR LOG SCALING FACILITY
Log Quality/Grades: scaling
INTRODUCTION: In 1999 Weyerhaeuser built a log scaling building at its sawmill in Lewiston, Michigan. Several factors drove the decision to build the indoor scaling facility. Safety, an in-line metal detector, improved accuracy of log grading and scaling, and extended scaling hours during winter months and during inclement weather all contributed to the decision.
GENERAL FEATURES: In a typical scaling operation, the logs are laid out on the ground, and the scaler has to bend down for each, turn the log, and bend again to measure important aspects of the log. With this scale house, the logs are loaded onto a live deck. From the live deck, a conveyor belt brings the logs through a metal detector and into the scale house at waist level. The scaler then turns the log with a hydraulic log turner to see the merits and flaws of each log. He then measures the logs on the conveyor, which is much easier than bending over to measure them at ground level.
Fig. 1: Scale house
Fig. 2: Personnel have access to each log and the means to check out every angle easily
APPLICATION: Apart from this ergonomic improvement, there are other safety-related advantages. The log scaler is in a controlled environment that is well lighted and free from the hazards of working in a log yard with variable weather, uncertain footing, and mobile equipment traffic.
With respect to productivity improvements, the in-line metal detector alone generated a significant financial return in reduced mill downtime and cost that justified the cost of the project. In the winter months, log scaling hours can be extended, since outdoor scaling is limited by daylight hours. Furthermore, during the winter, logs scaled outdoors can quickly be covered by snow. With the indoor scaling, logs can be left in a pile and loaded onto the live deck immediately before scaling, keeping them free from snow and thus easier to evaluate.
Fig. 3: It is unnecessary to bend down when measuring logs.
COSTS: While comprehensive cost totals are unavailable, the benefits over the life of the scale house have greatly exceeded the amount spent on establishing the system.
4111 W Four Mile Road
Grayling, Michigan 49738
FRA STAFF COMMENT: The control, flexibility, and added safety of this set-up, compared to typical scaling procedures, are immediately apparent when one observes the operation of the scale house. The ability to view the entire log without repeatedly bending down is a significant improvement.
Western/Lake States Regions Manager