Forest Operation Review

What a complicated question!

Or is it? The true question is, “What is the cost to a contractor or company who is always at the mercy of the nearest platform or built-in scales before knowing what the payload on any truck will be?” After all, the reason we do what we do, besides the fact that we love it, ultimately boils down to: “Am I making any money, and how can I make more?”

Willis Tolliver, owner of Team Excavating, LLC in Piketon, Ohio, manages an in-woods contract loading and trucking system in the Appalachians and is not willing to “wait for the weight.” His system incorporates automatic-dynamic weighing technology into a “weigh link” attached to the boom of a John Deere 200D excavator. Mr. Tolliver purchased a wireless weigh link from INTERMERCADO AB in Sweden, to help maximize legal payloads on the log trucks.
Team Excavating operates a high-production system that averages over 2,200 tons of wood deliveries per week (112,000 tons total in 2009). The contract truckers who deliver wood for Team Excavating are keenly aware of what it means to receive an overweight fine or even experience the loss of time while waiting for the DOT or “the scales” to leave an area before heading out of the woods with a loaded truck for delivery to a mill. These concerns justified the decision to invest in a weigh link that could accurately estimate the weight on the truck before leaving the loading site.

Weigh Link: What Is It?

This innovative in-woods wireless weigh link was featured in FRA Technical Release 08-R-7, which described a “decoupled” approach for a cut-to-length harvest system. Decoupling focuses on allowing each piece of equipment to operate independently, with a goal of maximizing the production of each piece. The wireless crane scale has eliminated the guesswork from estimating the production of the processor and forwarder as the wood is piled along the roadside, or guessing the payload of a log truck while loading in the woods.

When the forwarder operator begins to offload—or when the tracked loader operator begins to load a truck—he pushes a pedal to initiate a weighing sequence that takes the weight of the grapple-bite of wood for a set amount of time. (The weight is registered 10 times per second, and calculated a by means of a specially developed algorithm and built-in motion control. Typically the measuring takes place over a three-second period.) The calculated weight is stored in the computer, and it waits for the next sequence to start.

Over the course of the week, the operator continues to take readings, and the computer stores each reading cumulatively until the end of the week, when the operator prints out the week’s production with the tract name, contractor, operator, and dates that the work was completed. A logger can send the production record to the Glatfelter office in the form of an e-mail, to be paid for in the following week’s wood settlement. The measured in-woods production data can also be the green-wood basis for paying the landowner for the timber on a pay-as-cut contract. In the case of loading the trucks, it is a simple matter to read off the accumulated weight of wood placed onto the trailer.

The wireless crane scale has proven to be an accurate (within 2% or 3%), efficient, and reliable means of establishing the production of a totally decoupled CTL harvest system. The basic maintenance requirements are that the battery be changed weekly, a few fittings greased, and the friction brakes adjusted from time to time.

Recent improvements and upgrades to the wireless scale now provide the buyer with downloading and e-mail options for sending production numbers directly to customers. The introduction of an accelerometer and of a newly approved, temperature-compensated load cell has substantially improved accuracy. Typically, a Nordic truck driver loading with a self-loading truck is less than half a percent off. Unlike all other crane scales used in logging, the INTERMERCATO scale works independently of the operator; that is, any operator using the system will get the same result.

Deploying Weigh Link

Tolliver’s initial goal for this in-woods trucking operation was to load 25 tons on each truck (although truckers in other regions may run lighter-weight trucks than Tolliver’s and thus may have a higher net payload goal). As the operator became more familiar with the weigh link, he soon understood how easily the system worked and how accurate it truly was.

Currently, Team Excavating, LLC is loading each truck with a degree of accuracy that falls within 0 to 5 % per load. That isn’t to say that some loads don’t get out of that range, but they are few and far between.

Graphs 1 and 2 were built from data collected from two separate sales, one without the weigh link and the other with the link. The contractor was cutting 20-year-old white pine pulpwood with a cut-to-length harvest system. The median weight using the weigh link averaged 0.64 tons more per truckload compared to the wood loaded without the link. The variance for un-weighed wood compared to weighed wood was 1.19 and 0.55 tons, respectively.

Breaking Down the Savings

The value to Team Excavating, LLC can be measured in three ways.

First, there are significant savings from hauling an average of 0.62 more tons on every truckload for the year. That calculates to about 109 fewer truckloads needed per year or 2,725 tons (109 loads at 25 tons/load). Using a typical average price per load to deliver the wood—just insert a price that is typical in your region—the total savings will be in the five-figure range, annually. That would probably make the payback for this investment less than 12 months.

Second, the contractor can avoid fines and lower his repair and maintenance costs by hauling legal loads on every truck. The savings in fines will depend on the extent of enforcement efforts in each state. Repair and maintenance savings would vary based on the age of the trucks and trailers.

Finally, the contractor can be confident knowing what the payload is on the truck when it leaves the woods. It is stressful enough to load a truck properly, but if you know the weight on a truck, that in itself is a relief for an operator—and we all know that less stress allows us to work smarter and more efficiently in whatever we are doing!

Graph 3 shows the change in average weekly load weights before the loads were weighed in the woods and after the weigh link was installed.

The weekly average truckload in 2009 ranged from 26.5 tons down to 23 tons/load/week. There were other reasons for load weights averaging less than 25 tons at certain times of the year besides operator miscalculation. During the summer the wood might sit in a pile along the road for 30 days, and during that time water weight would be lost, and a 25-ton payload would not be a realistic goal. During the other seasons, drying wasn’t the issue, but still the loader operator could only estimate a truckload within 1 ton, plus-or-minus four percent. As Graph 3 illustrates very clearly, after the link was installed, the weekly average weight per load averaged between 25.3 tons and 24.8 tons.

But There Are Other Applications, Too!

The wireless weigh link system has worked so well that Glatfelter recently installed it on a knuckleboom loader at one of our woodyards. This “at-the-loader” weighing innovation saves time: we can load log trailers to the desired weight (that is, up to the legal limit) without having to run the tractor-trailer back and forth across the woodyard scales more than once while adding or subtracting logs to get the weight right. The weigh link works fine for our “treelength” hardwood sawlog stringers, not just cut-to-length wood. However, we load our log stringers by grabbing the tree near the center of the stem so it hangs freely in the air from the grapple.

But please note: for an accurate weight reading, one cannot use a loader with a heel boom to control the tree, because that will influence the free (hanging) weight of the tree.

Jeff Jenkins is Harvest Systems Forester for Glatfelter in Chillicothe, Ohio. Reach him at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .