Equipment

Trailer Report: Tales From The Road

If ever there were a piece of equipment that made sense, it's a scale plumbed into a tractor and trailer's suspensions.

May 2008, TruckingInfo.com - Feature

by Tom Berg, Senior Editor - Also by this author

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Hurry up and wait. "We don't have time for lunch," the owner-operator told me as we met at the truckstop in Ontario, Calif., about 10 years ago. "We've gotta be there by 2 o'clock." It was about 11 a.m., so we climbed into his Cat 550 King of the Hill-powered Kenworth and barreled north and west, over Cajon Pass and Tehachapi, then down into the south end of the San Joaquin Valley, to a produce packing house near Arvin. We got there on time - and pulled in behind about 20 other rigs. "That's about par for the course," he said with a wry smile as he climbed out to go check in.

Then he alternately dozed in the sleeper and moved the truck forward to stay in line, while I wandered about the company's premises. In spite of the false appointment, the place had a friendly look - big, well-maintained sheds amid nicely trimmed lawns. And under a shade tree I found, of all things, an old Jeep FC-170. Remember those Forward Control 4x4 pickups from the late 1950s and early '60s, with their non-tilting cab-over-engine design? This one was a four-door crew cab - a real rarity - whose interior doghouse was missing, which allowed me to see that its original Willys flathead Six had been replaced by a Chevy 350 V-8 - pretty neat. Its black California plate had a current sticker, and I dearly wanted to drive it away, or at least load it into the back of our Utility reefer trailer.

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Instead, after a couple of hours of waiting, we backed into the dock and took on a load of cantaloupes. Neither of us liked cantaloupe, but the consignee back near Chicago apparently did, because he wanted 'em there in less than two days. "He's particular, too," the o-o said. "We've gotta go weigh this load." So off we went, west and south to the Wheeler Ridge truck stop and its Cat Certified Scale, a one-way drive of, as I recall, 19 miles. The weighing went fast, but that was 38 non-paid miles and more than an hour out of the way. Well, at least we ate supper.

Oh, for an on-board scale, I moaned, and still would. If ever there were a piece of equipment that made sense, it's a scale plumbed into a tractor and trailer's suspensions. Use one with guaranteed accuracy and its readings should be enough to satisfy any reasonable customer - not that they all are, but on this day we would've had a really good idea right at the loading dock that the load was as prescribed, then could've gotten a certified scale ticket later, along our eastward route. Weighing on the spot also takes the guesswork out of distributing the load on the axles, because you know right away when one of the tandems or the steer axle is overloaded.

True, there are other ways to do it. For instance, with an air gauge plumbed into the tractor's air-bag tandem, a driver gets to know how many psi appear on the gauge when the tandem's loaded close to 34,000 pounds. And with a certain fifth wheel setting and the load's total declared weight (assuming it's accurate), he or she can guesstimate how much is on the steer axle and the trailer's tandem. It's easier if the trailer has a spread tandem, because with the usual 10-foot, 1-inch distance between axles, each can gross 20,000 pounds, lessening the probability of the trailer's axles being overloaded.

There must be a lot of other reasons not to buy an on-board scale, because representatives of trailer builders I talked with at the Mid-America Trucking Show said that only a small percentage of their customers specify them. Those who do are usually weight-sensitive operators who carry heavy cargo and therefore spec lightweight equipment, like aluminum flatbeds and dump trailers, or they operate in areas where authorities are strict about enforcement. These truckers want to maximize payloads and are more likely to see the benefits of on-board scales.

Here, though, are a few don't-buy reasons: You haul "feathers" rather than "pig iron," so are never overweight; you haul the same types of loads from the same shippers on the same routes and know what's in the trailers; your shippers' bills of lading are accurate, and your drivers are experienced and therefore good at estimating load weights; you pay drivers or owner-operators by map miles, so any extra miles and time are not your problem; your rigs don't encounter many official scales; you want to keep trailer purchasing costs as low as possible; and you've never bought the things and don't see any reason to start now.

Some of those - even that last one - really are valid reasons, from a manager's point of view, anyway. But with hours of service infractions getting more attention and driver recruiting and retention always a problem, maximizing drivers' productive time will help them make more money. They're likely to appreciate that extra tool and stay on their jobs longer. Meanwhile, citations for running overweight can each cost hundreds and even thousands of dollars. Eliminating most if not all of those, plus calculating time saved and reduced wear on equipment, and you might find that you can quickly pay for on-board scales.

Air-Weigh, one of the first in the business, has made the investment prospect easier with a new lower-cost product, the QuickLoad. It's meant for a tractor or a dedicated tractor-trailer, and costs $400 to $650, depending on whether the tandems have one or two height control valves. That's hundreds less than other, more sophisticated products in the Air-Weigh lineup.

Like them, QuickLoad works with air-bag suspensions. An electronic scale is plumbed into the tractor's tandem, and an air line is teed into the trailer's tandem; that line is run forward to the trailer's nose, where it's hooked to an extra gladhand. A corresponding glad-handed line on the tractor runs into the cab and is connected to the scale's gauge head.

So the scale now has pressure readings from both tandems, and it "learns" steer-axle weights through the calibration process, based on empty and loaded conditions, and where the fifth wheel is during calibration. An in-cab LCD readout displays the weights on each of the axle groups: steer, drive and trailer. These are on-the-ground weights in 20-pound increments, so they're very close to being actual, and, Air-Weigh says, are much more precise than a crude air gauge ever could be.

Because the steer-axle weight assumes a certain fifth wheel setting, sliding the fifth wheel often will throw off the scale's calculations. If that's part of a driver's routine, this is probably not the product to use, Air-Weigh advises, unless you also buy a mechanical "deflection sensor" for the steer axle (see below). And because of the extra air line and third glad-hand connection between trailer and tractor, QuickLoad should be used in a "married" rig.

QuickLoad will support two trailers and four air-sprung axle groups, so will work with B trains, the company says. Here each tandem would have to be teed into, and a separate air line run forward with a gladhand for each. It sounds like a lot of trouble, I told the folks who explained this to me. But they insisted that it's really rather easy, because the parts are simple and so is putting them in. Installation on a tractor and one trailer shouldn't take an authorized dealer more than an hour.

Another version of QuickLoad is designed for straight trucks, and includes deflection sensors for the steel-sprung steer axle. This provides exact weights for the front axle as well as the air-sprung tandem (and could be used on a tractor if an operator preferred such exactness, or, as noted above, the driver slides the fifth wheel often). The cost of the deflection sensors boosts the list price to $1,225.

By the way, the company employs deflection sensors, which measure the stretching of steel springs and calculate what poundage they're loaded to, for mechanically sprung trucks, and has qualified the sensors to work with two Hendrickson suspension models. Various scale products from other suppliers also use deflection sensors to use on vehicles ranging from trash trucks to forklifts. (Some operators measure each "lift" and capture data to later bill customers by weight - quite ingenious and not new, either.)

If I had known all this 10 years ago, while we were heading 19 miles the wrong way to cross that certified scale at Wheeler Ridge, I'd have really grumbled, and that owner-operator might have kicked me out right there. Since then, more suppliers have entered the on-board scale market and the resulting competition, along with higher production volumes, has brought prices down. You might go weigh your options, and your loads, and save money in more ways than purchase price.

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