East Coast Truck & Trailer in Portsmouth, Va., has a fleet of about 30 auto transport trailers, all outfitted with on-board scales. When loading them at auctions or car facilities, the drivers keep an eye on the trailer scales’ digital readouts, and use the information to adjust the vehicles’ position to better distribute their weight. “It is easy to see if you are exceeding your gross weight. We are always fighting with going overweight on the rear tandem axles on the trailer. We can watch the scales as we load,” says East Coast Truck & Trailer vice-president Barry Rudiger.

Simply turning a couple of cars end to end to move their engines for or aft of the axles can shift 1000-1500 pounds off the tandems, and the success of such maneuvers are immediately seen on the scales. The on-board scales can provide front axle weight, rear tandem weight and trailer weight.

The subtext is that vehicles have been getting heavier, increasing the likelihood that a fully loaded auto transport trailer will be overweight, according to Rudiger. As well, once the trailer is loaded it is too late to check the weight somewhere else and in any case, drivers do not want to play musical cars to bring the load into compliance with weight limits once the trailer is loaded.

As for the cost and inconvenience of getting caught running overweight, Rudiger uses Ohio, a state through which his trucks frequently pass, to illustrate. “If you are caught running overweight you simply have to remove cars from the trailer. Here is your ticket and you have to get someone to come pick up the car.”

East Coast Truck & Trailer has been using on-board scales for about three years, equipment that it purchased from the Eugene, Ore. manufacturer Air-Weigh. Air-Weigh scales tap into trucks’ air suspension systems to measure changes of pressure as small as 1/27 PSI. The company makes two types of electronic scale systems with digital displays: an in-dash model and a trailer-mounted scale. Scales on trailers that are hooked up to tractors can be read from inside the cabs as well.

“Many of the people using the on-board scales are looking at the weight as they load. The real advantage goes to those who weigh as they load,” says Air-Weigh product manager Jim Morton. “Flatbed, reefers, auto trailers and bulk are where the product-by-weight differs from load to load and where we have the most success.”

For trucks with adjustable fifth wheels, a deflection sensor on the steer axle immediately indicates to the driver by how much the weight on the steer axle has changed.

Last year Air-Weigh announced that it had begun equipping its 5800 series of on-board truck scales with a new feature that would allow weight information to be transferred to the truck’s J1708 data bus, setting the stage for transmitting weight information over wireless networks.

“We are starting to see some interest in seeing weight information transmitted back over the wireless with check calls. Some customers are asking for this. If the office knows that you are constantly leaving under- or over-loaded, it is useful for fleet management,” says Morton. “With the J1708 and RS32 we can talk to an on-board computer. We have talked to some people about including weight information as part of tracking. A couple of companies have indicated that they have sent weight information with the positioning information, to see if their trailer is empty or full. This has not gone far yet, but we see it doing that in the next couple of years.”

This March Right Weigh Load Scales, headquartered in Sherwood, Ore., launched a low-viscosity silicone-filled line of analog on-board scales. The silicone prevents corrosion and absorbs vibration and pressure spikes, according to marketing manager Scott McCulloch. Right Weigh swears by analog scales, which it says are accurate to within 250 pounds. A complete tractor/trailer package can be bought for less than US$200 and installation, since the scales tap into the air suspension system, is economical and fast – about 30 minutes, according to McCulloch. The company sells dash-mounted and exterior scales. The benefits of on-board scales will ring true to users. McCulloch ticks off the main points: “Our average customer has to scale out several times per week. Now consider the cost of each scaling, the number of out-of-route miles spent locating scales, operating costs incurred during that time, time delays per check-weigh spent reworking loads or offloading weight, as well as any overweight tickets received, and one truck can easily spend several hundred dollars per week on weight-related issues alone. The return on an investment in on-board scales is often substantial enough to pay for the purchase in a matter of days or weeks.”

Aggregate haulers are making good use of on-board scales to work more efficiently, according to Rick Talbot, in sales and marketing with Vulcan On-board Scales, manufactured by Stress-Tek, Inc., in Kent, Wash. The company makes a wide variety of scales for spring, air, mixed spring/suspensions and even a hydraulic sensor that obtain weight information from the front lift cylinders on dump trucks and roll-off’s.

“The visibility of scales is such that aggregate is the fastest-growing market, although not the highest penetration yet,” Talbot says. “I’m surprised how the aggregate business seems to be popping up all over the place in our market.”

Part of the draw of on-board scales to the aggregate industry is the unpredictable weight of the stuff. A given volume of wet aggregate will be much heavier than that same volume dry. Publicly owned fleets, such as those operated by counties, are adopting on-board scales to maximize the weight on each truck, and minimize the number of trips. This helps to minimize the cost of taxpayer-funded projects. Talbot also points out, “If the county is enforcing overweight they have to make sure their own vehicles are not overweight.”

Contractors working on a fixed-cost won contract basis are also turning on to on-board scales to maximize their legal loads and thus minimize one overhead area. “Maximize loads, minimize overweight fines, minimize costs,” says Talbot.

Talbot is also seeing a lot more clean out trucks, used to clean storm water drainage systems, outfitted with on-board scales. In the municipal waste arena, Talbot notes that although most transfer vehicles leave 20-25% underweight, overweight fines are actually a line item in some transfer sites’ budgets. The alternative to this hit and miss approach are on-board scales that drivers can watch as their trucks are being loaded, to get the maximum allowable weight every time. Talbot hears that some roll-off operators are checking their weight with the on-board scales, then heading either to landfills that charge by weight or to others that charge by volume.

“You can look at your weight and tell right away whether it is better to go to the weight or volume landfills. Some of these guys are saying they are paying for their scales in a couple of weeks,” he says.

There is the bottom line: “This is a money deal. You need to have a payback. If it pays, they buy it,” Talbot says. “[But] I think people don’t buy scales unless they have problems. It has to be in the top few problems. If it is just a simmering problem they will often ignore it, even if [a solution] is profitable.”

Carroll McCormick is an award-winning writer who has been covering transportation industry issues and technologies for more than a decade. He is based in Quebec.