Payload management systems can help construction companies optimize haul truck efficiency and productivity.
Payload management systems take control of productivity, while eliminating over and under-loading of trucks. These systems can also reduce loading time and truck traffic.
When operators load the right amount of material on the truck every time, more work gets done. Instant feedback improves operator accuracy and speed. This optimises time, fuel and component life — virtually eliminating maintenance and liability issues due to overloading.
Fewer trips are needed to complete the task. That translates to increased revenue considering that most loads run between five per cent and eight per cent under weight of maximum legal gross vehicle weight (GVW). The savings apply to fuel and other expenses related to operating the vehicle.
“A payload management system is a combination of sensors, software and display that collects real-time payload weight and provides useful productivity and efficiency reporting both on board to the operator and off board to the project/site supervisor through telematics systems like VisionLink,” said Scott Schmidtgall, product application specialist, Caterpillar.
“The key is the ability to obtain actionable data. Tracking production by using onboard weighing systems gives you the ability to monitor individual operators for both fuel consumption and production,” said Eric Yeomans, product manager – GPPE products, Volvo Construction Equipment.
“Tracking the payload can also help you understand material flow on the site.
“This can help in assessing and improving performance in the hauling processes on site — for example, the fuel cost of transporting material X from point A to B.”
Off-Road Environment Transformed
GPS systems have allowed contractors to track cut and fill locations on the jobsite and better manage projects. And while payload management systems have been available for quite a while, being able to integrate quantities moved with the GPS coordinates creates new opportunities.
“The application of this new dimension of measurement is driving a transformational change,” said Kevin Lai, segment manager, onboard weighing, Trimble LOADRITE.
“You can track material movement on the jobsite in real time. If you can link the loader to the truck, you know where the materials are going.
“You can tell if the job is progressing as planned.”
Several OEMs are tying their payload management tools into their telematics systems.
“The Volvo Load Assist system is integrated into CareTrack telematics, so you get to see total daily production and fuel at any time through the CareTrack portal,” Yeomans said.
“By installing a sim card or downloading machine data to a USB drive, you can also see all the information that is captured by exporting data from Volvo Co-Pilot.
“All of the data obtained can be used to improve operator efficiency and identify potential operator training needs.”
“It is possible to match loads to the optimum designated capacities. For articulated haulers specifically, proper load weight in the truck ensures maximum productivity and fuel efficiency with minimum overall maintenance costs.”
On a construction site with off-road trucks, overloading is often not perceived as a problem. But even in the off-road environment, loading trucks beyond capacity can drive up costs and slow cycle times.
“While DOT restrictions do not apply to off-road trucks, payload management systems provide information that eliminates overloading,” Yeomans said.
“Continuous overloading has the potential to reduce the life of components, axles and even tires. Overloading also increases fuel consumption and affects cycle times. You should never reach a 20% overload.”
“An onboard payload management system can provide managers with an overall view of payload averages and trends and spot excessive loading and change the behaviour to minimize the long-term effect of these issues.”
“Our truck systems are not designed to limit how customers use their trucks,” added Mike Mesnard, product application specialist, Caterpillar.
“They are simply to provide information to better manage payload and maximize the life and utilization of the truck.”
“Overloading an off-road truck doesn’t have the same impact on every jobsite. The impact of overloading varies by application.
“For example, an overloaded truck on a smooth haul road might not see the negative impact as severely as a truck in a high rolling resistant, soft underfoot condition that causes frame racking and increased stress on the drivetrain and other components.
“The rated capacity of tyres should always be considered in any evaluation, as well, as they can be major cost drivers.”
One thing to consider when dealing with road-legal trucks is that stationary scales do not improve loading efficiency. Even in quarries where there are platform scales, dump trucks don’t get loaded on the platforms.
Therefore, if they are under loaded, they simply leave. If they are overloaded, they pull off to one side and tip material out, then get back in line to be re-weighed.
“On-board weighing affects your production flow and helps eliminate trips by the truck to come back and dump excess material or to get additional material when under loaded,” Yeomans said.
Scales range in accuracy from 0.3 per cent up to three per cent, depending on the loading environment. A load cell-based onboard scale system measures typically within one per cent of GVW, and often better.
The more accurate the system, the less weight you have to allow for a safety margin. The safety margin depends on what leeway is allowed in a particular application. However, always aiming at one per cent under is a safe loading target to stay legal.
Typical dump truck onboard weighing systems can be retrofitted by replacing the truck’s rear hinge assembly and pin under the hoist cylinder, which is equipped with shear pin load cells to measure weight at hinges and the hoist.
Do some research and understand what is available before purchase. Some units only provide load weight, while others offer per-axle weight.
It is just as important to get the load distribution correct. Onboard scales have the ability to provide axle group weights as well as the total vehicle weight. The axle group weights can be used to assist in load distribution.