System Scale Corporation (United States) - Orthotropic Deck Ends Recurring Truck Scale Cracks.

This Truck Scale Used to Need Welding Every Year. Three Years Later, It Hasn’t Cracked Once.

A multi-site asphalt producer near Tulsa was fighting recurring deck cracks and slow junction-box troubleshooting on an aging truck scale. SSC’s Tulsa team replaced it with a Mettler Toledo orthotropic-deck scale and PDX Digital PowerCells. Three years in, the deck hasn’t cracked once, and the customer has since replaced four more scales the same way.

The Problem:

A multi-site asphalt producer near Tulsa, Oklahoma, had a truck scale that had held up for eleven years under heavy truck traffic. Then the steel deck started to crack. The crew welded it and patched it, and it cracked again. Every repair took the scale out of service, and nobody could say how long the deck had left.

System Scale Corporation’s Tulsa team recommended replacing the scale rather than patching it again. That was a bigger conversation than another weld, but it was the right one. The replacement was a Mettler Toledo truck scale with an orthotropic rib deck and POWERCELL PDX digital load cells.

Years later, the deck has not cracked once. The customer has since replaced four more truck scales at other sites with the same design.

Why patching wasn’t working:

The old scale used a conventional I-beam deck. Every loaded truck that crosses the scale is a load cycle, and an asphalt operation puts thousands of them through each year. I-beam decks concentrate that stress along the beams and the welded connections. A weld repairs the crack, but it doesn’t change where the load goes. So the cracks came back.

Service was slow too. The scale ran analog load cells through traditional junction boxes. Every adjustment meant a technician walking back and forth between the indicator and the junction box, on a scale that already needed too much attention.

The fix:

An orthotropic rib deck is built like a modern steel bridge deck. Continuous ribs under the top plate spread each wheel load across the whole structure instead of concentrating it at a few points. It is designed for high-cycle, heavy traffic, which is exactly what an asphalt plant scale sees.

The POWERCELL PDX load cells removed the junction boxes entirely. Calibration and adjustments happen at the terminal. Each cell reports its own condition, so technicians can see a problem developing before it shuts the scale down.

The result:

• Zero cracks or structural failures in more than three years of daily truck traffic.
• Four more scales replaced at the customer’s other locations with the same deck and load cell design.

That last result says the most. One good scale could be luck. A customer that rebuilds four more sites the same way has decided the design works.

About System Scale Corporation:

Founded in 1979, System Scale Corporation provides industrial weighing equipment, installation, service, and ISO/IEC 17025 accredited calibration throughout the Midwest and Southern United States. The company has been 100% employee-owned since 1995 and is a Mettler Toledo Premier Distributor.