You are not looking for loose change when you check the load cell pockets to compare truck scales. Instead, you’re looking at a possible major expense—the cost of downtime if the load cell pockets are welded or bolted on instead of incorporated into the overall weighbridge design.
The ends of the scale modules are one of the highest stress areas of any truck scale because this is where the truck traffic enters and exits the scale platform. On many competitors’ weighbridge designs, boxes to house the load cells are welded or bolted to the ends of the scale modules and have a tendency to bend and flex excessively as truck traffic enters and exits the scale. Over a period of time, these boxes have been known to break welds, and in many cases, even break away from the main portion of the bridge, causing loss of use and premature failure of the bridge.
One of the key advantages of the Rice Lake bridge design is its extraordinary strength. The Rice Lake OTR Weighbridge design is not only tied to the amount of steel we provide, but also the manner in which these individual components are fabricated and engineered into the weighbridge structure itself.
The weighbridge for a typical Rice Lake Survivor OTR consists of a 5/16-inch checkered steel deck top plate that is welded to the top of twelve 12-inch wide-flange beams that are positioned longitudinally to the traffic flow. The spacing on the beams is on approximate 11½-inch centers, which means that the distance between beam flanges is only about 7½ inches. This ensures that no matter where a truck axle or tire is positioned on the weighbridge, it is fully supported by the steel deck, and beams.
The individual ends of the twelve beams are welded to the ¾-inch end plate weldments running the width of the module, which include a load cell pocket fabricated from ¾-inch steel plate on each side. Most competitive models use ½-inch or ⁵⁄₈-inch end plates. The twelve longitudinal beams surround the load cell pocket, integrating the pocket into the bridge structure itself, as shown in the illustration to the left. This adds extraordinary strength and integrity to a very critical area of the weighbridge.
Rice Lake takes one more very important step to ensure the strongest bridge design possible. The ¾-inch steel load cell pocket plates have precision laser-cut dovetails that are inserted into the ¾-inch end plates by laser-cutting tabs on the ends of the ¾-inch load cell pocket plates, and laser cutting square holes in ¾-inch end plates for the tabs to fit.
Rice Lake assembles the steel components within the weighbridge, which allows us to provide our weighbridges to meet extraordinarily high volume traffic demands and heavier truck loads. It is these critical design criteria that make the Rice Lake OTR series a truly “generational scale.”
From an engineering standpoint, the wide-flange structural beam is one of the strongest structural steel shapes available. The beam is much stronger than steel tubing, channels, bent steel plate, or many other types of steel components. Steel as an element is designed to bend when loaded, and return to its original shape when unloaded. If steel components are improperly chosen or sized, or are loaded beyond their original design characteristics for the application, fatigue or stretching of the steel will occur, affecting the accuracy, performance, and life span of the scale.
Many competitive weighbridges use bent steel plate, junior beams, tubing or materials that are too light or improperly designed for the loads, resulting in eventual steel fatigue and a costly premature failure of the weighbridge.
Another one of the best judges of a steel weighbridge’s ability to withstand heavy and consistent loads is the structural steel content. At Rice Lake Weighing Systems we make the heaviest and “Toughest Truck Scales on Earth.” A typical OTR Low Profile 70 foot by 11 foot steel deck truck scale has a steel content of nearly 33,000 pounds— often several thousand pounds more than comparable products.