Duratray International

In the mining industry, the process to move mined material appears to be pretty straightforward. Shovels load the ore and dirt into the dump trucks. The trucks then transport the ore and dump it in another location. However, one company seems to have discovered a revolutionary system that makes this simple process as efficient as possible. Duratray International of Denver is the manufacturer of a unique dump body tray made specifically for mining and quarry haul trucks. The license for the Duratray was purchased in 2001 by Conymet, Chile.

Called the Duratray suspended dump body (SDB), the dump tray consists of a series of suspended elastomeric ropes that are anchored to the steel frame of the truck’s body. Key to the design is a large rubber mat that sits on top of the ropes. This “frame-and-hammock” design, capable of carrying up to 400 tons, replaces the traditional steel dump body used in most heavy haul trucks.

“Most dump truck trays are made of steel,” notes Matias Medel, president of North American operations. “The SDB is unique and features many benefits over standard steel truck beds.”

The rubber mat itself is crafted of a proprietary rubber formulation that is highly resistant to abrasive materials, especially compared to standard metal trays. “With steel bodies, maintenance must be performed after only 8 months,” Medel explains. “In a comparison of standard metal trays vs. our trays, Duratray’s required substantially less maintenance after three years of use.”

Reducing Carry-Back
One of the biggest issues in mining operations is carry-back, the ore that remains in the truck tray after the load is dumped. “Many of the operations we work with tell us that standard trays can retain up to 10 tons of carry-back,” Medel says. “Over a period of time, the increased carry-back reduces the tray’s carrying capacity and the operators must remove it manually using crews working with shovels, which can be both costly and time-consuming.”

Operator safety and comfort are also significantly improved with the Duratray. “The rubber bodies greatly reduce the noise made by traditional steel dump body operation,” Medel states. “Because the load is centralized in the dump body, it increases the truck’s stability, offers a smoother ride and even reduces fuel consumption.”

Custom Fit
A unique advantage of the SDB is its customization abilities. “When we approach a client, we’ll ask about all of their equipment and try to design a tray to suit their specific operation,” Medel says. Duratray’s engineering team considers the client’s truck type, target payload or capacity, loading height, material density and abrasiveness, and external dimensions. Other factors, such as maximum gross vehicle weight, its center of gravity and axle load distribution, are also taken into account. Engineers input a truck’s dimensions to create a 3-D model of the Duratray design. The mat thickness can be modified from 100 to 135 mm according the operation’s needs.

“Many times, we can create a slightly bigger tray than an OEM, which enables us to increase the truck’s payload,” Medel says. “This type of modification can actually help the company increase output using fewer trucks.”