Each year, roughly 100 trucks from Longmei Engineering carry nearly 12 million tonnes of excavated earth and rock from a coal-bearing seam at the Xiaolongtan coal mine in the Yunnan province of China. With every truck covering 100,000 kilometers (62,137 miles) annually, the company knew that reducing the cost per trip could produce substantial savings. According to Chen Hao, plant manager at Longmei, the company knew that redesigning the truck bodies would bring cost efficiency.
SSAB technicians discussed the matter with engineers at Longmei, and showed them how they could use thinner Hardox® plate to reduce the tare and maximize the trucks’ payload capacity.
“We were willing to try something new. We had several meetings and discussions with SSAB, and their technical team showed us examples of truck bodies that were used in Europe. The bodies were very attractive, so we decided to run a trial with Hardox®,” recalls Chen.
But when the bodies were delivered, eyebrows were raised.
“The truck body was a shock to us at first, and our drivers refused to believe that such thin steel plate could cope with more load. But after a few months of service, the drivers agreed that the new Hardox® bodies were up to the task,” he recalls.
The entire company backed the decision to continue with Hardox®, and it was then decided to switch to a U-shaped body to lower the weight and increase the capacity even more. The result met with great success. Chen recalls that Hardox® 450 enabled Longmei to reduce the body weight from 4.6 tonnes to 3.5 tonnes.
“Since we haul earth and rock, the empty weight of the truck is of major importance to us,” states Chen.
“Many truck body manufacturers in China use mild steel with many reinforcements. But Hardox® 450 needs no stiffeners, which is a major design benefit,” says Sun Mangui, design and production manager at Longmei.