A Washington producer purchased a six-axle trailer for the Pacific Coast's longest truck-transported beam and gained two three-axle trailers for normal hauls. With a tractor and trailer combination about 215 feet long and a permitted weight of 291,800 pounds, Central Pre-Mix Prestress of Spokane delivered six supersize loads and then converted the longer trailer into two separate units.

Larger, longer, and heavier bridge members are an industry trend. The average payload will increase. With delivery costs such a large portion of the bid package, fleet managers are being challenged to have the right equipment to deliver these members safely. Four-axle units may not meet a state's weight-bridge limit in the future.

The two 6x6 steerable trailers Central Pre-Mix Prestress purchased offered versatility for both the largest of loads and the average load. The trailer's design is modular. For delivery of the last of six super-sized loads, mechanics converted the longer trailer into two separate units by removing 1/2-inch-thick support plates from the connecting frame and bolting on an additional beam support to the rear-axle assembly.

Keywords: Parker Road Bridge, Zillah Trucking, Central Pre-Mix Prestress, steerable trailer, Elk River Machinery