The two-lane Saddle Road climbs 6,600 feet as it stretches from Hilo to the west end of Honolulu. Weather, steep grades, and bad pavement have given the road one of the highest accident rates in the state, but Grace Pacific recently won the contract to repave the notorious route.
With off-island competition bidding, Grace Pacific knew a highly productive truck could help it structure a more aggressive bid. The vehicle had to be capable of moving 25 tons of asphalt quickly from a plant to the jobsite 16 miles away, and nearly half of the haul is on a military access road where speed is restricted to 15 miles per hour.
"We needed straight-truck speed and efficiency at the paving site," says Lorne Fleming, director of Grace Pacific's equipment division, "but the capacity of a truck and transfer trailer."
The solution is a Super 18, a seven-axle straight dump truck rated at 80,000 pounds gross weight. Called a Superdump because of its high legal payload, the truck has a 20,000-pound set-forward steer axle, three 8,000-pound steerable pushers, and 46,000-pound tandem drives. The key to the truck's capacity is alift axle trailing the tandems.
Built by Strong Industries of Houston, Texas, the Strong Arm is a liftable axle rated as high as 13,000 pounds. Trailing 11 to 13 feet behind the rear tandem, the Strong Arm stretches the outer bridge measurement — the distance between the truck's first and last axles — to allow 80,000 pounds of gross vehicle weight. With a tare weight of 29,000 pounds, the truck meets Grace Pacific's 25-ton payload target.
Fleming bought 10 Kenworth T800s with the Strong trailing axles specifically for the Saddle Road project.
"Superdumps changed the way we go about paving," says Fleming. "We know we're carrying the maximum legal load of asphalt in the most efficient type of vehicle possible, and we're more competitive for it."