Oregon-based heavy hauler Omega Morgan recently hauled one of the heaviest combination loads in Washington State history, weighing in at nearly 1 million pounds.

Omega Morgan was tapped to transport a 460,000-pound transformer for the Bonneville Power Administration bound for a power substation in Rock Creek, Washington. The move required a massive 360-foot trailer with 48 axles weighing in at 484,000 pounds that was specially built for the move.

A Kenworth C500 was the lead truck pulling the trailer, accompanied by two Kenworth T800s as pushers. The two-day, 47-mile journey from Sundale, Washington, to Rock Creek needed months of planning, scheduling and coordinating with state officials and private groups to ensure a logistically friendly route that would not damage roads.

“For this transport, there were quite a few obstacles we had to plan for, not to mention two-lane roads that had to be closed,” said Troy Tallent, vice president of operations at Omega Morgan. “For instance, we had to widen the gravel road from 16 feet to 20, and reduce the grade by the rail head (where the transformer was lifted off the railcar and placed in the trailer-cradle) from 16% to 15%.”

The C500 lead truck was purchased from Papé Kenworth Northwest – Lakewood specifically for this job and was spec’d for giant loads. It features a 550-hp engine mated to an Allison 4700 RDS seven-speed automatic transmission, and four-speed air shift auxiliary transmission. The truck also has Sisu planetary tridem axles, rated at 105,000 pounds with cross locks and a 7.01 ratio, and a 22,000-pound front axle with 24,000-pound front slipper springs. The C500’s triple rail steel frame provides a 200,000-pound gross combination weight chassis rating.

Because of the weight and size of the load, the project required a specialty “superload” permit. The state of Washington usually issues between 600 and 700 of these permits per year, needed any time a tractor and trailer exceeds 200,000 pounds.

Even with three trucks moving the load, for the steepest grades a fourth truck was brought in, weighed down by concrete blocks and tethered to the Kenworth C500 lead truck. Two Kenworths were positioned in the back, connected through a 10-foot A-frame to generate power, while the C500 and other heavy-hauler were connected through a steel cable to help pull and direct the trailer.

“When going up steep grades, our drivers are zeroed in on their truck’s boost meters, talking back-and-forth on how much throttle they needed to give,” said Tallent. “Going down hills, the drivers used their engines – along with the trailer brakes – to slow down.”

Other obstacles included traveling over bridges which required the use of hydraulic dollies to spread the load out over more surface area. The journey even required turns that exceeded 90 degrees and demanded precise coordination among the three drivers. But the most harrowing part of the journey was navigating Hoctor Road, according to Tallent. Hoctor is only 20 feet wide and had to accommodate the 18-foot-wide trailer for 14 miles.

“With only a foot on either side, it was a little hair-raising, but we had great drivers that made it look easy. They were locked in,” said Tallent.

While this load was the largest, Omega Morgan has already completed more than 30 transformer moves for BPA using the 360-foot trailer and said that there are more to come.

“This operation got a lot of attention because of its enormous size,” said Tallent. “What we do is about as heavy as heavy transporting gets.”