Transformer Move the Heaviest Haul on Iowa Roads

By Curt Grandia | September 28, 2010

Contractors move some large loads of materials and heavy equipment, but the recent move of a super-large load in Des Moines would be hard to top.

Jan. 8, Diamond Heavy Haul, Inc., of Shandon, Ohio, moved a transformer about seven miles from the railhead in Grimes to a MidAmerican Energy substation in Johnston. The truck, trailer and transformer totaled nearly 750,000 pounds, was 18 feet wide, 18-1/2 feet high, and 230 feet long.

"This could be one of the heaviest loads to traverse an Iowa roadway," said Major Ned Lewis of the Iowa DOT's Office of Motor Vehicle Enforcement. "Safe movement of something weighing in excess of 740,000 pounds and extending 230 feet in length requires a lot of preplanning."

During the weeks prior to the move, Iowa DOT's offices of Motor Vehicle Enforcement, Motor Carrier Services, Bridges and Structures, and Design assisted Diamond Heavy Haul in preparing for the move. Coordination with local law enforcement and city and county officials was also necessary to ensure that the move would go smoothly. A number of special safety provisions were outlined in the Iowa DOT's permits authorizing the movement. For instance, six DOT motor vehicle enforcement escorts and civilian escorts accompanied the loaded unit and all utilities with service along the route had to follow the load in case a service was interrupted.

According to Diamond Heavy Haul Operations Manager Tom Gallagher, the company hired or rented the services of Iowa Signal & Electric Co. to move traffic signals along the way.

"We hired them to take care of the 'obstructions,'" Gallagher said. "We gave them the dimensions and they ran physical route surveys to determine which obstacles had to be moved. At the corner of Northwest 54th Avenue and 141, they lifted the arm so we could negotiate the turn without the transformer coming into contact with it."

The over-dimensional unit consisted of a semi-tractor and multi-axle trailer system with a total of 25 axles to carry and distribute the weight of the load. For comparison, the maximum limit for a traditional semi-tractor-trailer unit is 80,000 pounds.

The move went as scheduled and took approximately three hours.