Trucking key to wind farm projects 

MANLY, Iowa – If you’ve driven on Iowa’s roadways, chances are good you’ve seen one of those specialized rigs, hauling giant parts for wind turbines.

Transporting the turbines from the factory to the rural wind farm sites is no simple task. Each unit can take up to 10 truckloads.

MidAmerican Energy Co’s new 13-turbine wind farm near the northwest Iowa town of Pomeroy, completed this summer, required more than 130 separate deliveries, for example.

Siemens Energy supplied the 13 turbines for the 29.9 megawatt project in Pocahontas and Calhoun counties, as well as an additional 245 additional turbines for MidAmerican wind farms in Cass, Adams, Adair and Marshall counties.

The blades are delivered from Siemens’ plant in Fort Madison, Iowa, while the nacelles – the structure atop the tower that holds the electricity generating components – come from the company’s plant in Hutchinson, Kan.

The three blades, which weigh around 35,000 pounds apiece, are hauled separately on special trailers. The end of the 160-foot-long blades hang off the back end of the trailer, said Sally Chope, a transportation and logistics manager for wind energy for Siemens.

The nacelle is carried by a 19-axle trailer that extends 202 feet in length. Schnabel trailers are used to hauls the turbine tower in three section. A steerable double schnabel trailer features two pieces connected at each end of the unit with the capability to hydraulically lower the tower to the ground.

“The whole center of the tower isn’t supported by any trailer underneath it,” Chope said. “There is a trailer ahead of it and behind it.”

Chope said the hydraulic unit allows the driver to lower the trailer to clear bridges or highway overpasses, or raise the trailer to avoid bottoming out on low spots in the road.

Standard trailers carry the hub, containers and power unit.

Pilot vehicles help coordinate the huge rigs movements through turns and traffic. Typically, pilot cars or pickups are positioned in front and behind the tractor-trailers, but Chope said the number of vehicles depends on state regulations and the amount of traffic.

“If you’re driving in downtown Chicago with one of these, it’s going to be different than if your’re out in the middle of nowhere,” she said.

In addition to trucking, wind manufacturers also use rail to cover as much of the distance as possible from the factory. Siemens, which contracts with the nation’s two largest railroads, Union Pacific and BNSF, and some smaller carriers, off loads the equipment at central terminals, where it’s then trucked to the final destination.

In Iowa, one of those terminals is located near the small northeast town of Manly, just west of Mason City.

The Manly Terminal, which started as an ethanol-warehousing operation, also provides unloading and reloading services to several turbine vendors, much like a shipping port.

The 165-acre parcel is located along the eastern boundary of U.S. Highway 65 and the western right-of-way line of Union Pacific Railroad main line between 380th and 390th streets.

The Mason City Globe-Gazette contributed to this story.