Nearly a dozen Manitowoc crawler cranes and several Grove RTs have been key players in the development of the Rolling Hills Wind Project in southwestern Iowa. Helping erect 193 wind turbines are three Manitowoc 16000s, each with a wind attachment; two Manitowoc 14000s; two Manitowoc 888s; two Manitowoc 2250s, and several Grove rough-terrain cranes.
Mortenson Construction, the main contractor working for project owner MidAmerican Energy, rented the crawlers from two companies, Dawes Crane and Laramie Cranes.
Steven Klatt, crane manager for Mortenson, says the company chose the cranes because they could work together efficiently on the large project.
“The Manitowoc 16000s with the wind attachments are what we consider our main erection cranes,” says Klatt. “They have the capacity and reach for the heaviest and highest picks. The 2250s are our base cranes, and the 888s and 14000s are being used to build the rotors. During turbine erection, the Grove RTs are used for tailing as well as off-loading components from trucks.”
The Manitowoc 16000 has a maximum capacity of 440 USt and a maximum reach of 432 ft. To place the turbines on the 80 m towers, the 16000s have been configured with 301.8 ft of main boom and 24.9 ft of upper boom with the wind attachment. The wind attachment is designed to increase the reach and capacity of the Manitowoc 16000 at short radii, which is especially beneficial in wind turbine erection. At a 59 ft radius, the wind attachment yields a capacity advantage of 49% over a standard 16000.
The Rolling Hills Wind Project in Massena, IA will be one of the nation’s largest wind farms. Site preparation for the project began in April 2011, and turbine erection should complete by November. When finished, the turbines will produce enough electricity to power approximately 190,000 homes.
As part of a larger project owned by MidAmerican Energy, Mortenson Construction will also be working on two additional wind farms: the Laurel and the Pomeroy IV. The three farms together will span more than 150 square miles across six counties.