New roads leading to wind-turbines sites are one of the biggest cost items for wind-farm owners. Tower sections and long turbine blades, more than 120 ft in some cases, require large-radii turns in roads so trucks carrying the huge parts can make the journey. But the real estate is not always available. Pilots on the construction staff at Erickson Air-Crane Inc., say a less expensive alternative is to air lift turbine components to the site, 20,000 lb at a time. “Then the only roads needed are for much smaller and lighter crew trucks,” says Martin Cude, construction sales manager with Erickson. “The savings can easily amount to millions.”
Cude admits the idea heavy lift air transport is not new. “Erickson has been operating the S-64 Aircrane since 1971 to perform a wide variety of heavy lift work,” he says. “We acquired the type certificate to the design from Sikorsky Aircraft in 1992, which originally built the helicopters for the U.S. Army as Skycranes. Most of our recent work has been fighting forest fires, building electrical transmission towers, harvesting light-footprint timber, and lifting air-handling units onto rooftops of skyscrapers at heights ground-based cranes cannot reach.” Costs to lift depend on job location, number of lifts, elevation, and flight distance.
Moving equipment is nothing new for Erickson. “We’ve worked with companies like Caterpillar and Case to disassemble machinery, lift it to remote locations, and reassemble it onsite, so our experience is quite broad with respect to equipment moves,” says Cude. He acknowledges that individual turbine components may weigh more than 20,000 lb. Therefore, OEMs that would like to encourage building wind farms in somewhat inaccessible places might redesign their products with aerial transport in mind. He says his company’s precision placement capabilities make onsite assembly worth considering.
Although Erickson’s helicopters can lift some 25,000 lb, when considering elevation, temperature, and flight distance, Cude says 20,000 lbs per lift is a more reasonable figure. He adds that the company has made more than 1,300 modifications to the aircraft, including service-life extensions on the engine, and upgraded avionics and flight controls.
Upgrades to the Aircranes have made it easier to assemble transmission towers in moderate winds. “For example, an aft seat pilot flies the aircraft when the job involves assembling electrical-transmission-tower sections. Although the aircraft has great position-hold capabilities, the skill and experience of our pilots really let the Aircrane lead the world in heavy-lift precision construction,” says Cude.
So far, the company has completed several jobs lifting turbine blades. For example, one lifted three blades to the top of the 12,000-ft Grouse Mountain wind turbine near Vancouver. Another job involved lifting 39 blades, each measuring 144-ft long, to a mountainous region of Ricigliano, Italy, where Vestas built twelve 3.0 MW V90 wind turbines. Erickson and Vestas also designed a sling to carry turbine blades for the job in Italy. WPE