High wind winching

At a wind farm erection site near Fort Bridger, Wyoming, in the US, (pictured left) lifting contractor Mullen Crane & Transport is battling against the same elements that the turbines are designed to harness.

Among a range of all terrain and crawler cranes the company is using a Manitowoc Model 18000 crawler at the Mountain Wind project; a sage brush-covered area that has an elevation of about 8,000 feet (2,440 m).

According to company owner Ray Mullen, it is an ideal site for wind turbine erection.

“This area is the best case scenario for a wind turbine job. The ground is flat, hard and dry. It's not easy to find a site that will support a Model 18000 fully counterweighted and not have to lay down mats or compact the ground.”

Ironically, the only major challenge on the site is the wind. It is not uncommon to have 40, 50 or even 60 mph (65, 80, 95 km/h) winds, adds Mullen, which makes erecting impossible. However, the crew regularly conducts lifts in 30 mph (48 km/h) wind.

According to Manitowoc Crane Group (MCG) the Model 18000's lifting capacity and weight provide peace of mind that the crane can safely handle all the turbine components, even in high winds.

The 2.1 MW turbines stand 266 feet (80 m) tall. The blades are 133 feet (40 m) long and are attached to the rotor on the ground using a Manitowoc Model 12000.

The nacelle, which holds the rotor and houses the electronics, is the heaviest component on the turbine, weighing 95 tons (86 tonnes).

The Mountain Wind project is in two phases. Construction on the first phase began in the third quarter of 2007 and comprises 29 turbines. Phase two will complete in two stages; 15 turbines in 2007 and the remaining 23 in the second quarter of 2008.