Wind Farm ‘Boss’

Wind farm maintenance has become a specialty of Boss Crane & Rigging.

The beauty of wind power is that it’s environmentally friendly and sustainable. A hot spot for wind power in the United States is in Texas, which produces 17,713 MW of installed wind power, the most of any state.

Wind farm development has been a windfall for crane companies, although the work requires experienced crews and expensive cranes and equipment. And the crane work doesn’t end after the towers and turbines are erected and become operational. Wind tower maintenance is big business as well, and Boss Crane & Rigging is a specialist in replacing broken components on wind towers.

“There’s a lot of maintenance work to be done on all these wind farms in Texas,” said David Cowley, president of Boss Crane & Rigging. “We are called in to replace blades and pitch bearings. We also replace gear boxes, generators and main bearings.”

While wind tower erection requires specialized cranes and crews, maintenance is another specialty. Often the blades are erected all in one piece but when a blade fails, only the faulty blade is replaced. “There are a variety of reasons for a faulty blade,” said Cowley. “Whatever it is it must be taken down and replaced in a different way than it was erected.”

Blade Drop

Recently Boss Crane & Rigging was contracted to perform a “blade drop” at the Colbeck’s Corner wind farm in Groom, TX in the Texas Panhandle. The wind farm has 112 GE 1.79-100 turbines that generate enough energy to supply 64,000 households with power. “We mobilized two large all terrain cranes to the wind farm and we furnished the riggers and technicians to remove the bad blade and install a new one,” Cowley said. “We’ve determined the best way to do this is with two cranes. Because you are working in windy conditions, we’ve developed our own blade drop system.”

Through the years rigging equipment has been developed for grabbing blades. Some companies prefer to use a spreader bar system. “You have to keep in mind that this is an 80 meter turbine; you are talking 270 feet in the air,” said Cowley. For the blade drop in Groom, Boss used a Liebherr 1750-9.1 and Boss’s 350-ton Grove GMK 6300L. The LTM 1750-9.1 was rigged with 161 feet of main boom and 123 feet of fixed jib. The GMK 6300L was rigged with 262 feet of main boom and 39 feet of fixed jib.

Due to the ground conditions, Boss’ engineers performed ground bearing pressure testing and wind speed checks. “Our in-house engineers perform all of these checks to assure we are as safe as possible when starting this work,” said Cowley. “On this job we used engineered outrigger mats and timber mats.”

Wind maintenance work is not easy and requires expert planning, Cowley said. “As soon as you are awarded the job, the confirm planning starts. There’s the transportation logistics to consider and then our engineers calculate the ground-bearing pressures and the wind sail effect to determine safe lifting wind speed limits. These documents, along with certifications on all equipment and personnel, are given to the customer.”

Once at the wind farm, a Jobsite Safety Analysis is completed for the crane assembly and lifting work. “We have a safety meeting every day to plan and discuss the lifting that will be required,” said Cowley.

Even one blade replacement can be a complicated endeavor. Boss assures its engineers are involved in every aspect of the job. “Besides the lift cranes, we will need a man basket, blade drop rigging gear and light plants,” said Cowley.

Boss Crane & Equipment, based in Longview, TX, was started in 2015 as a division of Bennett On-Site Services. The company has a fleet of 21 cranes with capacities from 100 to 900 tons. Beyond wind farm maintenance and erection, the company serves clients in the oil and gas, commercial construction, paper processing, mining and steel, civil construction and petrochemical industries.

This article was originally published November 2016 in American Cranes & Transport.