Ultimate fixer uppers

By D.Ann Shiffler01 April 2019

In 1992 the Production Tax Credit (PTC) was approved by Congress and the modern American wind industry was born. Through the years, the PTC expired and was renewed several times, creating times of uncertainty in the wind industry. According to the American Wind Energy Association (AWEA), Congress cycled through the tax credit in one or two-year stints and allowed it to expire multiple times. This cyclical pattern resulted in boom-bust cycles of development, AWEA said.

Lead photo (11)

More than 56,800 wind turbines are operating in the United States making wind tower maintenance one of the most vibrant sectors of the wind power industry.  Photo: Buckner Heavylift Cranes

In December 2015, Congress voted to create a stable phase-out of the PTC, which will be completed by the end of 2019. But this time, growth in the wind industry is expected to remain steady, even when the PTC is fully phased out.

“This long-term policy certainty created a business environment primed for growth,” AWEA said. “Because of this, today over 100,000 Americans across all 50 states work in wind.”


Mobilization typically runs 80 percent of the operated rental cost for wind maintenance component exchanges, making location of the crane critical in selecting the lowest cost option, according to Barnhart Renewables.

Today there are more than 56,800 wind turbines operating in 41 states, Guam and Puerto Rico, according to AWEA. And while there are ample new wind farms still being developed, one of the hottest areas of the wind industry involves wind farm maintenance.

Wind turbine maintenance is good business for crane and transport companies that are working at wind farms coast-to-coast providing fixes at wind farms that have been operating from one to 30 years. It’s a matter of what goes up, must come down at some point. Nacelles and blades, and even the towers themselves, can sustain damage in a range of ways.

To take a closer look at the wind farm maintenance sector, ACT convened a forum of four wind energy experts, including Chris Drinkwine, regional business manager, renewables, Mammoet Americas; David Cowley, president, Boss Crane & Rigging, Longview, TX; Dan Ives, sales director, Buckner HeavyLift Cranes, Graham, NC; and John Clark, vice president, Barnhart Renewables, Memphis, TN.

Following are their answers to our questions about this important sector of the wind market.


DRINKWINE: Active, growing and healthy. We are through the 300 percent growth years and now in a very competitive, busy and established sector. We see extended healthy growth ahead. The change in the market allows for more opportunity in how site owners are sourcing the overall major component exchanges.

COWLEY: It’s a steady business but depends a lot on weather and peak times when more power is needed, during the winter and storms. Our wind maintenance business has been strong. Once these towers are up, they are going to need to be repaired.

IVES: Given the wind capacity that’s been added to the grid in recent years, and the current growth spurred by a rush to finish projects before the Production Tax Credit expires, maintaining all these turbines will be a growing market. Furthermore, many turbine suppliers are extending the design life of their turbines from the standard 20 years up to 25 and even 30 years. At the same time, the average hub height of newly installed turbines continues to climb. A hub height of 80 meters was common five to 10 years ago, and now it’s common to see 100 to 110 meters and even higher. Accessing components that are 350 feet off the ground will necessitate larger cranes to achieve the required hook heights while maintaining adequate capacity. That’s an exciting prospect for Buckner, because we specialize in large cranes.

CLARK: It’s a dynamic, growing business with much future potential for service companies that use innovation and drive efficiency in the field to continue lowering the cost of major component exchanges. There’s an innovation driven climate of continuous improvement in servicing the growing fleet of taller and heavier turbines. Cost per KWH are continually being challenged to continue the growth of this market.


DRINKWINE: Being a heavy lift organization, we perform primarily major component exchanges (MCE’s). Our scope of supply is lifting and transport equipment, supervision and operating personnel. Mammoet Wind Equipment Services made the deliberate move to only provide “core competencies” in the wind O&M market. This is where our expertise lies, providing the “hook” and transport.

COWLEY: We are doing rotor drops, replacing gear boxes and generators, nacelles and damaged blades. There are times when we will replace older components with a higher-powered nacelle and higher performance blades.

IVES: Our cranes are commonly leased to exchange major components, such as gearboxes, bearings and generators, as well as occasionally replacing damaged blades. A mobile crane is usually needed for handling all but the smallest parts that can be lifted with the wind turbine’s on-board service crane or hoist.

CLARK: We make all major corrective component exchanges. Gear boxes, blades, bearings, generators and transformers up to and including site repowering with new turbines.

Mammoet (2)

Mammoet’s expertise lies in providing the hook and transportation.


DRINKWINE: Site access, conditions and always weather – mud, rain, snow, lightning and of course, wind. Often it is important to provide an option that will reduce farm land impact for the land owners. Having options that will not only perform the work to the safest quality, but also less environmental impact can add to the challenge.

COWLEY: The biggest challenge is the wind itself. And it’s the reason for the wind farms. Most of these lifts are done in the 270 to 300-foot range, about 80 meters, so there are wind cutoff speeds that you can safely operate a crane. Wind, site conditions, weather, these are the most challenging issues.

IVES: There is usually high pressure to execute maintenance quickly, particularly major repairs that require the turbine to be shut down. Working against that is the fact that wind turbines are naturally built in windy locations, so crane lifts can be delayed due to wind. Besides the idle time costs of crews and equipment, any down time for the turbine is lost revenue for the project owner.

CLARK: There are wind and weather challenges while working exposed to the elements operating large heavy equipment and lifting components 80 to 100 meters high. We are continuing to drive cost out of the various scopes of work for our customers, while capturing a fair return for our stakeholders. This requires new tools, jobsite efficiency, crane and craneless technology continued improvement. We are growing our team of wind turbine professionals as fast as the need is growing in the industry. Trained competent professional personnel are always in demand in our growing market.


DRINKWINE: We have a 600-plus unit fleet in the Americas currently. Our busiest units for wind O&M work are in the 300 to 620-ton hydraulic class, and the 300 to 440-ton crawler class, and my favorite, the Liebherr LG1750. However, we are seeing more and more MCE’s requiring larger and larger equipment. The industry is requiring more and more 750-ton and larger hydraulic options, as well as crawlers up to and above 600 tons.

COWLEY: On the crawler side we use from 100 to 600-ton crawlers on wind maintenance projects. On the hydraulic side, we use all terrains for these jobs too, in the 100 to 900-ton range. For us, the crawlers and ATs perform well. Whatever is needed, Boss has that crane in its fleet.

IVES: Buckner specializes in crawler cranes, and although a large portion of wind maintenance is currently performed with hydraulic all terrain cranes, we anticipate a growing market share for crawler cranes in the years ahead. Hub heights continue to get taller and turbine nameplate capacity continues to increase into the 4 to 5MW range and beyond, which typically means the turbine has heavier major components to deliver the higher power output. That translates into the need for cranes that can deliver high capacities at high hook heights, a perfect fit for our crawler crane fleet.

CLARK: Smaller components such as generators, transformers and small blades are typically completed with 300 to 500-ton hydraulic all-terrain cranes. Gear boxes, heavy long blades, complete rotors or taller turbines require larger hydraulic AT cranes from 600 to 900 tons or lattice boom crawler cranes from 300 to 1,200 tons.

Cranes are sized to each specific lift requirement to minimize the cost of each component exchange. Mobilization typically runs 80 percent of the operated rental cost for wind maintenance component exchanges, so location of the crane is also critical in selecting the lowest cost option.

Barnhart is unique in that we are a crane company that has developed through our engineering team craneless options for blade and bearing exchanges to further reduce cost of these repairs. Soon we will offer craneless options for gearboxes, generators, transformers and completed nacelles. Our goal is to provide tooling innovation to lower cost of major component exchanges combined with continuous improvement in job site schedule performance, further reducing cost and improving uptime performance for our valued customers.

Boss 2

Boss Crane & Rigging transports many of the nacelles it replaces. Its parent company, Bennett International, currently has 200-plus trucks hauling wind components.


DRINKWINE: Yes. Typically, we are hauling drive train components (gear boxes, generators, transformers) and from time to time we haul blades as well. On occasion we will haul nacelles. With O&M work typically not involving any handling of the tower sections themselves, we don’t see much transportation of these. We will handle the over-the-road portion as customers request to add synergies to the exchange.

COWLEY: It varies. Right now, Boss is transporting a lot of nacelles. But we transport all the wind power components – nacelles, blades and even tower sections. Our parent company, Bennett International, currently has 200 plus trucks hauling wind components.

IVES: For a wind maintenance project requiring one of our cranes, Buckner would typically transport the crane components, but would not provide transport for the wind turbine components being replaced or repaired.

CLARK: Barnhart is continually improving to be the best heavy lift and transport company in the U.S. market. The larger and heavier the nacelles or tower sections the more competitive we can be with our unique fleet of Goldhofer trailers.

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D.Ann Shiffler Editor, American Cranes & Transport Tel: +1 512 869 8838 E-mail: d.ann.shiffler@khl.com
Matt Burk VP Sales Tel: +1 312 496 3314 E-mail: matt.burk@khl.com