Truck-mounted Bronto aerial lifts played key roles in the efficient and cost-effective refurbishing of turbine blades at a large wind farm near Sweetwater, Texas.
Although the wind-swept Texas plains are ideal for generating wind power, the area’s dirt, hail, lightning, insects, and other airborne particles, along with UV rays and other natural elements, can take a toll on blades over years of service. When the time came to inspect and refurbish turbine blades at a large wind farm, its managers decided to minimize downtime by having every blade on the property inspected and refurbished in scheduled groups, rather than individually as repairs were needed.
The first phase of inspection and refurbishing repaired a group of 1.5MW turbines damaged by a lightning storm. Because a 1.5MW turbine puts out more than 36MW daily, shutting it down can cost $800 or more a day. So minimizing downtime and maximizing efficiency are vital to making top ROI.
The Sweetwater refurbishment project required workers to inspect all blades in place, document all required work, and then repair any area that needed it. Because blades with smooth leading edges let the turbine deliver top output and life by reducing friction as the blades cut through the air, it was necessary for workers to sand each blade, fill cracks and gouges with putty, apply two layers of leading-edge protectant, and finish the job with two coats of polyurethane.
The company that won the contract to work on the first group of turbines performed most of the inspection and refurbishing from suspended scaffolding. To keep the work running on schedule, however, it chose TGM Wind Services, Abilene, Texas, to help. Instead of suspended scaffolding, TGM uses truck-mounted aerial lifts for this kind of work. Although these types of aerial lifts are relatively new to North American wind farms, they have been proven for many years in Europe and globally.
TGM’s performance on the first phase of the wind-farm project earned it a chance to bid on—and win—the contract for Phase 2 of the project: inspecting and refurbishing the blades of 25 1.5MW turbines.
High-reaching platform
TGM currently operates five Bronto Skylift S 90 HLA truck-mounted aerial work platforms, which it has used to work on wind towers since taking delivery of it first two in 2010. It plans to purchase seven more machines in the next three years to handle an increasing workload.
The Bronto S 90 HLAs’ six-axle Kimball chassis can drive directly to a turbine. Their advanced outrigger controls and one-button automatic leveling allow the lift to be positioned, set up, and elevated in 15 to 20 minutes or less.
The machines can work in winds to 28 mph while lifting 1,000 pounds of workers and materials in an 8’x3’ platform. The platform reaches up to 289 feet and out to 108 feet. Electrical, pneumatic, hydraulic, and water lines running from the truck chassis through the boom to outlets in the platform let technicians easily operate power tools and washers.
Safety was a major consideration in the wind farm management’s decision to award TGM the contract for Phase 2. A Bronto lift’s aerial platform is mounted on a telescoping boom connected to a turntable on the truck chassis. Th e lift is operated from the platform, so technicians have a greater degree of control in positioning the platform. Techs can get close to the blades while working.
TGM Wind Services’ Vice President Kevin Darby quoted a fixed price per blade, no matter what repairs or supplies were needed. He also said TGM would inspect and refurbish one turbine (three blades) per day, if weather was good. Most other companies’ quotes were based on time and materials or per-day rates.
TGM exceeded its commitment. One member of the wind farm site management team said he watched TGM drive up to a turbine and be at work within minutes. He confirmed that when weather allowed, TGM completed a turbine per day.
Darby said [thanks to the Brontos], “We are able to do more work in less time and give better service, while creating a safer work environment.” Darby also noted that quoting a fixed price per blade gives a better handle on the project’s total cost. “A win for everyone,” he said.
Lift & Access is part of the Catalyst Communications Network publication family.
