On-Site Machining Optimizes Wind Tower Assembly

"Having Climax precision portable machine tools on hand ensures that our machinists are equipped to get the job done in the most efficient manner. More importantly, it also assures our customers that their repair and maintenance projects will meet even the tightest specifications." - Rob Burnstad, co-owner and general manager, In-Situ Machining Solutions Ltd., Calgary, AB

Situation

• Wind turbine manufacturers are in a race to increase capacity while improving reliability and enhancing efficiency. As a result, there is a trend toward building larger turbines.
• When flanges of these larger diameter turbine towers are found to be out-of-spec, it is all the more difficult to machine them to the tight specifications set by turbine manufacturers. Yet it is even more critical that these flanges be extremely flat to avoid the excess vibration can damage tower components.
• Many turbine manufacturers have contracted the machining of the tower flanges to field service companies who have demonstrated experience working in this and other areas of the power industry. -For example, In-Situ Machining Solutions Ltd. has machined more than 200 wind tower flanges at wind farms all across Canada, and has extensive experience in on-site maintenance and repair throughout the nuclear- and hydro-power industries

Challenge

• In-Situ Machining’s field service crew was called in when tower tube flanges delivered to a Canadian wind farm project were determined to be out of tolerance. The tower flanges ranged in size from 9- to 13-feet (2.743 to 3.962 meters) in diameter.
• The project called for a flange facer that had both the precision and power needed to machine a range of sizes, could set up easily, and yet had the precision and power to meet the stringent specs set by the turbine manufacturer.
• In-Situ Machining had relied on its Climax FF8000 flange facer for smaller jobs, But the FF8000’s standard facing range up to a 10-foot (3.048 meter) diameter wasn’t long enough for the new, larger towers.

Solution

• In-Situ’s machinists found that they could modify the FF8000 to extend its arms to the full 13 feet, while still holding to a .004-inch (0.1016 mm) tolerance. Because the FF8000’s tool head/radial feed mechanism mounts on dovetail ways at the end of the turning arm, it can re-face to the edge of flanges or cut right up to a shoulder.
• Thanks to the FF8000’s unique modular design, In-Situ machinists could set it up to be work-ready within 30 minutes.

Results

• The flange facer’s rigidity and metal removal capabilities enabled In-Situ’s machinists to machine two to three 9-foot (2.74 meters) flanges a shift, or one of the massive 11- and 13-foot (3.352 - 3.962 meters) flanges every 10-12 hours.
• Measured again prior to tower assembly, all flanges were shown to meet the exacting tolerances set by the manufacturer, cementing In-Situ’s reputation as one of the power industry’s premier field service providers and troubleshooters.
• While the modified FF8000 flange facer proved more than equal to its task, In-Situ is now looking to support even larger towers by purchasing a Climax CM Circular Mill, which is capable of holding extremely tight tolerances on flanges with diameters up to 16 feet (4876.8 mm).

"In-Situ Machining is an excellent example of the wisdom of having tools on hand that are designed for precision and power yet can be easily modified to solve challenging new machining problems. We are proud of our close relationship with In-Situ -- one of the leading field service companies in North America -- and of the ability of our tools to help it grow its business." - Geoff Gilmore, President, Climax Portable Machine Tools