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Anchor Bolt Tension Verification Testing

Anchor bolt tension verification provides the 10% check requirement specified in structural drawings. It is a critical testing requirement for the proper operation of turbines. Under-tensioned bolts can allow premature failure of the foundation and increased long-term maintenance costs. RRC maintains a staff of qualified field crews capable of testing projects throughout the continental United States.

Each crew of two field professionals are equipped with a high-pressure hydraulic pump and generator, calibrated gauge, and an industry standard elliptical tensioner specifically designed to verify the design tension of a wind turbine anchor bolt. Foundation bolts as large as #11, Grade 150 can be tested, and with the elliptical tensioners, as little as 2 inches of clearance is needed from the centerline of the bolt to the turbine wall. Crews are able to work independently, professionally, and within the requirements of the Work Control Procedures of the site.

During testing, when an anchor bolt is found to be under-tensioned, 100% of the anchor bolts are then tested. Any under-tensioned bolts are brought up to the design tension. A professional report is then issued for each turbine tested with a description of the testing performed and the results of the testing. This report can then be placed in the permanent record for the turbine.