• In: Training | On: Jul 23, 2020

Wind Turbine Bolting Inspection


For today’s snippet, we will be looking at tension bolts featured in Wind Turbines, and the various types.



There’s many types of WT structure and foundation tension bolts.

Can you recognise any of the following?

• Differential threads (and what they are needed)

• ’Roundnut’ pretensioned bolts

• Washer-free bolts



If you can, try this WT Inspector-Cert question:


What’s the purpose of washer-free type tension bolts?

a) To better spread the tension load across the flange

b) To grip better on a poor surface finish

c) Improved accuracy of multiple hydraulic stretches

d) To avoid the need for lubrication during assembly


If you think you know the correct answer, why not drop us an email to tell us?

We’d like to hear from you!



Bolting Inspections


It’s the task of the WT inspector to report on whether structure and foundation bolts have been correctly tensioned and to look for any evidence that they’re not.


But why do bolts come loose?


Due to thread yielding, initial over-tightening or wind/wave fatigue stresses (‘ratchetting’).



Do you have any questions?

If you have any questions about the Wilkinson Coutts Wind Turbine Inspector Cert, contact Paul Wilkinson or Craig Coutts via these two emails:









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