Blade Repair

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At Viking wind services, we deal with every aspect of wind turbine maintenance and repair from internal workings to the outer structure. We often collaborate with highly experienced contractors to carry out some of the more specialized practices.

A large part of our service performance is the repair and maintenance of wind turbine blades. Wind turbine blades are susceptible to high levels of degradation within their life cycle. Wind turbine blades can cost in the region of €70,000 per new set. This makes them a costly expense for many wind turbine owners. We at Viking wind services are therefore working in conjunction with one of Europe’s leading blade maintenance and repair specialists offering our customers a more cost effective solution.

Our contractor within this area is a German based company specializing in the service and maintenance of wind turbine blades in the service with more than 12 years of quality assurance within the wind industry.

Therefore, their vast experience and proficiency makes them a reliable and professional partner for owners, operators, service and consulting companies. Currently, their team of technicians have undertaken projects all over Europe on approximately a thousand wind turbines.

The power spectrum of this organization provides services in the field of material testing such as x-ray examinations, surface crack and ultrasonic testing of wind turbine blades.

Results of inspections can serve as the basis for the preparation of remedial measures. A review on the design of repair work, the current status of the blades can be determined. Once the investigation phase is completed our certified professional team will then devise a schedule for repair works within a flexible and short-term period, so as to ensure short downtimes.


Process used within Wind Turbine Blade Inspection

Ultrasonic Testing (Scanning)

Ultrasonic testing is a non-invasive test method used upon sound-conductive materials by means of ultrasonic waves for inner defects. This process involves the pulsation of ultrasonic designated frequencies between about 20 kHz and 1 to 10 GHz, which are above the measurable human auditory frequency range.

This examination technique is based on the runtime measurement of sound waves discharged from an ultrasound source and their echoes are captured by the sound sensors. Deficiencies such as insertions, cracks, voids, or the occurrence of separation point interfaces cause a different reflection behaviour of sound waves.

Therefore, enabling our technicians to perform a precise analysis with high test speed, creating detailed cross-sectional images of the internal structure of the work piece to be tested. Once analysed our team of highly experience technicians will be available to carry out the repairs necessary.

Please contact us at Viking wind services for more information.

Or visit our VWS Youtube Channel to view the blade scanning process.



The following steps describe the different stages of the repair process………….


Based on high dynamic loads at the rotor blades during the life time of the turbine, cracks can occur at the end of the bore holes inside the aluminum ring.

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Vestas V47 / Gamesa G47: Cracks in the thread base of the rotor blade root

Issue: The sharp-edged design of the borehole promotes a crack initiation and propagation.


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Measurement: The test head unit will be moved over the entire circumference of the rotor blade connection until the borehole will be shown in the sector display of the ultra-sonic test device (phased array).



Repair: In case cracks are detected, welding work will be performed at the mounted blade and the borehole will be modified.



Preparation of the blade root in front of welding work:

A cooling device will be installed at the backside of the welding area to make sure that the temperature of the blade root will not exceed 70°C. During the welding work, a data logger is recording the temperature of the alu ring.


Data logger: Testo 176 T4


Preparation of weld seam and welding work:

The affected Area of the alu ring will be opened to delete the located crack.

In front of the welding work, a PT-Inspection at the prepared Area will be performed to make sure all indications have been removed.

The PT-Inspection will be reported based on a photo-documentation


Temperature control during the welding process.


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Inspection of welding work:

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