Friday 21 December 2012

It was my pleasure

Twentyeight years after this photo was taken, when the first wind turbine made by Ecotècnia was erected, where you can see (from left to right upright)
Josep Congost, Quim Corominas, Pep Prats, Pere Escorsa, Antoni Martínez, Ermen Llovet,
(and on their knees) Josep Puig, Miquel Cabré, Pere Viladomiu i Xavier Traver
Pep Prats and Miquel Cabré invited me to talk about blade strategy together with Richard A. Schmidt, Patricia Canalis, Alexis de Beaumont and Luca Feigl at Alstom Wind in Barcelona, Spain.
This is very honorfull for me, thank you.

Tuesday 27 November 2012

Reliability and Failure Analysis of Wind Power Plants

The international conference "Failure and Damage Analysis" is addressed to manufacturer of wind turbines, suppliers, service provider of operation and maintenance, energy provider, wind farm operator, consulting engineers, technical experts, financial institutions and insurances from all over the world.
Two days in March '13, on 20th and 21st, read more about the program here

Saturday 22 September 2012

Next Generation Unmanned Airborne Vehicles

Cassidian is the defence and security division of the EADS group and a major provider of global security solutions, lead system integration and aerial, land, naval and joint systems. Next generation of airborne military UAV or drones made me fall into evil mood. Visiting the ILA Berlin Air Show 2012 I had first time a feeling like being an engineer in astronautics and aeronautics is an embarrassment.

Never the less, civil use is measurable and we offer our expertise for damage analysis and root cause accessment for claim regulation purposes.

Monday 18 June 2012

After Sales Service Conference Frankfurt am Main

December 4th and 5th 2012 the 3rd German After Sales Service Conference supported amongst others by Bombardier Transportation, Lufthansa Technik, Bosch and MAN is held to learn from experience of others. Dr. Holstein's contribution is to give an insight in wind branch business processes and lessons learned with respect to off-shore restrictions.

Sunday 6 May 2012

Larger Rotors for low wind sites

Rune Schytt-Nielsen and Flemming Sörensen, Cofounders of SSP
"There is a strong trend towards larger rotors development in order to increase energy production and therefore decrease cost of energy production", Steen Broust Nielsen said when introducing today's challenges in blade design at the SSP site event on EWEA 2012 in Copenhagen. In the same time blade industrie will face an enormous price pressure due to very competetive environment in Asia Pacific.
Reliability concerns with longer blades will put an emphasis on suppliers and after sales service providers with clean records.
We at HMS feel very closed up to the SSP philosophy and have a similar approach to support the provision of blade quality through communication of approved service procedures, staff qualification and independant supervising services.
Feel free to get in touch with HMS Expert's Office, Berlin,

Sunday 4 March 2012

Damage class four incident (see also rotor blade damage classes)

Rotor blade maintenance and repair standards are to be correlated to structual blade condition and for repair decisions on basis of damage classes. This posting shows without any doubt a damage class four finding (total loss).

In this case there is hypothesis for fatal blade failure mode by carbon UD-girder  fiber damage due to transverse force stress induced by glass fiber helix winding technique in order to fix the UD-stack in semi-automated beam production process. This issue is discussed in preparation of next Technical Advisory Board Meeting of the AK R (a committee of the German Wind Association, see also

Less severe damages like cracks or delaminations have virtually two dimensions. The first dimension visible at a first glance is what we call inspection findings. The second and comprehensive dimension of a damage can be assessed after removing layer by layer of affected material. It is the difference about damage amount and it's range.

Thursday 16 February 2012

Interactive Knowledge Base on NDE of composites

In our every day analysis of failure modes and naming the root causes we recommend to standardize also well defined descriptions and in that sense definitions. Using the right classification for damage classes is one thing we often mention but also choosing the proper expression or definition for irregularities or findings is the other. We recommend the interactive knowledge base at netcomposites website. Http://
You will find 19 different failure modes of FRP material like "delamination" or "debonding" or "crack" and I find it very helpful.