Offshore service: Working on-site
Finding the fault
With the help of Operation Site Manager William, who is responsible for the respective North Sea wind power plant, Siemens Gamesa enlisted service technician Lars who bundles different site visits together and can visually inspect the main bearing that has caused the vibration alarm. At the agreed time, a crew transportation vessel of the Siemens Gamesa fleet takes Lars and his team out to sea. To ensure safe inspection, the turbine is shut down during the inspection phase of less than six hours.
Having arrived at the wind turbine, Lars knows exactly which bearing parts and locations he needs to focus on – thanks to the alarm report from the Diagnostic Center experts on hand. By using a camera or his smartphone, the technician documents the condition with pictures or videos – or, if needed, by using endoscopes.
The digital data is transferred to the service and engineering team in the back office on land in the Danish city of Brande. Based on the photographic documentation a team of main bearing experts further assesses the potential damage. Finally, there is certainty. The on-site technicians and the back-office experts are able to confirm the suspected case: a hairline micro-crack in the main bearing was responsible for the vibration alarm.
The vibration pattern was alarming, and the on-site checks made everything clear. The entire onshore and offshore team is certain: “We are talking about a developing damage that will require attention.” If left unattended, this damage could have serious consequences by having a negative impact on other important turbine parts as well as the turbine’s availability.
“Our goal is to always keep a turbine running as long as possible while monitoring it. By accurately forecasting the remaining useful lifetime of the affected component, we have the flexibility to safely run it for several more months. Thus we provide all parties with as much time as possible to proactively plan the main bearing exchange and bundle similar cases if possible,” William emphasizes.
The turbine will be kept in safe operation and continuously be monitored until the replacement can be made. This will typically take place in the low wind season and in close cooperation with the customer.
It does not happen often, but when a major component of an offshore wind turbine threatens to fail, agility and precision are needed. In some cases it’s even necessary to replace an entire component. This sets an extremely demanding logistical service process in motion: from accurate remote fault diagnosis to the transportation and replacement of heavy components weighing several tons on the high seas.
On- and offshore logistics experts work hand in hand to prepare the heavy-duty parts, tools, specialists, and jack-up vessels specially developed for this purpose. In wind, rain, and sea, every move made by the experienced crew has to be perfectly executed.
With our mini-series, you can learn more about the offshore service logistics concept from Siemens Gamesa, what matters when replacing heavy turbine components ("heavy-lift exchanges"), and why customers can save time and money if they have a reliable and experienced service partner by their side. This is part two of the triology.