Case Story – E.ON

The utility firm E.ON’s Success in Saving their Gearbox

“In August 2012, we received an alarm: High Speed Pinion on Turbine L01. Thereafter, we visually checked to see if we could see some cracks on the gear teeth. Additionally, we checked the in-line oil filter to make sure there were no shavings from the metal.

When we didn’t see any signs of cracks or shavings, we decided that we would start up the turbine again. But after two days, we received the same alarm again. We repeated the procedure, but we still didn’t find any cracks or metal shavings, so we started the wind turbine again, and immediately ordered a new high speed shaft.

The reasoning behind the purchase of the new shaft was a simple calculation . . . if there was a tooth that might break off and ruin a gearbox, the replacement costs for a new gearbox would be around $522,000-609,000 including a jack-up rig, whereas the replacement of a new shaft would only cost $17,500.
After changing the shaft we did not become much wiser . . . was there a crack?
We cleaned our old shaft using “Flawfinder®” (cleaning spray from Rocol). After that, we could conclude, that it was a really good decision to replace the shaft. We were finally able to see the crack.”

– JON PEDERSEN: Site Manager for Rødsand II Wind Farm

Thanks to TCM®, a cracked high speed shaft was detected early and replaced before it failed, potentially damaging a very expensive gearbox.

“TCM® provided us with an extra pair of eyes. Without TCM®, we would have had to replace a costly gearbox.”
– Jon Pedersen: Site Manager for Rødsand II Wind Farm


Between $522,000 and $609,000 for a new gearbox if the high speed shaft had not been replaced in a timely manner.