The theme of the hazards of confined space entry is one we frequently return to, along with importance of using the correct safety procedures both for the pre-entry check and while in the confined space. But confined spaces are not always immediately obvious, and thorough risk assessment can be essential.
The wind power generation may not be the first industry that would come to mind if thinking about confined space entry hazards. However, even though it may be in the middle of the countryside and hundreds of feet in the air, the nacelle (the cover that houses all of the generating components) of a wind turbine is an enclosed space which may well present a suffocation hazard.
The wings of the huge generators sometimes need to be adjusted. In some turbines, this is done using hydraulics, along with accumulators which feather the blade pitch. Accumulators serve as an auxiliary power storage device to rotate the blade to a null position in extreme wind conditions. They are also used as the energy source to activate the brake, in the case of an electrical power failure. The mechanisms in some turbines use nitrogen stored in a large tank up in the nacelle itself. A gas leak might easily result in an environment which would be fatal almost instantly. Gas detectors are becoming part of the standard equipment for service engineers.
Just another example of the how important it can be to consider confined space as part of any risk assessment.