The nacelle is the covering at the top of the wind turbine tower, housing all of the wind turbine's generating components, including the generator, gearbox, drive and brake assembly. The nacelle weighs ~82 tons. It is 3.8 m long, 3.77 m high and 2.8 m wide. Being inside the nacelle is allowed only when the wind generator is stopped. Temperature and wind sensors are located on the roof of the nacelle. The nacelle also contains a crane for lifting lighter equipment and tools. In addition, there is an equipment cooling system and a local control system inside the nacelle.