The behavior of a system call may be modified. The step is securely mounted in a manner for supporting the weight of a person. The FBG is disposed on the optical fiber at a portion where no adhesive exists inside the protective tube. After the turbine or motor is started and brought up to speed, successive CSTCs are operated from zero to lock-up speed sequentially to start each compressor or group of compressors in turn. The intermediate gear unit is capable of being optionally coupled with the set of first or second central holes.