The water spray is done for the NOx control and efficiency improvement (killing two birds with one stone )
All these answers are too obvious (may be except this one)
- Visit the GE site
- Siemen's site
- Any of the reputed manufacturer site
In GE site I am aware there are quite a few papers on these subjects (not all of course)
Why all these basic questions? Any Turbine man knows what is cranking, how the speed is controlled, ...Dual Shaft of course is a bit confusing But then check the 2 series frames of GE eg Frame5002E, 6002E, etc.