Hi Nikhil . i met the loco pilot of an express and clarified few doubts , he said me that depending on the running status of the train, the speed is varied. If the train runs late they cross 110 also but not more than 125 , VCD has a pedal which is used to beep every two minutes , the loco pilot should press it every two minutes to show that they are attentive and are nt sleeping. He praised WAP 7 like anything because of its regenerative ability.