Sir,
only on the subject of speed in terrain and plains, I would like to give one input, while travelling from LTT to Ernakulam by Duronto recently, I observed that when the slope upward came train was pulling at slow speed, and when the slope down came, train will have ease to speed up. again when the plains came, the train was at its peak speed.
Even the Mumbai Pune tracks have different positions and if you have travelled in that area, you will feel the slow medium and fast...
more... speeds, with Two loco at both ends each hauling the train is great experience.