Alteration Work In The Existing Electronic Interlocking (Ei) System At Sagour &Amp Narioli Stations By Designing, Manufacturing, Supply, Installation, Testing,And Commissioning Of Microprocessor Based Ei System For Execution Of Indoor And Outdoor Signalling Work Which Includes Excavation Of Trench, Laying Of Cables, Casting Of Foundation Of Macls Signals &Amp Apparatus Cases, Erection/Installation Of Macls Signals, Fixing &Amp Wiring Of Track Circuits &Amp Point Machines, Centralized Oper