Request for Proposal ( RFP ) for" Design, supply, erection, testing and commissioning of Traction Sub- Station ( TSS ), Sectioning Posts ( SPs ) and Subsectioning and Paralleling Posts ( SSPs ) in 2x25kV AT system with SCOTT- Connected transformer on VIJAYAWADA- ONGOLE section" as a part of" Upgradation of existing 1x25kV system to 2x25kV AT system of South Central Railway on Engineering, Procurement & Construction ( EPC ) mode