tender for engineering, design, drawing, supply, erection, testing and commissioning of 25 kv, 50 hz single phase retractable rigid catenary system (rrcs) connecting with existing conventional regulated ohe at either end of silo no -5 & 6 (double track in each silo) having single chute on each track with centralized programmable logic control system (plc with interlocking system-supervisory plc) to control the operation of geared motor assembly, motorized isolators, existing signal etc. and regulated ohe at either end of silo no -3 & 4 (single track in each silo) having single chute on each track with centralized programmable logic control system (plc with interlocking system-supervisory plc) to control the operation of geared motor assembly, motorized isolators, existing signal etc. at gevra, gevra area of secl including defect liability period of 02 years and subsequent annual comprehensive maintenance for 3 years.