Flex fell on metro over head electric wire affected metro train movement for 20 minutes

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Hyderabad: A flex banner fell on the overhead electric wires or Over Head Equipment (OHE) in between Begumpet and Paradise section on Sunday. Hyderabad Mtero Rail staff along with other crew removed it. Train movement affected for 20 minutes.

Managing Director of Hyderabad Metro Rail, NVS Reddy said, “We have identified about 95 hoardings, uni poles near metro tracks and requested GHMC to remove and relocate the banners.”

Whenever a flex or banner falls on metro overhead electric wires, it’s a difficult, cumbersome and dangerous task to remove the fallen flex which gets entangled to OHE. These are high tension(25 kV) wires & power needs to be switched off by isolating a section of about 5km.

Whenever power interruption takes place due to flex falling or any other here is how metro staff resolve it which is difficult.

  1. OHE has to be first isolated in the affected section. This isolation facility is available at every 3–3.5 Km for both Up track and Dn tracks independently.
  2. when power tripping takes place repeatedly, the OCC(Operation Control Centre in Uppal depot) alerts the OHE staff .
  3. The OHE staff immediately apply for “Permit to Work “ and obtain written orders and then proceed duly moving the CMV( OHE maintenance Vehicle) to the spot.
  4. OCC takes all precautions while moving the above CMV on either of the Tracks.
  5. On reaching the troubled location, the OHE staff first provide the Earth Discharge Rods to the OHE and connect them to Earthing System to ensure Electric safety to the staff going to work on the OHE to remove the Obstructions etc.
  6. After removal of obstacles the Staff will cancel the Permit to Work and then only the OCC will again energize the OHE . After the power position is stabilised, the System is ready for train movement.
  7. There is no Short Cut Method for Restoration as human safety must be ensured from any Electric shock while doing the work.
  8. The basic cause for train interruptions in last few months is falling of Flexies of hoardings .

It takes 25 to 50 minutes for this restoration process, depending upon the severity.

 

By Mohammed Hussain
mohammedhussain.reporter@gmail.com