L&T Metro Rail Hyderabad Ltd has begun to lay rails on the metro viaduct between Nagole and Mettuguda, a stretch of 8 km.
The laying of rails was inspected yesterday by Additional Member (Civil Engineering) of Railway Board, Pradeep Kumar, and Managing Director of Hyderabad Metro, NVS Reddy, near Genpact facility.
The high strength “head hardened” rails have been procured from Tata Corus in France. The first lot have been placed on the elevated metro viaduct.
Unlike the Indian Railway tracks which are laid on ballasted cushion provided by small granite stones, there will be no ballast on the Hyderabad metro rail viaduct.
Ballast will be spread only in the metro depots which are at ground level and the entire track system on the metro corridors of 72 km is ballastless. The rails, each one with a length of 18 metres, are first welded to form continuous rails with a “mobile flash butt welding plant”.
L&TMRHL has imported the mobile flash butt welding plant worth Rs 5 crore from Netherlands and placed it on the elevated metro viaduct with the help of heavy duty cranes.
Welded pararrel rails
The welded parallel rails are embedded into the concrete plinth and are fixed on special type elastic plates and pads with the help of “Vossloh fasteners”, all imported from Austria.
After the two parallel rails are fixed in their position to the required standard gauge of 1435 mm width and checked for the correctness of gauge, incline, concrete is poured to permanently embed the rail track.
Track alignment
The cushion which the normal Indian Railway tracks get from ballast is provided by the imported elastic plates and pads. This is a sophisticated technology requiring high levels of precision and accuracy in adjusting the track alignment.
All the track parameters are checked by a computerised machine called Track Master. The track system will minimise the noise levels.
Pradeep Kumar hoped that Hyderabad will have a modern metro providing high levels of safety and travel comfort to the passengers.
He later held discussions regarding the scope for indigenisation and transfer of technology for improving the railway track standards in India.