The laying of rails on the ‘Metro Rail viaduct between Nagole and Mettuguda (eight km) by L&T Metro Rail Hyderabad had started with the first lot of the high strength “head hardened” rails sourced from Tata Corus in France lifted on to the elevated viaduct in Habsiguda.
Ballast-less
These rails can withstand ‘rail fractures’ due to wear over time and also do not require high maintenance unlike the normal rails. And, unlike normal rail tracks which are laid on ballasted cushion provided by small granite stones, there will be no ballast for the Metro Rail. Ballast will be spread only in the Metro depots at the ground level which means the entire track system on the Metro corridors of 72 km will be ballast-less, explain Metro Rail officials.
The “head hardened” rails, each one with a length of 18 metres (about 60 feet) are first welded to form continuous rails with a “mobile flash butt welding plant”, costing Rs.5 crore and imported from Netherlands and placed on the elevated viaduct with the help of heavy duty cranes.
The welded parallel rails forming a continuous track are straightaway embedded into the concrete plinth and are fixed on special type elastic plates and pads (cushioning akin to ballast) with the help of “Vossloh fasteners” - imported from Austria. Once the rails are fixed to the required standard gauge of 1435 mm width and checked for the correctness of gauge, incline etc., concrete is poured to permanently embed the track.
All the track parameters are then checked by a computerised machine called “Track Master”. All these measures will enable better riding comfort and minimise noise levels, aver Metro Rail officials. The ongoing works were inspected by Railway Board’s Additional Member (Civil Engineering) Pradeep Kumar and HMR MD N.V.S Reddy on November 19.
Appreciating L&TMRHL and HMR for bringing in the latest rail technologies, Mr. Kumar later held discussions regarding the scope for indigenisation and transfer of technology. SCR Chief Bridge Engineer Amit Goel and L&TMRH Rail Systems Head Anil Saini were also present.
