Laying of rails atop metro girders in the city will begin within a fortnight, with 3,200 tonnes of rails for the Kochi Metro arriving here by ship from France on Saturday.
Another 3,000 tonnes of head-hardened rails are expected to arrive from Tata Steel’s factory in France. The advanced rails are not built in India and, hence, have to be imported.
“Around 100 tonnes of the rails will be transported daily by road and stacked at the yard near the Jawaharlal Nehru International Stadium, Kaloor, by IRCON, which bagged the contract to lay rails in the 25-km Aluva-Pettah metro corridor. The firm has already readied machinery to commence rail-laying work,” Delhi Metro Rail Corporation (DMRC) officials said.
“We opted for head-hardened rails (rails with harder surface) since they are more durable and can withstand more wear and tear than those used in railway lines. Metro trains will initially ply in each direction every five minutes, putting heavy strain on rail lines. Their frequency might go up to a train every minute and a half, depending on commuter demand. Moreover, the metro has sharper curves than the railway system and the rails have to withstand lateral force of trains at curves,” they said.
Every metre of the rail weighs 60 kg. Each rail is 18 metres long and many such rails will be welded together to form a 500-metre-long piece using mobile flash-butt welding plant. IRCON has readied a welding plant here for the purpose. Samples of rails have been sent to the Indian Institute of Technology Madras for strength analysis. “The results are awaited in a week,” they said.
Elaborating on the advantages and relative durability of the metro rails over those used by the Railway, experts said there was lesser chance of corrosion since metro trains do not have toilets and there is no problem posed by discharge of toilet waste. The impact of rains would also be minimal since the rails are laid atop elevated structures. Another advantage is lesser noise pollution and dust since ballast (granite chips) would be absent on metro rails.
