Speed of trains brought down to 80 kmph from 105 kmph,experts probe glitch.
Barely a year into operations,the high-speed Airport Metro Express Line brought down the speed of its trains from 105 kmph to 80 kmph in February this year after rail clips across the length of the tracks were found broken. Since December 2011,experts on the corridor have been replacing broken rail clips on the tracks every night but are yet to find the exact cause of the glitch.
Raising an alert,the Railways wrote to the Delhi Metro to look into the matter and also asked the Research Design and Standards Organization (RDSO) to conduct checks. Apart from Delhi Airport Metro Express Line (DAMEL) experts,Rail One (patent holders and designers of RHEDA track form for the line),Patil Vossloh (supplier of rail fastenings) and other stakeholders were called to conduct investigations. But no clear conclusion could be arrived at by the experts.
During routine track inspection in December 2011,two-three broken rail clips were discovered. A detailed inspection of the 2.8 lakh rail clips spread over 48 km of tracks revealed that as many as 5,100 rail clips were cracked. The rail clips were cracking in all the sections but the worst hit stretches were between Aerocity and Dwarka Sector 21 stations and between New Delhi and Shivaji Stadium stations.
Following an internal study by Reliance Infrastructure – the concessionaire responsible for operations and maintenance of the line – it was found that the failure mode was largely due to fatigue. There were more failures in the tunnel section compared to the viaduct (elevated sections) and comparatively very few failures in the vicinity of stations where speed was lower than about 90 kmph. The failed clips were largely confined to the left rail on the Up track and the right rail of the Down track.
Called RHEDA 2000 Ballast-less Track System,the new track technology was touted to be able to run trains at a speed of up to 160 kmph. However,even after one year of operations,the Airport Metro could not reach its targeted speed of 120 kmph and had to run at 105 kmph,which too was brought down to 80 kmph following the widespread technical failure.
Managing Director,DMRC,Mangu Singh said,There is a problem in the track structure and therefore a speed limitation has been imposed. It is a temporary speed reduction and will soon be rectified. The responsibility lies with the concessionaire in this case. Delhi Metro undertook the civil works while operations and maintenance is to be done by the concessionaire.
When DAMELs comment were sought,a spokesperson said: DAMEL have taken a series of measures to preclude any safety incidence on this count. These includes identifying failure-prone stretches,intensive inspection of rail clips every night,replacing all failed clips immediately,issuing caution order to train operators and imposing speed restriction in the entire section. This has now drastically reduced failures.
Central control room to monitor tunnelling work.
With large sections of the upcoming Phase III going to be underground,as many as 25 tunnel boring machines will be working at a time. The Delhi Metro is planning to set up a centralised control room to monitor tunnelling work.
To monitor the performance of the tunnel boring machines in sensitive areas,a centralised control centre will be set up,which will be connected through GPS to all the machines, said Mangu Singh,Managing Director,Delhi Metro.
Putting work on the fast track,Singh said detailed layouts for all stations have been finalised. All civil tenders for Central Secretariat-Kashmere Gate line have been finalized and work has started. All civil tenders for extension from Jahangirpuri to Badli have been finalised. Three civil tenders on Line 7 (Mukundpur to Yamuna Vihar-Shiv Vihar) have been finalised, he said.