Title - The peculiar case of Airport Metro clips

Inspection team finds more clips damaged on one track than the other, buildings far from the line have more cracks than those closer. The officials looking to fix the damaged clips on the tracks of Airport Metro are now in a fix. Inspection of the 22.7-km corridor revealed a “first of its kind” technical fault, leaving the analysis “inconclusive”.

The inspection found a peculiar pattern to the breaking of clips — one track has more damaged clips than the other. A senior official put the “weird anomaly” in ratio of 9:1.

According to the inspection report, the left track of line towards IGI Airport has more number of damaged clips and the right track of the line coming to New Delhi has more broken clips.

“So far the measurement results using the conventional sensors were inconclusive and inconsistent. The trend in the breakage is very peculiar. The tracks are giving some indications, but no conclusion was drawn. One of the possibility behind such a pattern could be electromagnetic interference,” a senior official said.

Investigation also pointed to high speed of trains as a possible reason behind the breakage. “The preliminary findings point out that large incidences of breakage in clips take place when the speed touches its peak. Until the root cause emerges, it would be difficult to run the Metro at high speed,” the official said.

The high speed Airport Metro was approved to run at a speed of up to 120 km per hour. The travel time from New Delhi to the airport was 18 minutes. After damage was noted in the bearings, girders and clippings on the line, the Metro service was suspended on July 8.A committee comprising Voslloh (supplier of rail clips), Rail Once (designer of RHEDA track), Patil Rail (Indian partner of RHEDA), Delhi Metro Rail Corporation, Research Design and Standards Organisation and concessionaire (Delhi Airport Metro Express Private Limited) has been formed to look into the problems.

The Reliance-backed operator has also appointed Hong Kong Technical University as a consultant for detailed analysis, along with the expert group. Spokesperson of the concessionaire confirmed the appointment of the committee.

“The expert panel is investigating the pattern of the damage in clips. The findings will be shared after the group arrives at a conclusion,” the spokesperson said.

Five meetings have been held so far. The first set of measurement using fiber grating sensors have been completed and are being analysed. Based on the results, second measurements will be taken, the official said.

Sources said the officials are also looking to solve the issue of cracks in the houses along the Metro line in Shahbad Mohammadpur village.

“It has been found that the houses closer to the Metro line do not have cracks, but the houses in the second row and little farther from the line have developed cracks. The conclusion in this pattern will be arrived at based on the solution regarding damages in clips,” the official said.