AAI against elevated Metro corridor

Says Raised Structure In Front Of The Airport Can Pose Danger To Aircraft Movement
V Ayyappan TNN

Dec 9, 2008
Chennai: Metro Rail’s plan to build an elevated track from Saidapet to the airport, as part of its first corridor connecting Washermanpet and the airport, has hit a roadblock, with the Airports Authority of India (AAI) saying the alignment will hamper aircraft movement. The AAI has objected to the alignment of the corridor because it feels the height of the elevated viaduct will come in the way of aircraft movement on the secondary runway. According to an AAI official, the Metro Rail had asked for a 30-metre height clearance, including the viaduct and overhead electric cables, for the stretch in front of the airport. “After we objected, Metro Rail scaled down the height and have now applied for clearance for 27 metres. Still, the structure will pose a hazard to aircraft movement. So we have asked them to take the track underground for the stretch in front of the airport,” the official added. These issues were discussed in a meeting AAI officials had with Chennai Metro officials recently. Sources said that Metro officials expressed their difficulty to change the alignment from an elevated structure to underground because of the high cost. Chennai Metro has informed AAI that it would cost them Rs 300 crore to build 1 km of underground line. Besides, they will have to take the line underground all the way from Saidapet to obtain the necessary gradient. There would be one more meeting between Metro Rail and the AAI officials before the issue is resolved. A senior AAI official said that permission was originally given to build an underground line. “But now Metro Rail wants to build an elevated structure. An AAI committee will study it to look whether a no-objection certificate can be given for the elevated structure,” the official said. Under the proposed alignment, Metro Rail wants to take the track on an elevated viaduct from Saidapet. The alignment will run up to the airport on the centre of the road except at Guindy and Alandur. Metro Rail plans to construct an inter-change station between corridor one and corridor two (Chennai Central-St Thomas Mount) at Alandur. A stabling area, where trains will be parked, is also planned at Tirusulam opposite the airport. Already, the AAI is forced to put up with security implications created by the newly-built flyover in front of the airport. As a temporary measure, police personnel have been posted on the flyover to prevent motorists from stopping their vehicles. AAI has suggested construction of a view blocker on the flyover to prevent line of sight to the airport as a long-term measure to secure the airport. The flyover, however, is not an impediment for aircraft movement because its elevated portion is in front of the terminal buildings and not the air corridor. HITTING A ROADBLOCK Corridor one of Chennai Metro Rail, which will be 24 km long, will run from Washermanpet to airport The Metro Rail will be underground up to Saidapet, after which it will run on an elevated track till the airport AAI, which has to give clearance, says the height proposed for the track will pose danger to aircraft movement Chennai airport has grown over the years. It occupies 1,152 acres and there are plans to expand it to 2,222 acres Domestic passenger traffic has grown tremendously over the years — from 3% growth in 1990-2000 to 51% in 2006-2007 The airport will be modernised by 2011. Consolidated Construction Consortium has been awarded the Rs-1,212 crore contract for it