Friday, November 24, 2006
Faridabad- Metro Rail would have better noise-pollution controls thru' Silencer
DMRC to silence Metro noise BY NEHA KOHLI
TIMES NEWS NETWORK[ THURSDAY, NOVEMBER 23, 2006 11:00:30 AM]
NEW DELHI: Delhi metro lines may soon be equipped with silencers. Delhi Metro Rail Corporation (DMRC) is considering the use of noise barriers and silencers to combat noise pollution. The proposal is mooted by the Central Road Research Institute (CRRI) and the manufacturers of noise barriers, such as Anutone Acoustic.
A DMRC official has said the company is employing latest technologies to protect the environment. The task has been assigned to the National Physical Laboratory for suggesting measures to combat noise pollution, especially, in the view of the Commonwealth Games.
DMRC has initiated an experiment to prevent noise pollution at the Vidhan Sabha tunnel station. This involves using a chemical spray to harden the walls, making it more noise-absorbent . If successful, the work for wall hardening will continue for other underground stations as well.
DMRC is already using silent generators in some of its Phase-I projects and has incorporated the use of silent vibro hammers while construction. Also, the bottom of the rails are coated with rubber pads and the joints are welded, preventing skipping of wheels at joints, which create noise.
However, use of silencers having high noise-absorbing coefficients is currently absent in metro rails. Anutone Acoustic is in talks with DMRC for the use of noise barriers such as Madtrax and Nsstrax in rails.
CRRI claims it had formally suggested , in the recent environment impact assessment report (EIA), for a metro line that noise silencers should be used. The EIA report was prepared for DMRC for its Badarpur-Faridabad and Mundka-Bahadurgarh corridor.
With 70-75 % of metro lines being open in Delhi and other cities with metro rail systems, noise pollution created by it, in addition to road traffic, has become an issue. According to CRRI, the coinciding of road traffic and metro rails along with reflection of noise under the bridges creates noise that can be too fatal - high blood pressure being the most common consequence.
With escalating road traffic already imposing noise levels on the environment, such a 'rail-under-a-road' arrangement takes these levels even higher. While a metro rail line alone may not cause as much noise pollution, it contributes significantly to the same in this setup. For example , a road alone as a line source may produce 78 decibel (dB) noise, but in such a setup, the figure goes up to 81 dB.
Prolonged exposure to this level of noise in traffic could create noise exceeding acceptable levels, depending on the time and kind of traffic like trucks, light vehicles, etc.
A study by CRRI shows that with silencers spanning a metro rail line running over bridges, noise pollution can be reduced by 25 dB under the bridge where there is flow of road traffic. Hence, cutting noise levels by more than half.
/photo.cms?MSID=537685
TIMES NEWS NETWORK[ THURSDAY, NOVEMBER 23, 2006 11:00:30 AM]
NEW DELHI: Delhi metro lines may soon be equipped with silencers. Delhi Metro Rail Corporation (DMRC) is considering the use of noise barriers and silencers to combat noise pollution. The proposal is mooted by the Central Road Research Institute (CRRI) and the manufacturers of noise barriers, such as Anutone Acoustic.
A DMRC official has said the company is employing latest technologies to protect the environment. The task has been assigned to the National Physical Laboratory for suggesting measures to combat noise pollution, especially, in the view of the Commonwealth Games.
DMRC has initiated an experiment to prevent noise pollution at the Vidhan Sabha tunnel station. This involves using a chemical spray to harden the walls, making it more noise-absorbent . If successful, the work for wall hardening will continue for other underground stations as well.
DMRC is already using silent generators in some of its Phase-I projects and has incorporated the use of silent vibro hammers while construction. Also, the bottom of the rails are coated with rubber pads and the joints are welded, preventing skipping of wheels at joints, which create noise.
However, use of silencers having high noise-absorbing coefficients is currently absent in metro rails. Anutone Acoustic is in talks with DMRC for the use of noise barriers such as Madtrax and Nsstrax in rails.
CRRI claims it had formally suggested , in the recent environment impact assessment report (EIA), for a metro line that noise silencers should be used. The EIA report was prepared for DMRC for its Badarpur-Faridabad and Mundka-Bahadurgarh corridor.
With 70-75 % of metro lines being open in Delhi and other cities with metro rail systems, noise pollution created by it, in addition to road traffic, has become an issue. According to CRRI, the coinciding of road traffic and metro rails along with reflection of noise under the bridges creates noise that can be too fatal - high blood pressure being the most common consequence.
With escalating road traffic already imposing noise levels on the environment, such a 'rail-under-a-road' arrangement takes these levels even higher. While a metro rail line alone may not cause as much noise pollution, it contributes significantly to the same in this setup. For example , a road alone as a line source may produce 78 decibel (dB) noise, but in such a setup, the figure goes up to 81 dB.
Prolonged exposure to this level of noise in traffic could create noise exceeding acceptable levels, depending on the time and kind of traffic like trucks, light vehicles, etc.
A study by CRRI shows that with silencers spanning a metro rail line running over bridges, noise pollution can be reduced by 25 dB under the bridge where there is flow of road traffic. Hence, cutting noise levels by more than half.
/photo.cms?MSID=537685
Labels: Faridabad, Faridabad Metro, Pollution
