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Old Posted Apr 14, 2014, 11:23 PM
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ardecila ardecila is offline
TL;DR
 
Join Date: Jun 2006
Location: the city o'wind
Posts: 15,938
The steel structures are not something we'd build today - the noise they create would immediately fail the EIS. The closest you can get is what they did on the rebuilt Pink Line... steel beams on concrete columns with shock absorbers at each joint. CTA cheaped out on that project, but they did it right on the Orange Line/Red Line where they fly over Chinatown... gravel ballast to absorb the rumbling and parapet walls to block the screeching. There's just a faint rumble when the train goes by.


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