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| Re: Latest updates: R-179 order saga, R-160 CBTC for (L) line & special reports ... (1134946) | |||
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Re: Latest updates: R-179 order saga, R-160 CBTC for (L) line & special reports ... |
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Posted by J trainloco on Wed Jan 25 22:31:09 2012, in response to Re: Latest updates: R-179 order saga, R-160 CBTC for (L) line & special reports ..., posted by Edwards! on Wed Jan 25 21:40:19 2012. No.Signal systems have a useful lifespan. When that lifespan is up, they must be replaced. NYCT could have replaced the signal system with a conventional relay based fixed block system with wayside signalling. Instead, they went with CBTC, ostensibly for the following reasons: 1. CBTC offers capacity that NYCT cannot achieve with fixed block signalling. 2. CBTC is cheaper than fixed block systems with wayside signalling. 3. CBTC can be used to implement ATO, which should theoretically reduce operating costs. People can say all they want about lack of fixed block signalling as a backup to CBTC, but there's no backup to the current fixed block system, and when it fails, I guess that's okay. The 7 line went completely kaput last summer due to failure of the signal system. There have been other catastrophic failures of the signal system, such as the Chambers st IND fire. I suppose the lack of a backup there was ok too. But if the L line goes down for half of a day, then we MUST have a fixed block backup. CBTC, particularly the way NYCT implemented it on Canarsie, has its issues. But it does have distinct advantages over the existing system, which riders should be able to benefit from when it gets fully implemented on Flushing and Queens Blvd. |
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