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| Re: Canarsie CBTC (99851) | |||
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Re: Canarsie CBTC |
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Posted by RonInBayside on Fri Jun 17 07:53:51 2005, in response to Re: Canarsie CBTC, posted by Jeff H. on Fri Jun 17 03:52:02 2005. "The paradigm shift of CBTC is to make the train responsible forknowing not only its speed, but also its position. There are a number of technological ways to do that, but they all boil down to measuring elapsed distance (and with a little d/dt, speed) and periodically checking that against fixed beacons." Or using GPS above ground, which is now accurate enough for use in transit (obviously it's a little difficult to reach a satellite from a tunnel). "In theory, this approach could allow trains to operate as quickly and as closely together as is safely possible, without any loss of efficiency from the signal system." And in practice it actually does exactly that. "People have this idea that Canarsie trains will be flying along at top speed only a few hundred feet apart, and that tph capacity will be greatly increased." I don't have that idea in my head. I do have the idea that there will be some improvement from the outset, with additional improvement as CBTC operation is tweaked. That, plus the reduction in maintenance and reliance on equipment which only one compasny in the US is capable of manufacturing anymore. CBTC is far cheaper to maintain than the type of equipment used now. It isn't just insulated joints; it's the relays that run to $60 million worth of equipment to control just 2,000 feet of route (Chambers St as example). Your post still doesn't tell me what Siemensis doing. Worse, I just showed you that you're ignoring whole topics within the debate. So not only are you incompentent in CBTC, you're also a liar. |
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