|
|
| Re: Canarsie CBTC (98629) | |||
 |
|||
| Home > SubChat | |||
|
[ Read Responses | Post a New Response | Return to the Index ] |
|
||
|
Re: Canarsie CBTC |
|
|
Posted by Stephen Bauman on Tue Jun 14 08:59:54 2005, in response to Re: Canarsie CBTC, posted by Stephen Bauman on Sun Jun 12 08:01:54 2005. I just came across the following:The agency plans to upgrade the entire network to CBTC, starting with the Canarsie L line in July. Between procuring funds and a work schedule restricted to nights and weekends, the upgrades could take 30 to 35 years, systemwide. CBTC "will greatly reduce the uncertainty by precisely locating the train," according to chief signal officer Nabil Ghaly. Optical lasers on the belly of each car will scan transponders positioned about 600 feet apart on the side of the tracks. The train will relay that information via data radios to the zone controllers, giving them a digital map of all trains in the area. Let me use another baseball metaphor, Casey Stengel supposedly asked his 1962 Mets: "can't anybody here play this game?" The maintenance cost savings projected for CBTC were predicated on a bare minimum of wayside equipment and the placement of that equipment within the stations. These optical transponders are simply substitutes for insulated joints. Their servicing will engender the same costs for transporting work crews to their location. Reading between the lines, I'd guess that they are not using dead reckoning to determine position. Position will be determined by block occupancy, just like a conventional block system. The quantization will be 600 foot intervals. The problem is that more accurate localization is required at certain locations for peak service levels. If the CBTC system is based on fixed block lengths of 600 feet, it will end up reducing line capacity over the present system. |
|
|
|