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| Point normalisation alarm 20/01/2015 at 22:42 #68198 | |
Hooverman
306 posts |
" said:" said:We it is, to prevent runaways on to the main line, but in this case these points feed into and out of a depot, could easily be a siding like Crawley New Yard. :-)Buzzer to remind us to normalise the points is broken in real life at the moment, so the amount of times we must forget to normalise the points into and out of Lovers Walk depot and lock it up so they can't move things around must be doing the shunt panel operators head in by now.Oh, is that the reason? I assumed it was for safety reasons, to do with preventing runaways! Log in to reply |
| Point normalisation alarm 21/01/2015 at 01:50 #68206 | |
DaveBarraza
88 posts |
" said:Whatever location is in control acknowledges the alarm, be it local tower, master tower, or central office. True it is a non-vitally derived indication. I was speaking to your point about the tower operator's involvement in the process. The point of the data-recorded-acknowledge is to put the acknowledging party "on the hook" "on the record" that they were aware that the overrun was sanctioned. Quote: BTW if you are wondering "why" things are the way they are, my friend worked in the TA's front office. Management considers the signaling system a form of "manual ATO" that aims to reduce the amount of skill necessary to safely/effectively operate a subway train. They have also proactively slowed the system down to prevent rulebook slowdowns. In Boston the unions have much more clout because if the Green Line is operated to rule the service completely breaks down. In NYC the TA has basically gotten the public used to bad service as the standard taking away the union's only weapon in a no-strike state.I appreciate the insight above, the general degradation of system efficiency concerns me deeply as a rider and as an employee/contractor of NYCT. But IMHO, based on my first-hand experience you are connecting dots that aren't connected. Every transit and rail property is treating human operators as more and more, well, human - fallible. Not just NYCT. The politics of rail accidents dictate that "something most be done to prevent this from happening again" and although some problems may be fundamentally unsolvable managers must be able to point to a "thing that was done", like axle-counting speed enforcement systems, data-recorded overrun acknowledgements, or point normalisation alarms. Log in to reply |
| Point normalisation alarm 21/01/2015 at 12:41 #68219 | |
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Jersey_Mike
250 posts |
" said:You see it's not an "overrun" because the most restrictive indication an automatic can display is Stop and Proceed. I know what the TA's new policy is, but the system was designed for automatic key by so don't let people ever forget that. The other thing is that the TA really doesn't want operators charging the timers because it screws up their headway management...which is accomplished by slowing the trains down. " said: Sometimes its a safety overreaction, sometimes that's just an excuse to cut costs. There are only 4 historic subway systems in the country, NYCTA, Boston, Philly and Chicago. Everything newer was built with cab signals and ATO in mind which reduces the level of skill and training required to operate the system safely, which in turn means you don't have to pay the operators as much. The SEPTA Broad Street Line and PATH (although that's a railroad) have both bucked the trend and kept speeds high while avoiding safety incidents with their old style signaling systems. The Broad Street Line is what the NYCTA could be if it actually cared about quality of service. BTW I got the low down on the switch to the composite brake shoes which increased stopping distances and required the massive round of speed reductions since the Williamsburg bridge incident. The old iron brake shoes worked too well at stopping the trains and every time some joker would pull the e-brake cord riders would fall down and the TA would get a raft of injury claims. Since all the new stock did away with the direct acting e-brake cords they could probably bring the speeds up, but I'm sure that would cost more $ somehow. Log in to reply |
| Point normalisation alarm 23/01/2015 at 00:19 #68298 | |
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DaveBarraza
88 posts |
Quote:You see it's not an "overrun" because the most restrictive indication an automatic can display is Stop and Proceed.1) If we're talking about NYCT now, today, I politely disagree. The rule book indication for a red aspect on an automatic or approach signal is not stop and proceed, it is: "STOP! Notify the Control Center. If permission is granted to key-by signal according to rules 2.40(m) and 2.40(n) proceed with RESTRICTED SPEED AND EXTREME CAUTION, be prepared to stop within 1/2 range of vision, expecting to find track occupied, a broken rail or other obstruction in the block NOTE: there may be a ten (10) second delay" (I enjoy the exclamation point, as if the rule is somehow yelling at you.) If we're talking about NYCT as it was or could/should be then it's time to start a new thread because using simulators to train tower operators wouldn't be a topic for discussion in that arena. 2) NYCT has always called the bell and flashing track circuit the "overrun indication" but I agree with you that it can be triggered by non-overruns, like a train legitimately keying by with permission. A better name would have been SPAD as in the UK. So the involvement of the tower operator is to determine by observation of the panel and radio traffic that a signal has been passed at danger without permission and then to report this infraction. This requires a level of interpretation and would be of some value in a panel simulator used to train tower operators. ...which is how we fell down into this rabbit hole. Quote: There are only 4 historic subway systems in the country, NYCTA, Boston, Philly and Chicago. Cleveland was built with trip stops, Hon. Mention Toronto. Quote: BTW I got the low down on the switch to the composite brake shoes which increased stopping distances and required the massive round of speed reductions since the Williamsburg bridge incident. I'm aware that happened but when I asked why car equipment didn't fix the problem they apparently created, I was informed of other factors. The WBB incident and Union Square also resulted in an independent system-wide analysis of the signal block designs by Parsons-Brinkerhoff which found some of the predecessor companies safety percentages were lacking (below modern industry-consensus standards). Also attainable speeds over diverging points were studies and the results were at times alarming. So it was more than just a car equipment issue, the block design had to be modernized to acceptable safety percentages quickly, without moving 1000's of signal locations. Altering a block design with so many variables fixed resulted in a high number of new grade timed signals, and a reduction in overall speed, which undeniably sucks the life out of "rapid" transit. Blame Gerald Ford if you like. If he'd bailed out NYC in the 1970's then NYCT would have been able to follow through with its 990Hz AF-coded track circuit ATO scheme. Log in to reply |