hiraki@ecf.toronto.edu (Lester Hiraki) (03/16/89)
I realize this topic might be a bit specific, but judging by the overwhelming discussion of the hidden subway station under Bay, I thought I might throw this in for discussion. Perhaps some people were inconvenienced by the subway problem on Wednesday, March 15. Although the problem was near Davisville, there was no service between Lawrence and Union. I know that there are gurus out there who will agree that there is a switch-over thing (=x=) just south of St. Clair Stn. Why not to have turned back the trains there instead of at Union?
howard@gpu.utcs.toronto.edu (Howard Lem) (03/17/89)
In article <810@mv03.ecf.toronto.edu> hiraki@ecf.toronto.edu (Lester Hiraki) writes: >Perhaps some people were inconvenienced by the subway problem on Wednesday, >March 15. Although the problem was near Davisville, there was no service >between Lawrence and Union. I know that there are gurus out there who >will agree that there is a switch-over thing (=x=) just >south of St. Clair Stn. Why not to have turned back the >trains there instead of at Union? > Trying to remember my TTC riding days; isn't there a switch over near Bloor? My guess is that it has something to do with the way the TTC setup their power grid. The section that was shutdown included all of the original subway line (except for Union station.) Maybe they did not / could not split there power grid on the original line. -- .signature follows! use the n key if you don't want to see it :-) <<<<<<<<<========= ALL Usual disclaimers go here :-) =========>>>>>>>>> Canada Post: Howard Lem - University of Toronto Computing Services 11 King's College Rd., Room 107A Toronto, Ont., Canada, M5S 1A1 Telephone: (416) - 978 - 4310 {work} Email: howard@gpu.utcs.uucp
soley@ontenv.UUCP (Norman S. Soley) (03/20/89)
In article <810@mv03.ecf.toronto.edu>, hiraki@ecf.toronto.edu (Lester Hiraki) writes: > Perhaps some people were inconvenienced by the subway problem on Wednesday, > March 15. Although the problem was near Davisville, there was no service > between Lawrence and Union. I know that there are gurus out there who > will agree that there is a switch-over thing (=x=) just > south of St. Clair Stn. Why not to have turned back the > trains there instead of at Union? Wednesdays problem made it necessary to shut off power to the rails, I'm pretty sure the power is "zoned" but likely Davisville and St. Clair are in the same zone. There are certianly other reasons too. A better question would be why the trains couldn't turn at Bloor instead of Union. -- Norman Soley - Data Communications Analyst - Ontario Ministry of the Environment UUCP: uunet!mnetor!ontmoh!ontenv!soley | Contents of this message are OR: soley@ontenv.UUCP | my ideas, not the Ministry's "Stay smart, go cool, be happy, it's the only way to get what you want"
msb@sq.com (Mark Brader) (03/21/89)
> > Although the problem was near Davisville, there was no service > > between Lawrence and Union. I know that there are gurus out there > > who will agree that there is a switch-over thing (=x=) just > > south of St. Clair Stn. The term you want is "turnback switch"; the particular layout you show is a "scissors crossing" (for obvious reasons). Actually, there *was* a scissors crossing just south of St. Clair, but it was removed two or three years ago. The original line from Union to Eglinton was more richly provided with turnback switches than the later parts of the system, and I believe the TTC observed that they weren't being used all that much and decided to save on maintenance costs by taking some of them out. It costs more to maintain switches than plain track because of uneven wear; with plain track you can grind away any irregularities, but with switches you have to keep the rail-tops level on both branches of the switch. The other turnback switches that were removed were also scissors crossings; they were just south of College and just north of King. You can see that the tunnel loses its center wall (and the ceiling becomes arched to span the extra distance) at these locations. > Wednesday's problem made it necessary to shut off power to the rails, I'm > pretty sure the power is "zoned" but likely Davisville and St. Clair > are in the same zone. There are certianly other reasons too. That's a sufficient reason all by itself, and I'm sure it is the actual reason. Eglinton station has turnback switches on *both* ends -- a scissors crossing south of the station and a center "pocket" track north of it -- but it must be in the same zone too. > A better question would be why the trains couldn't turn at Bloor > instead of Union. Apparently because Bloor is in the same zone too. This surprised me also. In fact, I was one of those affected by the problem, because I was trying to go from King to Bay stations at the time. I walked to Union and made the trip via St. George instead. While I was leaving the subway at Bloor station, I noticed that there was a train stopped at the northbound platform and its interior lights were off. So it seems there was no power on the Yonge line at Bloor either. It's possible that the accident happened very near a power zone boundary, and two adjacent zones had to be switched off. Maybe I'll ask the TTC about it. I too was surprised that they had to shut down so long a section. The following is a complete list of possible turnback switches on the subway system to the best of my recollection; however, I'm doing this from memory, and it's been some time since I've used some of the lines, especially the farther northern and eastern sections. This list is really posted only to give an idea of how they are placed; if anyone wants to correct it, please email to me and I'll post a followup. I say "possible" turnback switches because some of them may be intended for other purposes than turnbacks, and may not have the necessary signals to be used that way without special intervention. By "trailing" crossover, I mean one that the train has to reverse *before* using, i.e., as you approach it you see it cross from the left to the right track. "Leading" is the opposite. nearest station layout Finch scissors crossing Finch center track Sheppard scissors crossing York Mills scissors crossing Lawrence scissors crossing Eglinton center track Eglinton scissors crossing Davisville trailing crossover Davisville leading crossover Bloor scissors crossing Union trailing crossover Union to St.Andrew center track | Anyone know why they have Osgoode center track | two so close together? St. George scissors crossing St. Clair West center track Glencairn center track Lawrence West center track Wilson scissors crossing Kipling scissors crossing Islington scissors crossing Islington center track Jane scissors crossing Keele scissors crossing Ossington center track St. George scissors crossing Broadview center track Greenwood scissors crossing Woodbine scissors crossing Victoria Park scissors crossing Warden center track Warden scissors crossing Kennedy scissors crossing Most of the center tracks can be entered from either end, but I won't bother trying to remember which ones can't. Mark Brader "Well, I didn't completely test it, and SoftQuad Inc., Toronto of course there was a power failure the utzoo!sq!msb, msb@sq.com next day." -- Louis J. Judice
howard@gpu.utcs.toronto.edu (Howard Lem) (03/23/89)
In article <1989Mar20.211818.27937@sq.com> msb@sq.com (Mark Brader) writes: > [much info deleted] ... > Eglinton center track > Osgoode center track | two so close together? I think the centre track north of the stations were used to 'store' the trains between rush hours. Both tracks can only be entered from the south. Come to think of it they used to park a train off to the side at Warden(when that was the eastern end of the subway. > >Mark Brader "Well, I didn't completely test it, and >SoftQuad Inc., Toronto of course there was a power failure the >utzoo!sq!msb, msb@sq.com next day." -- Louis J. Judice -- .signature follows! use the n key if you don't want to see it :-) <<<<<<<<<========= ALL Usual disclaimers go here :-) =========>>>>>>>>> Canada Post: Howard Lem - University of Toronto Computing Services 11 King's College Rd., Room 107A Toronto, Ont., Canada, M5S 1A1 Telephone: (416) - 978 - 4310 {work} Email: howard@gpu.utcs.uucp
eric@becker.UUCP (Eric Siegerman) (03/23/89)
In article <1989Mar20.211818.27937@sq.com> msb@sq.com (Mark Brader) writes: >> Wednesday's problem made it necessary to shut off power to the rails, I'm >> pretty sure the power is "zoned" but likely Davisville and St. Clair >> are in the same zone. There are certianly other reasons too. >[...] >Eglinton station has turnback switches on *both* ends >[...] >but it must be in the same zone too. >[...] >Apparently because Bloor is in the same zone too. >[...] So it seems there was no power on the >Yonge line at Bloor either. According to a friend of mine, who once worked as an inspector of equipment in the subway stations, the emergency power cutoff switch (there's one at each end of each subway platform, with a blue light and dire warnings as to the consequences of misuse) cuts power to trains in both directions, at the station in question and at the two adjoining stations (ie. a total of three stations are affected). This suggests that each station is in its own zone, with the cutoff switch sending a control signal to the neighbouring stations. Two- or three-station zones would not seem to permit the interlocking scheme I've described. A way to test this hypothesis: when riding in one of the old red subway cars with the incandescent lighting, see how often the lights go off. I've always assumed that they flicker when the train crosses the insulated gap between zones (and that the newer cars' lights don't flicker because they are equipped with batteries -- necessary because fluorescent lights would take too long to come back on once power was restored.) -- Eric Siegerman, Toronto, Ont. eks@kneller.UUCP, eric@becker.UUCP, ...!utzoo!mnetor!becker!kneller!eks
chk@client2.DRETOR.UUCP (C. Harald Koch) (03/25/89)
In article <383@becker.UUCP> eric@becker.UUCP (Eric Siegerman) writes: >A way to test this hypothesis: when riding in one of the old red >subway cars with the incandescent lighting, see how often the >lights go off. I've always assumed that they flicker when the >train crosses the insulated gap between zones (and that the newer >cars' lights don't flicker because they are equipped with >batteries -- necessary because fluorescent lights would take too >long to come back on once power was restored.) The reason is actually much simpler. Normally, the power strip is on the left side of the train (in the tunnels). In center platform stations, and at switches, the power rail is on the right. When the rails switch sides, there is a short distance with no power. The old red cars are shorter than the newer silver ones. The new trains are long enough to bridge the gap, the older ones are not. Actually, another possibility is that the newer trains share power between cars while the older ones don't. That would also explain it. It is still because of the gap between sections of power rail, though. -- C. Harald Koch NTT Systems, Inc., Toronto, Ontario chk@zorac.dciem.dnd.ca, chk@gpu.utcs.toronto.edu, chk@chkent.UUCP Veteran of the Bermuda Triangle Expeditionary Force - 1999 to 1951. "be EXCELLENT to each other" - Bill and Ted -- C. Harald Koch NTT Systems, Inc., Toronto, Ontario chk@zorac.dciem.dnd.ca, chk@gpu.utcs.toronto.edu, chk@chkent.UUCP Veteran of the Bermuda Triangle Expeditionary Force - 1999 to 1951. "be EXCELLENT to each other" - Bill and Ted
msb@sq.com (Mark Brader) (03/25/89)
> > Eglinton center track > > Osgoode center track | two so close together? > I think the centre track north of the stations were used to 'store' the > trains between rush hours. Both tracks can only be entered from the south. Correct for Eglinton, backward for Osgoode. (Most or all of the other center tracks can be entered from either end, by the way.) While I have seen trains parked in center tracks many times, these sightings have been rare enough that I doubt this explanation. Trains not in service are normally parked in the various yards. Of course, it could have been a former operating method not followed today. Mark Brader "Great things are not done by those SoftQuad Inc., Toronto who sit down and count the cost utzoo!sq!msb, msb@sq.com of every thought and act." -- Daniel Gooch
msb@sq.com (Mark Brader) (03/25/89)
Eric Siegerman (eric@becker.UUCP) writes: > According to a friend of mine, who once worked as an inspector of > equipment in the subway stations, the emergency power cutoff > switch (there's one at each end of each subway platform, with a > blue light and dire warnings as to the consequences of misuse) Also at regular intervals between stations, each one marked with the same blue light and, in recent years, a sign giving the distance to the nearest station or other exit in each direction. > cuts power to trains in both directions, at the station in > question and at the two adjoining stations (ie. a total of three > stations are affected). > > This suggests that each station is in its own zone, with the > cutoff switch sending a control signal to the neighbouring stations. Did the ex-inspector say that the power cut is ONLY over the distance he described, or might it be AT LEAST over that distance? I repeat that I know from personal observation (of a darkened train) that the power was off at Bloor station during the emergency near Davisville that started this topic. If the power cut is AT LEAST over the distance he/she described, no such complicated interlocking is required; each cutoff switch needs to control at most two sections. > A way to test this hypothesis: when riding in one of the old red > subway cars with the incandescent lighting, see how often the > lights go off. I've always assumed that they flicker when the > train crosses the insulated gap between zones (and that the newer > cars' lights don't flicker because they are equipped with > batteries -- necessary because fluorescent lights would take too > long to come back on once power was restored.) I suspect that the actual reason is that the track power is 600 volts DC, and you can't run a fluorescent light on that. The easiest way to generate AC power (which can be transformed to any voltage needed) is a motor- generator pair. If this was used, the momentum of the armature would cause the lights to stay lit for, say, 1 second or so after power was removed. Guess what? That is exactly the actual behavior. If you're on a new-type car and there is a power failure, or if it stops at a place where the power rail is interrupted, you'll see the lights fade slowly over a period of 1 second or so. So I conclude that motor-generator pairs are used. (On the old cars, they must either have special incandescent lights that run on 600 volts, or they must wire them in series. I don't know which.) Both old and new cars are also equipped with emergency lights which are probably battery-powered: one incandescent light over each door. On the old (G, for Gloucester) cars these lights are on continuously, and form part of the normal lighting; on the newer (M, for Montreal Locomotive Works, and H, for Hawker-Siddeley (now UTDC)) ones they come on about 1 second after the normal lights have failed. By the way, in some other cities the subways use fluorescent lights and yet the lights do go off, almost instantly, when the power rail is interrupted. They usually light up again almost instantly, too. I guess that these cities' trains are using solid-state devices to convert the DC track power to AC. (Use of AC power for subways would be most unusual; DC motors have better characteristics for this duty.) And C. Harald Koch (chk@client2.dciem.dnd.ca) writes: | The reason is actually much simpler. Normally, the power strip is on the | left side of the train (in the tunnels). In center platform stations, and at | switches, the power rail is on the right. True, but the gap in the power rail is very short at these places. I believe that it is not intended as a section boundary for power cutoff purposes; those have a longer gap. Note that every car is equipped with contact shoes on both sides at each set of wheels. Power to the lights is cut off only when all the shoes are out of contact, so it is reasonable to assume that all four shoes are simply wired together. (One may observe also that when a train, of any type, enters a place where the power rail is interrupted, there is an arc when the rear shoe of each car leaves the power rail, but none when the front shoe does. This shows both that every car is independently powered and that the front and rear of each car are connected to each other.) Now, suppose a car is situated across one of these short gaps in the power rail with the rear in section A and the front in section B. Someone tries to cut off the power in section B. But look, the front shoe is still live from section A, and the rear shoe is connected to it, and the section B is connected to that. So section B remains live. Because of this scenario, gaps in the power rail intended as section boundaries must be long enough that in the case of the old cars the lights actually do go off; otherwise you couldn't count on them working. I believe that the gaps are in fact often located right at the turnback switches, perhaps to minimize the number of ends to the power rail. There are some switches where the power is not interrupted, so it's possible to do that if desired. In short, what I conjectured before has not yet been disproved. Mark Brader Also, be sure to include your signature TWICE in SoftQuad Inc., Toronto each article. That way you're sure people will utzoo!sq!msb, msb@sq.com read it. -- "Emily Postnews" (Brad Templeton)