ntt@dciem.UUCP (Mark Brader) (07/09/84)
First, the dates for previewing the new Scarborough Rapid Transit line are in fact from NOW to August FOURTEENTH, not to the end of August. As I said, Saturdays and Sundays, 10 am to 4 pm. Go to Kennedy subway station and they'll give you a ride to the first station (1.2 miles or so) and back - no getting off. Oh, and the new line is not directly connected to the streetcar network. > I would only quarrel with the statement that TTC's streetcar system is the > last such on the continent. It is a very good one, and perhaps the most > extensive surviving streetcar system. Mexico City also has a good one (I > limited my article to USA and Canada, but Mexico is on this continent). Oops, I did forget where the continent ends. > And at least Philadelphia (10 routes) and San Francisco (5 routes) still > include enough routes to merit the (subjective) noun "system" (as opposed > to a one-route remnant, such as New Orleans) with significant amounts of > street running. What is different about Toronto is that MOST of the route mileage is on the street. In SF, even after you take out the tunnels, most of the mileage is on medians. Not all, but most. Or so I understand; I haven't traversed all of it. I have read that the same thing is true of Philadelphia (it is in New Orleans too), hence my original statement. > As to trolley poles vs. pantographs: I suspect that the real reason that > trolley poles are going the way of the dinosaur, in favor of half-pantographs, > is that a pantograph (or half) can't slip off the wire, as a trolley pole can. This is a rare event with streetcars, as long as the wires are properly aligned with the tracks! With trolley buses it is another story, of course. > Junctions are also simpler, requiring no frog (that "thing" in the overhead > that connects one wire from one direction to either of two from the other > direction). Mmm, yes, but they already had the streetcar wiring in place, you know. > Obviously, if SF had wanted to, they could have used > trolley poles on their LRVs, but I think the problem of losing the pole while > in the subway probably made the difference. Yes, that's probably the critical point. Especially if the tunnels (no car traffic), enable higher than usual streetcar speeds to be reached. > You're right, though, about the > problem of crossing a pantograph line with a trolley coach dual-wire line; > I can't think of any way to equip a TC with pantographs! I'm not sure of > this, but I'll stick my neck out: I think SF may in fact have no such > crossings. SF has many such crossings. They use bars shaped like this \___________/ to depress the pantographs clear of the trolley wires. It was seeing these last time I was there that put the question in my mind in the first place. Even if you could equip a trolley bus with pantographs it wouldn't solve the junction problem, but would make it worse. There are a few electric railways that use dual pantographs side by side (three-phase power); I suppose they have to interrupt the power for considerable distances at switches! Incidentally, one early trolleybus design had one pole with contacts for both wires on a little four-wheeled trolley at the top of it. Mark Brader