The catcher works on a principle like a roller blind, but I don't understand how they work, either.
Toronto is supposed to have sensors operated by a button in the car. They don't seem to be reliable and a lot are out of use.
The old system had a contact on the trolley shoe, a strip of metal by the wire and a button on the dash. If the car went through the metal strip the switch point would throw straight. If the NA button were pushed, the point would throw curved. (NA= Necessity Action) Some were set so that going through the contact strip would set the point straight; to go curved the operator had to get out with the switch iron. (SR=Self Restoring) This system was abandoned when the articulated cars came and the poles were at two different distances from the front of the car.
After a rainstorm. there would be a great splash of water when the point changed over.
--David
Nearly all PCC's used catchers, PE's being the only exception.
I assume their CLV and ALV Toronto replacements were similar in that respect.
It sounds like Toronto uses catchers. The catcher has to be adjusted soft enough so that changes in wire height won't trigger it, which means that a pole will rise a couple of feet when it dewires.
In Toronto, there is a rope on a reel at the back of the car. When the pole comes off the wire, it just unwinds and the pole will bang around the supporting wires often sending out sparks. The driver pulls the rope down to reset the pole. The reel is shaped like a fire bell on the wall of a building.
Rcdrye: Have never observed a catcher but makes sense. The reteriver is the one that operator has to wind up after a loose pole ?
In the "classic" streetcar era, many lines used contactors in the overhead to control switch machines, swithc position depending on whether the car was drawing power or not when passing the contactor. The device used to pull down the trolley rope is either a "catcher", if it simply stops a fast rising pole, or a "retriever" if it will pull a loose pole down.
Did not see mentioned the take up spool. On both single pole and double trolley poles is a oversized bell shaped housing that the trolley pole rope is attached to. Whenever the pole jumps off the trolley wire the sudden extension of the rope releases a spring mechanism that takes up the rope pulling a pole away from the over head wire(s). TT bus or car operator then goes to rear of vehicle, winds up the take up spool by pulling on the rope several times then operator can then slowly allow trolley pole to re engage wire. If for any reason rope slips then take up spool the pulls pole down and operator can try again. Also this appplies whenever changing ends on double ended cars. Protects pole from snagging overhead power wire(s).
One time observed a trackless trolley ( 2 poles ) that had a rope break as pole jumped wire at a wire switch.. Quite a spectacular electric arc show. Then uderstood reason for take up spool.
This speaks to the present standard of new facilities using PANs and some older operators adding same.
Living in Toronto as I do and having nollij of the streetcars as I ride them every day, there is a remote control box up on a telephone pole near the switch itself. The driver pushes a button, and usually the points will move. Often it doesn't and the driver has to use a switch iron to move the points. Often when there is a diversion, there will be a TTC staffer sitting on a folding chair with his own iron and he will move the points as a specific car approaches. This happens a lot as there are car crashes, construction and track maintentance and so forth that requires a man to be stationed at an intersection, which are mostly of the "grand union" type.
You can be standing at a stop and the car that is approaching, say a Spadina car the is turning around at King Street and the point (only the one blade on the inboard side) will move with a loud "schwack" noise. Like I said, it doesn't always work due to snow and ice or for whatever reason and then the driver has to get out and use the iron.
Sometimes the pole comes off the wire and there is a loud BZZZAP! and you look out the rear window and the pole is bobbing around and the car stops dead, usually in the middle of an intersection such as near where I live at the junction of King st, Queen st, and Roncesvalles avenue near the car yard. Anyway, the driver gets out and puts the pole back onto the wire and on we go. Life in Toronna!
rambo1are there sensors in the tracks?
The "sensors" are usually current detectors wired in series to the overhead wire, which is arranged in insulated sections. They operate a signal system, if the trolley line has one, and could be wired back to the dispatcher's office to provide approximate location of powered cars.
As far as sensors for vehicles and people on the tracks, the motorman had to depend on the Mark I mod zero eyeball.
Chuck
The movable tongue mentioned in earlier responses was different from the RR type in that instead of bending the rail, it pivoted at a point about two feet or so back from the point. The other rail had a fixed frog-like arrangement that supported the flange and let it take either path.
Here is a picture that shows the switch rod that tomikawaTT mentioned. It's from "The Streetcars Of New Orleans" by Louis C. Hennick and E Harper Charlton. It is hanging next to the middle window at the motorman's right side.
https://www.flickr.com/photos/paulofcov/15573946851/in/set-72157626021256880
The practice in early days was for the motorman to lean out the front window to operate the switch. In later years, a current sensing method was used. Here is a discussion of it. Go to the "Pointswitching" section.
http://en.wikipedia.org/wiki/Tram_controls
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
The single-point switch and girder rail were specifically designed to be laid in pavement. The motorman would dismount and throw the switch with something like a crowbar. Some were locked with a little block of steel, others were left free so another car could come through a trailing point move without derailing. There were also single-point spring switches, used where the track was single between stops and double at stops.
The ultimate expression of street railway specialwork was the, "Grand junction." Double track crossing, right hand running, with connecting curves for every possible route on the cross street. Sixteen turnouts (or eight lap turnouts) eight curves, sometimes curved rail running right through an otherwise normal (for girder rail) frog. Putting one at the busy crossing next to city hall and the county courthouse meant that the company had reached the big time.
Of course, the authorities could (and often did) screw that up by creating one way streets.
By using switches. They usually only had one moving rail, though.
How do they change tracks to go on other streets?rambo1..
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