BR60103 Trolley bus frogs are mechanized. Two offset contactors get contacted at the same time when the bus is turning (parallellogram) and the frogs switch over. Partway through the frog the shoe causes the frog to return to normal. Trolley bus shoes swivel so that they can run off to the side of the wire route.
Trolley bus frogs are mechanized. Two offset contactors get contacted at the same time when the bus is turning (parallellogram) and the frogs switch over. Partway through the frog the shoe causes the frog to return to normal. Trolley bus shoes swivel so that they can run off to the side of the wire route.
Thanks, BR60103. I hadn't given much thought to the trolley buses, about the shoes swiveling though I should have, since I'd observed them moving a full lane over each way from under the wires. This makes me wonder about the case where streetcars and trolley buses run on the same route sharing one of the wires. I'm thinking of New Orleans before the mid 60' where bus and streetcar routes converged coming in to town then split, rejoined and split again. I guess the frog could be set up to default to the streetcar's position and be triggered to change for the bus's direction by the means you mentioned.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
Cincinnati's streetcars were unusual in that they operated with double overhead, like trolley buses. I have heard that the second overhead was used instead of the rails for the return to minimize interference problems with phone lines.
Does anyone know how any of cincinnati's streetcars ran? There's one car restored in the cincinnati history museum in Union terminal. I think its an older one (not streamlined) but I cannot tell.
I visited Washington, DC, from about age 3 in 1935 to a business trip and an evening singing with a synagogue choir in 1994, averaging about once a year. I even remember the conduit-only, trolley-pole-less center-door cars that were scrapped when the first PCC's came. If you email me at daveklepper@yahoo.com I will attach a return picture taken INSIDE the plowpit in Georgetown used either by the Frendship Heights or the Cabin John line, forget which it was and the documentation vanished. B&W photo about 1947.
As in NewYork, except during periods of the lighgtest traffic when one man was sufficient. there was one man in the plow pit whichs spanned both tracks under the street, and he removed the plow from under the truck of the outbound car and put it or a plow already in the rack for plows in the pit on the next inbound car. Man No.2 handled the poles. This was the proceedure until sometime in the PCC era. Then Capitol Transit's PCC's were equipped with motorized retreavers that could raise and lower the poles by controls by the operator. At the same time inverted-V wire mesh was applied to the trolley wires at the changeover points, on both tracks if my memory is correct, in case of wrong-rail single-track operation, so that the inverted V would guide the rising shoe to center on the trolley wire. At the time I took the picture, the only remaining changeover point that required two men was on the Benning line, whiclh still saw double-end lightweights and deck-roof cars, as well as the PCC's. The post-WWII PCC's with standee windows came with the motor-operated poles.
The conduit in NY and Wasington was very similar, a slot in the street with a one-inch high conductor on each side, one positive and one ground-and-negative. The wood plow had sprun copper contact shoes on both sides, leading to flexible thick insulated cables that were plugged into receptacles under the truck bolster, leadiing to other flexible cables to the car's control equipment. The plow could move side-to-side, but was lightly spring-loaded for centering. This did allow the plow to find the correct path when the slot divided into two at switches. London, Paris, and Budapest were the only other cities I know of using the conduit system. In London, the plow carrier was at the center of the car body, not under a truck bolster, and the carrier extened all the way to the side of the car. Instead of plowpits, the arrangement was that the conduit slot of the outbound and inbound tracks came together in a Y between the two tracks, and the plow would continue forward emerging from the side of the car, still in the slot, and the single plowman could match up the speed of a plow for an inbounnd with the car's speed, then the car would snatch the plow.
The Washington Baltimore and Annapolis was the only interurban with dars equipped for conduit operation.
saxhorn was anyone ever in Washington D.C. when Capitol Transit ran PCCs? did anyone read my question thereabout? i have not seen a reply that indicates so. the city forbad overhead; the streetcars gathered electricity from underground conduit accessed by a plough attached to the car through a slot between the tracks, NOT with overhead wire -- the poles were tied down. the change(s) were made by workers by hand in a trench at city limits, as normal overhead wire was permitted outside city llimits, whence the PCCs proceeded "normally." this procedure may have pre-dated PCCs, but those are all i remember. if i could find my book on the History of Capitol Transit all might be clarified (but the book has been misplaced). underground plough pickup was rare but, IIRC, not limited to Washington D.C. i feel i put out an interesting question which no one has read, or has bothered to address, or knows anything about and is hence ignoring. (or maybe i'm in the wrong place..........) y'all are self-proclamed "transit experts," and there have been mentions of TTs, but ................
was anyone ever in Washington D.C. when Capitol Transit ran PCCs? did anyone read my question thereabout? i have not seen a reply that indicates so.
the city forbad overhead; the streetcars gathered electricity from underground conduit accessed by a plough attached to the car through a slot between the tracks, NOT with overhead wire -- the poles were tied down. the change(s) were made by workers by hand in a trench at city limits, as normal overhead wire was permitted outside city llimits, whence the PCCs proceeded "normally." this procedure may have pre-dated PCCs, but those are all i remember. if i could find my book on the History of Capitol Transit all might be clarified (but the book has been misplaced). underground plough pickup was rare but, IIRC, not limited to Washington D.C. i feel i put out an interesting question which no one has read, or has bothered to address, or knows anything about and is hence ignoring. (or maybe i'm in the wrong place..........) y'all are self-proclamed "transit experts," and there have been mentions of TTs, but ................
I lived in DC during the last half of 1960 and the first half of 1961. I lived off of DuPont Circle, I believe it was on N Street.
I remember the PCCs that ran in the district. The contact poles, as you have noted, were secured whilst the cars ran in the district, and the cars drew their power from the pough - I did not know what it was called - that fitted through a slot between the tracks.
Your question is not clear. Are you asking about how they changed the switches? Or how the plough was engaged? Or how they switched from overhead to underground power, although I think that you have covered that operation.
If it's still priable then I'd say stuck ball is preferrable to cracked roof.
Of course the prying tool must be a swicth iron, in my opinion the duct tape of the streetcar industry. If you can't fix it with a switch iron it can't be fixed.
Patrick Boylan
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The trolley frog casting has a little ridge that the wheel or shoe can ride along. This is gapped at the middle and there is then one piece going off to the side.
At locations where the cars run through in one route almost always, the shoe may track that way even when the car goes the other.
On retrievers: when TTC rebuilt their PCCs in the 70s, they replaced the roof with a fiberglass molding. When a pole dewired it slammed into the roof so hard that it broke the fiberglass. The system mounted a rubber ball on the rope that stopped it before the pole struck the roof. I don't know about the CLRV/ALRV but the new Flexity cars have a ball on the rope.
The ball often got stuck in the retriever casting and had to be pried out.
--David
The frog must be level, horizontal, side-to-side, and this may require attention and adjustment,
Setting a trolley frog is something of an art, since not all cars track the same way. Often a frog will be clamped in place and then adjusted several times before being finally secured. A frog can also move when other wires move, making wirework over a steet intersection a very delicate thing indeed.
One reason it follows the body of the car is that the wire frog that is junction for the wires is located slightly beyond the point where the of center the two diverging tracks meet. This results in some sidways force applied to the trolley wheel or shoe for the curved route, with the straight route following the path of least resistance, thus going straight.
They just follow the body of the car. It works OK for the most part but they will jump off sometimes.
Here's a question maybe someone here could help me with. At a switch, how does the trolley contactor know which way to go? Is it only that it follows the angle of the body of the streetcar, or is there a switching arrangement? I suspect the former. The very few times I have seen one jump the wire it was at a switch.
I miss the trolley buses that Toronto used to have. The sparks would fly off the wire whenever they were at a crossing, like Bay Street (bus) at College Street (streetcar.) The last run was in 1993, the wires didn't come down for a few more years until David Gunn ran the show. You can still see evidence of them, like poles with brackets with a cut-off suspension wire hanging down and occasionally an abandoned pole like the one on Front Street just west of Yonge.
and for most of its history shared the right-of-way and one of the two wires with regular streetcars, Type 5's for the most part, but also some 4's and to the end some pcc's.
saxhornwhat about streetcars which used ploughs, rather than overhead (e.g. Capitol Transit within Washington D.C. limits)?
We've discussed them here -- look in 'search conversations' using the term "conduit".
... do they [trackless trolleys] even count as "streetcars," being essentially a rubber-tired bus powered from overhead?
I think this is a matter of taste. Personally I find TTs interesting, but not in the same way streetcars are... with some exceptions. The trolleybus operation through the tunnel under Harvard Square in the mid-70s was fascinating...
what about streetcars which used ploughs, rather than overhead (e.g. Capitol Transit within Washington D.C. limits)? ---- my first exposure to anything but the trackless-trolleys in Seattle; & do they (t-ts) even count as "streetcars," being essentially a rubber-tired bus powered from overhead?
The operating historic cars, PCCs and Milan Peter-Witts, have generally been moved from Geneva Division to the new Third Street complex, with the display historic cars, MUNI 1, Blackpool boats, etc., kept across the street from the old MSR building in a new display heritage car facility covering the old outdoor storage tracks. The old MSR building is no longer a car house but serves community purposes. See www.streetcars.org So even the new Third Street line is equipped for trolleypole operation as well as pantograph. In fact, I think the only part of the MUNI network that cannot accomodate pole-equiped cars in the subway itself.
Both exits from the subway surface tunnel are places where I'd have expected SEPTA to have changed over to the newer track switch control method sooner than other spots. At the 36th St portal oner route diverges from the other 4, so it has more traffic than the 40th St portal, which had gotten reconfigured from a 2 track T arrangement to a circle with 3 entrances and exits. I'd be flabbergasted if anyone has proof that they reconfigured it with the old fashioned overhead wire power on-open power off-close switch controls and subsequently changed it to the newer system. I think SEPTA calls it Vtag, but I have no idea what Vtag means.
gardendance Don't you mean you used to see it? I don't think SEPTA uses the overhead wire to control track switches anymore, I thought they had changed over to some mechanism buried in the asphalt, and did so sometime in the 1980's.
Don't you mean you used to see it? I don't think SEPTA uses the overhead wire to control track switches anymore, I thought they had changed over to some mechanism buried in the asphalt, and did so sometime in the 1980's.
I believe I saw it at the exit to the subway surface tunnel in the mid 1990s....
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Both San Jose and Sacramento have mods to allow trolley pole usage for heritage cars. Overhead has hoops around the frogs to allow pans to pass.
San Francisco's "J" line is used by "F" line cars to get to the San Jose Avenue maintenance area, on the site of a one-time Market St. Ry. barn.
Boston's "T" Green line still has a fair amount of pole-equipped work equipment.
Trolley poles will remain in use on San Francisco's F line. And to and from the carhouse, the track is shared with the Breda pan-equipped Light Rail cars. See www.streetcar.org
rcdryeIn 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.
I've seen this in action in the "modern" era on SEPTA...
CTA had to make similar adjustments to the overhead in 1964 when the Skokie Swift began service. Pan trolleys were used to allow one-man crews without a stop to change from third rail to overheard.
daveklepperHighg speed interurbans, such as the North Shore, usedd retrievers of necessity. This made raising and lowering the poles, using the rope between cars as well as at the end of the train, a paarticularly delecate operation, between howard St. and Demster, in rain and snow.
The raising of the trolley poles between Howard St. and Dempster always amazed me, as it was done on the run as the train was picking up speed. There was a long stretch of wire without cross-wire supports which gave a little grace if the pole missed, but it usually didn't miss. At the time I rode it most I was having to raise and lower poles on the west end of the Lake St. Elevated, and standing stock still it wasn't a simple task.
Jerusalem Light Rail uses a form of CTC to control all dispatch signals and all switches, with the position light signals (mineatures of classic PRR-N&W signals) showing the switch position. And all switches including the one street-imbedded slip switch, have pairs of movable points, not like the single-point classic streetcar switches. The position light signals are independent of the traffic road-crossing white-bar singals, coordinated with the traffic lights, with of ocurse a horizonatal bar indicated stop, vertical go, and dot about to change.
Newer streetcar lines use embedded radio receivers to operate switches. The switches will only receive the signal from an approaching streetcar once it is within the limited range of the receiver. Antennae for the switches are mounted under the floor of the streetcar and the operator presses a button in the cab to transmit the signal.
The large crossings that street railways used to make turns to every quadrant are called grand unions.
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