Railway Preservation News :: View topic - Trolleys and the problem of back-poling

The last streetcar line in Chicago went to 81st Street as I recall, and when the single pole westbound PCC cars got to Halsted Street (which was the end of the line) there was a wye in the pavement. The Green Hornet (as they were called in Chicago), went through the first leg of the wye and stopped facing south on Halsted. After the traffic light for Halsted changed to green, the conductor reached out the open back window and guided the trolley-shoe equipped pole in a slow speed backup move through the intersection. The car stopped when clear and then was ready to proceed around the last leg of the wye and head back east down 81st Street. I am sure someone out there, has a photo of this backup move.

I wonder if there are cases of trolley museums using single ended cars where backup moves are SOP.

Orange Empire has to back pole their 3 LARY PCC cars to get them out of the barn and down "Broadway" to the loop line. Its probably close to 1,000 feet.

At the Museum of Transportation, we regularly back up or ex PTC PCC #2740 in revenue service. As the trolley line exists now, there is only one loop. The long term plans call for a line extension and a second loop. In the meantime, the PCC shuttles passengers back and forth (we dare not try to back it through the loop) without any problems.

We use a wheel and a stadard PCC-length pole without any major problems.

Author:	robertmacdowell [ Wed Jun 24, 2009 12:34 pm ]
Post subject:	Trolleys and the problem of back-poling
Here's a problem that I'm sure is not new. A trolley operator starts his car on a run, without realizing that his now-front trolley pole is engaged to the wire. He's back-poling, pushing a pole ahead of him... eventually that pole will pop off the wire, skewering the overhead structure and tearing stuff down. So how did they handle that problem in the olden days? Did they have a system for making the operator aware of it?

Author:	Dave [ Wed Jun 24, 2009 12:52 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
Taking no potshot at todays one day a month volunteer motormen, but daily work experience over years in a real transit operation with very formally regimented standards, rules and practices did more to limit the likelihood of inadvertant backpoling than any amount of idiot-resistant technology. The old pros were just that - or they were fired and replaced. I'll never forget a meeting I sat in on with Charlotte Trolley (MANY years ago) when the subject of line-end turnarounds was discussed. I brought out a set of procedures and rules from a historic transit operation in another city which included a walkaround inspection, pole change, seat back changes, brake and reverser handle relocation, etc - all of which would take an experienced motorman about 3 minutes and included one walk around the car and one through the interior. The volunteers were overwhelmed at the amount of work, and the president actually came out against safe practices in the meeting..........not realizing that once it was done a few times it would become second nature. The only volunteer to speak up for it was a retired airline pilot who found it way less intensive than the average preflight checklist. I'm not implying that similar attitudes prevail anywhere else, but the value of daily professional attention to preserve a livelihood is a fine motivator. dave

Author:	artschwartz [ Wed Jun 24, 2009 1:49 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
Been there, done that (confession). Only with the line car, as we are frequently changing direction during wire work. Couple of points: Trolley wheels are much more tolerant than shoes of backpoling. A trolley wheel will generally stay on the wire until it gets to a facing wire frog. It will then generally go straight, if a wheel (duplex) frog is used. If an SR (shoe) frog is used, all bets are off. That is why we want to keep using wheels and duplex frogs as we have several single end cars that have to be backpoled into or out of our barns. That is also why Pittsburgh never converted to trolley shoes as most of their barns were not of a pull-through design. A few systems, such as Montreal, wired their double end cars so that they would not operate with both poles up. The power feed was connected to both pole hooks and a seperate cable connected the two pole bases. Thus, unless one pole was up and the other down, the circuit would not be complete.

Author:	Andy Nold [ Wed Jun 24, 2009 2:53 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
Having the trolley poles wired where direction of operation is tied to the raised pole is a pretty surefire way to keep backpoling from happening. However, it is a royal pain in the kazoo if you actually need to backpole. One of the electricians who worked at MATA devised a circuit that would allow backpoling when a key was inserted into a box on the switch panel. Motorman kept losing the keys, so he wired in a timer. If you knowingly needed to backpole, you would reach up, turn the timer and make your movement. The timer would run out in about 5 minutes and the protection of the circuit was returned. Some fools will get by even a foolproof system. One operator could not get the car to move so he turned the timer on to bypass the cutout. You would think that would have been a clue to take down the front pole. He proceeded to rip down a block of overhead wire. He was fired. Feel free to contact me if you would like details on the lockout bypass circuit.

Author:	Frank Hicks [ Wed Jun 24, 2009 3:35 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
IRM has been using a pretty low-tech method. The trolley rope is generally visible out the front window of the cars, particularly streetcars, so small pieces of colored tape are wrapped around the rope at eye level - red tape at eye level when the pole is up, green tape at eye level when the pole is down. This seems to work pretty well. I would agree with Dave that when these cars were in service, the motormen learned to do the job right or else they lost the job.

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Author:	Les Beckman [ Wed Jun 24, 2009 4:23 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
The last streetcar line in Chicago went to 81st Street as I recall, and when the single pole westbound PCC cars got to Halsted Street (which was the end of the line) there was a wye in the pavement. The Green Hornet (as they were called in Chicago), went through the first leg of the wye and stopped facing south on Halsted. After the traffic light for Halsted changed to green, the conductor reached out the open back window and guided the trolley-shoe equipped pole in a slow speed backup move through the intersection. The car stopped when clear and then was ready to proceed around the last leg of the wye and head back east down 81st Street. I am sure someone out there, has a photo of this backup move. I wonder if there are cases of trolley museums using single ended cars where backup moves are SOP. Les

Author:	softwerkslex [ Wed Jun 24, 2009 4:53 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
The Como-Harriet, Minnesota Streetcar Museum, has operated pole first for 30+years. Of course, they use wheel poles as mentioned earlier which makes it feasible. Their cars are all single-ended. I have personal experience as motorman there. Generally, it works, but they have a very well-maintained wire, and only one wire frog to transit each trip, at the station. Reverse moves are slow (never in parallel, usually not much more than 3rd notch). We were trained to be aware of the risk and be prepared to stop if the pole slipped off, but it never happened to me nor did I recall others mentioning it. One of the recent museum magazines has a nice article about the difference between frogs designed for wheels and those designed for shoes, and the wire changes necessary.

Author:	robertmacdowell [ Wed Jun 24, 2009 4:59 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
Les Beckman wrote: The last streetcar line in Chicago went to 81st Street as I recall, and when the single pole westbound PCC cars got to Halsted Street (which was the end of the line) there was a wye in the pavement. The Green Hornet (as they were called in Chicago), went through the first leg of the wye and stopped facing south on Halsted. After the traffic light for Halsted changed to green, the conductor reached out the open back window and guided the trolley-shoe equipped pole in a slow speed backup move through the intersection. The car stopped when clear and then was ready to proceed around the last leg of the wye and head back east down 81st Street. I am sure someone out there, has a photo of this backup move. Humans make great trolley catchers, it's how we move SN 654 and the line car around when the wire's not pan-happy. Call me biased since the usual 'catcher' is yours truely, but I say: hold out for a balloon track :) We have a car in the collection which is a double ended car, but has a single pole. The way it's told to me, the end of the line has a wye in the trolley wire (but not the track). You back-pole to the wye. The trolley shoe takes the diverging route. It swings oblique to the trolley car, a momentary lineman's nightmare, until it's at full 90 degrees to the car. As the car moves past, the shoe comes back on the third leg of the wye, and is now behind the car. Quote: I wonder if there are cases of trolley museums using single ended cars where backup moves are SOP. Sure. But single ended cars don't have turnable seats, and passengers don't like to ride backwards.

Author:	fkrock [ Wed Jun 24, 2009 5:58 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
The reason that Montreal had that elaborate system preventing two trolley poles from being connected together is that some lines used the same wires for both trolley buses and streetcars. If an operator put the second pole up on the wrong wire during poor visibility on a rainy night, a rather spectacular short circuit was created if the two poles were wired together. Apparently this happened often enough that Montreal Tramways went to the expense of modifying all its double end cars to prevent this problem. One way to prevent backpoling is to rewire the car so that a controller gets its power only from the trolley hook directly overhead. If the car has a line switch, that circuit can be modified so that power to close the line switch comes only from the overhead hook. If both poles are on the wire the car will not move. If one pole is on the wire and the other pole is under the hook, the only controller that will work is on the opposite end from the raised pole. Air compressors, car lights, and heaters can remain wired in the convetional manner so they will work if either pole is on the wire. You might have to wire an additional fuse into the circuit from trolley pole to controller to provide protection if needed. The only trouble with this system is when a car must be backpoled into or out of a carbarn or to get past overhead wire problems. Someone must stand on the forward platform to signal the person operating the car from in back. One trolley museum has modified all its regular operating cars as described. It has not had a backpoling incident ever since. fkrock

Author:	Randy Hees [ Wed Jun 24, 2009 6:17 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
Orange Empire has to back pole their 3 LARY PCC cars to get them out of the barn and down "Broadway" to the loop line. Its probably close to 1,000 feet. San Francisco and El Paso both installed a second pole on their single ended PCC cars to make back up movements easier.

Author:	RCD [ Wed Jun 24, 2009 10:51 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
The trolley we have at SFTM has a retriever that "reals in" the pole if it de-wires so it won't rip down the wire.

Author:	Brian Norden [ Thu Jun 25, 2009 12:54 am ]
Post subject:	Re: Trolleys and the problem of back-poling
Randy Hees wrote: Orange Empire has to back pole their 3 LARY PCC cars to get them out of the barn and down "Broadway" to the loop line. Its probably close to 1,000 feet. Actually, it is about 550 feet from the carhouse to the loop. Years and years ago, before the loop was completed, we carried passengers one-way and dead-headed the car back to the store. If we were using a PCC car -- which was rare, that meant backing it up about 2,400 feet and around four curves. Sometimes at the start of the day a PCC car has been backed the long way around the loop to the store and that means a total back-up move of about 2,200 feet and involves a total of five curves. Distances from Google Earth measuring fuction.

Author:	wilkinsd [ Thu Jun 25, 2009 1:58 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
At the Museum of Transportation, we regularly back up or ex PTC PCC #2740 in revenue service. As the trolley line exists now, there is only one loop. The long term plans call for a line extension and a second loop. In the meantime, the PCC shuttles passengers back and forth (we dare not try to back it through the loop) without any problems. We use a wheel and a stadard PCC-length pole without any major problems.

Author:	Les Beckman [ Thu Jun 25, 2009 2:49 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
wilkinsd wrote: At the Museum of Transportation, we regularly back up or ex PTC PCC #2740 in revenue service. As the trolley line exists now, there is only one loop. The long term plans call for a line extension and a second loop. In the meantime, the PCC shuttles passengers back and forth (we dare not try to back it through the loop) without any problems. We use a wheel and a stadard PCC-length pole without any major problems. David - Thanks for the explanation of the MOT operation. How much line are we talking about here? Les

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Author:	Bob Davis [ Thu Jun 25, 2009 4:10 pm ]
Post subject:	Re: Trolleys and the problem of back-poling
To add to the report from Brian about OERM's narrow-gauge PCC fleet, when leaving the barn in the morning, the PCC's are backpoling into "trailing" wire frogs (i.e. going from two wires to one), the direction less likely to dewire. Also, the operator opens a rear window and keeps one hand on the trolley rope until the backup move is complete. Regarding freight motors: both our Pacific Electric and Sacramento Northern locos have wheel trolleys, much better than shoes for switching operations, although pans are better still. On the PE, the crew member tending the trolley rope was called a "trolley pup", somewhat analogous to a fireman on an oil-burner. When some switching needs to be done, the motorman may ask another rules-qualified volunteer, "Can you pup the pole for me?" This leads to such facetious comments, as "All trolley pups will wear approved flea collars." One could say that in addition to preserving the "hardware" of bygone railways, we also preserve some of the "culture".