Question on pantographs and trolley poles

Could trolley pole equipped and pantograph equipped electric traction operate on the same lines?  And did they anywhere?  I don't know if there's differences in the wire set-up.




Yes, but....

Dear Irish,

In broad terms, sure. The wire may be different sizes depending on what the "normal" equipment on the line is setup with, and the format of overhead support structure may be significantly different, (gantries VS "offset poles and guy wires"), but that doesn't explicitly preclude equipment with the other system from running.

However, the biggest compatibility issue AFAIK is that trolley pole systems need "guidance" thru turnout locations,
(where the rails, and thus the overhead, splits/merges/crosses), and the "guidance" parts of the overhead may not play fair with pantograph systems. (Yes, just as with track, overhead systems have "frogs" too!)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

 

Zig Zag

The overhead catenary wire for locos with pantographs zig zags, so  the wire wipes across the pantograph as the train moves. If it was straight then it would cut the pantograph in half ,like a cheese wire. If there is someone who has information on the Melbourne (Australia) tram system, they should be able to help you.

Jurgen Kleylein's picture

Grand River Rwy

The Grand River Railway and Lake Erie and Northern lines of CPR's Southwestern Ontario electric lines were 600V trolley operations.  When they ordered their steeple cab freight motors, they came with pantographs, though the rest of the line was mostly trolley pole interurban cars.  They ended up removing the pans and mounting trolley poles anyway, though, because the wire wasn't taut enough for the pans to work well.  Probably if the wire was tensioned properly they would have worked fine, though the lack of zig-zag might have caused some excessive wiper wear in the center of the pan.

It's worth mentioning that those lines didn't use wire frogs in many places, but rather had the brakeman on the ground manually move the pole from the main to the siding wire, etc; they had parallel wires for each yard track on the ladders in yards.  It would be very difficult to model something like this correctly using poles, but would be pretty easy with pans.

Jurgen

HO Deutsche Bundesbahn circa 1970

Visit the HO Sudbury Division at www.wrmrc.ca

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Overhead cable tension

Dear Jurgen, Irish,

Hmmm, must admit I hadn't thought of cable tension, but it is a bit obvious after re-looking at the local examples. Pan systems are often used on higher-speed lines, and have very-highly-refined "cable swap-over and tensioning" systems...

http://www.clublockyer.com/rp005.jpg

http://i626.photobucket.com/albums/tt348/NZJeremy/002.jpg

http://www.railway-technical.com/ohl001.gif

In contrast, a "trolley pole" system usually requires more manual work,
but as long as the pole is trailing the direction of travel, can get away with murder as far as cable tension/position is concerned...

http://www.ilrms.com.au/images/photos/gemco_electric_locomotive.jpg

http://www.het.org.au/tmbs/ill/32_volt3.jpg

 

 

Happy Modelling,
Aim to Improve,
Prof Klyzlr

That video........

......... can you imagine the hordes of lawyers if it was here in the goood ole USA?. Can't get a more basic "trolley" setup no matter how hard you try....

_______________________

Long life to Linux The Great!

Awsome!

Love the rotary dumper!

George

"And the sons of Pullman porters and the sons of engineers, ride their father's magic carpet made of steel..."

Modeling the  Elk Creek Railroad in HO.

 

 

 

Jurgen Kleylein's picture

pans on trolley lines

I should point out that it's certainly possible to run a 600V trolley-style operation with pans.  The Inco Railway in Sudbury, Ontario ran with pantographs, and it worked well for many decades.  They even had temporary track which could be dragged back and forth up the slag heaps with overhead on it.  Speeds were not high on that line, though the system was quite extensive, larger than many common carrier short lines.  There was some rudimentary catenary used in some places, but most of it was just single wire overhead.  If the wire frogs were flush with the wire on the bottom, a pan would be able to get under them without trouble, and there would be no reason a trolley pole equipped engine could not use the same wire, though I don't know of any trolley pole equipment used up there.

An Inco electric running under single wire overhead near Sudbury.

Jurgen

HO Deutsche Bundesbahn circa 1970

Visit the HO Sudbury Division at www.wrmrc.ca

The preceding message may not conform to NMRA recommended practices.

green_elite_cab's picture

This is an ironic topic,

This is an ironic topic, since the reverse was a topic of conversation.  We're planning a modular Northeast Corridor, and some trolley runners were trying to see if they could run their trolleys on our PRR overhead!

 

While pantographs can work on trolley lines (given proper pressure),  Trolleys probably can't operate on heavy electric mainlines.    The PRR makes extensive use of air-breaks,  let alone the fact that there are no "frogs" in Heavy electric wires.

Heavy electric modeler

Jurgen Kleylein's picture

Danger High Voltage

While pantographs can work on trolley lines (given proper pressure),  Trolleys probably can't operate on heavy electric mainlines.    The PRR makes extensive use of air-breaks,  let alone the fact that there are no "frogs" in Heavy electric wires.

The Pennsy electrification was also strung pretty high up, so trolley poles probably couldn't even reach, to say nothing of the incompatible voltages involved... 

Jurgen

HO Deutsche Bundesbahn circa 1970

Visit the HO Sudbury Division at www.wrmrc.ca

The preceding message may not conform to NMRA recommended practices.

Trolleys & pans on the same system

Sir:

This happened more frequently than we realize! San Francisco is still using pans & trolleys on the same wire, and the Key System in Oakland used both for years. I've had a couple model traction lines & used pans & trolleys together, but the biggest problem is getting the wire exactly over the rails so it doesn't slide off the side of the pan, Pans are nice on locomotives as you don't have to keep changing poles every time you reverse direction! The span wires must not sag downward where they can snag a pan & frogs must be level & smooth. The upward pressure of a pan doesn't need to be as much as a trolley pole.    Hope this helps!

600V Bob


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