Traction overhead/rail DC Wiring

Discussion in 'Traction Thoroughfare' started by TinGoat, Aug 13, 2003.

  1. TinGoat

    TinGoat Ignorant know it all

    Biting off more than I can chew here....:cool:

    When you build a home or club layout, you can wire it to suite your needs/wants/budget.

    If you are operating all of one type of equipment, then you are home free.

    In my case, however, I am trying to cover all the bases.

    The On30 Modules will need to accomodate all types of motive power.

    There will be traction running on the same lines as Heislers, Shays as well as other steam.... There is also room for Diseasels. :D

    In Traction, the layout is wired so that the overhead carries one "+/- pole" of the electrical current and the rails are wired together to be the other "+/- pole".

    In regular Two Rail operations, one rail carries one "+/- pole" of the electrical current and the other rail is the other "+/- pole".

    The question is.... Is there a way to wire the modules so that I can switch between overhead power and rail power?

    Is there a standard for this? i.e.: The right-hand rail and the overhead wire are always the same polarity and the left-hand rail is always the other polarity?

    Or, should the Traction equipment get power from the rails and the overhead is just there for decoration????
  2. jon-monon

    jon-monon Active Member

    I think most of your traction loco's have a switch so they can pick up power from the track for + and -

  3. TinGoat

    TinGoat Ignorant know it all

    Well Jon, you are one clever fellow....

    Thanks for the schematic....

    I had worked out another way of using the DPDT switch, but it requires using resisters in the circuit to eleiminate shorts...

    In my schematic, light bulbs are used as resistors. They could be handy indicators of whether the track is on rail or overhead power.

    I'll post it shortly.

    In an ideal situation, I'd love to be able to double head a tram and a shay... :cool: :cool: :cool:
  4. TinGoat

    TinGoat Ignorant know it all

    Here's my idea...

    I would place an indicator light between #4 and #6 to indicate Track Power. An indicator light between #1 and #4 to indicate Overhead Power.

    The bulbs would be needed as resistors to eliminate short circuits...

    Attached Files:

  5. TinGoat

    TinGoat Ignorant know it all

    BTW, I think I'll go with your version...

    Yes, most manufactured traction loco's have the switch.

    Kit-bashed and or scratch-built loco's might not...

    At this stage, Paul and I will be building traction that will run on track power. But I want to keep our options open.

    Plus, since this wiring is for Modules, I have to plan for someone who might show up with a RTR Bachmann Trolley that is set for overhead power.
  6. interurban

    interurban Active Member

    Hi Ron you can easily put a switch in a scratch built traction dead simple , Think it out:D
    Dont you dare have fake overhead tut tut tut!!!!!!!!!
    It is a hard task to try and run all types of equipment on one set of tracks. I was goling to tackle it on my redo section I posted but in the end gave it up after working through the problems.

    It can be done but it will have to be operated carefuly as you may blow a moter if the wrong switch is thrown for the wrong equiment.:) kapow
  7. 60103

    60103 Pooh Bah

    There are a lot of posibilities in traction control. Some people use one rail and the overhead for trolley 1 and the other rail and the overhead for trolley 2.
    I think I used one of your schemes for a layout once; I might just have done it with alligator clips. :D
    And then there is Detroit control where you can run 4 trolleys (forward only) with an AC supply and a collection of diodes.
  8. TinGoat

    TinGoat Ignorant know it all

    Learning more every day...

    I've been trying to work out a way to use the overhead and one rail for the traction motors and both rails for the other motive power....

    I think that there might be a schematic on the East Penn Traction Club's website that would work, or be adapted...

    With judicious use of diodes to control the the flow of electricity within the Loco, and always having the overhead as the "+" electrical pole should work.

    Otherwise, using one rail plus the overhead would work fine as long as the Loco doesn't get turned around...

    The East Penn Traction Club's website showed a schematic for using the trolley pole to control the direction of travel. This was on equipment that had two trolley poles. So whichever pole was up was the rear of the car and the end that had the pole down was the front.

    I could use an arrangement like that perhaps...

    Another idea is to have the trolley pole center mounted. I'd need a switch built into the trolley pole so that when it was turned around, it automatically changed the direction of the Loco... Something like the way the tracks on a turntable are wired, except much smaller...

    Just like the prototype, back poling is possible, but it is avoided as much as possible...

    Hi Chris,

    No, I am trying to figure out how to avoid faking the overhead and still running both traction and non-traction equipment.

    DCC or R/C would solve many of the problems, but it is an interesting challenge to do this in DC...

    I thought that you would be interested in the following...

    I've got a couple of other traction reference books that I am studying too..

    Like a said before, this is an interesting challenge...

    When building modules, you have to plan for every eventuality...:cool: :cool: :cool:
  9. 60103

    60103 Pooh Bah

    There is a problem with using one rail when you get reverse loops.
    I have a couple of trolleys (old Tycos) that I put the pole reverse in. One of the others has a centred pole and I forget how it's wired. :eek:
    One of the details I remember from my only viewing of the GRR/LE&N was the absence of frogs in the OH. At the Preston car shed, the wires were carried parallel for a car length or so past the mainline switch.
    I think some railroads ran double wires along single track and separated them at passing sidings.
    On30 and HO traction may be incompatible. Some streetcar lines mounted the poles on platforms on top of the smaller cars to bring them up to height. Maybe 3rd rail and model the subway? :D
  10. TinGoat

    TinGoat Ignorant know it all

    2-rail and overhead combined...

    Hi David,

    I've been studying the East Penn Traction Club's wiring diagrams for using pole reverse wiring on their traction equipment....

    By adding another pair of diodes, I can make it work...

    As long as the left side wheels and right side wheels are electrically isolated from each other to avoid short circuits and they have diodes to control the direction of electron flow.

    The power will always run from the overhead to the appropriate rail, while allowing the operation of 2-rail locomotives at the same time....

    So I'll be able to double head a tram and a shay on the same train!!! Or have tug of wars with them... :D

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