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Controlling multiple trains that run on the same independently powered tracks

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  • Member since
    March 2018
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Controlling multiple trains that run on the same independently powered tracks
Posted by RAVEN18 on Saturday, March 10, 2018 8:22 AM

Imagine 3 concentric oval tracks, each connected to a seperate transformer and each has an engine with several cars.  Next, connect the concentric tracks with switches so that the trains on each track can leave their original oval and travel on the adjacent oval, where the train(s) will be powered by the transformer that is connected to that oval.  My questions are: can you assume that the switches will electrically isolate each of the 3 ovals from each other?  Will the 3 tracks continue to be electrically isolated even as the trains pass through the switches?  Also, will the trains be able to pass through the switches in either direction?  The layout I have in mind would use either LGB or Aristocraft track.  The engines each have 2 motors and there is no digital control; it's all analog.  The switches will be manual or controlled, or both depending on works best.  Thanks for your help!

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Posted by ttrigg on Tuesday, March 13, 2018 7:18 AM

NO. Switches will not isolate power supplies. You will need to install insolating connectors between the switches. If you hook things like you want without insolators you stand a 15% chance of strarting elecrtical fires in your power supplies. At a minimum you will burn out all three power supplies.

After installing rail insulators on both rails:

If you have power supplies at near identical settings and direction your trains will move easily between the ovals. There may be a slight 'bump' as the engine crosses the isolators and moves from one power supply to the next. 

As an self confessed analog dinosaur I would suggest "bank switching" for this layout. Pick up an elecrtical wireing book for the smaller scales to see how it is safley done. In my case I have bank switched everything. My zones are (1) the yard where all trains and street cars begin their runs, (2) main line, (3) long line (where trains are sent and do not return for a while, i.e. 700 ft run out and 700 ft back), (4) trolly line to the top of the waterfalls. I begin with all the equipment I plan on running set up in the 4 track yard. I set the rotary switches so that the yard, main line and trolly line are set to power supply "A" and drive the trolly to the trolly station. Once there all rotary switches are set to 'off' and I activate the auto reverse unit so the trolly begins it back and forth runs. I then set the rotary switches for yard, main line and long line to power supply "B" and move the freight train to the long line. Then I set the rotary switches for yard and main line power supply "C" to move the passenger train to the main line. My yard is right next to my control panel and bench seat where i control everything. Bank switching allows me to pull an eastbound "local freight" into a siding where it will wait for the westbound passenger express to pass. After everything is in motion I can control the yard so that my yard goat can build the next consist scheduled to depart.

Get a book on basic wireing that explains bank switching. I've not seen a garden size wireing book on bank switching, but it is well explained in the smaller scales. Wireing is the same for Z through O scales and will follow through to G.

Tom Trigg

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Posted by RAVEN18 on Tuesday, March 13, 2018 8:49 AM
Thanks very much for that timely, much appreciated, explanation and advice!
  • Member since
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  • From: North, San Diego Co., CA
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Posted by ttrigg on Tuesday, March 13, 2018 4:23 PM

Sorry, I answered this one way too soon after waking up. I used the phrase "bank switching" when I should have said "block switching". That happens when I talk before the first morning cup of coffee.

Tom Trigg

  • Member since
    March 2018
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Posted by RAVEN18 on Wednesday, March 14, 2018 1:57 PM

Yes, I understand you mean block switching.  But perhaps my use of the word "switches" is ambiguous.  By switches I meant devices like LGB 12000 manual or LBG 12050 electric.  I was not refering to things like DPDT, toggle or rotary switches, etc.  

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  • From: North, San Diego Co., CA
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Posted by ttrigg on Thursday, March 15, 2018 5:56 PM

Understood. Switches (turnouts) are not electrically isolated, as a rule. Marklin had rail switches (turnouts) (N scale) that had a wire clip that could be removed thus providing electrical isolation. Have not heard of any G scale switches (turnouts) made with this isolating capacity. I have read where several people used a rotary tool to slice the rails in the switch (turnout) just beyond the internal elec connection. My only attempt at this was rated as a total failure, basically I destroyed it.

Rail insulators come in two forms, (1) plastic slip on rail connectors and (2) rail clamps. The plastic version have a limited life span mostly determined by your micro climate. They are UV resistant but can weaken over time and allow some seperation and mis-alignment of the rails giving engine or car wheels an opportunity to 'pick the rail' and derail. When I started in 1995 I used the plastic version. In 1999~2002 I started noticing the failure of plastic isolators. I'm in Norther San Diego county, mostly warm (80's to a few days per year of 100+ temps, mostly sunny.) I have since replaced with isolating rail clamps, 'Split Jaw' as that was the brand carried by my local retailer.

Switches (elec, toggle or rotary) are used to provide assinment of elec power to rail sections.

Initial construction hint: Switches (turnouts) need a bit of TLC cleaning with a 1 inch paint brush to remove light debris collecting between the points. Deposits from pets (chickens, dogs, cats) and assorted wild life sometimes require removal for cleaning on the work bench, 3~5 years. Use of slip joint rail connectors require disruption of that adjoining rails. Rail clamps will allow non-disruptive lifting of the switch (turnout) for advanced cleaning. I have one turnout that seems to be located in a favored deposit location. Weekly cleaning with toothpicks and paint brush works well, 'adavanced' cleaning runs about 6~9 months for that one turnout.

Tom Trigg

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    March 2018
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Posted by RAVEN18 on Friday, March 16, 2018 8:33 AM

Thanks very much for the additional information and advice!

  • Member since
    February 2004
  • From: North, San Diego Co., CA
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Posted by ttrigg on Sunday, March 18, 2018 3:22 AM

That last point should have been titled "Learn From My Fail!". Nothing in maintenance of my GRR was more frustrating that the first time I had to pull a turnout up from the roadbed to get the dust and extra fine gravel out of the elec powered throw bar that moves the rail points from side to side. All were initally installed with the standard slip joint connectors that come mounted on the rails. To get the turnout up for cleaning disturbed all three tracks for about 5 feet. Rail clamps let me pull the turnout without the required track ralignment and balasting.  I think you have a good grasp of what and how to do it so, quit talking about it an get out and "Play In The Dirt." Enjoy, my friend.

Tom Trigg

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