Best Way to Run 2 Conventional Engines on a Single Loop?

Without going into detail about exactly how these systems work, the simplest one would involve seperating the loop into a number of blocks with kill switches wired into their power feeds so one can stop the faster train before it gets too close to its "partner"

A slight upgrade would be to switch in a resistor to slow the faster train rather than stopping it.

Most block-control systems I read about way back when had multiple "cabs", or power controls that could be connected to a given block by means of a rotary switch. Multiple inputs in, one lead out to the block. Individual operators would need to remember which cab they were assigned to, and select that particular cab with the rotary switch as they followed their train around the layout. More sophisticated variants put the power controls in portable boxes that the operators carried with them as they followed their train, plugging it into jacks at various places around the layout in order to take control of "their" train. Electronics were developed that allowed the train to continue moving while the operator unplugged his controller to move to the next jack.

The ultimate block systems married relay controlled signals with track power to automate the amount of voltage applied to any particular block based on the location of trains in other blocks farther up the track. If one train started overtaking another, it would run into a block with a below-normal voltage and slow down. If the train ahead stopped, the block immediately behind it would be electrically dead (or at least so low a voltage that any train entering it would slow to the point of stalling). The Bay Ridge Model Railroad Club* has such a system, run by banks of WWII aircraft relays.

After that (more or less) came command control

---PCJ

(*turn on your pop-up blockers for that second link)

With a close eye

Works best on a large loop.

Find out which of your two locomotives is the fastest at a given voltage. On the slowest one, lock out the reverse unit, so it stays in forward.

Then, when the fast one starts to catch up, hit the direction button. The fast one will go into neutral while the other continues and gets further ahead.

When far enough ahead, hit direction button twice so forward is resumed.

Repeat as necessary.

Put up a live catenary wire.

Rewire an Electric engine like a GG1 to actually use the catenary and ignore the center rail.

Run a steamer off the normal center rail.

Put one transformer on the catenary and one on the center rail.  Both outer rails tie together with both transformer commons.

Well of course, if you have legacy or DCS you can orogram the speed exactly and so they stay in lockstep.

If you have two Lionchief + locos (I do) you can set them up so they run at the same cruise speed and vary that if need be should one drift.  I run two, with about 12 cars trains each, on my 130 foot loop.  

The final alternative is something I have done a few times.  I have found several pairs of locomotives that have voltage-versus-speed curves that cross, as shown below.  One is my RK Y6B and a Lionel shifter 0-4-0.  Since the curves cross, there is a voltage - only one, but it exists - where they will run in lockstep.  Lower voltage and one slowly catches the other.  Raise it and the other runs away from the first.  In this way you can keep them running together.  It works, if a bit, well, silly.  I prefer LC+ frankly.  

I guess I should've been a bit more specific in what my operating conditions are. Oh well, still all good suggestions all. I think Dale's is around what I am looking for.

My layout includes a standard loop with no catenary system.

On the loop are a Lionel #785 Hudson with Irvington cars and a Lionel 18006 Reading T-1 heading an ore train.

VERY CAREFULLY!!!

Fredstrains

Check out this site:

https://www.azatrax.com/twotrains-onetrack.html

It may have what you are looking for. 

What you need to make it work is:

1. a single transformer capable of running two trains

2. A single loop of track divided up into three or more isolated blocks

3. Some sort of train detection system. Can be either IR detectors or insulated track sections. One detector per block

4. Relays, one per block. Relays are actuated by the train detector for starting or stopping each train within a block

One electric running off overhead wire and the other loco running from track power. That's the way I did it before all the new systems. Don

I use a section of 027 track as a detector by isolating an outside rail to be a switch when train wheels complete the circuit.  The circuit pulls in a relay.  The contacts on the relay supply a resister reduced 2 volts to an 8 section of track few sections behind the detector track section.  This allows the following train to come to a halt but has 2 volts to keep the E unit from switching direction.  After the first train clears the detector section, the circuit is opened and the full track voltage is sent to reduced 8 section of track and the chase is on again.

I use this system on two of my loops.  Each loop has one detector and two reduced voltage 8 section of track, one on each end of the detector track.  This will allow operation of the trains in both directions.  I have slide switches to turn on and off the relays, and to select the direction of the train operation.

I used the Lionel booklet "Lionel 0/027 Train and Accessory Manual" pg. 30 for guidance.  It is an old manual. 

The system works great but one must somewhat match the engine efficiencies and the train weight and number of cars to keep the train speeds in a near range as I only have one switched section on each loop.

Here are links to watch the loop in action.  The first one shows the trains stopping in the outside loop with 2 train relay control and operation of the scratch built clothes dryer belt driven turntable.

https://www.youtube.com/watch?v=szGr4ymfJEs

https://www.youtube.com/watch?v=GQJRxSNqvLk

Charlie

Thanks Charlie, and your layout is a perfect example of what I'm looking for. I'll give strong consideration to it when going through with this.

This is very easy to do by using insulated track sections. How big is your loop? How long are your trains? Do you want the trains to run in the same direction or opposite directions? Do you have any switches?Lionel in the 1950s had paperwork on this very subject. I used these methods before TMCC and it works great.

Basically one train sits on a siding while the other train runs the loop. Then by reaching a special section of track,  makes the 2nd train go around the loop while the first trains waits.  

Mikado

I have posted a better video showing the two train operation more clearly.  It is the first video on the list.

Charlie

Here is the simple circuit that I use on my layout and it works great.  You will need to lock out the reverse unit on the engines so that they run forward only.  The whole circuit consists of a few insulated rail pins and a piece of wire.

If you can't read the words, check out the attachment for a larger image.

Here is a video of my layout.  I have 2 loops and can run 4 trains.

I just don't worry about it.  One train at a time.  KISS.  Now, if they are diesels, I can lock out the e-units in the same direction, and run an MU set!