Creating a passing siding

[cnw1995]

I'm trying to do this right, using 027 track, and two manual switches on a big oval. I would like to bring a conventionally powered train into the siding, park it, and run another train on the oval, then bring the first one out and slide the second one in. I thought I would plug a plastic joiner in the center rail of the track by each switch, then put a lock-on with a small transformer on the siding, then switch the engine to go forward only. It's still stalling when coming in over the switch and past the isolated section. Any suggestions on what I'm doing wrong?

[FJ and G]

I used DPDT switches to turn on and off different sections of track as well as to switch to 2 different transformers.

The problem you are experiencing is with the 027 manual switch, I take it. I happen to like the 027 manual more than the powered ones, which fry the switch motor if you park a train over it.

Anyway, what I would do is run a train slowly thru the switch and try to find out where it is stalling. Do this with all you locomotives. Then, test all your switches. Do all of your locomotives stall on all of your switches? If not, then there is something uniquely wrong with that switch.

Possibly, one of the soldering connections could be defective on the underside of the switch. I would connect a wire, using alligator clips, to the various rails of the switch (stock rail, points, and closure rails), to see if power is on in the various rails.

If so, could it be the gap in the frog? Are the points coming in contact with the stock rails or is there dirt buildup behind them?

You could build up the frog by inserting a thin strip of brass where the gap is located and then dumping solder in the area and filing out a new flangeway.

You kinda have to tinker with this thing but first eliminate as many problem ideas as you can before performing surgery.

Dave Vergun

[cnw1995]

Thanks Dave, I never thought it might be the switch because they worked just fine before I tried to 'improve' the siding. I'll also look for the DPDT thingies. Radio shack should know what they are...

[zubillaga]

If you are using a separate transformer for the passing siding, you need to make sure that it is" in phase" with the mainline transformer, in addition to checking your switches.

[Big_Boy_4005]

Your slow down problem may very well be the out of phase issue mentioned by Zubillaga. Your train 's rollers could be bridging the two power supplies together. Are you trying to bring one train into the siding when the other leaves, or you trying to park it on the main??

Really a simple SPST and a single transformer could be made to work, if you just want to swap trains. An SPDT could be used to select which section of track was connected to transformer if you want 2 throttles.

[cnw1995]

I'll have to experiment with the phasing; I was using my Lionel trainset transformer for the main - it comes in two pieces with a power brick and the box with the dial on it. Since it didn't have any connections to it and just two wires coming out of the box for the lockon, I thought the only way to do this was to try to add a second transformer because I couldn't figure out how to put a switch on. The second transformer (for the siding) was a small one that came in an MPC-era set. Maybe I should switch to using an older refurbished RW transformer that has two dials and lots of screws in the back, then I can experiment with the switch. I think the two dials means it can run two trains. Do you think I could use an Atlas Selector (used for HO) for it or go to Radio Shack to find one? I was just trying to bring a train into the siding and park it there. Then be able to put another train on the main and run it, and ideally, be able to bring the second train into the siding and bring the first one out again.

[FJ and G]

cnw,

You could wire it with a dpdt switch and just use one power pack and later on add a second to give you more options. In dpdt, I designate the center position as off and the up position for brick #1 and transformer #2 is the bottom.

Ensure whatever switch you use can handle the amperage. I'd be leery about using switches designed for HO. I did hear one bad story about smoking them.

Instead of Radio Shack, surf the web and you will find some electronics stores that are much less expensive and have a much much better selection. Mouser is one such company.

Also, give a lot of thought as to where you wi***o break your track into blocks. If your siding is broken into 2 blocks, you could conceivably have one train come in as the other is leaving.

For my new layout, I'm dividing my layout into power districts because I'm using DCS and no longer will need traditional block control.

David Vergun

[Big_Boy_4005]

If I remember correctly, an RW only has one throttle. Types R, KW, TW, V, VW, Z, and ZW all have multiple throttles, and there are others that I couldn't think of off the top of my head. You may have the best luck with the MPC transformer and RW combination. I haven't really seen the new types, but I have an idea what you are talking about.

The Atlas selector is an EXCELLENT choice for your application!![:D]

For doing the train swap thing, you will want at least 2 electrical blocks on the mainline, and one for the siding, and one for the section of the main between the switches, for a total of 4 minimum, which is perfect for the selector. Any more and you will need another selector.

[Anonymous]

cnw1995:

I typed this once & it got lost in the bit bucket. Let's try it again.

For the purposes of this discussion, I'm going to call the things that trains use to move from one track to another "Turnouts." "Switches" will refer to the things used to control the flow of electricity in a circuit.

"DPDT", "SPST", and "SPDT" are all types of switches. The letters are abbreviations that describe the type of switch.

SPST = Single Pole, Single Throw. This is a common on/off switch. This kind of switch typically has 2 contacts that you wire in a circuit. In one position, the contacts are not connected (there is no circuit), in the other, the contacts are connected (there is a circuit).

SPDT = Single Pole, Double Throw. These switches typically have 3 contacts in a row. In one position, one of the outer contacts is connected to the center contact, and in the other position, the other outer contact is connected to the center contact. A variation of this switch is the "SPDT Center-Off" switch, which has 3 contacts & 3 positions. In the middle position, none of the contacts are connected.

DPDT = Double Pole, Double Throw. This is essentially 2 SPDT switches in one package, controlled by one lever (or throw). These allow you to control two separate circuits with one control.

SPDT Center off swithces are typically used by model railroaders with layouts powered by two transformers to select which transformer is connected to a block. I use them on my layout for exactly this purpose.

Hope this helps explain the terminology!

Tony

[Big_Boy_4005]

Tony, that is a handy summary of the different types of switches. There is also the DPST, but that has few uses in model railroading. One of the easiest ways to identify which is which at a glance at the number of terminals on the back.

• SPST = 2
• SPDT = 3
• DPST = 4
• DPDT = 6
• 3PDT = 9
• And so on

I mentioned the 3PDT, because I have a large quantity of relays with this configuration.

The Atlas selector is actually a 4 gang SPDT with 2 common inputs, and is made to be ganged together with as many more groups of 4 as you like. Really a very handy device.

[jkerklo]

Your engine stalling in the switch may be simple.

If you are using plastic isolating pins to separate train blocks for control, you are reducing the number of places where the center rail in the switch can get power.

If the remaining connections are loose, then the switch is not getting center rail power or power is interrupted by the weight of the engine.

I would check each piece of center rail with a volt meter and make sure there is power, with each combination of mainline and siding power applied. A little pushing an wiggling may reveal the problem. A lighted car would also serve.

John Kerklo
TCA 94-38455
www.Three-Rail.com

[lionelsoni]

I would reconsider trying always to keep the inactive train on the siding. Prototype trains pass either way, with the stopped train often being on the main and the moving train on the siding. You could duplicate this kind of operation by isolating the center rails of both tracks between the switches. Then connect one or the other center rail to the center rail of the rest of the loop through a single-pole-double-throw switch. So, after running one train onto the vacant track and stopping, you would throw both the track switches and the SPDT to disconnect that track and connect the other track to the rest of the loop, then start up the other train. I think that this would be the simplest and most trouble-free way to do it.

However, if you want to stop each train on the passing siding, with one pulling out while the other pulls in, there is a way to do it without any electrical switches at all: Isolate the running (outside) rails of a stretch of track (section "A") at what you want to be the exit end of the siding long enough to hold either train. Then fill out the rest of the siding (as long as possible) with track (section "B") having one of the running rails isolated from the other. Connect one running rail of section B to both running rails of section A, the other to the running rails of the rest of the layout.

When a train sits on section A, it will not move, because its running rails are connected only to one of the rails of section B. However when the other train comes into the siding behind it, the second train will connect together the section B running rails, thereby connecting the section A running rails to the rest of the layout and supplying power to the waiting train, which will then leave the passing siding. When the entering train moves completely into section A, the connection will be broken and that train will stop to take its turn waiting.

Obviously, the two trains must run at similar speeds for the same voltage setting. The longer section A is, the less critical the speeds are.

This second method is cute, but more trouble to build and actually not very prototypical in operation.

[cnw1995]

I checked the track connectors as John suggested - and that helped a lot. I would like to be able to run one train in and the other out but it never occured to me as Bob suggested that I could do this on the main as well as the siding.

[FJ and G]

Just goes to show that often the solution can be something so simple you overlook it. John wins the prize for this one.

Bob's idea is good as well. I've learned this by mistake but never thought about using it as an operational feature.

Some good thoughts here.

[yellowducky]

Once I was having trouble with transformer phasing and found out that I have one Lionel(printed on it !) lockon that is reverse of all the rest (about 30) apparantly identical lockons. Something to watch out for.[2c] FDM