# Thinking Ahead: What should I do first?



## Jimd0586 (Sep 20, 2021)

Good morning all. I am going to construct a small, modular, layout and want to know what I should do now so I am not stuck later. I am working in HO Scale, I have an NCE DCC Pro Cab, a DCC locomotive. So here is my plan:

Space is limited so I am starting with a 4'x2'8" layout. While small, it can fit in my place. I plan to have a couple unused turnouts on it in a couple different corners so I can extend to new layouts later. The play is a loop with a siding for now on this layout. I will create a diorama/scenery. I would like to add signal lights for the siding at some point. Does this necessitate creating blocks in the track? If so, is it as simple as cutting track and using plastic joiners and wiring the DCC system to each track? Can signals work without blocks? What's the best way to power the turnouts for the siding? At what increments do you wire feeders into the track? 5'?

I am new to this but have considerable experience building and painting model airplanes and some soldering because of my RC planes.

Lots of questions. Sorry and thanks!

JRD


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## Dennis461 (Jan 5, 2018)

back up a bit. Have you sketched out a layout that will fit on that postage stamp?


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## J.Albert1949 (Feb 3, 2018)

Get a little track down.

Don't worry about insulated joints on a layout that small. You probably don't need any.

Get some wiring hooked up (again, you probably need only a single connection to the power controller). Get an engine running, if only back-and-forth for a little bit.

With a layout that small, you don't need elaborately-powered switch machines.
Just reach over and throw them by hand.

When the layout "gets larger", then address issues as they present themselves to you.


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## JeffHurl (Apr 22, 2021)

Welcome!

I'd be concerned about the width of your first module. 2'8" means the absolute largest radius you can have is 16" if you want an oval. That's a pretty tight curve for HO scale


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## MichaelE (Mar 7, 2018)

That's not going to work for much more than an 040 tank locomotive. And that puts the track on the very edge of the sub-roadbed. Not good for equipment longevity.


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## traction fan (Oct 5, 2014)

Jimd0586 said:


> Good morning all. I am going to construct a small, modular, layout and want to know what I should do now so I am not stuck later. I am working in HO Scale, I have an NCE DCC Pro Cab, a DCC locomotive. So here is my plan:
> 
> Space is limited so I am starting with a 4'x2'8" layout. While small, it can fit in my place. I plan to have a couple unused turnouts on it in a couple different corners so I can extend to new layouts later. The play is a loop with a siding for now on this layout. I will create a diorama/scenery. I would like to add signal lights for the siding at some point. Does this necessitate creating blocks in the track? If so, is it as simple as cutting track and using plastic joiners and wiring the DCC system to each track? Can signals work without blocks? What's the best way to power the turnouts for the siding? At what increments do you wire feeders into the track? 5'?
> 
> ...


Since you only have 32" of shelf depth you're likely going to be restricted to a switching layout if you stick with HO-scale. You simply won't be able to fit a loop of HO track, of any reasonable radius, on that narrow a shelf.
Eighteen inch radius is the common tight inside curve on most layouts. It is usually on a 4' x 8' table. The radius is measured from the center of the track, not the outside ends of the ties. Of course to make the 180 degree turn necessary for a loop, you need to figure on two radii, not one. Together they form the diameter of the loop, and that's the limiting factor as far as what will fit on a given depth shelf. Even the two radii added together aren't the whole story, since half the track's width extends out about 3/4" beyond its center. This is true for both sides of the loop.

Let's do some basic math.
One 18"radius + another 18" radius = a diameter of 32" center-to center. + 3/4" +3/4" (for the two sides) = 33-1/2", outside-to outside, of the track loop. As they say in those infomercials, "But wait, there's more! The bodies of cars, and locomotives, overhang quite a bit on such a tight curve. So lets add 1-1/2" on either side for overhang clearance. That's another 3" to add to our 32-1/2" , which takes us up to 35-1/2" required minimum shelf width.
Can we shrink the curve? Yes, there are 15" radius HO curves available, but, as mentioned, they are so tight that what cars & locomotives will operate reliably on 15" radius curves is a short list of very short equipment. Trolley cars, very short switcher locomotives with four, or maybe six, driving wheels, and 40' freight cars, with lots of overhang.

Recalculating for 15" r curves. 15" + 15" = 30" + 3/4" +3/4" + 2" on each side to accommodate the extra overhang of the 15" curves. Total depth will still be 35-1/2" so you don't gain much by going to the 15" curve. These figures are approximate, (there may not be 2"of overhang on the tighter curve, depending on the car length) , but they're reasonably close. 
Either way you still have too narrow a shelf for a loop of HO track. 2'-8" = 32". 
32" divided by 35-1/2" won't go.  Therefore HO-scale = no continuous running. 

N-scale, or Z-scale, would fit. much better. If you're not too heavily invested in HO-scale, (one locomotive?) you could switch to N or Z and have room for the loop you wanted. You could keep the HO-scale locomotive as a static shelf display for now, and build a bigger HO-scale layout later, if you acquire more space. Your NCE Pro Cab will work just as well with an N-scale DCC locomotive.

However, there's nothing wrong with a switching layout. They can be a lot of fun. You could build a nice one in your limited space, in HO-scale if you like.

Adding "a signal for the siding" doesn't necessarily require any insulated track blocks. You won't be able to fit enough track on your small layout to have a fully functional block signal system anyway. However, many use signals to indicate turnout position. There are also commercial signals that see a train pass and change the light from green to red, then wait for its own internal timer to re-set the light to green. Kato makes such a signal I believe. You could also just operate the signal with a toggle switch.

Good Luck & Have Fun;

Traction Fan 🙂


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## mesenteria (Oct 29, 2015)

Jimd0586 said:


> Good morning all. I am going to construct a small, modular, layout and want to know what I should do now so I am not stuck later. I am working in HO Scale, I have an NCE DCC Pro Cab, a DCC locomotive. So here is my plan:
> 
> Space is limited so I am starting with a 4'x2'8" layout. While small, it can fit in my place. I plan to have a couple unused turnouts on it in a couple different corners so I can extend to new layouts later. The play is a loop with a siding for now on this layout. I will create a diorama/scenery. I would like to add signal lights for the siding at some point. Does this necessitate creating blocks in the track? If so, is it as simple as cutting track and using plastic joiners and wiring the DCC system to each track? Can signals work without blocks? What's the best way to power the turnouts for the siding? At what increments do you wire feeders into the track? 5'?
> 
> ...


First step is to pause, take a breath, and then re-read all of the previous replies. They're all telling you, nicely, that you're a long way from plunking some track on a large shelf.

What gives it away for me is the question about insulated joiners. If you have to ask, you don't really know what you're doing, and you probably don't have a concrete plan in mind. That has to come first. First you need the concept, then a scale diagramme showing turnouts, lengths of tangent, curve radii if any, and then you'll know what other considerations must come at about the same time or somewhat later.

What you have described sounds to me like a switching layout. With so little depth from front to back, again based on your description, it has to be a shelf switching layout. If that is so, you almost certainly won't need any gaps or insulated joints. So, you'll see why your question gives us the heebie-geebies. It says you think this is going to be simple, or that it ought to be for some reason.

Please, post a plan that appeals to you, hand-drawn if necessary, and then we can begin to advise you. 

Do you even know what era of railroading you're going to run? Do you know why you're wanting to power turnouts? Do you know which brand you're going to use? These are all pertinent questions.

Deep breaths....!


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## Jimd0586 (Sep 20, 2021)

Thanks all for the feedback. Admittedly, I was a bit embarrassed when reading through them all. Size was always going to be an issue where I am currently at, but I thought an HO train could navigate a 16" radius. I am laying down flextrack tonight (not permanently, just for testing) to see if it can. Below is a picture of the layout. It is an oval with a siding. At the bottom right is another turnout for potential expansion when room increases down the road. I build and paint model airplanes, so the idea of building a small scene intrigues me.












The idea behind this layout (albeit in a very small space) is that there is still room for some scenery, and because of the siding, there is an opportunity for maybe installing signals at some point. The base is already built (Plywood and pine 1'x3" boards).

I know the wise thing may be N scale, but I want to stress two things: 1) I will be moving in a year or two and will have more room, 2) this is just a start, of course it's small. But if it can work without derailments then I am fine with HO on it.

As for Block detection and such that I mentioned earlier, I am going to skip that for now.

Ok, so now that I have explained myself, I am ready for the probably critical feedback... be gentle guys. By the way, the Loco I got is a GP9 Union Pacific. It works great on the test track I set up with my DCC. So time period is 1954-1980's I suppose. My guess is they probably were still in use into at least the 1970's. As a proud Washingtonian, I would probably set the scene in fields in SE Washington where UP passes through (at least currently, maybe not in the 60's). But I digress, you're here to tell me my layout is impossible in such small dimensions! 🤣


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## Jimd0586 (Sep 20, 2021)

And please ignore that the track is slanted. It should be level along the top. Freehand drawing was never my specialty.


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## J.Albert1949 (Feb 3, 2018)

OP wrote:
_"Size was always going to be an issue where I am currently at, but I thought an HO train could navigate a 16" radius."_

I'd try for at least 18" radius. That will suffice for just about all 4-axle diesels and many 6-axle diesels of "the earlier period" (before the huge long diesels in use today).


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## traction fan (Oct 5, 2014)

Jimd0586 said:


> Thanks all for the feedback. Admittedly, I was a bit embarrassed when reading through them all. Size was always going to be an issue where I am currently at, but I thought an HO train could navigate a 16" radius. I am laying down flextrack tonight (not permanently, just for testing) to see if it can. Below is a picture of the layout. It is an oval with a siding. At the bottom right is another turnout for potential expansion when room increases down the road. I build and paint model airplanes, so the idea of building a small scene intrigues me.
> 
> 
> 
> ...


Jim;

It may be physically possible, (if not particularly wise) to get your HO-scale GP-9, and some short cars, to go through the 14"-15" max. curves that will actually fit in your 32" deep space. Sixteen inch radius will not fit, even though 16 is half of 32. Remember the radius of track is measured from center-to-center, not from outside edge-to outside edge of the track. Also, there will be plenty of equipment overhang on such a tight curve. The tighter the curve, the more overhang. The overhang may work out if your layout is on a simple board, with room past the edges, though if that's what you have, why not use a wider board that will accommodate an 18" radius curve?
I had, for some reason, assumed your 32" deep shelf was just that, an actual shelf, with some sort of back wall that limited the depth to 32." If there are any such limiting surfaces on either of the long sides of your shelf, the the curve will have to be tight enough to let the considerable overhang of the cars and locomotive clear the obstruction. Can you post a photo of your layout space? That would help.

Some other problems are very likely to come up, sooner or later, when you try to force equipment to run through tighter curves that it was designed for. The likelihood of derailments increases a lot on a too tight curve. If the curve is too tight for the amount of swivel built into the trucks of the locomotive, It can actually bind in the curve. If the curve is not quite that tight, but close, the locomotive may slow down as the wheel flanges rub against the rails. The wheels sometimes relive this pressure by climbing up the inside of the rail, then over the top, and derailing. Cars will be even more likely to do this, because of their lighter weight. The chances of the cars derailing increase exponentially if the train backs up, as in backing into a siding. 

All scales are good, but you seem to have some sort of obsession with HO-scale, that makes you try to force an HO-scale layout into what is clearly an N-scale space.
For most N-scale equipment, a 14" or even 12" radius curve is quite adequate. Some eight-driver or more steam locomotives, or really large diesels, might not be reliable on a 12" radius curve, but an N-scale GP-9 and a string of 40'-50' freight cars would breeze right through it, and what's more, they would do it reliably, time after time, because you would not be pushing them to, or past, their design limits.

So, given all that, Why insist on HO-scale at all? As far as I know from your posts, your HO-scale investment to date is one locomotive and a few pieces of flex track. That's hardly enough to cause major economic problems if you switched scales now.

Now I've modeled in N-scale for decades, but I have also had HO-scale, and O-scale layouts, in the past.
Here on the forum, I have defended N-scale when somebody poo poos it, but I truly don't care spit which scale another modeler chooses. That's his/her business, not mine.
In your case though, you simply are forcing things. Yes, it is possible that you may be able to force a loop of HO track onto a 32" deep shelf, but doing that is likely to cause problems.

An HO-scale switching layout, with no loop, will fit nicely.
So will a loop of N-scale track.
Either of these options, built properly, will work very reliably, and give you hours of satisfaction & fun. However, what you are trying so desperately to force-fit into your small space is more likely to provide hours of dissatisfaction & frustration, so why do that to yourself?

OK, you expect to get a larger space later. That's great, but it doesn't change the present situation a bit. You could do the HO-scale switching layout now, and incorporate that into a larger HO-scale layout when you have the space.

Or, you could build your planned loop & siding layout now, in N-scale, and then you would have two options for your future, larger, space.

Option 1 stick with N-scale, and build a larger N-scale layout, possibly re-using the track, and equipment, from the little layout.

Option 2 Keep the little N-scale layout intact, and build an HO scale layout in the larger space. There's no law against having two layouts.

Good luck & have Fun with whatever you choose;

Traction Fan 🙂


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## Jimd0586 (Sep 20, 2021)

traction fan said:


> Jim;
> 
> It may be physically possible, (if not particularly wise) to get your HO-scale GP-9, and some short cars, to go through the 14"-15" max. curves that will actually fit in your 32" deep space. Sixteen inch radius will not fit, even though 16 is half of 32. Remember the radius of track is measured from center-to-center, not from outside edge-to outside edge of the track. Also, there will be plenty of equipment overhang on such a tight curve. The tighter the curve, the more overhang. The overhang may work out if your layout is on a simple board, with room past the edges, though if that's what you have, why not use a wider board that will accommodate an 18" radius curve?
> I had, for some reason, assumed your 32" deep shelf was just that, an actual shelf, with some sort of back wall that limited the depth to 32." If there are any such limiting surfaces on either of the long sides of your shelf, the the curve will have to be tight enough to let the considerable overhang of the cars and locomotive clear the obstruction. Can you post a photo of your layout space? That would help.
> ...


Thanks Traction Fan.

I could widen my layout a little. I took a 3/8" sheet of plywood that was 4' x 2'8" and based it on 1" x 3" pine boards. I have a couple 2' x 4"'s available I could add to widen a bit. If I added one to each side I would gain 3.5 inches or so. I could take the foam board and overhang it some and stretch it out to 4 or 5 inches gained... so 4' x 3' roughly. Honestly, I was just planning to set this on a recreational table I have in the spare bedroom.

As for N scale, I have no problem with N scale at all. I just like the bigger look of HO. But I may look at N if that's the only option.

If I wanted an HO scale for a switching setup instead of a loop, is there a layout you would recommend that would be about 4' x 2'8"?

But, I think I can stretch this out to 4' x 3'... maybe 3'2"


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## CTValleyRR (Jul 26, 2014)

It's not enough to test the loco. You also have to test it pulling a couple of cars. Details on the ends kd the cars and / or loco may bump, so a train won't corner while a loco or car by itself would.


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## traction fan (Oct 5, 2014)

Jimd0586 said:


> Thanks Traction Fan.
> 
> I could widen my layout a little. I took a 3/8" sheet of plywood that was 4' x 2'8" and based it on 1" x 3" pine boards. I have a couple 2' x 4"'s available I could add to widen a bit. If I added one to each side I would gain 3.5 inches or so. I could take the foam board and overhang it some and stretch it out to 4 or 5 inches gained... so 4' x 3' roughly. Honestly, I was just planning to set this on a recreational table I have in the spare bedroom.
> 
> ...


Jim;

1.5"-2" thick foam can support itself well beyond the edge of the plywood 2x4s sound a little extreme for a layout base, but they could work. If you can get your table depth up to 36" or 38" then you will be able to fit, just barely, a loop with 18" radius curves. your siding would need to be inside the loop. There wouldn't be room for it outside the loop. So, if you can widen the shelf to 36 or 38 inches, then HO-scale with a loop becomes possible.

Probably the most famous switching layout would be John Allen's "timesaver." He built this little switching puzzle and people competed to see who could perform a list of switching chores in the fewest number of moves. You should be able to google it. The book "101 track plans also has switching layouts in it, and there must be a lot of track plans for switching layouts online.

Traction Fan 🙂


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## OilValleyRy (Oct 3, 2021)

Just a thought here. I don’t know what kind of space allowances you have at each end. I personally feel anything smaller than 18” radius will pose problems.
That said, could your space accommodate temporary dog bone loops at each end? Meaning that they would connect only for operating and rest atop anything stable (dresser, shelving unit, bookcase, etc).
The rest of the time the loops could be disconnected, stored behind said furniture, and your layout would at that time be a static diorama display.
Again, not sure it would work with your space limitations, but thinking outside the bun as they used to say.


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## Jimd0586 (Sep 20, 2021)

traction fan said:


> Jim;
> 
> 1.5"-2" thick foam can support itself well beyond the edge of the plywood 2x4s sound a little extreme for a layout base, but they could work. If you can get your table depth up to 36" or 38" then you will be able to fit, just barely, a loop with 18" radius curves. your siding would need to be inside the loop. There wouldn't be room for it outside the loop. So, if you can widen the shelf to 36 or 38 inches, then HO-scale with a loop becomes possible.
> 
> ...


You’re in Puget sound? I’m in Everett! Great to see train enthusiasts here!


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## traction fan (Oct 5, 2014)

Jimd0586 said:


> You’re in Puget sound? I’m in Everett! Great to see train enthusiasts here!


Just a wee bit south actually. San Diego. "To Puget Sound Electrified" was a corporate advert of the Milwaukee Road. I model the Seattle area, but live in the San Diego area. G.N. Fan actually does live in Seattle though.

Traction Fan 🙂


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## Jimd0586 (Sep 20, 2021)

Here’s how I got it to 4’x3’


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## Jimd0586 (Sep 20, 2021)

traction fan said:


> Just a wee bit south actually. San Diego. "To Puget Sound Electrified" was a corporate advert of the Milwaukee Road. I model the Seattle area, but live in the San Diego area. G.N. Fan actually does live in Seattle though.
> 
> Traction Fan 🙂


Good lord Traction Fan, your work is incredible!


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## traction fan (Oct 5, 2014)

Jimd0586 said:


> Good lord Traction Fan, your work is incredible!



Thank you very much!
However, if you want to see some really great work, check out posts by Latestarter. I'm reasonably good, after many years of experience, but he, and a host of others here, are at a level way beyond anything I can do!

Traction Fan 🙂


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## GNfan (Jun 3, 2016)

traction fan said:


> G.N. Fan actually does live in Seattle though.


Actually, I was born in Seattle and grew up in Edmonds; but have lived the last 40+ years in the Tri-Cities. And I don't model anything in particular, but I love "playing with trains".


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