After about 25 years I have decided to get back into model railroading. Since space is a limiting factor, I have decided to go with a 4x6 HO scale layout. I used “Right Track” to design my layout and had to use 15" radius. Because of the small size, I am going to limit my rolling stock to 40 footers and my loco’s to switchers like the SW1 (although I really want at least one RS3). I’m also going to be running DCC. My question is, what high quality loco’s will run on these curves without uncoupling or derailing my freight cars. Will I have any issues with body mounted couplers on my freight cars? Maybe I’m worrying about nothing?
I tired this once. An HO layout on a door. My P2K SW8 and Bachmann 44 ton had no problems with the turns. I believe I ran as many as 6 cars with no issues. The real problem is S curves. It is imperative that you have a straight length of track, longer than your longest car, between curves. When I first started modeling everyone said to watch out for S curves but I never really had any problems with them until I tried the door layout. You can watch the locomotive and cars yank another car right over the rails with 15" radius. Its actually a good exercise to show how bad S curves are.
I think you’ve got the basic idea of what will work and what will not. Most of us consider 18-inch curves to be the absolute minimum. Most engines are designed to work on those, but 15-inch is pushing it.
My 50-foot cars with body-mounted couplers have no problems with 18-inch curves, so I’d imagine that just about any 40-footer would work in 15-inch.
I’d also predict that you won’t get too many first-hand testimonials to what will and will not work on such tight curves.
The only diesel on my 350mm absolute-minimum-radius line is a four wheel diesel-mechanical that will barely move itself, never mind a load. OTOH, it sees a choice collection of steam:
Bachmann Spectrum 0-6-0T
Roundhouse kit 0-6-0T
Tenshodo die-cast Baldwin 0-6-0T
Toby (imported by Ken Kidder) Baldwin 0-8-0T
Mantua Uintah 2-6-6-2T
No tender locos - the line isn’t long enough to need them, and 4% grades suggest keeping all the weight on the drivers.
Non-powered rolling stock is all short - either JNR 4-wheel cars or hopper cars about the size of DM&IR ore jimmies.
All of the above have been tested down to 300 mm radius - a tad under 12 inches.
Chuck (Modeling Central Japan in September, 1964 - including one route only a mountain goat could love)
While your 4x6 is shorter than a standard 4x8, you still have the standard 4’ wide area that would accommodate 18" radius curves, allowing you to run a wider selection of locos. Now of course I haven’t seen your track plan so please feel free to ignore me if it won’t work with your needs, but is it possible to modify your track plan to allow for the 18"?
I have very limited space. My layout is HO 3.5 ft x 5 ft. I would almost kill for a full 4 x 6. I have a 15 R and 18R loops. I will push space limits to add a few inches to the layout to make it about 40" wide, maybe 42" and an inch or two longer. The reason is I want two 18R ovals. This is so I can run a wider selection of locos nicely.
15R isn’t much good for anything but small steam locos as mentioned above, though small diesels will run on it. Mikes don’t like 15R,and my F series diesels do ok.
AS far as the body mounted couplers, I do find they get strained a bit on the 15R, but do not seem to derail, on 40’ cars. 50’ can be another matter.
I am about to find out how 15" curves work with a few locos. Just finished laying track and verifying that my 0-6-0 runs everywhere. There is one 90 degree bend that has 15" radius track. Will be putting some freight cars on the layout over the next few days as well as running a 4-6-0 and a 2-8-0 around. Only have one desiel (GP30) and it doesn’t have a DCC decoder in it.
Well first, keep in mind you could do an oval of 22"R track on a 4’ x 6’ layout. The straight parts of the oval could be up 18-20" long or a little more. You could then have a couple of turnouts branching off of that into the interior that were tighter radius curves (though maybe not down to 15" R.)
Second, you don’t have to use the Atlas 22" - 18" - 15" geometry. Kato makes track with roadbed (Unitrack) that is easy to use and comes in roughly 21" - 19" and 17" radius (it comes out in weird fractions (because it’s metric?) but it rounds out to that).
Third - you don’t have a lot of room!! If you cram it full of track, you won’t have room for buildings and scenery. I could be wrong but I suspect when you say you ‘have to use 15" radius’ it means you may be trying to fit in too much stuff. In the long run, a simple layout with 18 to 22" radius curves is going to work and look a lot better IMHO.
I would also look at the Heisler or Shay as they were designed for very tight curved track. The biggest (no pun intended) concern on any locomotive is wheelbase and coupler overhang. You could also look at the Roundhouse “Critter” (EMD Model 40) 2 axle switcher.
Thanks for the reply guys. What I did is used a layout design from this website
It is this one:
I like the idea of being able to run two trains at once (say one on the outside while I do some switching on the inside loop). These plans use Atlas 15" curves. I then used these plans to design the same layout on “Right Track”. Perhaps I could sit down and try a variation of this using 18" radius. I like the idea of using Altas track is it’s cheaper here in Canada (and I already bought a used lot of it cheap on Ebay!)
Speaking of Right Track, is there anyplace on line where folks swap layout files for this program? I thought it would be really neat to find a place that I could download different 4X6 track plans.
Something else to consider is European models. European freight cars, even modern ones, are considerably shorter than North American ones. I think the engines are generally shorter, too. While the price is a bit higher, and availability isn’t as good, you might find that a small European layout would give you a unique modelling perspective in a small space.
Unfortunately, that site has a lot of plans that are just plain bad. It’s a shame so many newcomers rely upon it.
This one is not the worst, but you may find that it soon becomes boring, with the two spurs in the same direction. The 15" radius into an immediate crossover s-curve is also likely to cause problems.
If you absolutely must have an HO 4X6, here are better-designed layouts on this site, for one: Gateway NMRA project layouts
I model modern times, and I have a Dash 8 and 50’-55’ cars in a full train that will run through a 15" radius curve full speed and backwards! So 40’ cars will run.
Try Atlas. The RS3 should run through the curve. Ask your LHS owner whether or not you can demo the loco before you buy it.
