radius of curves - planning question

Hi all,

I have decide like most from time to time that the current benchwork is too much like an "aircraft carrier" island type setup. It leaves much to be desired in terms of viewing. since I just have track down with little or no scenery, I have decided to rework the entire deal.

Now to the question, with my new benchwork plan which is sort of U shaped, there is one section that would need 22" radius curves to comfortably make a 180 degree turn.

I have several steam and 3 axle diesels that I might want to run. Is 22" truly enough to run some of these? The section is 4 ft wide, so I do not think I can get the full 24" radius on it.

If I can't run these, I may have to rework the track plan as more of a point to point plan, and I'd like to have a continous run option. currently I have it set up as 2 loops with a yard in the middle.

I have the plan on Atlas RTS software if anyone wants to have a go at a different plan for my space.

Thanks

Shaummy

 

You don't say what scale you are in but I assume HO since 22 inch curves would be just fine in N scale. Some steam engines require larger radius than 22 so I would definitely do a test track of 22 before going permanent with it. Also if your present steam can do 22 radius, you will be restricting your purchase of steam to smaller engines; that situation may be okay, but just remain aware of it. Your compromise to a smaller radius may come to haunt you if you don't make a conscious decision now as to what you are going to run.

 

rsn48,

Yeah, I guess I left that part out. I indeed am using HO scale. While I have old steam like 2-8-2 and 4-6-2's, the majority of locomotives I'd want to run are the diesels. I have a U33C and a SDP-40, GP50, GP60 and SW1500. the only ones that worried me were the SDP and the U boat.

Ultimately, I would not be crushed if I couldn't run my bigger steam engines.

Hope this clarifies the items I forgot to mention.

Thanks
Shaummy

 

D'oh - guess I dropped the ball here I see you got an answer in HO.

Try to make sure you get an easement into that 180 degree turnback. It will help greatly.

At 22" you may have some issues with long equipment (SDs, 89' flats, etc) coupled to short (less that 40') equipment (again, easements will help.) But it's a big improvement over 18 and to be honest, if you can pull off 24, the extra 4 inches of diameter makes a really big difference.

 

In N scale, 20 inches is wonderful....lol. I am using 16 inch radius and all large stock will be able to run on it. 20 is around 38 inch radius in HO (or 39... haven't done the exact math). A 30 inch radius in HO handles just about anything.

 

Don't get too hung up on this minimum radius stuff. Use as BIG of a radius as you can. It helps things a lot. Equipement looks a whole lot better on a nice 26" radius curve than on a 20" radius curve, and will run better also.
Always use an easement when going from a tangent(straight) track into a curve. The easement will let rolling stock flow into a curve rather than lurching into the curve from tangent track.

 

I'm running 22 to 24 inch radius on my layout! I run Big Boys and Challengers on it and they handle it well! Alot better then the ole 18 inch raduis I was using at first when I bought my first articulated steamer! I hated the way that looked with its articulation showing real bad so. I converted to 22 and 24 inch radius. Not only does it look a whole lot better but the loco's run on it great too! Not saying the 18 prohibited their preformance its just they seem to run smoother on the larger radius. Most times when buying loco's you'll run into things like this:
Minumum radius 22, which actually means, they look and run smoother on 22 inch raduis. They will however run on 18 inch radius, but looks bad and don't run as smooth so.. Anything from 22 inch radius and larger is good.. "Larger is Better" well in some cases anyway...

 

This whole minimum radius thing can make you crazy. I'm in HO. Right now the layout ends in my living room where i am building one end of my double[as in two track] dogbone. This will be a focal point for visitors, so i made the loop 42" outside diameter so my long passenger cars and locomotives will look their best-fact is that even with this wide a radius those full length passenger cars still have some overhang, but they do look really nice overall. I've built 5 layouts over the last fourty years and never had what i thought was enough space for broad enough curves, but still had fun with what i had. Make what you have room for, and if you need to, use the Athearn shorty type passenger cars-they don't look all that short if they're not sitting next to the AHM types-it's all relative folks. Curt

 

Yes this whole min radious thing can make you crazy A good way to 'hide' sharp curves is to build the layout close to eye level. You don't notice the overhang as much if you arn't looking down on the layout.

Hemi - 3rd PlanIt has a demo that you can download at http://www.trackplanning.com/3pi.htm