I am a newcomer and am designing my layout. I will be running passenger trains and some six axel diesels which will pull up to 15 cars. My plan includes a U turn and my question for experienced modlers is how tight can this turn be and not cause problems. I hope I can get away with a 18 inch radius?? Thanks for expert imput.
With 6 axle diesels and 85’ long passenger cars, you will need a minimum of 24" radius curves. 30" or more is better if you can manage that.
hi,
without knowing anything about your trackplan and your ideas…i would never try to come away with something.
You are a new kid in town…a 1:2.5 ratio AT LEAST between the length of your longest car and the minimum radius is considered to be good practise.
The min. radius will be about 30" at least , miles away from the 18" you are thinking of. It also means the use of #6 switches and #8’s if crossovers are involved.
The 18"radius would be appropriate in N-scale
Paul
The previous two posters are talking about aesthetics and best practices. Simply put, it means that if you use curves smaller than suggested above, you are likely to have derailing and binding problems, and that your trains will certainly look toy-like rounding those curves with half an inch of car protruding over the rails. Bigger is generally better when contemplating the use of long equipment.
That said, I was able to run a Proto2K PA loco (a long 6 axle diesel) and Bachmann Spectrum heavyweight coaches around 18" curves without much more difficulty than the occasional derailment. I now have 22" curves and have nary a problem, except for the fact that there is still some un-prototypical overhang.
Model railroading is about trade-offs. If you need prototypical appearance and trouble-free operations, make your curves as wide as possible. If you can handle the appearance and accept some operating issues, then you can get away with smaller.
My recommendation, though, would be to make the U turn in the widest radius that will fit in your space. Note that by using a crossover, you can often use a wider curve than would otherwise be possible.
I did kind of what you are planning to do with a Turn around my Furnace; I did have a 24" radius and no problems with 6 passenger cars; problem was when I exceeded that; I would get a Derail on the inside. Now that I’ve moved and rebuilding; I’m trying to keep a minimum of 28" on the main lines.
Like PTValley, I built mine with some 18" curves. It was my biggest mistake. I do run some large articulated steam engines and some long passanger cars, but getting the track to work was a beast and I still have derailments. It can be done, but if you have not laid a lot of track and gotten good at fixing small imperfections, you will get good at it before the big stuff will run. I wish I had at least 24inch curves.
Welcome to my favorite railroad, the N&W. What are the dimensions of your train room? As has been pointed out, the larger the radius of the curve, the fewer problems you will encounter when you operate your trains. I use a minimum radius of 36 inches. I am modeling the 1950’s so steam is still king on the N&W. I love the class A’ Y’s and J’s. For a little variety, I am running 1st generation F units of the Southern Railway. I too, like passenger trains and will have the Powhattan Arrow and Pocohantas on my layout. You will enjoy the asthetics of larger curves with 6 axel diesels and 85 foot passenger cars. I would recommend #8 turnouts for the mainline and #6 turnouts for the sidings. Hope things work out for you. But, remember to ask questions if there are areas that give you problems. Model railroaders are a great group of people who are willing to help others.[8D]
An 18" radius curve in HO scale to run 85’ passenger cars and 6-axle diesels is all but impossible without derailments. On my first layout, a double mainline with 22" and 24" radius curves, I still found running 85’ passenger cars and 6-axle diesels troublesome. So, when I built my current layout with 30" and 32" radius curves, I could finally run 85’ passenger cars and 6-axle diesels without much trouble. If I ever build a third layout, I would go with 36" radius curves - - - they just look better.
Rich
I agree with all who say to stay clear of 18R curves if you want to run 6 axels and 85’ passenger cars.
Derailments will plague you. Even if not derailing “say you go real slow like” you will have severe overhang issues and the 85’ers will be “stretched and pulled” off the tracks around the curves.
I have 18R curves and am limited to up to about a SD40-2 and 65’ passenger cars overhang severely and get “pulled and stretched” along.
If I want to run passengers I run my Old Tyme 40 footer with my steam engines.
Just my thoughts, experiences and opinions, others may vary.