Hey guys!
Im in the process of building my first layout on an L shaped 12 x 8.
ive been told that 18” radius are tight but can be used.. is this true since reading some of these threads I would believe it’s impossible to do this. I don’t have much choice in my layout to not use 18” or something close to it and these are for One spot for a lead into a yard and one spot potentially for my double track mainline! Any help would be nice :)
It depends on what time period your going to model, which will help you to decide what equipment your going to run.
18" radius is not conducive to modern, say early 90's to today, long rolling stock, like 6 axle locomotives, and 89' rail cars. If you plan on running 4 axle locomotives and 50' freight cars, you'll probably be OK.
Just a starting point, untill you can give more info on what your going to model.
Mike.
EDIT: Mel got there as I was typing, he gives great information.
My You Tube
I'm on board with both responses so far. I model the 1950's and my layout has lots of 18" curves. I run 4 axle diesels and 40 ft rolling stock and have had no issues. I do not run any passenger cars.
Bear "It's all about having fun."
Modeling BNSF and Milwaukee Road in SW Wisconsin
I have a small layout in N but I'll add my $.02. I use 9 3/4" on my sidings (roughly converts to 18") and 11" on my mainline (roughly converts to 22"). Pretty much all 4 axle power and a lot of 6 axle power looks good on my main. I have mostly 40' and 50' cars which look fine but I do have a 60' or two and they look okay. The biggest caveat with small curves is you will not be able to run most passenger equipment and have it look even close to realistic.
Just an N scale guy in an HO scale world.
Reading Railroad in a small space.
Hello Cali, I agree, bigger is better, but yeah, 18"R can work, I've a spur on my switching layout that has two 18s. Most 50' cars can negotiate an 18 curve without issue, even some 60' & over can make it with care at slow speed. Some fancy RTR 50' cars with detailed under frame brake rigging may need mods to do 18"R.
Allowing for overhang is a must, but the beauty when running on 18"R is in the eye of the beholder.
Good luck and have fun, regards, Peter
John Armstrong's Track Planning for Realistic Operation is a must book to read, before you get much further in you planning. There is need to know information on curves and distance between parallel tracks.
Henry
COB Potomac & Northern
Shenandoah Valley
It looks like 18" is a given fact due to your space limitations.
No problem at all but make a clever decision selecting
- the time of your layout
- the theme of the layout
- the engines used at that time
- the cars used at that time
Reinhard
CaliIm in the process of building my first layout on an L shaped 12 x 8.
Maybe you can describe your plans a little better, I get the 12'x8' L shape, thats kinda-sorta what mine is.
How wide is the bench top? Do you plan on a continuous run loop?
If you can provide more details on what space you have, there is a track planning guru in here that can help.
Even if you can post a drawing, that would be of great help.
Like others, I think it would be helpful if you could post what era you plan to model and what type of rolling stock you are going to run on your layout.
I am modeling the steam era in HO on a L-shaped 9' x 5' layout, and my 4-4-0, 2-6-0 and 4-6-0 engines have no problem navigating 18" curves. I am running nothing longer than 40' cars, and (personnaly) believe that anything longer would not look good through those curves.
One thing to consider also is your inclines, since relatively tight curves such as 18" will create more friction on an incline and for practical purposes make it harder for trains to negotiate.
If you can provide a bit of detail what you plan to model, you will get some improved input.
My first layout had 18 inch curves. It was fine at first because I had toy trains made by Tyco which were designed take those curves without any problems. Later when I switched to running scale models I started having problems with cars 60 feet or longer as well as large locomotives. I would recommend minimum radius 22 inch curves. 90% or more of all cars and locomotives will run ok on them. Of course if you can go larger like 24 inch that would be better. In a perfect world everyone would have 36 inch radius curves. I rebuilt my layout to be 22 inch radius on the mainline. I still have a few spur sidings which are only 18 inch radius but they are for industries which receive shorter cars and are switched by 4 axel locomotives. On the other hand I have a collection of old time 1800 cars and locomotives which have no problem at all running on 18 inch radius track.
Athearn C44-9W requires 22 inch radius curves.
Walthers B40-8W will run on 18 inch radius curves. It is shorter that the C44-9W and only has 4 axels.
This old timer 4-4-0 American locomotive has no problem at all running on 18 inch radius curves.
This bad boy 4-8-4 Northern needs 22 inch curves and #4 or larger turnouts. Northern
Thanks for all the input guys!
so I would be trying to model the modern era. 4 axles will probably be mostly what I use but it would be nice to be able to get a big 6 axle :)! I guess it would just be trial and error until I figure out what will run and what won’t with the cars, 50’ will probably be most common on my layout I’m assuming.
I will be doing mostly CN maybe CP, I would like to try to run some passenger GO trains and VIA rail if possible.
The width is 4”. It is just two 4 x 8 sheets put together to make and L. I’m trying to get some pics on here but it doesn’t seem to be working! I have no inclines or declines on this layout I more or less just wanted to try one with a tiny bit of complexity so it’s pretty basic but it is a loop all around the outside double track with yards running off the inside mainline to yards and such I do have 2 crossovers!
if I missed any information let me know and I’ll try to figure out how to get the pics up here!
First layouts are famour, or infamous for being built with sharp curves. Then as you find you can't really run what you want to with out issues, you "level-up" for the next layout and build it with larger curves.
Rio Grande. The Action Road - Focus 1977-1983
Cali trial and error
Full size mock-ups using paper turn-out templates give a good idea about what track combinations will fit. A mock-up with actual turn-outs and track really tells the tale.
Maybe not real pretty, but with overhang clearance and good track work some 72' talgo truck equipped passenger cars will round an 18"R.
Regards, Peter
Welcome to the forums.
I have a 4'x6' and use 18" radius track. As others have said, most 40' rolling stock and 4 axle diesels and steam with 6 drivers work fine. I have found that most steam with 8 drivers will also make it. However, there are a few cars that play well on 18"r. In my case it was one of the Walthers 30' wood caboose, 3 window, offset coupla. The wheels hit the steps on the tight curves. MR had an article on two methods of altering it, cut away some ot the steps or cut and reverse the frame. Since I am planning a new layout with larger curves, I have not tried the modifications. There are probably other shorter cars that don't do well on 18"r, but none come to mind at the moment.
Have fun,
Richard
CaliThe width is 4”. It is just two 4 x 8 sheets put together to make and L.
OK, so 48" wide, so if you use flex track, you can make a radius that will fit within the 48" , you'll end up something around a 22" radius, maybe a little more, or maybe a little less, as you don't want the track right to the edge of the plywood.
For a double track main line, the inside track will have 18" radius, by the time you figure enough space between the tracks so passing trains don't side swipe one another.
This all sounds doable.
mbinsewi Cali The width is 4”. It is just two 4 x 8 sheets put together to make and L. OK, so 48" wide, so if you use flex track, you can make a radius that will fit within the 48" , you'll end up something around a 22" radius, maybe a little more, or maybe a little less, as you don't want the track right to the edge of the plywood. For a double track main line, the inside track will have 18" radius, by the time you figure enough space between the tracks so passing trains don't side swipe one another. This all sounds doable. Mike.
Cali The width is 4”. It is just two 4 x 8 sheets put together to make and L.
Gonna have to agree with Mike. You want the biggest radius you can manage, and I'd guess a 3 inch gap between track centers should provide good clearance.
So if your outer radius is 22 inches, you can have an inner with flex at 19 inches. Every little bit makes a big differnece with sharp curves like that. I'd be tempted to add a couple inches onto the sheets of plywood so I could fit 21 and 24 inch curves - you could even run some longer cars and engines on the outer curve that way. Sharp curves are somewhat of a straight jacket which limits what you can run.
BigDaddy John Armstrong's Track Planning for Realistic Operation is a must book to read, before you get much further in you planning. There is need to know information on curves and distance between parallel tracks.
And for someone considering the use of 18" radius curves due to necessity (and face it thousands and thousands of layouts have had 18" radius curves), maybe the most important part of John Armstrong's book is the section on easement curves. His wonderful analytic phrase being "the co-efficient of lurch."
With any tight curve - any curve at all for that matter -- the "pinch point" that causes the most problems is where the tangent stops and the curve begins. A tangent leading to a fixed radius curve for example (2 pieces of snap track being the classic example) will cause more problems than would a perfect circle of that same radius curve. That is where easement/spiral/"French" curves, even fairly slight ones, can help tremendously. Armstrong shows how the problems certain cars or engines are reported to have with tight curves of 22" or 18" or 15" curves are often not with that radius curve at all, but where the curve meets tangent.
Smoothly laid track with no kinks in the curve is another necessity.
Dave Nelson
dknelson And for someone considering the use of 18" radius curves due to necessity (and face it thousands and thousands of layouts have had 18" radius curves), maybe the most important part of John Armstrong's book is the section on easement curves. His wonderful analytic phrase being "the co-efficient of lurch." With any tight curve - any curve at all for that matter -- the "pinch point" that causes the most problems is where the tangent stops and the curve begins. A tangent leading to a fixed radius curve for example (2 pieces of snap track being the classic example) will cause more problems than would a perfect circle of that same radius curve. That is where easement/spiral/"French" curves, even fairly slight ones, can help tremendously. Armstrong shows how the problems certain cars or engines are reported to have with tight curves of 22" or 18" or 15" curves are often not with that radius curve at all, but where the curve meets tangent. Smoothly laid track with no kinks in the curve is another necessity. Dave Nelson
Preach it.
Read and heed what was written closely. I can attest to the joy of wide cuves. To create them, my wife gave me a flexible plastic drafting tool. You can bend it to different radi.
The joy of wide curves arose after experiencing the pain of running my 1st layout with tight ones. It was a challenge having to shift around cars on consists. Some cars couldn't even operate together without derailments. Go for the widest curves you can.
Finally got a pic!!
https://imgur.com/gallery/jdNHuc7
Great, I'll make them veiwable to all.