OK, stupid question to a point. Bigger is all wise better when it comes to turns. But where do you draw the line?
As most here know I love Big Steam and Diesels but have all so had great luck with good track laying getting them around 18 inch radius.
Now, as I plan my new layout I am looking at turn size. I have finally got to the point to where I know how goofy bigger cars and engines look going around 22 and 26 inch turns.
I have been playing with 40 inch turns, but they eat up the Real Estate pretty quick. Most of my viewing of the turns will be from the inside so that helps.
Bigger Engines are Big Boys, Y6 b, GE AC 6000, Dash 9's SD 50's E'6's and a SD 40 -2, rest are smaller steam and diesels. Most of my rolling stock is 50 box cars and 54 foot covered hoppers. Only one passenger train with short Con Cor cars.
Any input is welcome.
Ken
I hate Rust
I would say 30-36" would be a happy medium, doesn't take up too much real estate and all the big power and long passenger cars look good.
I have 24" on my new layout, and wish I had gone with at least 30".
Michael
CEO- Mile-HI-RailroadPrototype: D&RGW Moffat Line 1989
40 inches is the NMRA RP minimum radius for the largest engines and cars http://www.nmra.org/standards/sandrp/rp-11.html.
You can of course go larger. John Armstrong in his book Creative Layout Design (out of print) suggested using a very broad curve for scenic purposes.
Enjoy
Paul
Ken.
When I had planned my layout, it was designed with 28" R curves. Then along comes Sunset models announcing a Brass 2-10-4 CP Selkirk. The specs said it needed 30" R curves minimum. AAAAAHHHHHHH!!! But I had to have this engine. Anyway I had just began to lay my 270' of mainline so everything came to a halt to see if I could get my 30" R for that Brass engine. By shortening a couple of bridges, adding two inches to one bench and changing a few other miner details I got my Radius up around the 32" range ( a little extra padding if you like)
I learned that Brass (and maybe others) engines require a larger radius to run. So look into the future and allow yourself some breathing room.
I pose a question to our more seasoned members. What is the largest Radius required by a any engine that you may know of? And Ken will you want it someday?
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Ken,
36" radius with good easments would be the bare minimum I would use with the equipment you have.
Actually, on my ATLANTIC CENTRAL, 36" is my minimum, and I would never buy some of the stuff you have for appearance reasons, but it would run fine.
Sheldon
Sheldon is right - 36" curves are the minimum if you plan to run Big Boy & Co. on your layout or plan to employ those 89 footers.
However - you need a fairly large room for that, if you want more than just a loop around the wall. From your other thread I know that you intend to have a peninsula type layout - that won´t work in the room of the size you have.
Ken, if you won't be running any brass, and know it for a fact, then anywhere upward of 24" is good. I have a folded loop for my essentially rail fan layout, and because I operate it from a central pit, I can stand and watch my trains inboard of end curves over 46" in radius. The trains look great. But, look what I have to do in order to achieve those curves!
You need to accurately draw up your available space with all the limits and barriers to access. Make a good copy and scan it so that you can doodle on the copies. Then, maybe with a minimum radius template made to scale out of card stock, or the cardboard in a cereal box, fiddle with some ideas.
For any space that is not a full 9' across, you aren't going to be able to have 40" and larger curves unless you stand inside the curve and the tracks go around you. Otherwise, you'll have to have a point-to-point or a helix, and we all know how helices swallow large mouths full of real estate.
I like using 3/4" masking tape laid out on the rug or the floor before I build the benchwork. I use a trammel or a string and tack with a known radius to get a good curve established. Once I see how the track plan works from birdseye level, I can spot where I can adjust things to improve or to conserve track laying effort and costs. There is nothing like standing in the middle of this array of masking tape and noting how it all looks from above. And, as you know from your statement above, being inboard of curves helps to cover up the tighter ones. So, if you would be happy settling on 26-30" curves, you would be in dream territory for many of us. You know how to lay good clean track now, so derailments on even tighter curves are a non-issue except when you have problems with an engine's or a car's wheel gauge, and this includes especially trains operating at speed.
I have that brass Selkirk on order, too, and I will have to re-lay much of my yard track since the minimums are 28". Walthers heavyweight passenger cars need 24" curves, or so they claim. I find them iffy on 26" curves. Is there a chance you might want to run longer passenger cars in the next three years? Then bear 28" in mind.
Crandell
I have a double mainline with radius curves of 30" and 32", and I can run 4-8-4's, 2-10-2's, and 2-10-4's quite nicely without derailments. All 6 axle diesels negotiate those curves as well.
I had less good fortune on my old layout with 22" and 24" radius curves.
I have never gone higher than 32" radius curves, but wouldn't 40" radius curves be just glorious?
Rich
Alton Junction
The best word I can use is "feasability". If you are able to get your big steam around that 18"r reliably, then great, thats the "MIN" you must have. Pushing up that radius to 30 or 36" might look awesome, but it doesn't do much good if all you can have on a penninsula is 48"wide. I would be more apt to try and hide any sharp curves but still leave them accessible for any "incidents". Even having full trees that are tall but still off the ROW can limit sight of the full curve and still leave room for the big-bear hand that will eventually need to get in there. My own planning will have some 18"r curves and even a turnback, but will be restricted for smaller engines that will handle it.
I would go at least 30" radius. I agree with Sheldon's minimums in your case.
There are many ways to deal with larger radii in track plans that can minimize their impact on the space. Get creative and use larger curves. Walk in design for one, the peninsula blob for another. Running tracks through a scene at an angle to the walls and fascia to permit larger curves in the corners etc.... Check out some of the track plans in the MR track plan data base for ideas.
Guy
see stuff at: the Willoughby Line Site
Layout Design SIG curve radius rules of thumb based on equipment length
Layout Design GalleryLayout Design Special Interest Group
I figure a model locomotive should be able to fit the same curvature as the prototype. So far in my research, the locos that I'm interested in and that needed the broadest curves were a UP 4-12-2 and their DD40AX. For them, an HO equivalent of 50" will do the job. Not for mainline speeds, of course; but still.......
Now, if you're going to run the PRR S-1, who knows????
It's a concept, anyway; and it explains why I went with a 48" mainline minimum radius--figuring that two inch difference really won't make a difference.
On the "downward" side, an Alco S1 would take, without cars, a 7" HO equivalent--an option I don't need to toy with.
Ed
cuyama Layout Design SIG curve radius rules of thumb based on equipment length
I'm in total agreement with Byron on this one. For an enjoyable layout, don't mess with less than 3X times longest car length for minimum radius. Then everything just works.
If I can get the room, I'll run 22" minimum radius which is 3X for 50ft passenger cars. 18" is feasible, but there's always one car or locomotive that causes me trouble when I dip below the 3X line in the sand.
Fred W
....modeling foggy coastal Oregon, where it's always 1900....
selector You need to accurately draw up your available space with all the limits and barriers to access. Make a good copy and scan it so that you can doodle on the copies. Then, maybe with a minimum radius template made to scale out of card stock, or the cardboard in a cereal box, fiddle with some ideas. Crandell
Guess what I just hooked up today Crandell? A scanner. My printer died so I bought a scanner / printer for that very reason.
I have three ways to go.
1 Work with the 19 X 20 foot area that I have currently and not move the desk
2 Knock down a 8 X 8 storage room and leave the desk where it is. (will only gain 5 in depth, need to leave a 3 foot walkway for breaker box.
3 Move the desk to the center of the layout and either have a tall layout with duck under or a lift up gate.
Here is the plan that Ulrich said would not work.
Now this is just a doddle, not my plain. The section that looks like a tonsils would be raised about 3 to 6 inches and all the turns are 36 inch radius. I don't off the top of my head see why Ulrich said it would not work? Do You? Each square is 1 foot.
Thanks again for all your time and effort.
Ulrich may be right. It depends on where the edges of your bench are. Remember, you need access and reach. You need places to stand and to do all the track laying, ballasting, scenicking, and later on the operations, including fixing derailments and reaching turnouts. As I see the outline above, if you can have aisles near 3' wide, and don't mind a central operating pit, the only worry I have is how you would reach the stuff in the upper right quarter of your diagram. Reaching into the lower right quarter won't be a problem with the tracks pulled close to the central pit (as it seems to be), but you have a ton of space behind, tucked into that lower right corner, and I don't know what you would do with it...a huge mountainside?
The other concern I have is with the close proximity of two levels of tracks. I have done this little experiment with my current layout....it won't be something I repeat. Close-set tracks with vertical separations mean retaining walls or unrealistic rock faces and such. Since the diagram above shows a couple of cross-over points, keep in mind the grades and the transitions into/out of them.
Ken:
I take it that this is going to be a garage layout like your present one? If you're lucky enough to entail using the entire garage, say 24x24' or close to it, 30" to 36" radius should give you plenty of good radii plus lots of operating space. My Yuba River sub is about 24x24', and my minimum radius is 34", maximum 36". In my case, of course, it's to handle all of the large-wheelbase brass Rio Grande locos I've been collecting, but even a brass 2-10-2 can negotiate a 30-32" radius with not much problem, and actually, my big brass articulateds have no problem with even a 28" radius because of their articulation (with a HUGE boiler overhang, of course!).
The Sub is built with a non-parallel double-track mainline based somewhat on the old SP Donner Pass route--the original line was built in the 1860's, and the 'newer' second track on an easier gradient was installed later in the early 20th Century. In certain spots, the two mainlines parallel and even cross each other at various elevations, so there's a lot of cuts and rockworks that seperate the two main lines, just as on the prototype.
So if you're running big articulateds--at least the current ones that have the non-prototypical 'double' articulation, I would think that you'd be okay with a 30" or 32" minimum radius and still have a lot of running room. They won't look TOO 'unprototypical' because of that double hinge under the driver sets. However, if you're going to be running a lot of current 85 or 89' rolling stock, you'd probably be better off thinking in terms of at least a 34" minimum. Even my 85" Pullman Standard passenger cars look a little weird on the two or three sections of my 34" radius--but look much better on my 36".
Just my thoughts. Oh,and the wider the radius on a grade, the less chance you have of 'stringling' a long train going up.
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!
I agree with many of the others. The best compromise is around 30. We have some 28" radius at the club that I have been able to get everything I own through. Other people have had trouble.
Personally I'm currently shooting for 44" as my minimum for mainline on the future permanent layout.
cudaken Here is the plan that Ulrich said would not work. Now this is just a doddle, not my [plan]. The section that looks like a tonsils would be raised about 3 to 6 inches and all the turns are 36 inch radius. I don't off the top of my head see why Ulrich said it would not work? Do You? Each square is 1 foot.
Now this is just a doddle, not my [plan]. The section that looks like a tonsils would be raised about 3 to 6 inches and all the turns are 36 inch radius. I don't off the top of my head see why Ulrich said it would not work? Do You? Each square is 1 foot.
Mmm - you should be able to in a peninsula with 36" radius curves (or 40" radius curves) and still maintain quite reasonable aisles in 19 x 20 foot of floor space. In the drawing below I have used 36" radius curves.
But the center of the peninsula (inside the orange "square" in the drawing below) will not be accessible from the aisles. In your drawing the upper and lower right hand corner won't be accessible either (at least not from inside the layout):
Smile, Stein
Ken´s idea would work, but it leaves some of the track too close to the wall for some nice scenery. There are also two spots where the aisles get a bit to narrow for my taste. A 2´ aisle is the absolute minimum, though not being really comfortable. Ken´s plan has also a part which is out of reach, unless you plan to put in some "man holes" - also not really a comfortable solution!
I bet that with all the combined knowledge we have here, Ken will be able to come up with a super plan for his new layout!
On my double track main, I prefer to have the track centers spaced 2" apart, so to make sure all equipment clears on curves (such as a N&W A on the inside curve and an 86' auto rack on the outside), the minimum radius is 42". Of course, all this has changed with the purchase of the Baldwin Centipedes.
Dave
Just be glad you don't have to press "2" for English.
http://www.youtube.com/watch?v=zQ_ALEdDUB8
http://www.youtube.com/watch?v=6hqFS1GZL4s
http://s73.photobucket.com/user/steemtrayn/media/MovingcoalontheDCM.mp4.html?sort=3&o=27
Always test! My previously layout has 30 and 32" curves but a 2" seperation on the curves did NOT work for full lenth 85' passenger cars. I had to bump it out a bit for them to properly clear.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Stein, Thank You for your drawing. I had thought of something like that my self. All so as i learn more using the RTS software my ideas will be coming clearer. On the last one posted the upper right hand section would have a duck under so I could reach it.
Here is what I was doodling on today This was based on the storage room being taken down.
I did some measurements today and found the old garage is not as big as I remembered. I had thought it was 28 X 20, but turns out it is only 26 X 19.
Thanks again for all of your interest and ideas.
cudaken Here is what I was doodling on today This was based on the storage room being taken down. I did some measurements today and found the old garage is not as big as I remembered. I had thought it was 28 X 20, but turns out it is only 26 X 19.
Let me suggest that you indicate (using lines on your drawing) where the edges of the benchwork will be, and that you draw your entire room, not just the layout part of it - that would make it a lot easier to estimate whether aisles are adequate, reaches not overly long and access seems sensible.
In your drawing above, there is no indication about e.g. you in the lower right hand corner are planning to have seven squares diagonal (ie about 9 feet - the diagonal of a foot square is about 1.4 feet) of scenery, or whether you plan to have the bench maybe 2 feet deep in this area, and have 5 feet of access aisle on the outside of your layout in this area.
Likewise, between your yard and your peninsula - ie a place where you are likely to spend some time, the aisle seems like it would be less than 2 feet across - ouch!