Take a look at the chart, up at the top it indicates 30" Radius (not etched in granit). The grade rise at each point is in the chart too. Sorry about the resolution. for waht ever reason my adobe 11 decided it was too big to do a jpg so I had to do some odd stuff just to get it to print. I wish these sites would just take a download from the computer; life would be far better.
Thanks Jim!
Nick, thanks! I did try to expand the chart but was having difficulty reading on my screen. I think with 30-inches you should be fine. Above 30-inches it's more about appearance if anything - I was running some 89' autoracks around a 36-inch curve on one of my past layouts and even that looked visually sharp underneath those cars. About the same time, I visited a train show in Louisville KY and there were some autoracks rounding a modular layout curve and they looked pretty nice - I asked the guy what the curve radii was in that situation - as I recall they were around 56-inches! So you have to get pretty broad before curves look pretty under long cars. I've built one "scenic" curve of 56-inches into my current small layout just for the visual effect!
After reading so many articles with 30-inch minimums back in the day, I'm pretty surprised with how many folks are still going with tiny 18 and 22 inch curves. I can only assume it's because the 4x8' plywood board and sectional track is still the gateway for many new modelers, so they feel constrained to those limitations. I'm here to preach the "gospel" of broader radii!
Do yourself a favor and get a copy of John Armstrongs "Track Planning for Realistic Operation". It's a little long in the tooth but still an excellent primer for folks who are building a layout. It has been updated since I got my copy back in the 1980's. One of the best parts is the chapter on Minimums.
Even in my 30+ year old copy of the book, John Armstrong classified HO curves as: sharp = 18", conventional = 24" and broad = 30". That was the mind set of a an engineer and professional model layout designer of the 1970's. Personally I'd update that list for the 21 century and re-classify as: extremely sharp = 18", sharp = 24", conventional = 30" and broad = 36" for HO model railroad curves. Club layouts, of course, frequently us 42 or 48 inch mainline minimums.
I have gone with 32-inch minimum curves but in reality - I'm told the #8 curved turnouts inner radii while labeled by the manufacturer as 32-inches is really more like 28-inches, but all my flex track is laid out on 32-inch minimum center lines. I've got only a small 10x18' room so I'm going around the wall with a small twice around layout - will have to do for now.
Think of model curve radii like a flat screen TV. People will usually tell you whatever flat screen TV you think will be big enough, you'll usually wish you got a bigger one after you've started watching it in your living room! It's like that with trains too, if you think 24 inches is big enough, you'll wish you went with 30 inches later! Of course I know we all don't have air craft hangers to build layouts in but the truism still holds, bigger is always better for model train curves!
Looks like you are off to a good start!
Rio Grande. The Action Road - Focus 1977-1983
Doug is building another version last I heard. A group of us from the NMRA Michiana Division were some of the last to operate his Conrail layout before it was torn down.It was a blast!
Dan
Dannyboy6 Doug is building another version last I heard. A group of us from the NMRA Michiana Division were some of the last to operate his Conrail layout before it was torn down.It was a blast! Dan
Version of what, I hope he is back to D&RGW again! I've heard he tore down the excellent D&RGW that was in MR some years ago and built something else since, or maybe a couple somethings!
NickPPJR A 30" radius? Dang, that's a 5' circle. Will I need that much?
A 30" radius? Dang, that's a 5' circle. Will I need that much?
If you are running 85' brass pax cars, then yes, you will.
The truth is, you want all you can get.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
One thing about appearance of long cars and locos is that it being on the inside or outside of a curve makes a huge difference. Also ho wmuch of the curve is visible - ie, a bit 180 degree turn right there for all to see, or the same 180 degree curve that goes through sme cuts and/or tunnels, hiding portions of it.
There certainly are two parameters - curves big enough for reliable operation, and curves big enough to make it look good. Indeed most anything can get rhough a 30" radius curve without falling off the rails, but it may need 36" to actually look decent, depending on the viewing angle and how much of the curve is visible.
This was the subject of an article in one of the publications not too long ago, showing the view of different length cars from the inside of the curve, outside of the curve, and overhead. Just a few pictures fully makes the point.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
OK, listening and reading the expert commentary I have done a redesign of my Elevation process. I am below 2.5% so I think it should be good. Where 9a crosses over 2a, I have 5 -5/8" TOT to TOT. The intent is for this to be a valley and use a long bridge to do the overpass. Your continued thoughts are appreciated.
I have setteled in on an area of Pensylavania (Dad's old stomping grounds as a kid) Emporium, PA to Driftwood, PA. In contacting the Chamber of Commerece in Emporium, I found an old lost relative (Cousin) that works there (small world) and she has assisted me greatly.
Layout.
Roundhouse in Emporium. Gone now. Came to the ground in the 70's.
NickPPJR:
I like your elevation change solution a lot! Much more creative than a helix and pretty decent radii to boot, and it gets to be seen.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Thanks Dave! So, I rotated a portion of the elevation solution and added some more track along with an Altoon HairPin. Once the unit reaches top elevation there is a flat transition for about 6' and then it takes a dive and reaches 0.0 at the middle of the hairpin. The centersection will represent Emporium and have the roundhouse and other features (Undecided). The parallel track at the curve going out to the begining is the passenger station that was in Emporium. Nothing is etched in granite so feel free to show me my errors.
Looks interesting so far!
One point to consider is the reach in distances from the fascia to the track. The rear right corner looks like you are a bit over three feet to the rear track. If you are planning on putting any switches back there you won't be able to reach them from the aisle. Even just a simple derailment on the curve will present a challenge.
There are several means of overcoming the problem so you don't have to change the track arrangement. For example, you can work an access hatch into the bench work, or you can get specially designed ladders that allow you to lean in over the layout without having to touch the layout itself.
If you want to be able to reach in directly then 30" is considered a stretch for most people, depending on how tall you are and how high the bench work is.
It should be noted that lots of great layouts have been built without regard to the reach in issue.
Thanks Dave! Good info.
Added some more. Corner of concern now has access.