Hi Y'all, I have a question surrounding the center lines of parallel tracks running around curves. The NMRA says that the minimum for centerlines on curves is 2 1/2 inches. Now I am designing a wide loop with 30 and 28 inch radius curves. Problem is, I can only get 2 inch centers, not 2 1/2 inch centers. I must admit that this is my first time with working with NMRA standards. How do I fix this? Do you run 30 and 26? or 32 and 28's? Thanks for putting up with my stupid question. Manny SABRR, Chief Cook and Bottle Washer
22 views and no ideas? Will someone help me out so I avoid making a major mistake in planning? Thanks!
Manny - this is not a stupid question: We are all here for each other. As I don't write very many posts, I thought I'd better contribute something here. I hope this isn't a stupid answer! You might be confusing spacing between the tracks, rather than spacing between the center-line of the two tracks. If you want to stay with the NMRA formula, you could go 27-1/2" and 30", for example. I believe (could be wrong) the emphasis is on centers: the distance between the center of each track. An old trick in model railroading: the nail, string, and pencil to draw your center lines for the curves. If you tie a nail to one end of the string (which will be your center point), then measure out the distance of your radius (ex. 27-1/2"), then tie your pencil onto the string at the end of this distance. You can draw your center line on your curves. Repeat the same steps and increase the string length by 2-1/2". You can then draw your next center-line. I hope this helps answer your question. I am not a master model railroader - maybe someday. There are a bunch of very talented modelers, on this site, which I can attest to. Just thought I'd take a stab and let others rest their fingers. If I'm ridiculously off base, everyone, please let me know! Bob McKeighan Lenexa, KS
Hey Bob, Thank you so much for your response. I thought about that very method. What I'm concerned is that if I do that on the tables, the computer layout I make will not work any longer since it is designed by 30 and 28 radius instead of the 27 1/2. I'm using Anyrail v. 4.8 and am using Fast Tracks as I intend to hand lay my trackage. I've always wanted to do this. My problem comes in with things like double cross overs, where the straight track have 2" center lines. Maybe I just need to learn how to manipulate the software through the usage of easements to properly align the track. I do realize that hand laying rail will give me the ability to "fudge" any type of shortage or misalignment. I know this happen on the real rails a lot. I've been over rails you swore the train would never negotiate. Your response was no where near stupid. Thank you so much for posting up. Hopefully some of the Frisco experts here will chime in and will help out. Thanks! Manny SABRR The Texas Road...Ship it on the LONE STAR ROUTE!
Here is a picture of the West Wing of the SABRR that I am putting together. You can see the main line wraps around the roundhouse engine facility. The engine facility will enter into the yard through the two leads and can access the mainlines or can run through to the East end of San Antonio Yard. You can see my concern about the double main line loop around the roundhouse. I need to make sure that 40' freight and 60' passenger cars can negotiate. The largest engine will be either a 4-8-2 or a possible 2-6-6-2 or 2-8-8-2. I haven't finished the engine facility or the East end of the yard. I wanted to get your thoughts at this point. Thanks! Manny SABRR The Texas Road...Ship it on the LONE STAR ROUTE!
Are you saying that the 2"-centers is a limitation of your software, or do you need 2"-centers for your, perhaps commercially built, scissors cross-overs?
Fast tracks double crossover's are 2" centers between adjacent rails. This is per NMRA standards. My problem is when I take straight sections into the curve, all the curve manufacturers' keep even numbered radii. Now I know that with Fast Tracks you make your own curves, however, their templates are still based on an "even" radii platform. So how do you make a 28" radii inner curve, evenly spaced at 2 1/2" when the outer is 30" radii and only a difference of 2". That doesn't seem to work. I hope I didn't confuse you.
You guys are more scientific about this than I am. I made my double mains on 18 ft centers (about 2.25 inches) based on BN practices I learned from a KC friend. I made a radius tool out of a 3 ft aluminum rule ($10 or less) I got at Home depot by drilling holes in it (for the pencil) for 30",31" and 32" radii. I have never had a issue with clearances on my double main or the double main curves. PS I run 89' TOFC flats and 85' passenger cars (not together) and they look pretty good on the 30-32" radii.
So Rick, are you saying that with 2" centers you have no problem in negotiating trains around the curves with 89' TOFC and there is no collision/side swipes? If so, then why the heck would NMRA say it's supposed to be 2 1/2" ctc? That's not right on their behalf.
Manny, it is important to note that Rick is describing the relationship on 30"+ radius turns. Don't forget the use of transition radius track entering a fixed radius curve (some railroaders will call the curve a spiral curve, referring to the changing (decreasing) radius from a straight into the main part of a curve. Flextrack will naturally assume this transition curve if you don't force the section between straight track and a given radius. This transition section will allow you to widen or tighten the spacing between tracks.
Hey Manny - I think you can take some good advise from all of these posts - especially Keith's below. Suggestion: incorporate the transitions like Keith recommends. These are really important, especially if you have lengthy rolling stock and locomotives. Start your outside curve about one-half inch, or so, further out than the inside curve. This should quickly increase your centers to 2-1/2", so that you can adhere to the standards and avoid side swipes. As you complete the curve, and repeat what you did at the beginning, you should be back to the 2" center spacings for crossovers, etc. This might be difficult to replicate with your software, however you will know what you'll actually do with the curves, once you've played with them a little. Are you going to super-elevate your curves? Bob
Thanks for the great response Bob, Yes, I'm going to learn how to include easements, just like the real railroads do. The software allows easements. I just need to learn how to do them. As for super-elevating, I forgot all about that. I need to learn how to do that in HO scale. I think it will add realism and will help the trains roll through the curves better. Most curves on the mainlines will remain around the 26-32" radii. If I can go higher I will. Yards and branchlines will see tighter curves since they wouldn't have larger than a 2-10-0 Russian move through them. I appreciate the help guys. I have to learn this stuff all over again.
For super-elevation on the radii that you are talking about, think about elevating the outside end of the ties about half the thickness of a matchstick (for visualization). There are better, more accurate values out there, I just can't pull them out of the grey matter right now.
Manny - I just checked a couple of sites out, as I Googled: super elevation. I discovered one particular site that's very straight forward and talks about both easements and super elevation. Here is the link: http://modeltrains.about.com/od/layoutconstruction/ss/easements.htm The techniques described here seem like they are easy to use. Hope this helps you out. Keep us posted on your development of curves. It's fun to see layouts develop from plan, to construction, to their reality! If you can, please take photos, so we can share in your enthusiasm. Take care and have fun! Bob
For super elevation I simply put Kappler wood ties under most of the curved part of a major turn in the track. The transition section of the flex track floats until I can ballast it. I have not had any derailment issues and a lot of operators like the way a train looks when it leans into the curve. The HO flex track system is very forgiving from an engineering perspective and very easy for the novice (me) to use. It also speeds time to operations and the code 83 track from Atlas looks pretty good.
Thanks for all the info guys. I really appreciate it. I'm continuing to work on the ideas for the railroad. One small obstacle I am dealing with is that I will be moving in about 3 months into a new place. I'm hoping for a home rather than an apartment. If I can secure a 2 car garage, I may set the layout up inside the garage. If not, it will get the largest room. So for right now, I'm just simply throwing track plans together. I will super elevate the curves. I appreciate the push towards flex track, but I'm hooked on laying my own rail. I really want the added realism and I have always wanted to do it. I've discovered that there are so much more possibilities in terms of rail configurations with hand laid, vs. commercial made. No knock against commercial. I just want to do it a bit differently. That's all. No worries about lack of pictures. I love to take pictures and am a particular persuasion when it comes to pics. Read in between the lines... Thanks Y'all! Manny The Texas Road...Ship it on the LONE STAR ROUTE!
