I forgot to get the important questions out there. since I’m new to N scale, what are the minimum radius curves for N scale? I want to get as tight as i can without causing operation problems (longest locos running- Kato SD80MAC, longest cars- amfleet passenger cars, 89’ tri-level autorack).
Second, since I’m builing a mountain railroad, I want my trains to climb actual grades, in a sense, i want my trains to actually “work” upgrade. Originally for HO, i wanted to have a 4% grade on the shorter east slope, and have a 3% on the longer west slope. are these gradients too much for the scale and/or length of trains i want to run over them? (since N scale gives me more room to stage and run trains, i want them to look realistic, and have anywhere from 20-40 cars) I heard that after a certain gradient %, you can supposably only run short trains, since they are the only ones that will make the grades. But i have no problem using my helpers and longer locomotive consists, which is planned in my layouts construction. I plan to have the higher grade east slope to have more curves, and also a loop, which ill get into later, while the west slope to have more straightaways and less dramatic curves. Just give me some imput on what gradients you recommend.
ps- a main reason of the desired 4% grade is to gain elevation quick, i want to have a two level layout, not with shelves, simply the higher level to be higher up on a mountain, the same as the lower level track is on. I didn’t want a helix, because i wanted my trains to be visible most of the time to be able to fix problems quickly.
You’ll need at least 11" radius just to get most of your equipment to operate, but the 89’ cars and 6-axle diesels might still have problems with binding in the curves. I’d go with 13"-15" as a bare minimum (obvously, the broader the better for both appearance and operation). I think 11" would be too troublesome.
Grades… If you want to pull 15-20 cars even with helpers, I think the best you’ll do is a 2% grade. Two locomotives could pull about 12 cars up a 3% grade on my old layout, but I was never happy with it, and they slowed down quite a bit. N scale engines don’t have as much heft as HO engines, so they typically pull less than the equivalent HO loco on the same grade. N scale cars weigh less too, but not by enough to match performance.
You can modify your engines by adding traction tires and additional weight (although these days N scale engines have little toom for additional weight) to help them pull.
thanks, and being that my grades might be cut in half, so you think that there is no other option than a helix to elevate trains to a higher level? I plan to have the shorter but steeper slope in the same general area, with lots of curves and a loop to gain the elevation, and let the lower grade slope go down around the walls 1 1/2 - times, or whatever it calls for.
My neighbor, Bob, has his layout in his two car garage. We’ve constructed scenes reminiscent of nothern Arkasas with some grades and a few tunnels.
The gradient is limited to 2% and the curves to 12" minimum.
There are several unit trains that run on the layout, the most impressive is a 44 car unit coal train. It needs three Kato SD90s to pull the consist up the hill.
I’d recommend staying closer to 15" radius curves for your minimum. The long wheelbase of the SD80s will deal better with it and look alot better too.
Below are three pictures of the coal train climbing the hill. I’m pretty proud of the trestle, it was my first scratch build project on Bob’s railroad.
Do you have a track plan that you can post? It will be much easier to figure out the helix issue if we had something to look at.
Warning: These are only my opinions and experiences. Others opinions and experiences may vary. [:D]
As to your original question, like Dave said, it all depends, but try to use the largest possible radius you can. If I had to design my N scale layout over again, I would pick an HO scale track plan and convert it to N but keep the same minimum radius. 18" in HO is rather small but it’s broad in N scale. Your SD80MAC has the ability to run on a 9¾" radius, but it won’t look pretty. For your auto racks and passenger cars the minimum operating radius would be around 11" but in order to look decent you’d probably want to keep it above 18" My SD70M looks okay on a 15" curve, but there is still more overhand than I’d like.
For your grades try to keep them at or below 2%, especially if you want to run 40 car trains. In my opinion 2.5% is pushing the limits, and 3% is too much. There are many variables when it comes to how steep of a grade a train can handle. Metal vs. plastic wheel sets, proper car weight, and locos with or without traction tires are a few that come to mind. Again, it one of those “it depends” questions. Good luck!
My N scale Kato Santa Fe diesel derails every time it comes to an Atlas 11 1/2" radius. I think 13" radius would be my minimum. My Atlas diesels are ok with it, but they are a bit tight. One of my small steams doesnt like them either. I have grades as steep as 6% (don’t do it unless you just want to watch them try, I have another way around this entertaining grade). Straight track 4% and curved track 3% which is ok if you consist. My two atlas engines can pull about 20 cars up these grades. Running singly, about 10 cars. My best small steam can pull about 5 cars up these grades. My 2% grade is better, but compromises had to be made. I am ok with straight track 4% and 15" curves at 3". My track work is only so-so. This is my first flex track/ballasted setup, so I made some mistakes. Biggest mistake was using those Atlas 11 1/2" fixed curves in three places. Stick with the 19" curve or 14" fixed if you can find it. The fixed curves do help you, I use fixed curves whenever I am going on a curve from a switch. Works better than trying to do curved flex right to a switch, which stresses the track.
I think most would be ok with 3% grades if we dont mind consist. 4% might work out, but it’s risky. 2% for the guy who wants to be sure. 12" curves might work out, 13 1/2 is better, 15" for the guy who wants to be sure. I think with thos long cars, you should stick with 15" or even less if you can. You might buy some plug together track and some Woodland scenic risers and do some experimentation.
did you say that you built that tressle yourself? haha, I don’t think I’ll ever be in the posistion where I can ever pull off something like that from scratch! Great Job!
Trains like that unit train is the type of railroading I envision on my layout, big power, big consists, long trains! Just curious, are those Bethgon Coalporters on that unit train? I had a set of NS and CSX in back in HO, and those are the cars I want to use for my unit trains in N scale. If you have any idea how much money goes into buying enough sets to run unit trains like that, please let me know if you know the cost!
How are the speeds of that train, or other trains of that length on the 2% grade? Thats the one thing that does not matter to me, I have no problem with long trains like that dragging slowly upgrade, but I want to know if you have to keep your speeds under a certain level before problems arise (I don’t mean speeds that are in the “obvious unrealistic insanly fast” category).
All but eight of the cars on that coal train are Deluxe Innovations. To be honest, I don’t know if they’re Bethgons or not. The other eight are Kato Bethgons.
As far as the trestle is concerned, It wasn’t my first attempt, building a template for the bents makes it alot easier to reproduce the shapes.
Here’s a wider shot of it. It’s a double track trestle on a 2% grade. The second track is a passing siding that feeds a paper mill on the other side of the scene divider. The track behind the trestle, with the retaining wall, is the down grade after the train passes the paper mill.
Here’s a view up the grade.
Mike, none of this happens over night. Set a plan for what you want to accomplish and lay the track. Details will follow.
I would NOT recommend the tightest curves for anything other than industrial area street track-age.
That said the tightest radius available commercially is 9" radius and you can get points and crossings that tight as well given that you are using I assume US outline trains forget nine inch curves.
When it gets that tight set track becomes the best option and is a bit harder to get get good track work.
you can use the same grades in N as you can HO but 4% is getting a bit steep.
The NMRA’s recommended practice for curve radii for specified types of cars calls for curves to be three times the length of the longest car which that curve will be called upon to handle. In your case that is your 89 foot autoracks. Three times 89 equals 267 feet which boils down to a little greater than 20 inches. Remember this is recommended and is offered as a figure designed to insure operational reliability as well as cosmetic appearance. These cars will operate on - but look a little bit strained doing it - on two times length or 178 feet or 13 3/8 inches. You could probably even come down to 12 inches but I would only come smaller than that if I were going to run my railroad in the dark which is the only way I could stand to look at them.
Now, lets tackle the subject of grades.
In HO Scale - I know we are talking N Scale but I need to make a point about grades and HO Scale is a very good place to make this point - it takes 300 inches to climb 12 inches on a 4% grade. Whether you realize it or not that 300 inches is only a fraction above 4/10ths of a mile. That’s only about 43 × 50 foot freight cars, a relatively short train in HO Scale. If you had room to climb 24 inches you could do that in 600 inches and that is 87 × 50 foot cars, a more prototypically length train. How many HO Scalers, however, have room for that 600 inch climb???
In N Scale that 12 inches boils down to 80 cars and the 24 inches boils down to 160 cars and those are considerable length trains in N Scale. Looking at this from a more practical way you only need 163 inches and a climb of 6 1/2 inches to give that 43 car long train. The 87 car train requires a 326 long grade and a climb of 13 inches. Even an N Scaler, however, may have a little difficulty finding room for a 300 inch climb.
We usually let it crawl up the grade just so it looks good, but it could climb that hill much faster. We haven’t experienced any issues at all related to speed.
I have Kato 12 3/8" Radius curves and Kato passenger cars. The Business car and the coaches have too much overhang but they will go through okay. No problems with the baggage car, But the diner car derails every time. The diner car and coaches are about the same length but the diner has more skirting so the trucks won’t swivel sharp enough. All couplers are truck mounted.
