My apologies for the cross-post from the Atlas forum. I am interested in any additional feedback. So far the comments have tended towards don't do grades on the mainline. I'm surprised at this, given some of the layouts I have seen in magazines (specific reference below) and the fact that the prototype (at least where I live) tends to have a few grades to contend with. Anyway, on with the re-post: I have just finished completing a layout room in a corner of our basement. I was able to maintain a space slightly larger than 10ft x 10ft while fending off all the usual competing family demands. I have also been able to setup the door so that it opens into a hallway rather than into the room. So, it is layout planning and benchwork construction time! My interests lean towards the CPR in the mountains. I would like to be able to run up to 20 car trains (MT trucks) using 2 (maybe 3 at the most) locomotives (likely C630, SD40-2, etc.) with a focus on mainline operations (minimal, if any, switching). I would also like to have hidden staging so that a train enters and leaves the scene. For a trackplan, I have landed on what is effectively three turns around the room and a single peninsula climbing and descending from a summit. Working this into the space available means 3% grades and a minimum radius of around 15" (a pair of hidden turnbacks) with the visible curves around a minimum of 24" radius. This lets me have a base height of 48" for the benchwork (staging level), a base height of 54" for the lowest visible track climbing to a maximum of 66" at the summit of the "pass". It also provides what think is a pretty decent mainline length given the size of the room. The starting point for my design was a layout concept published in the Nov. 2003 MR by Bernard Kempinski - "N Scale Mountain Action". This layout using 3% grades to what appears to be good effect. Recognizing that I don't have as much space, I thought the approach had a lot going for it. Bernard does mention that he completed the initial trackwork for this layout and that he was happy with the result. Any thoughts on this? Am I being too ambitious with the combination of grades, radius and train length? What grades have you got on your layout? And what has the experiance been? Looking forward to your input! Fred.
Real railroads have grades .. the model can also .. try to stay below 2% .. and try not to have a grade more than 1% in a curve .. those are my rules of thumb .. The flat earth folks don't know what they are missing
Hi Fred, and welcome to Trainboard. I have a 2.75% ruling grade around a 24" radius curve. I've pulled a 45-car train up and around it. My biggest problem is not engines stalling, but couplers pulling apart or, with lighter cars, "clotheslining" the curve. The clotheslining is perhaps caused because the track is not level side-to-side--it's obviously not level on the grade! I don't have this problem on 2% grades. Quite frankly, I made a geometry mistake laying out the section with the 2.75 grade. My layout is on three decks, so I'm not too ashamed of making one mistake. The general rule is that curves add to the grade. At 15 inches, I'd guess that's about a 50% addition--it may be less, but I'm always conservative. Two 630s will probably pull 20 cars up what is now an effective 4.5 percent grade. There are tables somewhere that guesstimate the effect of grade and curves, and I hope someone here at Trainboard can point you to them, as I'm not able to find them at this time. My own coupler breaking problem is due to early Accumates, which I'm swapping out for MTs as time permits.
A 20 car train with 2 to 3 diesel type locos perhaps one of which is mid-train can "manage" a 3 percent grade. But: There are many problems associated with steeper grades Some of these include: String-lining around curves Higher derailment rate especially at turnouts and imperfect track The probability of a runaway train goes up The consequences of a runaway train go up There are more reasons. Those are the ones I learned the hard way.
Thanks for the insight Pete - I would certainly be interested in seeing those tables. Interesting point on the clotheslining, I know some other modellers have superelevated curves. Is this mainly for esthetics or would it actually help? I think I will also have a look at broadening the curves on the plan. It sounds like it is the tighter radius where I am more likely to have an issue. Unfortunately reducing the grade is probably not an option although I suppose an altenative could be too reduce in the area around the tighter curves.
Actually, my problem is too much superelevation. The cause? About 18 months ago, I fell onto that section of layout. My benchwork is very lightweight--mostly foam board used like plywood. So that section was probably pushed down a bit. I'll jack it up in the near future. But the clotheslining happens only to a long string of Bowser hoppers, which had been my "demo" train. I'm putting together another demo train tonight.
Compensating grades for curvature . Maximum grades on access lines will be compensated 0 .04 percent per degree of curvature .
ABBA diesel sets (Intermountain F's, ER Sharknoses, Life Like FA's) and Life Like AA sets (PA's) have no difficulty pulling 30 car trains up 3% 18" radius grades on my layout. Kato Mike's and the Bachmann Heavy Mountain will pull 15 cars up the same grades. My old HO layout was "flat earth" and didn't have near the visual impact that my graded N scale layout has. I would think 20 cars and three diesels would be fine on your layout. I might add though that all my rolling stock has low profile metal wheels for the code 55 track.
If you're into 'big iron' like Kato SD45's, C30-7's, Kato & Intermountain F-units, and some of the other good pullers - you'll have very little issue. I run 25-30 car trains up and around 2.5% grades with 13" curves, usually 2-3 units. But new units with light frames, like the Atlas GP38's, have very low tractive effort. If you've got a big fleet of Atlas newer diesels, think again.... I'd try to hold no more than 1.5% with those or with most N steam. There's a huge difference. I like grades, for the scenic impacts, and for the operational challenges. It's nice to see a train really dig in, and to have to 'work' a heavy train around a layout. Flat is boring. It's not a simple answer. You can't equate pulling power with prototype pulling power, or with axles. Appearance may be across the board good to excellent, but man alive, the difference at the drawbar these days can be apalling. The Atlas C628 and C630 pull less than an Atlas Classic GP7 from ten years ago.
Fred, grades are wonderful to make operating a layout more challenging. You can simulate railroad activity like adding helpers, doubling the hill or reducing tonnage and sending two trains over the mountain instead of one. All this adds excitement to the operation. A few things that worked well for me (or I wish I had done): Keep the ruling grade (adjusted for curvature) on the visible and easy to access portion of the railroad. Mine is in the hidden helix, so it falls in the "wish I had done differently" category) Use a constant minimum radius in the visible and hidden part, otherwise the hidden portion will cause the derailments on long-wheelbased engines (not so much an issue with diesels...) What goes up must come down: Getting up a hill is a matter of piling up more engines until they get the job done. But getting a train downhill can be a different matter: The first cars will sustain a tremendous amount of "push". I have neaver measured the effort to manually hold a train on my 2.25% grades, but it is substantial. Sometimes lighter cars are derailed and pushed over the outside curve by the weight of the following train. This can be mitigated by operating rules (nerver put a Intermountain woodchip gondola in the first spot on a 30 car train: It will jump out like a toast from the toaster) or by putting helpers at the rear of the train to help breaking it. I have also seen small springs on caboose axles serving as a break, but this increases drag going uphill again. I would avoid anything over 2% if I would build again.... If you model a mountain road have a "signature" hill where all really heavy trains require a helper, but a passenger or fast freight (with a higher horsepower to weight ratio) can make it. This will allow you to simply "run a train" if the mood strikes whilst offering the challenge to coordinate the move of a heavy train over the mountain as part of your operating scheme. For my ops team the highlight of each ops session is adding two 2-8-8-2 helpers to a drag freight to lift it up Stampede Pass.... But first and foremost: It is your railroad, so enjoy it and have fun with it!! Cheers Dirk
One thing about the Atlas GP38s - They make great mid train units even for DC. Due to the lack of tractive effort they are just enough to reduce the drag but not so much that they will push cars off if the lead units stop. I have used them on 6% grades. Note: This may take some trial and error before you find the right balence. It may require putting heavier cars in front with lighter cars in the rear. In general people will tell you this is not a good or safe practice. I learned it by accident when I forgot to remove the loco and I was amazed at the Atlas SD60 hauling 20 cars up a 6 percent grade around a curve.
Being a mountain grade Locomotive Engineer, and a renegade modeler, I'll share my story... When I graduated from "table top" layouts, I decided I wanted to run 25-30 car trains, big SD's, helpers etc... I built the layout in two sections, the original section was a loop/spaghetti bowl that featured a 12" min. radius(ex HO'er). Leaving the yard one direction, the grade stepped up anywhere between 1 and 3%. Moderate climb, 25 cars with two units worked just fine. The other direction featured a grueling 5 feet of 5.5%:tb-shocked: then stepped down to about 1.5% to the summit. 25 cars with two units did not work... Had fun with this for a while, then I got tired of the loop and decided to expand..... A double deck, "L" shaped expansion that featured an ovular helix... The "engineering marvel" as I called it... You came out of the yard on the lower level, turned down the short leg of the "L" then started up a 4% grade entering the helix. 1 3/4 turns. The grade lowered to 2.5% for the first 3/4, then returned to 4% for the last turn. The whole time maintaining 12-13" radius curves...... At the top, the grade leveled off until the "junction" with the old half of the layout. It worked fine for a few years, then all the headaches with broken solder joints and kinks etc... took it's toll:tb-sad: My advice, keep you grades below 3% and curves above 18" radius. This will give the operations you are looking for and save you from a lot of headaches...
Second Note: Despite the above post I agree with the consensus here. Don't exceed 2% unless you are willing to deal with the potential issues. Yes - I exceeded it using GP38s. It took a lot of what some would call aggravation / frustration. I enjoyed it but that is me. Oh, but I now have a _flat_ layout soooo, I did't enjoy it for that long.
My layout is one really LONG 2% grade. The helix (rises 9.5") is all 2%, and another 40-50' is modeled on a 2% grade. My prototype is a 50-mile 2% grade. Build your curves gently, stick to your minimum radius, and use easements. Compensate for tight curves on a grade, and solder your curves.
cpr fan: 20-car trains + 3% grade + 15" radius = not going to work You can easily have any two of these things without the other, but all three in combination is going to cause stringlining (aka clotheslining), even if you are real careful with your trackwork and weighting of cars. Avoiding it will require extra extra diligence and work. That's been my experience. On my first layout I had a 15" radius, one level helix type arrangement. I could pull a 12 car train up this grade, but not a 20 car train. It would pull the middle of the train off the tracks. At the club where I run now, it's sometimes a struggle to pull a 20 car train up the 2%+ grade with an 18" or greater radius and easements. Of course, that's usually because rolling stock hasn't been properly maintained or weighted, but still.... The point is, give yourself some room to work with, so you don't have to tinker non-stop with your rolling stock to avoid derailments. Taking your 20 car limit as given, I'd say no greater than 2% grade max with 15" radius. If your radius is over, say, 21" you could safely increase the grade above 2%. Come to think of it, I'd say a good rule of thumb might be "no more than one percent grade per 10 inches of radius" in any given spot. e.g. 20" radius can have 2% grade, 25" can have 2.5%, etc. Of course don't want to go over 3% grade anywhere, really.
This is a great thread for anecdotal information. It is good data and clearly points to what will and will not work. It would be nice to have empirical data, but that might have to be scale specific. Thanks to those who have posted. Also, I am surprised at how many people have experience with grades like this. (My layout is completely flat. Too much NTrak, I guess. I do like the operation, though.)
