Grades and level clearance help

Model Railroader Layouts and layout building
1

Hi Everybody

I’m in the process of designing a N scale layout, I’m in a pretty limited space so I decided to go with a freelance design, meant to replicate prototype operations. It’s a walk-in 8x8 layout, so it’s fairly restricted in terms of actual mainline running space. To amend this, I decided to add multiple levels that loop around the logical left and back sides.

This brings me to my 2 questions.

First Question:

how steep is too steep when dealing with tight curves? I’ve made sure that I don’t have any grades beyond 2%, but several of those 2% grades are on 16" radius curves. Most of my trains are pretty short (7-10 cars with one (newish) engine), but I also want to run a few 25-35 car trains with more powerful engines. The engines I will be using for these longer trains are as follows: The BLI T1 duplex, the SP daylight GS-4, The Bachmann EM-1, The Athearn Bigboy/challenger, and a pair of Kato GG1’s. Will those engines be up to the task of hauling long trains up sections that are both steep and tight?

Second Question:

What is the recommended distance between levels?, one of my levels is accessed with a Helix so that’s not hard to deal with, but the other is achieved via inclined track, so it’s not that far off the previous level (it’s tucked in the back so it doesn’t get in the way, but it’s still only raised about 6") which is why I’m worried. I have several areas that I could make into incline track in order to help, but I don’t really want to if I don’t have to.

As a new modeler, I really appreciate the help.

2

I haven’t done much with N but I did have a N GS4 and it preformed pretty good on a 16” radius. In comparison 16” in N would be about the same as 30” at HO. I have a 30” radius helix on my HO layout and the stock out of the box HO locomotive won’t pull many cars up my 3½% grade of my helix but do pretty good on straight grades.

I built a 4’x 8’ N layout with my grandson and the GS4 did pretty good on his 2¼% grade.

If you have a locomotive I would see how it does on a test grade. I bought a hanging postal meter to check the locomotive drawbar.

Most of my stock locomotives out of the box didn’t have much drawbar. I remotored them with more powerful rare earth magnet motors then add as much weight as I can to increase the drawbar, typically doubles to tripling the drawbar. The original motors overheat with added weight.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

3

I’ve found NMRA web pages handy for this type of question.

Here’s a good start point for your issues:

https://www.nmra.org/clearance-and-grade

4

Different locomotives will behave differently in different conditions. What works for a T1 (is this the N Scale Duplex) trailing five or six heavyweights on Buddy’s “2%” grade (his claims) will only approximate your results, your particular version of the same engine, your cars, your ‘2%.’ That is to say, relying on anecdotal evidence is fraught with iffyness, and quite possibly the forehead slap and “D’Oh!!”

Many of us advise mocking up the conditions you druther, the way you craft them, and then try your own stuff to see how well it works and where the limits are.

I model in HO, so I can’t speak knowledgeably about N Scale. However, 16" curves seem somewhat generous, all things considered, and if you aren’t trailing a lot of ‘tonnage’ that wants to stringline about three cars after the tender, 2" grades are probably going to be quite forgiving. I’d test, though, as I suggested above. Nothing like empirical information.

You have 1:1 fingers, and they have to fit between layers to extract jammed/derailed items where tracks run parallel in layers. A simple overhead is one thing, normally a single car deep, but a helix is an entire train…usually. Your 6" is okay for the forearm and reaching hand, but how will you get the rest of your body into position for that reach? Something to be aware of.

As a general rule, and I’m one to spout it…'cuz I learned why it’s a rule…hidden trackage, or hard to reach trackage, is what will throw a ton of cold water on your train enjoyment. It’s where the lion’s share of troubles will eventually take place as things age, settle, or shift, …did I say I found all this out the hard way?

Another hour, today, spent figuring out how to keep things easily reached, with good clearances in all directions, will be worthwhile before you commit to a track plan that looked like a great idea, but that tur

5

RR_Mel, thanks for the help across several of my posts.

Do you happen to have a link to how to swap the motor.? I saw you mention that you swapped your motors on another forum question, but I couldn’t find any explanation of how to do so online. Swapping the motor doesn’t seem that hard but I would think that the increased amperage draw might be an issue if done incorrectly.

6

I haven’t done a remotor in an N locomotive, finding a small Neodymium magnet motor could be a problem. The rare earth motors draw about ¼ the current as an Alco magnet motor with twice or more power, for all I know the newer N locomotives come with them.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

7

I have a 2% grade on my N Scale, coming off a 24" radius.

I have a Kato which will pull 12 cars up without a problem. However, I now run that train with two Katos in consist. I have no doubt they would pull a lot more than 12 cars through the turn and up the grade with no issues.

Other brands of locos – I don’t know.

8

I suppose my initial post wasn’t clear, the thing that’s 6" above my main level is my second level, not a helix. It creeps around the back in a straight line and then turns around and goes back the way it came.

The reason that it’s only an 8x8 layout is that it’s going into my bedroom, not a spare room, but my fully-occupied bedroom. Because it’s inside a living space, its surrounded on most sides by walkways or relatively short furniture. Due to that fact, both of my helixes, and all of my deeper areas are directly reachable. About 75% of my track is less than 6" away from any given side, and the rest is less than 20". No finger jamming is necessary, I made sure of it :slight_smile: Plus, I’m only 15, so I’m still rather bendy if it really came to it.

I was more thinking about it from a visibility perspective. my upper-level track loops around and over a major section of my main level track, I have it so that the elevated level is recessed by about 3" inward from my main track, but with only 6" of vertical clearance, I’m not sure if it’s enough.

9

can I ask which Kato/what type of cars?

10

I have an E9 A&B in consist pulling 11 cars of the City of Los Angeles.

I have two GE C44-9Ws in consist pulling 12 intermodal cars, each car with two containers.

The only reason I keep the number at 12 is that my small layout doesn’t have a siding long enough to fit more, and I have several other trains I also run. I have had 15 intermodal cars on it, and the two locomotives move without any noticeable effort around the curve onto the grade.

I have run both those trains with only one locomotive, and they moved up the grade easily.

11

Well, that’s good news for me, my GS-4 will be running a similar number of passenger cars so I can check that off the list.

And my GG1’s will be pulling 50’ boxcars/flat cars, which, since they’re smaller, should mean that I’m covered on that front as well. Maybe I could even get away with 30ish box cars between my two engines. Especially since the Kato GG1s are some of the better pulling engines made currently…

Thanks so much for your reply!

12

Okay, I got it, and thanks for the clarification. Sometimes you have to live with what fits and what works. For your parameters, 6" difference in height will have to be ‘it’. Will you like it in the long run? Probably not. It depends on how you mask, conceal, deceive the eye with hedgerows, tunnels, bridges, trees, anything that breaks up the lines of the two tracks running just a few inches apart. I have done this, and it takes some thinking…otherwise you just have two nested ovals or loops of some fashion, with trains running a few scant inches above and below…sort of the old spaghetti bowl problem.

On my second layout, which was a ‘folded loop’ configuration, and had me in a central operating pit watching the trains run around me, close to the walls, I had about 8.5" of height disparity, and the illusion of a large real world worked only if only one train passed in front of me at a time. This is in HO.

With the camera down on the main level, the effect wasn’t so bad (IMO), but standing over it all was a different matter:

13

there’s also the effective grade of a curve. looks like the rule of thumb for n-scale is 17.5 / radius. so a 16" radius adds an additional ~1%.

14

Greg

When I did the effective grade on my helix it became obvious why my Cab Forwards have wheel slip going up my helix. The actual grade is 3.55% but the effective grade is 4.6%. The opposite grade (non helix) is 3.86% with one large radius curve and none of my locomotives have wheel slip on it.

Edit:

Most of my Cab Forwards have good traction with good drawbar at 5.8 oz or more. Most of my diesels have over 10 oz of drawbar each so no problem on the 4.6% grade, I normally run them in pairs too so plenty of power. If something down stream hangs up with a pair of E7s it’s disaster.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

15

When calculating grades, many folks forget to allow for the length of track needed for a transition from level-to-grade and also that they must avoid changing grade within, or too close to, a turnout. Once these practicalities are considered, grades may be shorter, and thus steeper, than they hope. Just something to keep in mind.

16

I designed and built my layout in the late 1980s without any thought to the consequences of a curved grade. I simply laid out 1x6x96 board with straight track and played around with the angle of the dangle. I filled the track with cars and a 4-8-4 then figured out where the wheels slipped. That became my starting point.

The 4-8-4 was a Bowser and the cars were out of the box freight cars. The slope where the Bowser went into wheel slip was at 4” or 3.8% so I went with a 3½% grade for my layout, without any thought about curves. That was an error however due to space limitation I couldn’t reduce the percentage anyway. Over the years I learned to live with the steep grade.

The real difference became adding weight to my locomotives for added traction. Quite by accident I discovered the super powerful Neodymium magnet motors. I bought a Canon EN22 motor from BGMicro Electronics for $1.19, when I found out what I had I ordered 40 more.

I have added from 8 to 16 ounces to every locomotive at least doubling the drawbar at less than half the current. Now the 3½% (4.6%) grade is nothing but another section of track.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.