Just got the new August '03 issue of MR and Tom Danneman wrote a nice article on modelling a bit of Montana Rail Link in N-scale. The plan is a sweet little scenery emphasised set with a double loop that’ll fit in my basement. One catch - 3% grades.
Anyone have any comments on 3% grades in N-scale? I’m a beginner (again) at this and the last time I tried a 2% grade on an 18" radius, my Kato SD-90 had a hard time getting about 20 cars with Micro-Trains trucks up the hill without serious slipping (I was using a mdoified Atlas N-11 plan). I thought 3% would be almost horrible! I was thinking of keeping my next layout to <=2% max on mainlines and possibly steeper on branches.
Cheers!
Christopher
Hi Christopher;
You just need to add more locomotives; just like the real MRL.
Hello Christopher,
This is a rather tough question to answer because so many things come into the calculation of traction.
For example: 20 loaded cars on a 2% grade is fairly close to the prototypical limit for a 6000hp locomotive! 20 cars x 130 (gross) tons = 2600 tons + 200 tons (locomotive) = 2800 total tons. 6000 divided by 2800 tons = 2.14 hp per ton. For the sake of argument, assume a railroad uses 1 hp per ton for each 1% of grade. I think AC traction can get lower, somewhere in the .7 or .8 hp per ton. Interesting, all our models are DC -ha, ha.
So, if your cars are prototype weight and you locomotive has protyotypical traction, you are maxing out, just like the prototype. If the locomotive is either: 1) a little slippery; 2) not as heavy as prototype; or 3) the cars are heavier than prototype, then the traction will decrease. Also, each degree of curvature incrases traction demand, and our model curves are VERY sharp, requiring a good bit of the locomotive’s traction. Kato may be a little slippery, as the Bachmann C40-8W pulls more than the nearly equivalent Kato C44-8W in a test I remember seeing in a hobby magazine.
Also, the condition of the track and wheels affects traction. Clean, dry wheels and track = maximum pulling. Gummy or oily track and/or wheels = extra drag (gummy) or slipping (oily).
For practical application, a quick test bed is the best answer. I suggest taking an 8-foot long straight, connect one end to a 180 degree curve, and connect the other end of the curve to another 8-foot long straight. Since 8 feet is 96 inches, for a two percent test, the starting end of the first 8 foot section is level with the floor, the opposite end is 2 inches higher, if your mainline curve is 19" radius, you would add 1-1/4" of height for the length of the curve, then add another 2 inches to the far end of the second straight section. Your railroad should climb a total of 5-1/4" for this distance (96"+60"+96")For 3%, just add 50% more to ea
Hi Nigel & Rail61.
Now you have me curious. That’ll take a bit to set up, but I think I have the materials around to make the test.
Though operating helpers is neat, I thought it might be a little sad looking if I had to run 5 engines to get a 30 car train up a 3% incline. I thought 2 SD-90’s would be a reasonable maximum for 30 cars on a model layout (maybe 4 or 5 SD-40’s). One often sees CP running 3 AC4400’s/SD-90s with 100 car trains through the mountains including the spiral tunnels near Golden BC.
Cheers!
Christopher
My first post to this new forum!
Cristopher:
The discussion about grades in Nscale caused me to get out my Ntrak How to Book material. The kind of grade you need to use depends on what kind of train you are trying to run:
On the 2 outer red-yellow mainlines, no grades are permitted. These lines get the 50-100+ car long freights & fast passenger trains. On the blue branchline (or optional blue line) a grade of 1.5% is permitted (change 3/16" per foot) On the green Mountain Division, a grade of 3% is permitted. So you could have 3% grades with short trains. Or a 1.5% grade with longer trains. The space you have available may prevent the use of any practical grades.
Ntrak has produced some great material for Nscalers for a modest price. Give them a try or go visit a Ntrak club in your area. Have fun Nscaling! [:)]
I agree, Christopher, a 3.0 percent grade seems a bit steep, but since the layout is up and running, I can tell you that I am able to run an 18-20 car coal train from E&C Shops up that grade with three Atlas or Kato locomotives. On a small layout like this, an 18-20 car train looks nice even with three locomotives. This is about the maximum amount of cars I can fit on the siding anyway, so it works out fine. I even have an 18-car Red Caboose grain train that runs up the grade with only two Kato Dash 9s. I think the grain cars might be a bit light, however. In addition, the only place with the 3.0 percent grade is on the right side of the layout where the lines cross over each other. From the point where the lines cross each other on the front of the layout (where the bridge with Montana Rail Link logos is) towards the trestle and Mullan Tunnel, I flattened the grade out to somewhere around 2.2 percent. This is the grade of the MRL’s prototype Mullan Pass. Hopefully that makes sense.
Thanks!
My layout uses 3% grades.When the train is going to the dock a the bottom of the mountain i only double head a loaded train of 40+ loaded cars. but the return trip if group 5 locos to pull the 40+ loaded cars with 2 locos in the middle. this system works fine for my n scale layout and is prototypical here because i remember seeing a 150+ car train running like this on a trip to rockhampton.
Well, it sounds as though 3% is doable, just not with very large trains (I still dream of modelling 60+ cars one day).
Tom, I’m looking forward to photos of the finished (are they ever?) layout. One question if I may - I noticed that it is a bit of a reach in to the staging area, especially since its hidden by the mountain/hill in front. How do you access troubles in the staging area? From the back or from underneath? I’m thinking that I usually derail something in awkward places (Murphy’s Law).
Cheers!
Christopher
Christopher,
You are right, it will be a bit of a reach to get to the rear staging yard. I have a small stepstool that should give me just enough reach to get back there in most places. I also have access on the left side of the layout where I can get all the way to the back wall. In addition, I have good access from below the layout. I plan on having the mountain ridges end abruptly and angle straight down, if not even in a little bit, to facilitate access from below. I guess I’ll have to wait and see if this all works out as planned.
Sincerely,
Tom
Tom,
I am at the VERY beginning stages of building an “L” shaped layout when I saw the article in the Aug MR. What a Great Layout. I’ve been having trouble coming up with a workable layout for the 7’6" x 15’ area in my basement that has been designated “The Train Room” I would love to try the MRL layout as it is in MR, unfortunately my “L” bends on the other end. I have been using ATLAS’ RTS software for track layout, but I haven’t been having very good luck. Any Suggestions would be appreciated.
Thanks
Steve
Steve, I’d say try simply mirroring the layout left to right. Trying to “move” the “L” portion to the right hand side would be tricky. I, too, found Atlas RTS software a bit frustrating but you can’t complain about the price. I think I remember someone saying that they’re all difficult in some way, anyway.
Good luck. Christopher
Thuban,
I found that I could place a piece of FlexTrack in the RTS and the connection to another section of track would have an unnatural kink that looked like a derailment waiting to happen. I do like the Mirror Image idea though Thanks.
Tom,
I noticed there are several Curved Turnouts, where do I find those? I don’t handlay track. I think that part that scares me the most about starting a layout is getting the benchwork right, if you get a bad start there it is all downhill.
Steve
Steve,
Those are Peco code 55 #8 curved turnouts. They are available in both right and left hand curves. This is the only manufacturer that I am aware of that makes N scale curved turnouts. So far, they have been super reliable and they work great. I agree, take your time on the benchwork, and especially the subroadbed. It will make the tracklaying that much easier.
Tom
hey Nigel i did not know you were on this board too!! I,m Alex from the bachmann messageboard that asked you about Comrail.
Tom,
Is there a Peco Website, my LHS doesn’t sell Peco
Thanks
Steve
Steve,
I got mine from Walthers (walthers.com). I’m sure they are available at many other places like Caboose Hobbies and N scale Supply as well. I hope that helps!
Tom
Tom,
It sure Does, Thanks a lot for your time.
Steve
Just got the new August '03 issue of MR and Tom Danneman wrote a nice article on modelling a bit of Montana Rail Link in N-scale. The plan is a sweet little scenery emphasised set with a double loop that’ll fit in my basement. One catch - 3% grades.
Anyone have any comments on 3% grades in N-scale? I’m a beginner (again) at this and the last time I tried a 2% grade on an 18" radius, my Kato SD-90 had a hard time getting about 20 cars with Micro-Trains trucks up the hill without serious slipping (I was using a mdoified Atlas N-11 plan). I thought 3% would be almost horrible! I was thinking of keeping my next layout to <=2% max on mainlines and possibly steeper on branches.
Cheers!
Christopher
Hi Christopher;
You just need to add more locomotives; just like the real MRL.
Hello Christopher,
This is a rather tough question to answer because so many things come into the calculation of traction.
For example: 20 loaded cars on a 2% grade is fairly close to the prototypical limit for a 6000hp locomotive! 20 cars x 130 (gross) tons = 2600 tons + 200 tons (locomotive) = 2800 total tons. 6000 divided by 2800 tons = 2.14 hp per ton. For the sake of argument, assume a railroad uses 1 hp per ton for each 1% of grade. I think AC traction can get lower, somewhere in the .7 or .8 hp per ton. Interesting, all our models are DC -ha, ha.
So, if your cars are prototype weight and you locomotive has protyotypical traction, you are maxing out, just like the prototype. If the locomotive is either: 1) a little slippery; 2) not as heavy as prototype; or 3) the cars are heavier than prototype, then the traction will decrease. Also, each degree of curvature incrases traction demand, and our model curves are VERY sharp, requiring a good bit of the locomotive’s traction. Kato may be a little slippery, as the Bachmann C40-8W pulls more than the nearly equivalent Kato C44-8W in a test I remember seeing in a hobby magazine.
Also, the condition of the track and wheels affects traction. Clean, dry wheels and track = maximum pulling. Gummy or oily track and/or wheels = extra drag (gummy) or slipping (oily).
For practical application, a quick test bed is the best answer. I suggest taking an 8-foot long straight, connect one end to a 180 degree curve, and connect the other end of the curve to another 8-foot long straight. Since 8 feet is 96 inches, for a two percent test, the starting end of the first 8 foot section is level with the floor, the opposite end is 2 inches higher, if your mainline curve is 19" radius, you would add 1-1/4" of height for the length of the curve, then add another 2 inches to the far end of the second straight section. Your railroad should climb a total of 5-1/4" for this distance (96"+60"+96")For 3%, just add 50% more to ea