I was wondering what is the max grade a large steam engin can go up like a challanger pulling 25 cars also what is the max grade for a single diesel locomotive pulling 15 cars. I was thinking a 6% grade in a few small places.
Six percent is to much. Even if you can find engines that can do it you will be severely limited. 2 % is better.
Magnus
what about 4%
That will work. But some engines will have difficulties with just a few cars. But if you want a hill to climb for the sake if climbing it 4% is a good grade. Just create easements when you enter and leave the grade.
A Challenger will easily climb a 4% grade with a lot of cars(atleast in HO).
Magnus
Ok i might do 3.5% on my challager line but will a single diesel pull a 15 car train with a 2.5%.
Depends on what diesel, what cars, what brand and if there are any curves. I’m not familiar with N scale so someone else might be able to help you with specifics.
Magnus
I have several diesels that will pull a 15 car train up a 2.5% grade, but some of them will have wheel slippage on that same grade [mine is curved, though; straight grade will be different]. My best puller is my Kato C30-7, but a number of the more modern prototypes will pull as well. If you are looking for a reason to use a helper engine, you could go up to 4% if it’s a short pull. If it’s long or curved, I’d recommend you stay around 3-3.5%.
FIrst of all, he is in N scale. The Athearn N scale Challenger of BigBoy wont pull much on level ground, let alone a 6% grade.
If you want to do this right, then limit yourself to 2%. Unless, of course, you want to double or triple head your big articuleds.
David B
But I think that “ham99” uses N scale and he has a 2.5% grade on his layout and he pulls 11 cars with his Challenger. He said he had no problems with that. And also im not going to use 6% grade any more im thinking more along the lines of 3.5% for my challenger line and 2.5% for my diesel line.
You could try experimenting. Take a long plank, attach some rail to it and try different incline percentages. The way you do it is simple. Lets say you have a 100 inch long plank. Then, one inch is one percent. Just keep adding an inch or a half until you find a percentage that works for you. That way you will have no guessing and more actual data. Now, do remember that if there is suppose to be a curve you have to estimate that it will be able to pull a lot less.
Magnus
A jump from 2.5-3.5% doesnt mean that you just pull a few less cars on the 3.5% grade than you can on the 2.5% grade…it inst linear like that, it is exponential.
If you can pull 11 cars on a 2.5% grade, it means on a 3.5% grade you can pull (if you are lucky and the grade is not on a curve [curves add %]) 4-5 cars. Now, this difference is conservative, but it gives you an idea. At 4.5%, you will be lucky if the loco can pull itself up the grade.
3.5% isnt a little bit more than 2.5%, it is alot more.
This is speaking from decades of experience…take it or leave it.
David B
3% is the steepest I would go.
A 6% grade (a rise/descent of 1 foot for every 16.67 feet of forward travel) is an extremely steep grade. A grade of that percentage on the Interstate, if it’s of any substantial length, will result in the placement of runaway truck lanes. On a railroad, a 6% grade would be the province of Shays, Heislers and Climaxes.
Runaway truck lane on I-5 at Grapevine (where the freeway finally descends into the San Joaquin Valley) : http://rides.webshots.com/photo/2220206910099816979dCDdcK
25 cars with a 50 ton capacity and 20 ton tare (unloaded weight) would result in a train of 1750 tons if all cars are loaded to weight capacity. IIRC (books are packed away), an SP 4-8-8-2 of classes AC-6 thru AC-12 was rated at about 1150 tons or so on Donner Pass’s ruiling grade of 2.2%. Those engines were rated at 124,300 lbs of tractive effort. The tractive effort of a UP Challenger is approximately 78% of an SP cab-forward. IOW, the Challenger would lug about 900 tons up the same grade.
Andre
I have to share what 4-6-6-4 sent to me in a PM.
**
Can anyone confirm that in Model railroad planning 2008 they say you can have an 8% grade? I find that hard to believe.
David B
I can not remember reading that. But perhaps Mr 4-6-6-4 can give us a page so that we can look it up. It seems quite unreasonable since that would be one tough grade to make considering length and curves.
But give us a page number and we can check it.
Magnus
I found the page that I think he is referring to. It’s page 69. It has a chart that shows radius and height in inches. On that table it shows what 8% will result in. But I can not say that I found anywhere that they say it should be used. But I haven’t read the whole thing right now.
Magnus
Only a handful of N scale steam locomotives pull very well out of the box.
Most, however, can be coaxed into pulling more by proper tuning. This includes adding additional weight, rotating the driver bearing blocks (or shimming if neessary), adding a traction tire driver set (if one isn’t already attached), etc.
Be aware, though, that opening one of these up tends to void the warranty. My argument is that you will want to learn how to do these things anyway… I can do most “warranty work” short of replacement by myself. Saves time and postage.
I’m picturing your 4-6-6-4 struggling upgrade with 5 cars up a 4% and it doesn’t look terribly realistic!
Suggestion: Use the minimum possible grade. Use N scale’s inherant advantage of requireing less distance to clear a lower track than HO. Trust me (I used to have 3% grades) when I say you want the absolute minimum grades you can get away with when using most N scale steam.