# Incline grade vs decline grade



## Hotrackguy (May 11, 2018)

After receiving some advice on my first post concerning my layout I have done some deep thinking about grades. I've changed my track plan around just a little bit and before I nail it down I thought I'd try and get some more advice.

There was some concern when I mentioned that I was going with 3 and 4% grades. I don't think it's practical (for what I'm looking at doing) to go as low as 2%, so I was wondering... If I only run my trains in one direction and my incline was 3%, would there be a problem with a 4% decline?

Also, is 3 1/2 inches enough clearance to run most engines and cars under a bridge and through a tunnel (HO scale)?

- Dave


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## 65446 (Sep 22, 2018)

Far as 3% up and 4% down if you plan on running short trains I don't see why not..
Far as 3'5" clearance, it's ok if you have no overly tall loads like double stacks and such..


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## CTValleyRR (Jul 26, 2014)

3-1/2" from the rail heads (tops) to the lowest point in the overhead obstruction should be fine for most things.

If you run short enough trains, the grades themselves aren't the problem (so long as they're straight -- curves add additional resistance and further lessen the number of cars you can pull). The problem is the transition onto and off of the grades. Many locos will have a tendency to dig in their nose and / or pilots and couplers at the bottom of a grade. The more the loco overhangs the wheels, the more this will be a problem. Because locos don't flex vertically in the middle, there is a tendency to "pop a wheelie" at the top of a steep grade, perhaps breaking electrical contact or allowing the wheels to come off the track entirely. To solve these problems, you need easements onto and off of your grades, and by the time you have added those, you might as well just stick with a gentler grade, because you'll be giving up much of the savings in horizontal space that the steeper grade gives you.

As an alternative, you might consider having your main layout area at a height of 2", so that you can go up AND down with a gentler grade.


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## Aard D'Vaark (Aug 1, 2019)

If you only run one way, 4% decline is okay ...
you can -try- it the other way, depends on loco traction and car drag though ..


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## MichaelE (Mar 7, 2018)

The Rhätische Bahn railroad on my layout uses 5%+ up and 6%+ down with easements so 3% up & 4% down should be OK for short trains.

My ÖBB 2143 will pull seven 303mm length cars up that 5% grade, but European equipment has traction tires.

In reality, the steepest grade on the RhB below St. Moritz is 7%+. Those locomotives are heavy and have a lot of tractive effort. They can pull quite a bit.


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## Gramps (Feb 28, 2016)

I would give serious consideration to the suggestion in Post #3 about running the main line 2" high and decreasing the grades.


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## 65446 (Sep 22, 2018)

📌
I agree..And this is where open grid and L girder benchwork shines;....the ease of installing risers and sub-roadbed on them...
If the entire main line is on risers 2" above the bench grid and ascends on risers 2" more (the grade in question) it's now 4" above the top of grid where a track running right on top of grid is now 4" below prior track that rose up 2", it having descended 2".. creating a 4" spread between the two, both only having lifted or dropped 2"....
Note: This system still calls for two ramps long enough to have a say, 2% grade, each...
Stats: up 2" in 100" = 2% grade. Up 2" in 50" is a 4% grade...But 2% can be accomplished with curves and loops. IE. It doesn't have to be a straight line (tangent) to gain this length...
Just beware curves [spirals] add drag to a climbing train as if grade is steeper than it is... M


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## cid (Jul 3, 2014)

I would give serious consideration to a short spur at the bottom of the 4%, where you can park a helper. A little operational interest...


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## 65446 (Sep 22, 2018)

*Dave*, did you savvy and digest my post #7 ? This is how to do it with I believe, best results; same for a 'shelfie' (my shelf layout name), or, an around the walls layout...
If you don't already know much, try and get "Model Railroad Benchwork" by Linn Westcott;
the bible on it..
*M*


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