# How steep is too steep?



## Stradawhovious (Feb 28, 2012)

I'd like to add some altitude to my layout in the future, but am at a loss as to how. How steep of a grade cna I put in and still have it work reliably, and how would that translate to scale?


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## T-Man (May 16, 2008)

search for helix the ultimate incline, 2 to 3 percent is normal but test first since engine are tempermental.


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## sstlaure (Oct 12, 2010)

Scale doesn't really matter when you're talking grade. 3% is 3%. The only difference is the clearance required to have 2 tracks cross over/under each other.

Grade is rise/run. If you need to rise 4" to clear 2 tracks (typical in HO), then to get a 3% grade:

4" rise/"x" run = .03 (or 3%)

x= 4"/.03 = 133.3" or 11.1 ft

Here's a link to the NMRA clearance stds for each scale.

http://www.nmra.org/standards/sandrp/s-7.html

My steepest grade is ~2.5% set on a 26" radius curve (inside helix) and any of my engines (P1K GP15, P2K GP38-2, Athearn Genesis SD60i) can pull 10 regular cars up the grade, the largest one has hauled (24) Michigan ore cars up (empty)

Thomas (with some weight added) can do 4 Annie/Clarabel cars + Brake Wagon. Any more and he slips.

Bachmann 2-6-2 Prarie can pull 5 cars and a caboose, but it's slipping as it climbs.


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## gunrunnerjohn (Nov 10, 2010)

As stated, when you get into grades, it really depends on the specific locomotive. I have an experimental grade here that I have been experimenting with. Some of my Legacy dual-motored diesels can pull a dozen cars up a 6% grade with ease, most of the steamers have trouble on half that grade. I don't have a long enough run on the test track to see if I could pull more with the diesels, but I suspect I could.


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## Southern (Nov 17, 2008)

if the grade is to steep, add more engines. 3% is as steep as I recommend


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## gc53dfgc (Apr 13, 2010)

I have been experimenting with the same idea as John except in HO scale. I have maxed out my Bachmann SD40-2 at about a 7.333333 percent grade hauling one-two car train. This is actually lower than what the actual one can pull as i got rid of about a third of the weight in mine to make room for DCC and sound. I have tried the same with a small switcher that had been doused in vegetable oil (one of my you-tube videos) and it had a terrible time doing that itself (because of oil residue) I will try this summer with some small steam engines as that was the original reason for the test bed, a small 4X5 layout with steep grades and Passovers that required a 6 percent grade.


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## jzrouterman (Nov 27, 2010)

I'm running a 3% grade and to climb it successfully, it really boils down to what type of engine is pulling and how many cars it's pulling. Without any cars, all of my engines pull it with no problem. However, with some of the engines, pullings cars up the grade is quite a different matter. My Atlas RS36s each alone, pulling seven cars make it about 2/3s of the way up and then just sit there and spin. But connect them both together and they've pulled as many as 10 cars up the grade which I guess is really nothing to write home about.:laugh: 

My Athearn RTR SW1500 is extremely pitiful, as it has a problem with the grade pulling four cars up it. Though it runs great, it's really the weakest engine I have. My Bachman GP30 and SD40-2 on the other hand, each alone can easily pull 10-12cars up the grade. My Athearn RTR GP35, alone can pull 8-10 cars up the grade. My GP38s, each alone have pulled 15 cars up the grade. Together, they both seem to have no problem pulling almost twice that many cars at all. Connect both of them together along with my Bachmann GP35, and they all seem to be able to easily pull any amount of cars I throw at them up the grade.

Of course, at the same time it does help to have a strong transformer with a little bit of extra power when doing an operation such as this. lol.:laugh: So when pulling the grade, the transformers I use are either one of my two MRC Power Command 9500s or my MRC Sound and Power 7000 transformer, each one being capable of pushing out right around 30 VA of power. 

So for me anyway, supplying enough power isn't a problem. Neither is any of my heavy road engines. Instead, the climbing problems are with the road switchers and the yard switcher. The road switchers (RS36) each have adaquette motors but the engines themselves are too light. The yard switcher (SW1500) has a small motor along with the engine itself is also too light. 

One answer to this of course is to make a longer incline with a less percentage climb. But unfortunately I don't have the extra room for that and at the same time being able to keep the other features I have. So.... I just don't run these particular engines mentioned up the incline. What I do instead is too bring the cars up with the larger road engines, unhook and than hook up with my smaller road switchers and then pull the cars to their destinations. 

Routerman


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## Kwikster (Feb 22, 2012)

Another thing in O scale, type of car matters as well. Most post war cars don't have the easier roll of later cars. My MPC era cars roll so easy it's scary.


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## gunrunnerjohn (Nov 10, 2010)

I have been slowly selling off the older PW cars in favor of the later models with the fast angle wheels and needle bearings for that very reason. Rolling resistance is a MAJOR factor when the consist gets to be really large. Of course, when the grade increases, the weight of the cars starts to enter in as well.

An interesting experiment you can do using a spring scale is to measure the pulling power of a locomotive. I've tinkered with my trigger pull scale, but I think I need something with a little more precision to measure tractive power.


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## sstlaure (Oct 12, 2010)

Micromark sells a small drawbar pull scale just for that purpose

http://www.micromark.com/DIGITAL-PULL-METER,9577.html


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## gunrunnerjohn (Nov 10, 2010)

I like that little scale, pretty cool.


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