Building an HO layout and I don’t have any idea how to determine what I should set as a maximum grade for changes in the elevation of my track. I would assume that it would be related to the number of cars you might expect to be pulling up that grade. Given that I don’t want to pull a lot of cars in one train (max would probably be 8 to 10 cars) can anyone telll me what rise in elevation I can get away with before I will start having problems trying to get up the hills with one engine.
2% is usually pretty steep for normal operations but I know some folks who would say 4% would be a good limit and still have some what normal running routine. All though I am sure some folks will chime in with some real world expeirence.
Sort of also depends on the engines you’d be using. Also your available space may force you to use a steeper grade than you’d like. A 4 wheeled loco might be able to pull that many cars on level track, but could stall on even a 1% or 2% grade, while something with 8 or more powered wheels could pull a larger train up a significantly steeper grade. The length of the grade could have an effect as well as having a curve on the grade. The engine weight also afffects the traction, or pulling ability. The tighter the radius, the more likely to have a longer train tip on you.
Best practical thing I can say from experience is that about 40 years ago, I built a figure 8 with about a 3.5% grade.with 18" radius curves. A 4 or 6 wheel switcher could haul maybe 6 to 8 cars up grade (wheels weren’t quite as free rolling then), while locos with 8 powered wheels were doing about 8 or 10 cars: anything more, and cars near the head end started tipping on the turns. The only other layout with a grade I’ve built since was a small shelf layout that had a steeper grade, very little curved track, but used small switchers moving no more than 3 or 4 cars up/down hill at a time…
Maybe you could build a mock-upof the section you’re thinking of for your layout, and try it out with the locos and cars you’d be using?
I have 2% grade on my layout, one is using the Woodland Scenic grade foam thingies to do a climbing loop and at the othe end is about a 2% grade straight down (might be a little bit less since my garage does have a slight slope) and I have no trouble with 10 cars and one engine. I have pulled 55 cars with two Atlas GP-38 and pulling was not the problem, the slack action caused most of the headaches since I would end up part of the train on flat ground and part climbing or decending the hills.
If you have a good heavy engine and it is intended to draw a slow freight, or what we call a ‘drag’ freight, then you could have fairly steep grades. If you have faster passenger service in mind, beware the grade that exceeds 2.5%! My grades are at or slightly above 3%, and I can assure you that my passenger engines struggle with anything more than four factory-weighted passenger cars and a head end reefer.
The sure-fire way to determine your eventual grade is to first get the engine, get the typical cars behind it, and do a test on a mock-up. When you determine your last successful rise-over-run grade, I would back off about one half a percent and call it a good standard for your current needs and some unforeseen needs.
My next layout will not have grades in excess of the N. American standard grade of 2.2%. It is too hard on my engines, particularly steamer rods and their cranks, to try to run trains of a reasonable length.
Even a good engine and 3 cars can be difficult to pull a too-steep grade.
I am in HO and tried the Woodland Scenics {WS} foam {flexible ramp} thingys {as someone called them here} for a 4% grade. I found it too steep especially if you add a curve to it {which increases the resistance the engine must overcome}. SO I also tried a 3%. same thing. It did not matter which engine I used or how many cars I used, I was very unhappy with the results.
I now only use the 2% grade WS foam flexible ramps and will stick to 2% or less. Less stress on me and the engine.
If you want a 3 or 4% grade, I can send you a whole bunch of barely used WS foam flexible ramp thingys as I never intend to use them ever again {*though I can’t throw them out…*see the thread on MRR’s NOT throwing things out}.
I would agree that 2-2.5% is a good grade to shoot for. My layout has a 2.7% grade that ends with a long curve. My Spectrum 2-8-0’s can handle 7-8 NMRA weighted cars up that grade with no problem. Most of my diesels will handle 10-12 cars, easy. A combination of steep grades and sharp curves will really restrict what your engines can pull, and may cause derailment problems.
BTW, grades are measured in a ratio of rise to 100 units. So, a 2% grade will rise 2" in a run of 100". A 22" radius curve will add another 2% of compensation. Thus, a 2% grade on a 22" radius HO track will act like a 4% grade. The actual ‘compensation’ will depend on toe ‘friction’ of the metal or plastic wheels on teh metal rails.
My advice: Test it before you build it. Just buy a 1" x 4" x 8’ or 10’ board and tack some flextrack on it. Add power via alligator clips, and you have a great test track. Just raise one end with temporary supports (books work fine), and see what maximum elevation works to your satisfaction with your rolling stock.
Keep in mind that if your grades will be curved, the curves will increase the rolling resistance and thus decrease the maximum grade.
If you’re serious, I would be interested. Is there any way I can contact you off line, so to speak? I can’t find a Private Message feature on this site.
Second the motion. An ounce of direct experimentation trumps ten tons of opinions.
After you determine the MAXIMUM that each locomotive (or combination of locomotives) can pull up the steepest grade you decide to use, set your plans to limit yourself to 85-90% of that maximum for normal operation. That will allow some wiggle room for those situations that just seem to happen every so often.
An alternative is to ease the real grade to about 80% of the test grade. Then ease it a bit more around your curves. One way is to measure the grade along the curve’s chord rather than along the actual arc. If the curve is 180 degrees or more, measure grade along the diameter, rather than the circumference.
One last item. Make sure you provide vertical easements where the grade begins, ends and changes. Vertical kinks are even worse than horizontal kinks when it comes to smooth tracking during operation.
Chuck (Modeling the heavy prototype grades of Central Japan in September, 1964)
Space for layouts is always at a premium. Therefore, when we plan our layouts, calculating with a grade of 3 % (not more), although unprototypical, should be common practice. It is our locos, which sometimes do not have enough pulling power.This can be remedied by adding weight, traction tires or “Bullfrog Snot”. You also have to ensure, that all cars are really free rolling and are properly weighted.
A “standard” 2-8-0 should be able to pull a string of 10 cars up a grade of 3 %.
Btw., there is a prototype for just about everything - the Rhaetian Railway in Switzerland has a max. grade of 7 % and the Ruebelandbahn in Germany, originally built as a rack railroad, has grades up to 6 %, serviced by powerfull steam tender locos.
My layout is made up of mostly grades and curves, with a flat and relatively straight spot where each of the towns is located. Long trains (over 50 cars - which I almost never run) can be going uphill and downhill in several places all at the same time. [(-D] I’ve limited the grades to 2.5% maximum and most locos (all steamers) can handle the usual twelve car trains single-handedly. For longer or heavier trains, or when using smaller locos, I doublehead or add pushers, and when additional locomotives are not available, shorten the train accordingly.
Each locomotive has been tested on the layout and assigned a “tonnage rating” based on its actual capabilities, so I know before sending a train out what its motive power requirements will be.
If, because of space constraints, you’re forced to settle for steeper than normal grades, adjust your Motive Power Department’s locomotive purchasing budget up, to allow for either more or bigger locos. Steep grades and an abundance of curves should be viewed as an opportunity to improve your railroad’s roster of locomotives. [swg]
I’ve put in a long 2 percent grade on my previous and current HO layout, going from the main line to a lower level staging/storage. I would not attempt anything steeper than that (unless I was building a logging or narrow gauge RR).
The thing is, a steeper grade will drastically reduce the pulling power of your locos. AND, perhaps even more important, it could give your layout at “toylike” appearance (i.e. the Lionel & Flyer layouts some of us had in earlier years).