What is a safe grade in ho? I’m thinking about a 1/2" per foot or could I go more? thanks in advance, Mike
That works out to 4.2%, a little on the steep side…probably. There is more to a grade than just making a ramp. If you add a curve, say 18" radius, you will add resistance to the loco and train =more amps & heat…and maybe slipping. How many cars, of proper weight, will you be pulling? Are you prepared to use a helper if needed? How will you get the helper to meet the train? Also, if you are using steamers, they need a transition into and out of the curve if the drivers number more than 4. A Hudson or a bigger loco, like a Northern, will loose traction below the middle sets of drivers if the grade starts and ends over any distance less than about 12" (that means your tracklaying will have to be very good, even with the transitions).
In the real world, mainline engines rarely take grades greater than 2%. At 3%, they will need help, and you may find the same thing on your layout.
If you have a solid heavy loco, and intend to pul no more than 6-10 normally weighted cars, you should be okay. Bottom line is to make the ramp on a counter or basement floor (properly supported so that inadvertent sags don’t give you a false failure), and see how your loco performs.
-Crandell
A good lawyer’s answer - depends. Depends on what the reason for the grade is, how long you want your trains to be, will the grade be on a curve, and so on.
1/2" per foot is a little bit more than 4%, a pretty severe grade. Most HO engines will pull less than 25% of the number of cars they can pull on level track. If the grade is on a curve add about 1 to 1.5% to the actual grade to get the effect on train length.
Vertical transitions are very important, especially with steep grades. If you are bending plywood to construct the grade, you pretty much get a good transition automatically. Other materials will need more checking. Based on some calculations by Larry Blanchard, a 10ft vertical radius is recommended for the grade transition. Sounds worse than it is. For a 4% grade, that give a transition length of just under 5 inches at the bottom and at the top. But that transition is critical for keeping trains on tracks, coupled, and locos operating smoothly.
Once you get above 5%, train length is rarely more 3-5 cars with a single engine (and often less, depending on engine). This is usually only done on logging and mining branches, where the revenue would justify the short trains. I have heard of successful operations with selected locos and a couple of cars on grades as steep as 11%. But that’s not the norm.
Another issue with grades is coming down with free-rolling and/or heavy loads. If the cars start to pu***he locomotive faster than it is going, and there is any play in the worm and/or motor shaft, the loco will “buck” as it comes down.
Finally, avoid spurs that require switching on grades. Where are you going to leave the rest of the train while you pick up or set out a car? Is the car going to stay where you set it? Also, couplers require slack to uncouple. Difficult to do if gravity is taking slack out. Of course, if gravity is taking slack out, it means train is ready to roll down hill!
Best bet if you are goin
See if this doesn’t help;
Here is a simple way to keep track of your grades, or too plan where and how much grade you can get out of your room or layout
Measure out 100 inches in length, come up a 1" rise 1% (very simple, not taking in to account curves)
100" to 2" rise, 2%
100" to 3" rise, 3% and so on.
As you can see, as it was a bit of eye opener myself, a good grade takes up alot of room.
Well it’ll be diesel only,(bb trucked,gp-9’s,fa’s,sw’s) on a branchline, so trains will be relatively short,so I’m thinking maybe 3% will work. Part of it will be curved(24" radius), I can raise the other track by 1%,that should do, I guess I’ll use plywood on this section and save foam for the level areas. Thanks guys,Mike
I have a 24" radius helix with 2.6% grading and diesels. It works fine. Just be very careful that the sub roadbed remain perfectly flat in the turns or if you eleveta the outside rail (super elevate the curve) that you remain consistent throughout the curve between the inside and outsidee rail elevations. If not, you’ll have problems on longer 6 axle diesels derailing. I spent three weks fixing this type of a problem. For the rest of my layout I am going to avoid elevation changes in curves as much as possible. Leave them for the straight sections (within reason) or use lower grade changes in the curves.
BXCARMIKE -
My recommendation is to build a test track and conduct your own tests. I was surprised at how much of my equipment (HO & On30) ran fine on 10" radius curves and 4% grades.
Uh, I don’t know what your situation is, but I’d recommend nothing much more than 2 or 2.5 percent (2 or so inches rise in 8 feet) in a room-sized layout unless you are dealing with a “specialised” railroad (short trains, helpers, etc.)
The key words, again, are - what is your prototype (faithfully modeled, or just inspiration) and what is the rationale behind the grades it used?
Some rail lines, like the old NYC (PC, Conrail, ???) main on the east bank of the Hudson River, used a pancake for a profile, and any deviation from dead level was considered a significant grade.
The worst grade on the B&O circa 1863 was 2.2%. That became the ruling grade for the Union Pacific and Central Pacific by Congressional fiat - written into the law that provided Federal subsidies for building the transcontinental railroad.
Tennessee Pass on the D&RGW had sustained grades of 3% eastbound. The narrow gauge over Cumbres Pass (now the Cumbres and Toltec Scenic Railway) climbs at 4% eastbound out of Chama, NM.
The worst mainline grade in Japan, 6.8%, was converted from rack to adhesion operation in the 1960’s, with no reduction in grade. To prevent runaways, light 4-car electric MU trains (which would have slid like a toboggan alone) were given two heavy, low-geared Co-Co ‘brake helpers’ for the downhill trip. The same two locos could bring about a dozen four wheel goods vans upgrade.
In the model railroad world, Dr. Bruce Chubb’s new Sunset Valley Oregon System (Model Railroad Planning, 2006) lists maximum mainline grade 3.5%, and up to 8% on a logging line.
Short momentum grades (like up and over an overpass) can be, and frequently are, steeper than sustained grades. Trains, like aircraft, can exchange speed for altitude within limits.
The one nasty grade on an otherwise level division was usually handled as a helper district, that being less expensive than providing road locos with sufficient tractive effort and horsepower to climb ten miles that would then be excess capacity for ninety miles of relatively flat running.
Having said all that, my own standards, arrived at after considerable experimentation with my own rolling stock and motive power, are 3% u
The railroad is the New Haven,circa '68, faithful locos and rolling stock for time frame,inspiraional layout,basically the essence of NH, with no specific branch in mind. So,I know it had grades with helpers(Maybrook) and a tunnel, so I’m incorporating that feel, but going for a more rural New England feel,like Rhode Island or so.