What is the formula please for building a 2% grade. Taking into account the rising height in inches per running foot. I’ve always used small switching shelve layouts but now have the space to build a larger one in a U shape.
Thanks,
Percent for grade is rise divided by the run. The units have to match. So a 2% grade is 2" rise over 100", or 2 foot rise over 100 feet. Or 2 centimeters rise over 100 centimeters run. Or 1 inch rise over 50" run. Or a half inch rise over a 25" run.
The last makes it easy - 25" is close enough to 24", you can buy bubble levels in 24" lengths. Add a 1/2" spacer to one end. Set it on your grade - when the bubble is level, you have a 2% grade, well technically a 2.08% grade.
–Randy
The formula is that for 100 units of length it should rise 2 units or 2/100 = 2% or .02. So if you have 100 feet the rise is two feet. If you have 100" the rise is 2". If you have 100 milimeters the rise is two milimeters or two miles rise in 100 miles.
A 2 percent grade is 2 inches rise by 100 inches length (2/100 = .02) so you need to increase the height 1 inch for every 50 inches, 1/2 inch every 25 inches, 1/4 inch for every 12 1/2 inches, and 1/8 inch for every 6 1/4 inches.
I use 1/4 inches to the foot, saves a lot of calculating and results in a .020833 grade, a negligable increase.
Be sure to increase the first foot only 1/8 inches to provide an upward easement for better operation. The same at the top of the grade.
To obtain a 3 inch clearance you will need a length of at least 150 inches (12 1/2 feet) and it doesn’t look like you have that much room.
…so, you could do what others have done, not being one to be daunted, and actually design in a downard slope someplace where you cross over your track if it is a loop. Therefore, you make the rising approach more modest, but manage to get in your easings in and out of the grade, while also making the lower track that gets passed over descend as it approaches the overpass, with both easements. Result is your overpass, nicely eased, and in the space you have. Of course, you’ll still need a minimum area so that your curves don’t get too tight and you manage this height differential that you desire.
You may have to redesign your track plan, or at leat modify it heavily, but you can get a lot of main into a smallish space by being creative.
Thanks much for your help and ideas, all are very helpful.
I havent decided yet what I’ll be doing trackwise. I’m leaning toward point to point with a 9" turntable rather than a wye turnaround, I really dont want a loop. I was thinking of working off of the Big Foot Lumber plan I picked off by surfing for shelf layouts. The overall dimensions for this would be exactly what I could fit in, no more. Once I get the shelves up then I can play around with it better. I like the idea of going down to make the clearance.
The upper left storage yard I could go through the burner room wall and put that in there, and possible come out the other end.
Actually Craftsman now makes levels with digital readouts in .1 degrees. My wife bought me a set for Christmas.
Oh great ANOTHER gadget I have to buy [:D]
It never ends … there’s always something to buy because “I really need it honey” as the wife grimaces again. 
Thanks again everyone for the info.
But have you seen them ?
$80? I’ll pass. I’ll stick to my FREE scrap of wood or foam on my existing level.
–Randy
But then you have to convert degrees to grade percentage. Randy’s original suggestion of the half inch shim on one end of a two foot level is the way I’ve been doing it for years. Plus, compared to measurements, this has the advantage of compensating for any variations in the benchwork and giving the roadbed a true grade percentage.
But they have a thermometer built-in too. You’ll know the temperature of the room while you work …
I already have a thermometer…and a humidity gauge…in the train room. And a heater and a dehumidifier. And a ‘plain’ laser level I got for like $5 on clearance, but have yet to actually use. And a tripod to mount it on, well the tripod was for the camera but it works just as well for the laser level.
–Randy
It is a nice piece of equipment but something I dont need at this stage of my life. My son is a general carpenter and uses some laser stuff. For me, eighty bucks gives me some decent lunchs at the local restaurant … I’ll eye my slope grades.