Hi I'm new here. I'm setting up a new layout and would like to do an overpass for a crossing what is the best rise and run to do this? Any help would be great.
Hi and welcome to trainboard where the sun shines most of the time. For a new guy into the hobby I would recommend you buy the woodland scenic risers in its series of goodies designed for the new person. You have a choice of 2 and 4 percent grades, but somewhere in the back recesses of my brain I seem to recall something about 3 % as well. NOw the formula is easy, 2% of 100 is 2....so... to rise two inches you need one hundred inches of run. A lazier formula is 2 inches for every 8 feet (96 inches). By the way, in model rail roading "inclines" mean something different so hence forth for the rest of your life they are called grades. You are probably thinking well what grade should I use. First you have to take into consideration the equipment you are going to run. The laziest way is to take the highest car you have, figure in some for clearance and that is what you need to clear the car, but remember to include track, ballast, etc. in the height. Generally small grades are better, if you can do it, two percent is best. An engine can lose an amazing amount of pulling power on a grade with cars behind it. Of course to complicate life, there are exceptions. One, you want to emphasis a grade because you are going to use helper units (then four percent). Or two, it is a short line with short trains, then you could go to three percent. Only chose four percent if you absolutely have to but this is really really steep in model railroading. Personally I would never use four percent.
