elevating track

[bobles]

I am a new user of Bachmann trains and have just purchased the Overland Limited and Durango & Silverton sets. I am trying to create a rise so that one train can pass over the other.
My question is how long must the riser be to reach a height of 4 inches on each side of a 12" trestle and what size switch do I need.

[jward]

the length of run to get up to 4" in elevation varies with the steepness of the grade. 4% is considered the maximum practical grade for model trains, and the percent is a ratio of rise to run. thus 4inches rise means you need 100 inches of track to reach this height. this equals 11 setions of track. the straights, 18"r curves, and 22" curves are all approximately 9" in length.

for a 2% grade you'd need twice that length.

to make things much easier and take the math out of making a grade, you may want to look at the foam risers made by woodland scenics. they make them with 2%, 3% and 4% grades. you can set them up and visually see how much run you need to get the height you want.

[bobles]

Thanks for the information.

[Doneldon]

bobles-

You can do this easily with a figure-eight track arrangement. The secret is for the track under the overpass to be two inches below grade and the track on the overpass to be two inches above grade. That means that your entire track is used to gain the four inches. You can do this from grade, too, if you start the grades immediately from the point where the tracks cross. By the way, you can pull out or compress the WS foam risers which allows you to adjust the grades a bit.
                                                                                                                                                                                          -- D

[jward]

what point on the layout you use as your zero elevation is up to you. i use the lowest track on the layout as my zero, so that all other elevations are positive numbers.

btw, the formula i use to figure out how much elevation i need is 3" plus the thickness of the track board over the lower track. the 4" of elevation quoted is quite generous, especially if you are using a bridge over the lower track. in that case you could probably get away with 3" total, and make your grades up to the bridge less steep.