Feb 26 2009
Planning Your Outdoor Garden Railroad - Part 10 - Tracks
Planning Your Outdoor Garden Railroad - Part 10 - Tracks
Track planning for the garden railroad is more complicated than connecting circles and arcs with straight lines.
Outdoor railroads are often on a slope. The most visually interesting railroad operations are when tracks cross each in the same spot. I’m not suggesting arranging crashes at grade, although that certainly appealed to Gomez Adams. I’m suggesting having one track section cross over another as in a bridge over a grade level crossing.
You need to figure out the slope of the track needed to accomplish this. The track does NOT need to be straight. In fact, the most common arrangement is having the track run in a circle or arc. Trains struggling to get up hill are not fun. You need a grade or change in elevation that is gradual and extends over a distance of track to make the trip easier.
Railroad grade is expressed as a percentage. A 1% grade is a 1 unit rise for every 100 equal units run. So a 1% grade could be a 1 foot (12 inch) rise over a 100 foot length of track. A 2% grade would be a 1 foot rise over 50 feet. A 3% grade would be a 1 foot rise over 30 foot run. 3% grade is pretty much the maximum that most trains can handle. A flatter or lower grade takes more track, but it is substantially easier to have your trains run on it. This same principle applies to all scales. If you are modeling in HO Scale you can use inches for your units. 1% grade is 1 inch rise for 100 inch run. In HO you’ll probably want a 3 to 4 inch rise so the train clears underneath the crossover track.
Grade dramatically effects the length of trains you can run on your railroad. If you are into long trains or very large equipment (such as modern equipment) try to plan a railroad with gradual grades.
TIP: You can “split the difference” by having one one track go downward, and another rise upward. The crossover point clearance is the critical measurement. It can ripple back to two different points (one for each track). This way each track only needs to rise or fall one-half of the total elevation.
Have fun!
Trainguy
