This page contains modeling tips and answers questions sent by visitors to this site.
Sent: Wednesday, June 27, 2001 9:47 PM
Subject: Rise
> I would like to know on a HO train layout what is the distance to rise
> ratio, or how far do I have to go to get to a certain height....
>
> Thanks for yor help
> Hans Heeling
In HO scale grades of 8% is practical with standard equipment. Normally for a smaller layout you should consider the 3% to 4% range; on a really large layout 1.5% to 2.5% would be preferable.
On the prototypes, at least for most railroads in the US, grades are kept well below the 3% range, with anything over 2.5% being considered "steep". The maximum for a real US main line prototype is 4.5% for the New York Central near Kingston Point in New York State. It is probably true that some logging and mining railroads out here in the Western USA had to deal with steeper grades, but they would have used special equipment such as Shays.
Here is how to work it out, regardless of scale:
Therefore, to rise 9 cm (about 3 in) at 3% you will need 3 metres (about 7 ft) of linear running room. Since, 7 feet is usually a lot of linear space for most average sized layouts, most modellers would use a loop for the rise as is often seen on figure 8 layouts. If you are using 18" radius curves for the loop the linear requirement would be approximately 40 inches to rise 3"
at a 2.9% grade.
Take into consideration also the equipment (models) you will be using also when planning your grades. Generally, the heavier the model is the better it will be at climbing. The Bachmann GE 44 Tonner I use on the PLC, which is very light, really begins to struggle on anything steeper than 2.5%. Bear in mind that model tracks and wheels are a lot smoother than the real thing. This is why curving the grades really helps the models as it introduces some lateral binding on the wheels.
One thing you might want to try is to tack some straight track on to a board and put it on an incline and gradually make it steeper; see how your equipment performs on the different grades. Real trains may make a "run on the hill" (increase speed) before tackling a grade. This usually does not work well with HO Models, especially on a small layout. Unless you have an exceptionally sensitive train controller, it would just look silly.
Have you ever wondered how fast your model trains are travelling? The table below can be used to calculate the speed of your trains.
| Time to travel 3 feet at scale speed: | ||
| Prototype Speed | N | HO |
| 5 mph | 65 sec | 36 sec |
| 15 mph | 22 sec | 12 sec |
| 25 mph | 13 sec | 7 sec |
| 60 mph | 5.5 sec | 3 sec |
| 90 mph | 3.5 sec | 2 sec |
On a small layout, your trains look most realistic when operated slowly.
© Sean Lim 2001
