I'd like to add a grade to break the monotony. Since I'm totally inexperienced my question is whether or not I need to add additional track sections for the graded portion? It seems like I do
since it will be gaining altitude, thus increasing the distance as opposed to a straight line. If so, how do I calculate the extra track sections necessary?
Theoretically, there is an increase in the track length on a grade over the equivalent track length on the horizontal, but it is very, very small and can be "taken up" in your track.
If you apply Pythagoras and calculate the hypotenuse on a 2% grade (1" rise in 50) you will find that it is one hundredth of an inch longer than the horizontal 50", which could be taken up in your
track joints.
Even going to a 4% grade (1" rise in 25") only gives an increase in length of four hundredths of an inch over 50" on the horizontal, or about a millimetre. And 4% is quite a steep grade for the
average model railway - a 2% grade is better to aim for.
Jim.
Yes, you will need more track, but by adding a grade, unless you are very accurate in building the grade, the height, etc., it is VERY difficult to accurately determine exactly how much additional
track you will need. You could calculate the length of the track as the hypotenuse of a right triangle, with the original track length as the base, the height of the grade as the height, and apply
the Pthagorian theorem to determine the track/hypotenuse. This will be only marginally accurate, because you will actually have curves up and down in the track that must be calculated as portions of
arcs - YAAAAAAAA! Why not do it the easy way - simply build your railroad! As you go up and over your grade, you will naturally come back to the place your railroad was originally to be, and you can
simply fill in with additional track. You will find, in fact, that using flex track rather than sectional track will make your track laying much easier, unless you are just building a temporary plan
on a table top.
Here is what you should in fact really spend your time worrying about -
1.) Unless you really enjoy one car trains, your grades should not exceed 4%, and 2% is much better. This means you should not go up more than 4" in 100". I have an 8% grade on one part of my own
layout, and it takes one loco with one car - that's it! It happens to be a switchback area to a single car siding for a small mine, but I cannot imagine putting such a steep grade in the mainline of
your layout and having much fun with it.
2.) I used to calculate my grade risers, and then build everything from wood, etc. I recently tried the track grade kit from Woodland Scenics, and all I can say is "WOW!" For most new modelers, this
is the best I have ever seen for making easy and accurate grades. You simply glue down the grade foam form, install roadbed, and lay track. It could not be easier. Try it.
3.) Do not start or end a grade in a turnout. This means keep the turnout flat along the grade; don't permit any vertical curves in a turnout. Your couplers will hang on the rails, the turnout will
invariably derail your trains, etc. I know from experience - it will be a headache until you replace it!
4.) Try to keep the radius of the vertical curve from flat level track to your grade at least 72". The larger the vertical radius, the more likely your trains will simply flow up your grade rather
than uncouple, etc.
5.) At the top of your grade, you should allow at least two car lengths before again going down. This allows the train to curve over the top rather than "teeter-totter" over directly from up to down.
Again, the longer the better, and the transition radius is a minimum of 72".
BTW-How do you know its 72", or any other particular radius? Simply take a string, tie around a pencil, and then pin down the end at 72". Draw an arc at least 1 ft to 18". Cut out. You now have a
template to match against your trackwork. TA-DA! You can make similar templates for your track work (I have radius templates every two inches from 12" to 96" that I cut from masonite with a jig saw,
and you can't imagine how often I use them!)
Tom Jones III
Your best bet would be the "cookie cutter" style design. Also, you want to always start your grade with one piece of wood transitioning from the level part of the layout to the grade. This way the
wood forms a natural easement in the start of the grade so you don't get cars uncoupling.
Ken Bessler