Super elevated curves for open rainge fast freight

Started by cheerfulchomperofcheese, July 15, 2017, 06:25:15 PM

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cheerfulchomperofcheese

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WoundedBear

I'm gonna go out on a limb here, and say no.

I'm sure someone will prove me wrong.

Sid

Len

You could use 0.080" Bookbinder's Board, a.k.a. Davey Board, to shim the outside edge of the track. It's available from several places on-line, and some craft stores.

Len
If at first you don't succeed, throw it in the spare parts box.

Maletrain

Just a comment on your superelevation plans: 

Your post sounds like you will be increasing the amount of superelevation from the beginning to the midpoint of the curve, then starting to decrease from the midpoint.  That would not be prototypical looking.  The real railroads would have an easement to the curve, with the radius beginning at infinity and decreasing to the constant radius section in a smooth fashion.  In that same horizontal easement, the superelevation would start at zero and increase to its maximum value where the curve radius becomes constant.

The purpose of the easements on the real railroad is to make the centrifugal forces on the passengers and equipment increase at a comfortable and constant rate from zero to the constant value that occurs on the constant radius part of the curve , rather than by an almost instantaneous jerk to the side.  The superelevation likewise makes the curve more comfortable by making the force seem to go more "down" instead of "sideways".

On a model railroad, neither of these factors is really an issue, except for making the shape of the curves and the motion of the train seem realistic when we run our models.

There is quite a science to making easements to curves for real railroads and hhighways.  (Basically, the reciprocal of the radius, 1/R, increases linearly with distance around the curve, which makes centrifugal force build up linearly from zero to the maximum value for the curve.) 

On a model, it is just a matter of making it not look like a "train set" layout.  I am not going to try to explain easement layout here, but I will tell you that it does not have to be complicated.  There are several books that you can use to find methods for making easements for model railroads.  For instance "Track Planning for Realistic Operation" by Jack Armstrong (Model Railraoder Books) has an easy method using flex track.  If you do not want to use flex, you can get a similar-appearing effect by starting your curve with a piece of sectional track that is the largest made by your track manufacturer and then use sections of the available decreasing radii until you get to the desired radius for your curve.

Be advised that putting easements on curves needs to be planned well in advance of settling on your track plan, because it adds a lot of length and a bit of width to a curve, compared to just jumping from straight to your selected radius.  But, it really adds to the visual effect, as does superelevation when done right.

Flare

I'm a bit new to DCC myself, but I'll share what I can and I apologize in advance if my any of my knowledge is mistaken.


Answer 1:  I don't know of any programs that will automatically match speeds.  But there is a program called JMRI (Java Model Railroad interface) that is compatible with many DCC systems and gives a graphical representation of the speed curve on your computer and allows you to adjust the voltages.

Each locomotive is a little different, so you'll have to create a custom speed table for each decoder.  You can use a model train speedometer like the Accutrack II or Bachrus to measure each speed step and fine-tune the voltages from their readings.  http://www.sprog.us.com/speedo.html


Answer 2:  You'll definitely need a system that supports multiple power boosters.  I use NCE's system, Digitrax is good too, both have systems that allow for multiple operators.

Most decoders draw up to 1.5 amps, and boosters tend to add 5 amps.  So 30 locos times 1.5 equals 45 amps divided by 5 equals 9 boosters.

Use 14-gauge copper wire under your layout to deliver power to the rails every few feet and you shouldn't need to worry about voltage drop.

rogertra

Superelevated curves are not really needed in HO model railroading.  Even with toy train 18" curves, you can trains at full throttle with no ill effects.

However, superelevation does look good on scale model railroads.  I super elevated all my main track visible curve but do not elevate any siding curves.  This is very prototypical as sidings (passing tracks) are usually slow speed.  I elevate my main track, 36" minimum radius on visible track, by raising the out side edge of the subroadbed.  I use Donnacona fibre board as my subroadbed.  To raise the outside edge I use 1/16", 0625", balsa wood glued down starting about a foot into the curve at both ends.  For single track, I use four inch wide plywood  going to six inch wide for sidings..

The reason I leave a foot at each end is for the transition from level track to superelevation.  I then glue and temporary screw down the Donnacona, when the glue is glue, overnight, I then remove the temporary screw and lay track.  Simple system and it works well.

Cheers

Roger T.