Since Fillmore is “essentially complete” (defined as: all of the trackage is in place and operational, scenery is plausibly detailed, and the operating scheme is working), I find that I can now explore some more finer points of railroad modeling.  One aspect of operations that I was slow to jump on is momentum & braking.  It was something that I was aware of before, but it was not a priority at the time.

Two things influenced me to adopt m&b.  The first is a brilliant posting by Riley Triggs, one that very much got me thinking.  In it he describes the “levels of play” that operators on his Port of New York layout may choose depending on their level of experience and interest.  The baseline level of play is locomotives with programmed momentum & braking along with switch lists.  The complexity of play increases from there, an excellent read – here is a link to that post Op Session 3.

The second influence is a recent article in Model Railroader (July 2016, page 54) by Mat Thompson “A practical guide to MOMENTUM AND BRAKING”.  Since Mat runs with Sountraxx decoders, as I do, I found it very easy to understand how he implements m&b.  Now all Fillmore locomotives currently with Soundtraxx decoders are programmed with m&b – not overly so, but enough to create a behaviour that is more prototypical just as Mat describes.  His article is highly recommended reading for a better understanding of m&b.


This past Sunday I spent an hour adding m&b to my four steam switchers.  I used JMRI DecoderPro3 and my programming track to change the settings based on using the MR article as a guide.  I remapped the brake function to key F6 (normally found at F11) as this key is easier to use than F11.  The starting momentum gives a sense of weight to the locomotive.  If the engine is moving and the F6 button pressed, it will decelerate and a brake squeal sounds.  On my switchers, from a normally high yard speed of 10% (Digitrax), the braking momentum is about 1/2-3/4 tender length.  At speeds 4% and slower there is no brake squeal, however and air release is heard.


This change has caused a slight re-ordering of the function keys and the current standard configuration is shown below.


For operator convenience, I don’t want to add any more functions as I have used the first 9 keys.  There are many more function keys available, but that requires using a shift button to access those levels which I feel is a bit too much fuss for the average operator.

The usual functions for headlight/backup light, bell, & whistle are found as F0, F1, & F2 respectively.  F3 & F4 are for my QSI equipped Alco HH600 switchers.  F5 is for the dynamo (steam turbo generator) – I separated this from the lighting function so that it can be on while the head/backup lights are off.  F6 actuates the aforementioned brake.  F7 for coupler clank, handy when switching cars.  F8 is the standard mute button.  Lastly, F9 is a steam release which is also used for blowing down at the wash pits.

This listing is printed and then attached to the back of my DT-402D throttles for quick-reference  by my operators.