What is a
speed step?
That is the
way that the
command
station tells
the locomo-
tive where
you have set
the throttle
controlling
a particular
loco.
To make
things easy,
consider how
it would work
if there were
10 speed
steps. As soon as you move the throttle off zero, the locomotive
would be told to run at 10% of top speed. As you advanced the
throttle, nothing would happen until you reached about 15% of
the total throttle range. Then the loco would be told to run at 20%,
until you turned the throttle up past about 25% of the range. So,
the loco would immediately try to jump from 10% to 20% of top
speed, its acceleration limited only by the momentum setting in
the decoder, the loco's flywheel and the load of whatever cars it is
pulling. Not very realistic.
From Mr. DCC’s workbench ...
SPEED STEPS IN PERSPECTIVE
11: Diesel control stand on an EMD MRS-1.
12
DCC Impulses Column - 11
MRH-Dec 2013
