1
1: The N scale modular railroaders of Appaloosa Junction
face special dispatching challenges with a layout that can
change from show to show.
A.
The photo shows a single-track mainline without signals, and
Bernd says they are operating under Track Warrant Control.
Dave Husman said: “Current UP practice is to give warrants
only to the yard limit board, which simplifies things. So the
warrant would read:
Check box 2: Proceed from XY to yard limit mp 37.5
or
Check box 2: Proceed from XY to east yard limit Appaloosa Junction
Questions, Answers & Tips - 2
When the train fully enters the yard limits, the conductor
reports it clear of the limits (of the warrant). There is no need
to clear or hold the main track at the last named point, since
the train is in yard limits. The train does not need the dispatch-
er's authority to occupy track within yard limits – just to get
there. It can then work within the yard limits to do its switching
with no other authority. When it is ready to leave, it asks for a
warrant to "proceed from west yard limit Appaloosa Jct to AB."
“The real question is,” suggests Jurgen Kleylein, “should there
be yard limits at Appaloosa Junction in the first place? Yard
limits require all trains to operate on all tracks at restricted
speed. Is there enough switching going on there to require
yard limits? It might be better not to have yard limits and give
the trains working there 'work between' instructions so that
when there is no work taking place, mainline trains can run at
track speed.”
Bernd answered, “The biggest problem with our modular
layouts is the lack of 'track-only' modules so the distances
between the yards are rather short. For this reason it´s not bad
to slow the trains down with yard limits. On the other hand,
it´s a welcome relief for the dispatcher, that he need not con-
trol the traffic in these yards.”
So this is a case of model railroad expediency setting up a dif-
ferent situation than most 1:1 railroaders would meet in their
daily work. Bernd and his modular group could choose to post
a 25 mph limit on their mainline to slow traffic.
Let's take a short peek at yard limits. Yard limits are for trains
pretty much the same thing that school zones are for road
traffic – anyone in there has to move with extra vigilance, and
MRH-Jun 2013
