This is just a guide though.
A basic two-track corn syrup
facility could take two or three
hours by itself to be switched,
and one complex industry is
a good design solution if you
don’t room for eight indus-
tries. (See “A modern industry
for a compact space” by Jim
Lincoln, in Kalmbach’s “Model
Railroad Planning 2010”)
If your design starts running
to more than a dozen indus-
tries, you may be designing in
and building in more capacity
than you can utilize.
There may be other reasons
beyond operational variety
for having a larger layout
but you have to start asking
yourself some very pointed
questions as to what you are
accomplishing with that extra
capacity and square footage.
3: Shown here is the
switch list of the eight
industries worked in the
three-hour session.
3
yourself that you go for 20 minutes to an hour at most. Let’s
say you do this once or twice a week (ideally more).
At this point we know the lay of the land. If the maximum load
on our layout is when we have guest operators over, we only
need enough capacity for, at most, a three-hour session.
Design to operate
Now we get to the design part. The key question is this: how
much layout does it take to create a three-operating-hour ses-
sion? How many industries, or to be more accurate, how many
car spots do we need? This is where people get into trouble. It
takes far less layout than you would think because the individ-
ual operational tasks take far longer than you’d think.
Eight industries will give you a three-hour session. Certainly
there will be some variation in this number depending on the
type of industry but this is a good starting point. It certainly
isn’t 15 or 20 (or 50).
If you have the space, it doesn’t hurt to put in a few extra to
allow for some variety from session to session. A dozen indus-
tries would give you enough cushion so each session wouldn’t
be identical. I don’t view this as being critical, though, because
in the real world there IS a fair amount of repetition from week
to week. The larger, more active customers are often switched
every session. Remember also that the full-blown three-hour
session is the exception, not the rule.
Of those eight basic industries I’d shoot for:
One or two industries that have three or more car spots each
Four or five that have just one or two car spots
A couple of team track locations for unloading into the
street or a parking lot
Layout Size Using Op Session Timing - 3
MRH-Jan 2013
