Getting Real column - 6
I also measured how long it took for each train to perform the
typical switching needed at each location during an operating
session. From this information, I could start building a working
timetable. I used Excel for this task since it was easy to continu-
ally change arrival and departure times at various locations
along the line and to adjust times for the meets.
In order to build a timetable, you’ll also need to decide on
a fast clock ratio. Of course if your layout is large, with long
distances between towns, the fast clock ratio can be fairly
low such as 2:1 (meaning that 10 minutes by the fast clock is
equivalent to 5 actual minutes). Over the years, it seems that
operators are moving to lower and lower fast clock ratios. One
argument in favor of this trend is that some tasks can’t be com-
pressed, such as the time needed for switching and issuing
train orders.
However, one of my goals in developing the timetable for my
layout was to also produce a timetable which provided travel
times between stations reasonably close to the prototype
timetable. For example, the prototype YV log train departed
Merced Falls at 8 a.m. and arrived in Incline 3 hours 10 minutes
later. On my layout the same train takes about 22 minutes for
the same run. But if I use a 10:1 fast clock, that 22 minute run
will take 3 hours 40 minutes, very close to the prototype time-
table run time.
Now, a 10:1 fast clock is a very fast ratio! That means that one
minute on the fast clock takes only 6 seconds. If you need to
leave a yard at 9:55 a.m., you only have a “6-second window”
to leave on time. This can be stressful for some operators.
However, while I built my timetable using a 10:1 scale time
ratio, I actually operate it with an 8:1 fast clock.
While that might not seem like much, it does give a little more
time for things. More importantly, when I timed how long it
took to run between yards, I ran trains at only 18 scale miles
per hour. In addition, I was very conservative when timing
3: This is a prototype YVRR switch list from August 13,
1945. This switch list was written up for a Merced yard
crew, since all of the cars on it are to be taken to the
SP and AT&SF interchange tracks. Note that this form
shows the name of the railroad as the Yosemite Valley
Railway. That change was part of a bond refinancing
plan which took place in 1934. I chose to retain the
original name since that was the name most commonly
associated with the railroad.
switching moves. Together, these factors allow operators more
time to run between times and complete needed switching.
In addition, all of the major
switching needed to build the
two locals prior to departure is
done long before their depar-
ture times. For example, the
operator for the Merced Local
typically needs to pull their
caboose from the caboose
track and then pull 4-5 cars
from the yard tracks to build
their train. Some of these cars
might be “buried” behind
other cars which need to be
put back where they started.
But the operator of this local
will typically “go to work”
at 5:30 a.m. for a 9:55 a.m.
departure.
The fast clock is set to 5:30
a.m. when this operator has
looked over their switch
list, figured out an efficient
approach for the work, and
3
MRH-Jul 2013
