Shortly after the mainline
trackwork for the Southern Maryland Railroad was completed in March
2008, I hosted my round-robin group meeting at my house.
Part of the planned activity was to conduct timng trials of a train
over the line to arrive at a benchmark fast-clock speed for use on the
entire layout.
Two complete round-trip runs were timed, each with a different
engineer, and the results recorded. At the outset I believed
that a 12:1 fast clock would be required in order to arrive at a
reasonable run time over what I perceived as a relatively short layout
distance. Once the times were computed and averaged they were
converted to 12:1 times. They were found to be way too long when
compared to the actual time over the same route by the real-world
Chesapeake Beach Railway timetable which scheduled 37 minutes between
the two stations of Chesapeake Beach and Upper Marlboro. A little
recomputation determined that an 8:1 fast clock would almost exactly
duplicate the 37 minute timetable schedule.
The averaged time from the trials, conversion to 8:1 times, and the
small adjustments to the results to duplicate the Chesapeake Beach
Railway schedule are shown in the table below.
Timing Trials -
Southern Maryland Railroad
Westbound
|
Time
|
Elapsed-s
|
Convert
8:1 s
|
8:1
- m
|
8:1
-BtwSta
|
Cum.
Run Times
|
Sample
TT
|
Adj
|
Rev
Sample TT
|
Depart
- Chesapeake Beach
|
|
0
|
|
|
|
|
8:00
|
|
8:00
|
|
|
|
|
|
|
|
|
|
|
Arrive
- Owings
|
|
97
|
776
|
13
|
13
|
13
|
8:13
|
+1
|
8:14
|
At
Station
|
60s
|
60
|
480
|
8
|
8
|
|
|
-3
|
|
Depart
- Owings
|
|
|
|
|
|
|
8:21
|
|
8:19
|
|
|
|
|
|
|
|
|
|
|
Arrive
- Upper Marlboro
|
|
140
|
1120
|
19
|
19
|
40
|
8:40
|
-1
|
8:37
|
|
|
|
|
|
|
|
|
|
|
At
Station
|
30s
|
30
|
240
|
4
|
|
|
|
|
|
Turn
Train, Uncouple
|
|
104
|
832
|
14
|
|
|
|
|
|
Run
to Engine Service
|
|
26
|
208
|
3
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Eastbound
|
Time
|
|
|
|
|
|
|
|
|
Engine
Svc. to Couple Up
|
|
98
|
784
|
13
|
|
|
|
|
|
Boarding
|
30s
|
30
|
240
|
4
|
|
|
|
|
|
Depart
- Upper Marlboro
|
|
|
|
|
|
|
5:00
|
|
5:00
|
|
|
|
|
|
|
|
|
|
|
Arrive
- Owings
|
|
124
|
992
|
17
|
17
|
17
|
5:17
|
+1
|
5:18
|
At
Station
|
60s
|
60
|
480
|
8
|
8
|
|
|
-3
|
|
Depart
- Owings
|
|
|
|
|
|
|
5:25
|
|
5:23
|
|
|
|
|
|
|
|
|
|
|
Arrive
- Chesapeake Beach
|
|
107
|
856
|
14
|
14
|
39
|
5:39
|
|
5:37
|
|
|
|
|
|
|
|
|
|
|
Given the serendipitous
results achieved at an 8:1 fast clock setting for the Southern Maryland
Railroad portion of the layout, it is currently planned to use 8:1 for
the fast clock ratio on the entire layout including the much longer
runs on the Solomons and Patuxent Railroad.
Back to Operations Planning