Page 8 - July August 2008

Operation on the Baltimore and Ohio Paquettin Division
Mindful of the advice that one soon gets bored running trains round in circles, I designed my fictional part of the B&O railroad with operation in mind. The B&O Paquettin Division mainline runs between east and west staging tracks passing through Port Trenton Yard and a smaller town, Harmond, en-route. There is a connection between Port Trenton Yard and a large yard, imagined to be on the outskirts of Port Trenton, called Eckingham Yard, represented by a single staging track. The PRR also has trackage in Port Trenton and crosses the B&O mainline at grade. Further interest is added by a B&O car ferry terminal, dockside Port Trenton. A schematic of the layout is shown in Figure 1.
I envisaged running B&O passenger and unit coal trains interspersed with local B&O and PRR freight trains. I imagined that freight traffic would flow east to west (and vice versa) on the B&O fed by, and feeding, cars from and to Eckingham Yard, the PRR and the car ferry. Surprisingly, perhaps, I planned no industries at Port Trenton; rather, operational interest would arise from receiving, classifying and dispatching trains at Port Trenton Yard.
The first task was to estimate how many freight cars would be needed to operate the layout. The east and west B&O staging each have four tracks, half of which would be taken up by passenger and unit coal trains, leaving four tracks for local B&O freight trains. After allowing for space for locomotives and cabooses, the B&O west and east staging tracks can accommodate 40 and 30 forty­foot freight cars respectively. Eckingham staging can accommodate 20 cars and the PRR staging a further 15. Five spots each at Harmond, the car ferry and the B&O/PRR interchange track make for a further 15 cars, making a grand total of 120 local freight cars (see Figure 1). It should be noted that the number of cars was deliberately underestimated and that I decided not to include spots in Port Trenton Yard lest the layout became overcrowded. At the time of planning how to operate the layout I had about 80 cars. This meant that two of the B&O staging tracks could not be occupied, thereby foregoing two of the possible four B&O local freights per operating session.
I decided to use the tried and tested car card movement system. In essence each freight car has a car card containing information about its type, railroad and road number. The car card also has a pocket for a waybill (rather like a library ticket, before the days of bar codes, scanners and computers). During an operating session the cars are routed to their prescribed destinations as specified on the waybill. At the end of the operating session the waybills are rotated to reveal a new destination for the car so that a new cycle and operating session can begin. At the end of this the waybill can be turned over to allow two further sessions, making a total of four in all before one gets back to the beginning.
Having made out a car card for each car, the next job is to fill out the waybills. This could be done at random, but the chances are that at some point during an operating session one could end up with, say, a 30­car train going to the car ferry which only has sufficient spots to accommodate five cars. So this is where things start to get a bit tricky.
Fortunately Ted Smaile came to the rescue and pointed me to a number of helpful websites. To avoid overcrowding within any cycle, preference needs to be given to destinations which can accommodate the largest numbers of cars. To achieve this I placed the cars at each of the destinations in the numbers described above, ie 20 cars west staging, 15 cars east staging, five cars Harmond etc, using 70 cars in all. I placed the remaining cars on the PRR staging. I then filled out (in pencil) Cycle 1 for each car card waybill, giving the car’s current location (note that the cars on the PRR staging are assumed to shuttle back and forth, with only the head end cars being exchanged with the
Mike Tricker
B&O, so these did not have waybills). To complete the remaining cycles I constructed a table of destinations. Part of the first line of this table is shown below (where W = West, H = Harmond, E = East, EK = Eckingham, CF = Car Ferry and PRR = PRR).
If this is repeated five times you will see that there are 20 waybills with west as the destination, five with Harmond, 15 with east etc. I then displaced the first line by four places and put it under the first to give destinations for Cycle 2.
Note that this preserves the ratio of the number of cars that can be accommodated at any of the locations, so avoiding over­ crowding. This procedure was repeated to get Cycles 3 and 4.
Unfortunately this resulted in some cars staying where they are between Cycles 4 and 1. For example, the first column shows that the car would travel from west to west. I eliminated this by swapping some of the destinations around to yield the ‘final table’ below and filled out all the waybills.
I then realised that by swapping some of the destinations I had altered the ratio of destinations in cycle 3 and 4! Nevertheless I decided to press on.
The great moment then came when I turned all the waybills to reveal the cars’ next destinations. To my surprise (horror) I saw that there were a lot of cars travelling east to west and a lot from Eckingham Yard going east (in retrospect, I should have realised this was going to happen). As this would not generate sufficient switching moves in Port Trenton yard I changed about 15 of these waybills to get more cars travelling from the east to Eckingham Yard and more from Eckingham Yard travelling west. This did not have an impact on the ratio of destinations within the cycles.
In the first instance I decided to run a sequence of trains showed in the table. This sequence is interspersed with passenger and unit coal trains. The first train is a transfer freight from Eckingham Yard to Port Trenton. Once the transfer freight has arrived at Port Trenton the train engine is detached and sent to the depot. The east end Port Trenton switcher, usually a GP7, then takes over and classifies the cars. A track plan of Port Trenton is shown in Figure 2 (see page 25). Once the cars are classified (or during this process, if there is more than one operator) an east to west PRR local picks up and drops cars at the B&O/PRR interchange. An EMD switcher moves these cars, together with those from the car ferry, to Port Trenton yard. These cars are then classified. An east–west local then arrives. The train engine switches out cars bound for the PRR, the car ferry and Eckingham yard and picks up westbound cars. Cars destined for Harmond are then switched to the front of the train. A second engine is usually attached at this point as a steep climb up the Appalachians lies ahead. Alternatively the steam power is replaced by an A­B­A set of EMD F units. A local west–east freight then arrives at Port Trenton. The train engine is detached and the east end switcher classifies the cars. The train then departs, usually with less powerful motive power. A transfer run is then made to the car ferry and the PRR and the cars are classified. The cars on the
Cycle 1
W
W
W
W
H
E
E
E
EK
EK
EK
EK
CF
PRR
Cycle 1
W
W
W
W
H
E
E
E
EK
EK
EK
EK
CF
PRR
Cycle 2
EK
EK
CF
PRR
W
W
W
W
H
E
E
E
EK
EK
Cycle 1
W
W
W
W
H
E
E
E
EK
EK
EK
EK
CF
PRR
Cycle 2
EK
EK
CF
PRR
W
W
W
W
H
E
E
E
EK
EK
Cycle 3
E
E
EK
EK
EK
EK
CF
PRR
W
W
W
W
H
E
Cycle 4
W
W
H
E
E
E
EK
EK
EK
EK
CF
PRR
W
W
Cycle 1
W
W
W
W
H
E
E
E
EK
EK
EK
EK
CF
PRR
Cycle 2
EK
EK
CF
PRR
W
W
W
W
H
E
E
E
EK
EK
Cycle 3
W
W
EK
EK
EK
E
CF
PRR
EK
EK
W
W
H
E
Cycle 4
E
E
H
E
E
EK
EK
EK
W
W
CF
PRR
W
W
8 ROuNDHOusE