[OT from cottage renovations]
the railroad is seldom mentioned in this space though its proximity is a great deal of what first drew me to the Grove and to this cottage so many years ago.
now and then, though, it provides comedic opportunities that are too good to pass up.
the CSX AU dispatcher desk is responsible for train movements from Halethorpe, just outside Baltimore, down the Capital Subdivision to Washington DC and thence out the Metropolitan Subdivision to Point of Rocks and past Brunswick to Weverton; also from Halethorpe out the Old Main Line to Point of Rocks and the Frederick Branch off the Old Main Line to its namesake city.
the territory consists of about 175 route miles with 36 control points.
the Capital and Metropolitan Subdivisions are bidirectionally signalled double track while the Old Main Line and Frederick Branch are single track.
there are crossovers or passing sidings, respectively, at ten mile intervals.
the dispatcher has voice radio communication to trains and remote control of signals and switches at the control points.
weekday mornings see MARC "Brunswick Line" commuter trains coming down the Metropolitan Subdivision (three of them originating in Frederick and running out the Old Main Line to the junction at Point of Rocks), as well as the "Camden Line" running both ways up and down the Capital Subdivision.
other morning regulars include hot westbound intermodal train Q139 out of Portsmouth VA for Cleveland OH; the K951 first trick Rock Runner on its way in from Millville WV (a stone quarry out beyond Harpers Ferry) to Bladensburg; and the D765 trash train, which runs from Derwood out to Pepco.
the Rock Runner generally follows the last inbound MARC train but the trash train is usually ready to come out and play while the MARC trains are still doing their thing.
day in and out the trains need to move at about the same time, but how well it works depends greatly on who's sitting in the AU desk chair down in Jacksonville.
Q139 and the trash train are the two oddballs, and a good dispatcher can weave them into the flow without compromising safety or incurring delay.
Friday morning they were the stars of the show, though the director's performance was less than stellar.
voice and data radio made it possible to follow all the steps in real time.
the setting
the 17½ miles of main line over which the trash train operates looks like this:
Metropolitan Subdivision, Derwood (R) to Pepco (L)
it amounts to 10% of the route miles under this dispatcher's control.
(Washington Grove is located at milepost 20.5, a bit to the L of the Derwood control point)
the objective is to move the D765 trash train from the trash plant spur just E of the Derwood control point out to the Pepco Lead without delaying the passenger trains.
because the sidings face opposite directions D765 backs out of the Trash Plant siding onto the main line, runs forward through the Derwood, Buck Lodge and Pepco control points and then backs into the Pepco Lead siding.
later in the day when the empties come back he puts the locomotives on the other end and the pattern is the same: backing out, running forward and then backing in.
Plan A
the best way to do this is to cross the trash train over at Derwood and then again at Buck Lodge:
crossing over twice
this allows the commuter trains to take the customary inbound track, which is in accordance with passengers' expectations, and also provides the opportunity to hold the trash train on the outbound track at Buck Lodge in order to let one of the passenger trains by if need be.
the trash train then runs out past the Pepco control point and backs into the siding there:
Plan B
the next best way to to this is to run the trash train straight out the (nominal) inbound track.
the inbound passenger trains are then obliged to run on the other track until the trash train can get out of their way.
it's inelegant, and a bit less safe (at each stop passengers will have to cross both tracks to board their train) but hey, it works:
straight shot
it ends the same way as Plan A, with the trash train backing into the Pepco lead:
Plan C
when the straightforward possibilities have been exhausted, there's always room for creativity.
yesterday's first trick AU dispatcher, let's call her PAB, has the usual inbound commuter trains as well as Q139, a priority intermodal freight running outbound.
after it has cleared she gives the trash train permission to back out onto the main and then lines it up to move like this:
cross over at Derwood and ... oops
having set up the trash train to follow the intermodal train, that's what he did, running through both control points and ending up on the wrong track at Pepco (with his train, of course, sitting on the high bridge over the Monocacy River).
once the crew passed the clear signal at Buck Lodge they were on the wrong track with no way to get where they were supposed to go.
recovery steps
the only way out was to back the train through the crossover at Pepco to get from track no. 1 to track no. 2 ...
... and then to pull forward through the control point, out onto the bridge again but this time on the right track ...
... and then to back into the Pepco Lead as usual.
all this extra backing around tried up the control point and main tracks on both sides of it for however long it took to describe the double figure Z.
in this case the consequences of a moment's inattention were minimal.
the trash wasn't in that much of a hurry to get to the incinerator, Q139 and the passenger trains had already made it through, and no unsafe moves were made.
just stupid ones -- PAB shouldn't have lined the trash train onto the wrong track, and its crew should have called her on the radio before taking the signal at Buck Lodge.
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