Last July I had to take a trip out to Cumberland, MD to see someone about a horse and that provided a wonderful excuse to get out and take some pictures at some of the well known railfan locations long the CSX Cumberland Sub. You might remember these locations from such trips as
CSX Freight Spectacular and my
B&O Survey 2009. This time I was actually going to put some boots on the ground and see these locations up close and personal.
Unfortunately I didn't get much if any actual train action until I hit Cumberland so anyone who tunes in for trains instead of signals and scenery do not have to read more. For those of you who are still interested my road trip included stops at the very popular
Magnolia CPLs, the
Paw Paw CPLs,
Green Spring interlocking, the abandoned tower at
Patterson Creek and finally the
railfan bridge at Mexico. The first two locations are situated on the Baltimore and Ohio Railroad's
Magnolia Cutoff which was built around 1914 and literally cut off several miles of curvy Main Line track that followed some twisty bends in the Potomac River.
Blah blah blah you can see the full set of photos
here.
We begin with the CPLs at MAGNOLIA which are located just east of the Bridge-Tunnel-Bridge complex where the Potomac takes a sharp dip the the south forcing the B&O Main Line to cross into Maryland for the duration of the 1600 foot
Graham Tunnel. While the day wasn't too hot, it was still the height of summer and the sun was nearly straight overhead. The intense light, heat and humidity not only made the photos somewhat bright and washed out, they also were affecting the quantum structure of matter causing it to distort in the same way one sees with gravitational anomalies in Star Trek.
You can see the effect here in this telephoto shot of the Graham Tunnel across the first Potomac River bridge. It is hard to emphasize how huge that tunnel is although it is still not able to accommodate double stacks due to the arched roof profile.
In the heyday of the B&O both the cutoff and the old alignment were
in use and the line had three or four tracks between West Cumbo
interlocking near Martinsburg and Mexico interlocking at the eastern end
of Cumberland Yard. On either side of the cutoff signaling was mounted
on bridges that spanned all the tracks. On the Magnolia Cutoff, which
was built as a 2 track RoW, signaling came to be mounted on
bi-directional bracket masts, of which a pair was installed at Magnolia.
The eponymous Magnolia CPLs are a bit less impressive when you meet
them in person as opposed to how they
appear on Wikipedia due to the fact that they are approach lit and in this sort of sunlight tend to blend into the background.
Up close the brackets are clearly in need of buckets and buckets of Rustoleum and it was no big surprise when
photos appeared last month of
new CPL masts getting ready to replace the westbound bracket. It is for these reasons that it is so important to document this classic infrastructure before it is gone forever.
Even tho the Cuttoff and its CPLs are configured for bi-directional
CTC, the ultimate fate of these signals will be sealed by the pole line
that still transmits signal state and electrical power. Old school pole
lines are a big ticket maintenance item that also have serious
reliability ramifications as well. The current state of the art in
signal power and communications is to transmit block state through coded
track circuits in the rails and deliver electric power either through a
utility grid connection or via solar panels and batteries. The old
state of the art was a classic multi armed telegraph pole carrying a
multitude of single strand copper wire.
These copper
wires would transmit single bit state information between the signaling
locations such as if the local signal was at Stop and Proceed it would
cut voltage to the state wire to the next signaling location triggering
an Approach indication. Also included would be some sort of code line
to transmit information to any interlockings via pulse code modulation
as well as a 400-480v AC power line that would be appropriately
rectified at the signal sites to light the signals and power the relays
and track circuits.
Here we see the eastbound
Magnolia bracket with its wrist thick umbilical of copper signal wires
stretching from the telegraph pole to the
relay boxes. The
box hanging below
the crossarm is most likely a power transformer changing the 440V power
feed to a lower voltage for consumption by the equipment in the relay
box. You can see the difference in the insulators between the ones for
signal state and the ones for power supply.
Looking west along the pole line we can see how only a small number of
wires are needed for a modern two-track CTC setup. Back in the day
before modern communications this pole would have been crammed full of
telephone wires connecting not only lineside booths, but also railroad
towers and offices stretching hundreds of miles in either direction.
Keep in mind that before such things as the power grid and public
switched telephone network existed the railroads had to roll their own.
Here we can see the top of the westbound bracket. The sheer quantity of rust is one indication as to why this unit may be marked for replacement.
Here we see the eastbound bracket from the rear showing the pole line and its subsequent journey up and over the mountain that the Graham tunnel bores through. Is it any wonder that pole lines are near the top of a C&S department's capitol improvement list?
Magnolia is also the site of a pole line utility power feed. The power
for the pole line's 440v single phase supply has to come from somewhere
and this is one of those places. The power comes from a
utility pole, through
a meter, through some sort of
converter box that probably changes the frequency to 100hz or something and then onto the pole line's feeders.
Moving on to the next location we find the CPL bracket mast at PAW
PAW. Unlike Magnolia, this signal governs eastbound trains only as the
Carothers Tunnel and a curve blocks the sight lines in the westbound direction.
