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Saturday, May 18, 2013

PHOTOS: Magnolia Cutoff Pole Line CPLs

A summer before the major re-signaling project I took a road trip out along the B&O Main Line to see someone about a horse. On the way I made a series of stops to document some of the more remarkable (and accessible) signaling locations west of where HANCOCK Tower used to be in West Virginia (the Wales of the United States, only with more open mines). Two of these locations were on the famous B&O Magnolia Cutoff, which was constructed in 1914 to bypass the old alignment that followed several bends in the Potomac River as it weaved its way through a series of mountain ridges. The Cutoff consists of a series of 4 tunnels, two high bridges and a number of rocks cuts. Sometimes around 1957 the portion of the Main Line between Mexico and Hancock was outfitted with bi-directional signaling over three main tracks and CTC. The three track portions retained wide signal gantries that were held over from the earlier days of 4 single direction tracks, but the Magnolia Cutoff was only two track wide so it was equipped with a bevy of CPL bracket masts that has become one of its signature trademarks. (The third track followed the old route before being completely abandoned).

Anyway,  I was able to visit the automatic CPL signal locations at Paw Paw and the eponymous Magnolia and this turned out to be an inspired move on my part as fast forward 9 months and CSX is preparing a re-signaling effort in the area that will see the elimination of many if not all of the CPLs on the cutoff. This is a real shame as the two bracket masts at Magnolia are one of the most iconic railfan locations on the B&O main line, often being compared to the PRR's horseshoe curve (which ironically lost its classic signals in 2010) and a photo of them adorns the top of the Wikipedia page on North American railroad signaling. What makes the Magnolia signals special isn't so much anything about the signals themselves, but their surroundings, specifically the bridge-tunnel-bridge combination where the B&O main crosses the Potomac river, punches through an imposing ridgeline via the Graham tunnel, then crosses the Potomac again.

Of course the Achilles Heel of the classic B&O signaling on this route can be seen in this photo where we can see a thick bundle of wired heading out of the relay cabinets, over to the line of wooden telephone poles and then way in the distance is the scar of cut trees where this same pole line travels up and over the mountain. Multiply this across all 4 tunnels plus the intervening track mileage and you can see how this can become a maintenance nightmare not only keeping the pole line in a state of good repair, but actually getting people out to the location to do the job in the first place. 

So anyway while I had numerous photos of the Magnolia signals taken from the rear of passing Amtrak trains, I had never actually ventured out to see them up close. On this trip I sought to change that and I will share my findings here, but I should mention that the actual signals at Magnolia are not very special consisting of a pair of opposing CPL brackets with a pair of 3 aspect automatic block signals on each. Therefore I will try to focus on the humble pole lines that power the signals on their daily routine.

Here we see the CPL brackets facing east. They are approach lit and therefore dark as no trains went by during my visit. While located at milepost 145 they are plated as milepost 6.3 due to the cuttoff getting its own numbering system separate from the signals on the original alignment. When the old main line was abandoned no need was found to replate the cutoff signals.

The signals are simple 3 aspect ABS types able to display Clear, Approach and Restricted Proceed. The 12 o'clock orbital is illuminated for all three aspects, but when originally installed the orbital would darken if the flow of traffic was set opposing to the signal thus enabling a 4th, absolute Stop aspect. However updated signals rules have overridden this extra level of safety and the numberplate overrides the dark orbital making the signal a Restricted proceed even when traffic is set against it. (The absolute signal of the last interlocking can be assumed to provide protections against two trains meeting head on). To say these signals would need a coat of pain would be an understatement and given the upcoming re-signaling it is doubtful they will ever receive it. 

The westbound signals show an equal amount of corrosion, but at some point they got some new wiring as evidenced by the somewhat fresher blue insulation snaking about. The junction boxes on the rear of the westbound CPLs are of the original large, fluted type.

The eastbound signals newer compact versions made by GRS and were possibly installed with the CTC project. 

Below view of the westbound bracket showing the steel mesh the maintainer stands on to service the signal heads.

Both brackets were originally painted with a silver base and a black top to aid in providing contrast for the signal lamps and visibility for the signal post itself. Eastbound signals are numbered 62 and 64, westbound 61 and 63.

 Other reasons old style bracket masts such as these are tagged for replacement are the lack of "OHSA compliance" for the ladders and handholds used by the signal maintainers. Bracket masts must be tall enough to be visible over trains on intervening tracks so its a pretty long climb up a very narrow ladder.

Looking at the rear of the eastbound bracket we see the battery box for backup power, the relay cabinets and the bracket mast. 

Signaling cables travel up the outside of the bracket mast supports.

Here we see a closeup view of the battery case in the foreground and the double-wide relay cabinet. I am unsure why this cabinet is larger than others that perform a similar task, but it is.

From the opposite angle we find a concrete pole line post that anchors the wire bundle that heads back to the wooden pole line. The B&O had a thing for concrete posts for its trackside junction and telephone boxes. Also note the little loop down in the table that prevents water from running down the wires and into the relay case.

An unnervingly thin wire running from the top of the bracket mast supports the bundle of cables as it leaves the anchor pole and heads over to the wooden pole line.

The bundle of signal wires is about as thick as a wrist, but one can expect to see larger bundles at interlockings.

Finally we reach the pole line where about 8-10 signal wires terminate and then feed into the bundle bound for the relay box. At the far end of the lower cross-arm area pair of power feed wires each carrying about 440V @ what I assume is 60Hz. At the near end of the cross-arm are a pair of CTC code lines, although I am not sure if they are still in service. These would only be tapped into at interlockings where the dispatcher can exercise control. You can tell they are for communications because the wires cross over at regular intervals to cancel out electromagnetic interference

With the bracket mast standing vigilantly in the background we see the power supply transformer connected to the 440V line as well as the terminal insulators for 3 of the westbound signal wires. They are run along the cross-arm to be bundled into the thick cable which then is anchored to the central pole.

An underside view showing the power transformer and both sets of signal wire terminals along with the wire bundle. I should explain at this point that the signal wires are used to transmit state between signaling locations. Note the difference in insulators b/t the 440V power feeds and the signal state wires.

Here we see the terminal insulators for the eastbound signal wires. From this photo we can see that there are 8 in each direction. Each wire can be thought of as a one bit digital input that then drives the delay logic. Each automatic signal location must get at least one input from the next signal location to determine if more than one block is clear and it must also know if a flow of traffic is set to then set opposing signals to Restricted Proceed. The other 4 wires can be a mix of spares or extra block state that need to be transported to the nearest interlocking where the information can be sent out over the CTC code line.

Here we see the entire west side of the pole from a lower angle. The upper cross-arms are no longer in service and were used for the communications lines that connected the various interlocking towers and wayside telephones. As radio and public switch telecommunications became more available and reliable there was little need for the railroad to maintain its own closed system.

Here we see a non-terminal pole with 8 glass or plastic insulators (including two on suspended mounts) for signals and 4 rubber or ceramic insulators for the 44V power feed.

The fun doesn't end there because just a little ways down the track is a feed from the Utility power grid into the railroad signal power line. That transformer on the pole is what supplies it. I suspect that the railroad power line has multiple feeds in case any one goes down.

The utility power then goes through this fairly new digital electric meter and fuse box.

Through this equipment box which...does something.

And then onto the pole line which has a separate power feed in each direction. The westbound feed doesn't seem to be doing so well. Not another one of those concrete posts to which all of the power feed kit is attached. Also note an earlier power tap to the utility line which had been rendered redundant when the new electric meter was put in.

Here is a closer view of the power feed as it hooks into the 440V power lines as well as a good view of the glass insulators holding the signal lines.

Here we see the whole thing in one go, utility pole, concrete post mounted power feed equipment and the pole line.

A few hundred feet to the west the signal cables are placed into another bundle as the pole line crosses the bridge over the Potomac River. The code line continues on in its single wire state. Note another concrete post with the junction box for the wire bundle.

And here we see the pole line crossing the bridge on a series of stub poles mounted low on the support piers. I am not sure if the signal wires had always been bundled across the river or if they were originally mounted on insulators like the balanced pair communications lines were.

At the risk of going a little long here I will travel about 2 miles as the train flies to the eastbound bracket mast at Paw Paw. This signal location is in the eastbound direction only due to the position of the Carothers tunnel that limits line of sight for westbound movements. Westbound trains have their own signal at Carothers.

 Paw Paw is still on the Cutoff numbering system with signals 86 and 88. Like Magnolia the bracket mast and associated signals have been suffering from a strong lack of rust proofing. I believe the central CPL targets may have been replaced more recently as they do not seem to have the same level as rust as the rest of the mast.

 This is backed up by the fact that both signal heads are fitted with the newest style of junction box that is not GRS branded and started to be installed around 1990.

 Anyway Paw Paw is at the end of the Cutoff pole line and as you can see here it comes down from its journey over the most recent hill before reaching a full termination at the tap for the Paw Paw relay box. Can you imagine having to climb up that hill with a ladder to attempt to repair a broken strand of copper wire?

 The relay box was originally a single-wide unit, which befits the single pair of signals, but had a new case installed next to it. This may be fore more modern coded track circuits that are in service west of this location. The bundle of wires is a bit thicker than the one plugged into Magnolia which is partly due to a section of 4-block signaling for westbound trains that incorporates the signals at Carothers, Little Niagara and finally the interlocking at Okonoko.

 The pole line termination shows two full arms of 10 wires each, more than double the amount at Magnolia. There is also no code line or power line present. Electric power has been patched in via an independent feed that is probably obtained from a nearby utility pole connection.

 The wire bundle assembly on the pole looks like quite a rats nest and I would not be surprised if many of the 20 wires were either spare or just disused.

 As you can see from the rear this is a complete terminal for the pole line signal wires. The PVC pipe delivers the power feed up to where the wire bundle is being assembled. It can be assumed that the 440V box transforms the current to the proper voltage just as the cross-arm hung box at Magnolia did.

 Side view of the same. If anybody has some knowledge about pole lines and what all the wires do please let me know and I'll update this little essay.

 Here is a somewhat backlit view of the Paw Paw bracket, the relay case and the pole line terminal.

 I'll end on a good photo showing the bracket, tunnel and the pole line snaking up and over the hill on its journey east to Hancock.

Unfortunately all the end came far too soon for this historic section of pole line connected signals on the old B&O main line. By the summer of 2011 the section containing the Magnolia Cutoff between Okonoko and Orleans Road was re-signaled and the former 4-track section between Orleans Road and Hancock followed suit in Spring 2012.  The former location of the Magnolia Signals themselves became a new interlocking to provide flexibility in an upcoming tunnel clearance project. CSX and other railroads continue to rip out their remaining pole line systems so if you happen to encounter one take some extra pictures because what was once a nearly invisible part of the railroad landscape is on the verge of extinction. However, with the help of a camera we can always remember the good times.

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