MG Tower Update w/ Photos

 A few months ago I posted about the impending demolition of AR and MG towers on the PRR Main Line Allegheny summit.  While I believe the more accessible AR tower was indeed demolished, the demolition of MG is on hold due to the remoteness of the location.  After the tower was no longer needed for air compression and 100hz power conversion after the interlocking was re-signaled in 2019, NS crews went about removing anything of value, leaving the tower open to the environment. 

MG Tower in 2018

Although MG is heavily patroled by NS police to deter railfan activity (MG, with its tower and PRR signals was a very popular photo location), a railroader and friend of the blog sent me some interior photos they were able to obtain on a visit in the October/September time frame, which contain some interesting revelations.

The all brick tower was built in 1943/44 as part of a WW2 capacity improvement program to install an extra crossover on the East Slope. MG stands for "Mid-Grade".  It's robust construction fended off the demolition and fires that befell the mostly wooden towers between Harrisburg and Altoona.

Here we can see what I believe is some of the old power equipment that would convert 60hz utility power to 100hz railroad power.  When I visited AR I noticed that this equipment was still in service and as both towers were closed and re-interlocked around 1994 I would suspect the power board seen above was in service through 2019.

Unlike most other PRR Main Line towers, MG had an external stairway which has since been removed or fallen down.  Therefore my agent was unable to verify the presence and condition of the Model 14 interlocking machine and other equipment on the operator's level.  Here on the ground floor we can see racks for the 1940's vintage plug in style relays, which were a step up from the shelf relays still employed by the PRR in the 1930's.

The Conrail era CP-MG relay hut is also still present and open to the environment.  The real surprise here is that this 1994 vintage interlocking appears to be relay based, using the same plug in style relays employed in MG tower some 50 years before.  While I am sure there were some modern/solid state components, the mid-90's was well into the era of microprocessor controlled interlocking technology that would eliminate most glass case railroad relays.  While the mid-80's signaling that went in between Harrisburg and Altoona was clearly relay based, I am surprised that Conrail would not have been faster in its embrace of solid state.