24-03-09 PHOTOS: Power Director Office Powered Up

In the spring of 2024 it had been over a year since I had been able to get out to the Harrisburg Power Director's office, which had been between 1939 and 2013 in service to manage to manage the PRR's western traction power network. In 2022 the office had been taken over by the Harrisburg Chapter NRHS as an adjunct to their operation at HARRIS tower, however due to staffing considerations it is open much less frequently. The first time I had been there, pretty much only the room lights were functioning with the Big Board and control consoles all dark and lifeless. However in the 18 months since that first visit, the team of volunteers had managed to reactivate a substantial portion of the equipment and today's photos ( mirror ) will cover both the trains passing by on the adjacent Harrisburg Lines and the condition of the power office, with a few surprises mixed in.

The occasion of this Power Office open house was the train show the Harrisburg Chapter organizes in March of each year. Although HARRIS tower has ample free weekend parking, the power office is located inside the current Amtrak station and does not. Therefore, despite the drizzle, I parked at HARRIS to walk over. This put me in the position to catch a westbound NS doublestack intermodal train lead by SD70ACC #1850 and AC44C6M #4012.

Due to the train show, the power office saw healthy crowds all day.

The biggest change since 2022 was that the status lamps on the Big Board were now all lit.

However the more surprising development was that some of the SCADA panels had also been activated.

By "activated" I don't mean that the lamps had been turned on, but that the elements that drive the lamps and respond to the switches had also been restored to functionality. The office contains banks of relays that store state from the field equipment and encode/decode messages to/from said equipment. While the real field equipment no longer exists, the chapter volunteers were able to replace it with virtual equipment run off an Arduino type setup.

As of the spring of 2024, only the Westinghouse supplied "Visicode" equipment had been reactivated as its pulse code communications protocol was both dead simple and easy to reverse engineer. What makes this restoration extra surprising is that most of the Westinghouse consoles had been deactivated around 1983 when Conrail threw in the towel on electrified operations, as opposed to 2013 when Amtrak replaced its portion.

I'll probably write up a much more detailed post about this equipment on my dedicated signaling blog, but for a quick summary, the consoles function by first pulling a knob to select a module. This is sort of like taking a phone off hook and results in the back end relays taking action to accept the command. One then moves the switch to the desired position, activating the "out of correspondence" light. Then one chooses "Master Trip" or "Master Close" depending on the action and the message is coded out to the field equipment. If that didn't make sense, hopefully this video can make things clearer. 

Because the PRR western electrification was carried out with depression era WPA loans, the PRR had to spread the resources around and Westinghouse and GE split the contract. At the time of my visit the GE "Polaricode" consoles had not yet been activated as they have a more complex protocol that was not as clearly documented. Most of these consoles had been in use through 2013 controlling the power on Amtrak's Harrisburg Line west of Thorndale.

However, the biggest surprise on the visit didn't involve the power office, but STATE tower, which closed in 2017. Due to some renovations, STATE was accessible and I managed to get in for some photos. I had actually gotten into state back in 2003 while traveling to Chicago and and even been given the opportunity to use the Model 14 machine. While the Harrisburg Chapter does not have any control over this space, a restoration similar to HARRIS is not beyond the realm of possibility.

The other surprise was that the STATE relay room was also accessible. The reason for the access was a general renovation so that Amtrak could reclaim the space for offices. Apparently signal staff had left some of the relay equipment active after STATE closed in 2017 causing space auditors to assume the relay room was still in use until someone figured out the ruse. While all of the relays had been removed, the shelves, cableways and work areas were still in place.

Heading back to my car at HARRIS I was lucky enough to catch one more NS train with AC44C6M #4401 and BNSF ES44C4 #8161 passing by in the rain.

That's all for this trip. Next time I'll be heading back to Dallas for an attempt at riding the Denton A-Train.