Caught on Camera: Modern Signaling Inside Tours

Just discovered this recent video from a Union Pacific signal maintainer giving a tour of a modern interlocking hut and other signal relay cabinets.  While getting the occasional photo inside one of these is not all that uncommon, narrated videos from North America are almost unheard of.  Anyway I'm not going to summarize the whole video, but some important takeaways are as follows. 

• Compare how little has changed between a 2019 setup and this 1992 setup I profiled from GREENBELT interlocking.  The US&S Microlock II card based, microprocessor controlled vital interlocking hardware especially.
  
  
• Track circuits, switch motor controllers and possibly signal lamps are still still relay controlled and not even the solid state upgrade variety.
  
  
• The local control board has reached peak levels of simplification/cheapness.
  
  
• Make sure you watch the whole video for a tour of a 1980's or 90's Southern Pacific all-relay interlocking hut at the end for comparison.
  
  
• The wiring job is quite professional.  I'm not sure if the installers have put more points into wiring over time or have benefited from computer aided routing.
  

In this video he discusses power operated point machines (specifically a US&S M23), however also heads into the relay hut to locally throw the unit.  Here we see an example of the protracted throw times that used to be common for low voltage DC operated points.  Due to the gear ratio, the motor takes around 20-30 seconds to throw the switch points as opposed to 1-2 seconds seen on 120v examples.

We also have a complete guide to electric hand throw switch locks and their operation.

In addition he posted a video tour of a grade crossing relay cabin, which, although not my wheelhouse, interacts with the signal system in some interesting ways. The first crossing profiled uses a speed predictor that uses audio frequency overlay circuits to directly measure the speed of the train instead of a fancy wireless negotiation. Others still have quite a few electro-mechanical relays present in various roles.

 

SHORE Tower Catches Fire

In a situation that should surprise absolutely nobody, the PRR's SHORE tower, located at the old Frankford Junction, caught fire and suffered significant damage.  The 1896 structure was built to support the then new Delair Bridge to Southern New Jersey and was the oldest surviving tower on Amtrak's Northeast Corridor. The wooden tower closed at some point in the late 1980's and had somehow managed to remain standing stood for the next 30 years before someone or something set it ablaze.

SHORE post-fire

Although the damage was not total (see SO tower in 2009), this event will likely hasten SHORE's demolition.  As one can seen from the above photo, the tower is surprisingly accessible and is probably something I should have taken time to visit.  The exact state of the interior pre-fire is unknown, but while in service SHORE features an old school US&S 23-lever Electro-Pneumatic machine and a panel to control the remote FORD interlocking.

SHORE pre-fire

Just another reminder to get seek out photos when you can least you have events start to dictate your schedule for you.  If I am able to gin up any more photos of the tower, its interior or the interlocking plant I'll post something a bit more comprehensive.

What's Up With RTD and Caltrain's Grade Crossings?

Ever since the Denver RTD A Line opened in 2016, it's been plagued by strange grade crossing issues that eventually resulted in human crossing watchmen being posted for a number of years followed by a regulatory battle with the FRA.  Since then Caltrain has reported similar issues with a new grade crossing activation system citing them as one reason for the delays in their new electrification project. This begs the question, WTF is going on with RTD and Caltrain that would involve trouble with grade crossing activation, a problem that has been solved for well over a century. 

RTD A-Line Crossing Guards in 2017

A Twitter threat got me to Google this issue and I found a communication filed with the FRA from Denver Transit Partners that appeared to answer most of the questions if one read between the lines a bit. If you've tuned into my PTC reporting before you might remember how the entire concept was lifted from a grade crossing safety technology and while that has had a lot of implications on the signaling side it also means that project planners and political leaders have a ready made tool they can use to "solve problems", chief among these being NINBY complaints about grade crossing related crossing delays. 

RTD A-Line WiMAX PTC/WCAS Antennas

To make some more technology connections the RTD commuter rail network uses a traditional pulse code cab signal based ATC system and as it is an isolated network one might assume it would look to use ACSES as its PTC solution as that's the best way to leverage the cab signal system and avoid issues with wireless data.  Well for some reason they decided not to go in this direction and the reason is likely tied to the desire to implement a Wireless Crossing Activation System (WCAS).

At this point you might be wondering why an isolated 80mph commuter rail line needs a Wireless Crossing Activation System.  Well I was also confused until I saw that Caltrain had gotten itself into the same trap. Anyone that has ridden Caltrain knows that it's crossings tie up a lot of congested downtowns, especially around station stops and while Caltrain is in the process of a pretty extensive grade crossing elimination project, it's pretty clear if one reading the WCAS capabilities outlined in the previously mentioned DTP document that local motorists have a pretty strong voice when it comes to a frequent (4tph+ all day) commuter rail line snarling downtown traffic. 

Typically the example to justify WCAS is one of differential train speeds.  A "snow" freight train will activate the gates longer than a "fast" commuter trains will. While that is technically true there are scores of rail mileage in the US where 80mph passenger trains are mixed with 50mph or slower freight trains wit no ill effect.  On systems like Caltrain or RTD the number of freight is so tiny as to render this a non-issue.  The real "problem" is stopping trains.  Trains stop adjacent to a crossing and then keep the gates down for the duration of the station stop.  In addition to the longer delay there is likely a psychological element with drivers being delayed by a train that is just sitting there.  I have been told that some commuter rail operators like SEPTA and the LIRR have made use of timeouts to more aggressively raise the gates during long station stops, but I have no first hand experience with these. What WCAS looks to do is to have trains approaching the crossing negotiate if they are stopping or non-stopping  and then the crossing system delays the crossing activation and uses the attached PTC system to protect the crossing using a temporary speed restriction of some kind. 

This sounds great, but remember we have wireless involved as well as general complexity so, in the case of RTD, if this process fails, the backup is to use the full length signal block to trigger the crossing, resulting in a 90 second activation time.  There are additional issues of stopping trains (or trains that need to stop) getting non-stop activations that again result in a longer than planned crossing activation.  This brings us back to the DTP submission.  They are upset because CFR Part 49 Section 225 specifies a minimum 20 second activation time and at no point has this ever been a problem, in their eyes the FRA is baselessly trying to prevent motorists suffering from a few seconds of extra delay here and there.  Unfortunately Section 225 also says that a crossing system has to function AS DESIGNED and any deviation is considered a crossing malfunction.  This means that if your crossing protection uses neon lights and an air raid siren they had better work even if those aren't generally used elsewhere. 

From the FRA's point of view, the WCAS systems (at least used by RTD) was designed to have a certain activation time, the implementation isn't meeting the design spec so regardless of the 20 second minimum activation time the WCAS is not operating as designed and is therefore in violation of the regulations, thus the watchmen.  Sure, there are safety considerations involved with inconsistent crossing times, but the real issue is the meeting a design spec that was driven by the political considerations of crossing delays. 

TLDR NIMBYs demand the lowest possible crossing latency, planners see their shiny new PTC driven WCAS tools as a way to placate the NIMBY's, the technology fails to live up to the promise and finally the FRA gets mad.  There are multiple points to "fix" this issue  The FRA can be more flexible, the politicians can stand up to the NIMBY's or maybe the technology can be simplified.  Whatever the ultimate solution hopefully this sheds some light on the problem. 

Searchlight News

 I just realized that I had a growing backlog of news items regarding searchlight signals, some of it a little bit old, but still worth highlighting. First up the TWC/ABS territory on the end of Harvard Sub north of Harvard, IL is having its US&S H-2 searchlights replaced along with an associated code-line.  There are reports that this will not include CTC, however without any sidings on the track segment the addition of traffic control would be expected. This is the most up to date news so anyone in the area can probably still document the old signals.
 

Next, the former ATSF diamond in Plainview, TX is also losing its searchlights as of November, 2020, so they might alread be gone. 

Next, with the CNW ATC out of service, UP appears to feel free to now alter the interlockings on the Geneva Sub (former CNW main line) between West Chicago and Iowa, which had formerly gotten a reprieve. This will see the replacement of the CNW hallmark oval target searchlights.

Finally I have another case of some signals that got away.  In early 2020, the Guilford Rail System retired the signals on the Northern Main Line between Nashua and Manchester, NH due to low traffic and the generally failing state of the system.

While the above diagram doesn't make this abandonment look that bad, there were 6 automatic signal locations and 3 interlockings north of Nashua compared to only 2 automatic locations and 2 interlockings to the south. What's even worse was that I was in the are last Labour Day, however I was fixated on the Lowell terminal area due to the MBTA's Rule 562 project and didn't even realize that the North Main Line was even signaled.  I passed within 1200 feet of the retired CPN-28 without realizing it was there only to find out a few months that the signals had been taken down.  Not sure what the state of the other locations are, removed or just turned, but its probably still worth checking out.