AR Tower - Hanging In There.

As with my previous post on the state of MG tower, I can confirm that AR tower is in a similar state of limbo, partly gutted of some components, but left standing and even more open to the elements.  I found this video tour on YouTube showing the current state of AR Tower, but also the adjacent 100hz power house and compressor hut.  Shockingly, the double Model 14 interlocking machine is still in place and roughly in the same condition I found it back in May of 2018.

If everything plays out right I should be able to revisit AR tower towards the end of May.

FAIR Minus Air

 As I previously reported in 2019, Amtrak's FAIR interlocking in Trenton, NJ was having its pneumatic point machines replaced by electric M3's.  I can confirm that this process has been completed and the air compressor infrastructure generally cut and disabled. 

FAIR was one of the larger pneumatic plants remaining on the NEC, however a few others still remain such as HOLMES, PENN, RIVER, POINT, BAY, CHARLES, FULTON and LANDOVER. Of those PENN and BAY have been partly replaced and LANDOVER is slated for complete replacement by a new set of high speed crossovers. The New York Penn Station complex is also still pneumatic and is actually seeing refurbished A-5 point machines installed with the general rebuilt of the trackwork there.

PHOTOS: GREENBELT - The Last CPLs

In the fall of 2014 CSX completed multi-year re-signaling efforts in the heart of its former Baltimore and Ohio territory that included the Philly, Capitol, Metropolitan and Cumberland Subdivisions. B&O style Color Position Lights, some installed as late as the 1990's, were replaced by the typical hooded traffic lights. Beyond the odd siding exit, drawbridge, diamond crossing or distant on non-signaled track, the main line CPL era east of the Ohio River was over. There was however one notable exception on CSX in the form of GREENBELT interlocking in Greenbelt, Maryland. Located just inside the Beltway adjacent to the DC Metrorail-MARC transfer station of the same name, GREENBELT was distinctive in being an interlocking that only really served the MARC commuter train service. These CPL signals would stand for an additional 6 years until their replacement in late 2020. In May of 2020 I went out to GREENBELT for a documentation run so I could present to you photos of The Last CPLs.

GREENBELT interlocking was installed in 1992 as part of a general re-signaling of the Capitol Sub to better support the MARC Camden Line. This saw the elimination of any residual Rule 251 ABS territory, a new Camden terminal complex in Baltimore and the closure of any remaining manned towers such as JD TOWER in Hyattsville. Both the Capitol Sub project and a similar one on the Metropolitan Sub turned out to be some of the last where B&O CPLs were installed new. Like several of the new Capitol Sub interlockings, GREENBELT was commissioned solely for the benefit of MARC commuter trains and consisted of two side pocket tracks that would provide an ADA compliant high level platform connection to DC Metro's new Green Line terminus (The The Americans with Disabilities Act having recently come into force). Pocket tracks were necessary as high level platforms conflict with the clearance envelope of main line North American freight trains. The interlocking consists of two switch pairs, #1 and #2 and 4 signal pairs, 1E/1W. 2E/2W, 3E/3W and 4E/4W.

The signals were in turn broken down into 4 high mast CPLs for the main tracks and 4 dwarf CPLs for the pocket exits. The dwarf signals were placed following the old "right hand" style, while the high masts were not.

In addition to the 12 o'clock orbital for normal routes, eastbound main track signals sported 6 o'clock orbitals for Medium speed diverging movements into the pocket tracks as well as 10 o'clock orbitals for Approach Medium indications for crossover routes at AMMENDALE interlocking, one full signal block beyond GREENBELT.

Eastbound pocket track signals featured a 6 o'clock orbital for diverging routes back onto the main line as well as an 8 o'clock orbital for Medium Approach Medium indications when trains needed to immediately diverge again at AMMENDALE.

 
The westbound signals have a slightly more complicated history. As originally configured westbound main track signals featured both 10 o'clock and 2 o'clock orbitals for Approach Medium and Approach Slow indications respectively. This is because GREENBELT was also one signal block away from the former JD TOWER complex in Hyattsville. Trains approaching from the east would get an Approach Medium for track 1 to 2 crossovers or routes onto the Alexandria Extension at RIVERDALE PARK interlocking. However if a Stop signal was displayed at JD TOWER interlocking, a Slow Approach indication would be displayed (at least for diverging routes) at RIVERDALE PARK due to the short block distance between RIVERDALE PARK and JD TOWER. This then necessitated an Approach Slow capability at GREENBELT.

The westbound dwarf signals operated in a similar manner, just with a full row of lower orbitals including an 8 o'clock orbital for Medium Approach Medium and the somewhat rarer 4 o'clock orbital for Medium Approach Slow.

What the KCS - CN/CP Merger Means for Signaling

 A few months ago I discussed the absolute signaling disaster the potential purchase of Pam Am by CSX would be.  Since rail mergers are suddenly in vogue again, Canadian National and Canadian Pacific are nowboth bidding for Kansas City Southern and I am sure at least someone out there is interested in what this will mean for the signaling on the KCS.

To make a long story short, not much.  Not only is KCS pretty much entirely Darth Vader masts or slightly older traffic lights, both CN and CP are good about preserving the unique signal rules of their subsidiaries.  For example the CN owned Grand Trunk Western route uses a very NORAC style speed signaling system.  That feeds into the CN owned Illinois Central that still uses a bland weak route signaling system, which is also distinct from the CN owned EJ&E's signaling system. So yeah, don't sweat this one, just sit back and enjoy the C40-8s or SD70ACUs.

FTA 2013 CBTC Case Study, With Takeaways!

It's time for another government document hiding in plain sight! This time we have CBTC case study from 2013 that covers the NYCTA 2003 L line project and SEPTA's 2005 Subway-Surface trolley tunnel project. You may recall my often cited MBTA study that determined that CBTC was not cost effective compared to coded track circuit cab signals. This document's primary goal is to explore the derails of each project and determine what lessons can be learned, however it does reach the conclusion that both projects reached their goals and were worth the investment. That might sound like an endorsement of CTBC, but a careful read of the document paints a more complicated picture. Yes, CTBC works, but should it be the preferred option? Read on to see my enumerated list of takeaways. 

1. Both SEPTA and the NYCTA had their own specific reasons for adopting CTBC and the paper does not bother to evaluate those reasons. From the point of evaluating the paper's endorsement of CTBC, the paper does not do much to actually compare it with the alternatives, especially from a cost basis. It basically says, NYCTA wanted to do X, CTBC allows for X, NYCTA is now able to do X, CBTC works.
   
   
2.  The paper reveals why the NYCTA and SEPTA chose CTBC systems and the answer might surprise you! SEPTA wanted a trolley tunnel ATC/ATP system and got one free as compensation from AdTranz for late M-4 cars. The NYCTA needs to be able to run both equipped and unequipped trains in mixed service. I suspected that the issue was the NYC Subways extensive use of single rail track circuiting and I was mostly correct in this regard as trying to install a jointless audio frequency track coded circuit system on top of a single rail track circuit system would require some costly hardware "hacks" as opposed to less costly software hacks.
   
   
3.  Cybersecurity is a ticking time bomb for CBTC systems. For both SEPTA and NYCTA "A complete description of the necessary security measures for the product over its life-cycle was not included in the System Safety Certification Plan." Even if best practices were followed when the systems were installed in 2003-2006, they have almost certainly aged out (think SHA-1 or RSA 1024). Both systems communicate on the 2.4Ghz WiFi band using a deterministic spread spectrum technique to avoid interfering with WiFi. Wireless message integrity on SEPTA's system is provided by CRC checks (not secure) and "authenticity" is provided by header formatting and train ID (also not secure). It is highly likely that tools could be created that could interfere with operations, although human operators would mitigate potential impacts.
   
   
4. The paper confirms that the the pre-2003 L line capacity was 20tph under DT-ABS/ATS and was raised to 24tph under CBTC with a possible increase to 26tph with traction power upgrades.
   
   
5. The L line re-signaling was contracted for $217 million and SEPTA's trolley CBTC was valued at $24 million. No effort was made to track down cost overruns, the cost of alternative signaling or the cost of debugging the CTBC.
   
   
6.  Both systems were indicated to have experienced 1-2 years of service impacts due to debugging issues. SEPTA's were noted as "significant". As of 2013 SEPTA's CBTC outages were pretty rare, however a trolley needing to cut out CBTC and operate manually via traditional ABS happened about 5-6 times per week. It was mentioned that SEPTA desired additional degraded service modes for the future Rt 101/102 install as "cut out" and "crawl" were insufficient.
   
   
7.  SEPTA's system was intended as a safety upgrade only. It did not increase or decrease capacity, nor did it save money due to the retention of the fixed ABS as backup. The capacity standard was 60tph.
   
   
8. The number of maintainable items is as high as ABS systems. Long term maintenance was not addressed, nor long term availability of proprietary parts. Note, parts for cab signal systems are still available from multiple vendors. If the original vendor cuts off support it may force another round of re-signaling, raising CBTC lifecycle costs.
   

I had been generally aware of all these issues before I found this paper, but they had all come from first hand experience and unofficial sources on various forums. I encourage you all to read the paper and leave your takeaways in the comments.

PHOTOS: Bonus Port Road Trips - Inside COLA Tower

Opened in 1938, COLA tower, in Columbia, PA was closed around 1986 and then served as a glorified relay hut until 2012 when the interlocking it controlled was re-signaled. In the decade that followed, the tower, sealed up against the elements and scrap enthusiasts, has been left largely untouched. Possibly still used as an employee clubhouse or storage facility, the stout construction and generally benign location have managed to defend the structure from demolition. I recently came into possession of some interior photos, taken a some years ago, that shine a light onto the tower's life and post-life.



Built at the same time, with the same design and for the same electrification project as the previously covered THORN tower, COLA used CTC remote control technology (although not much actual CTC territory) to streamline operations at what would be the hub of the low grade freight network between the Main Line junctions at Parkesburg and Perryville, and the massive Enola Yard near Harrisburg. COLA interlocking and its extended CTC territory were all extensively covered in my Port Road Trips series and so I will try to avoid covering the same ground again, however the key point worth remembering is that COLA's status as an all-relay based interlocking plant meant that when Conrail's NEC operations were severely curtailed in the mid to late 1980's and the east-west portion of the low grade network was abandoned, Conrail was able to close the tower as a Block and Interlocking Station, brick up the windows, install an interface and control the whole plant from a computer terminal in Mt. Holly, NJ just as easily as it had from the operator's console on the second floor. 

25 years later Norfolk Southern finally got around to replacing the still 1938 vintage signaling at COLA as part of an area re-signaling scheme that covered much of COLA's former CTC territory and it turns out that they pretty much locked the door and walked away. On the operator's level, the CTC console has vanished (most likely into an employee's basement), but it's outline is still present along with the operator's chairs and a pretty snazzy Kelvinator.

Lockers for the operators are still standing against the wall and one can see the crudeness of the 1980's brick job compared with the large tile on the proper walls. At least Conrail decided to opt for brick as opposed to cinder blocks or plywood. Also note the institutional grade water fountain, which were the style in the days before bottled water.

On the wall behind the operator's position are a variety of railroad preservation related news clippings, pasted up an "enthusiast" operator along with various notes of a more work related nature. Banana stickers abound along with clues that smoking as still permitted inside.

The washroom appears to be of PRR vintage and along with the radiant heat system speak to how the ostensibly value focused PRR wasn't afraid to pay for quality. COLA, with its CTC system and indoor heat and plumbing was state of the art in 1937, on par with today's amenity filled Silicon Valley HQ's.

Failed a Spot check 2

Unlike last time, I'm the one that failed the roll, completely missing a classic signal in the DuBois, PA Buffalo and Pittsburgh CTC Island, even thought I was looking right at it. 🙄