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. 🙄

The Final* Wig Wag

In March of 2021 the final active Wig Wag style grade crossing warning device on a North American main line railroad was retired from service on the former ATSF Raton pass route, also known for hosting the last instances of main line semaphore signals. Located in the ghost town of Delhi, Colorado, the Wig Wag was signed for the Santa Fe Trail, but according to the map serves county (dirt) road 88 and was about 100 off of US Highway 350.

Preserved, along with the semaphores, because of the only use of the line is for Amtrak Trains 3 and 4, the Southwests Chief and, until recently, the route was under perpetual threat of abandonment.  With additional funding obtained to keep the Chief routed through southern Colorado, BNSF is engaged in a slow process of replacing the traditional signaling elements. 

Although the Delhi Wig Wag will join several other Wig Wags in various states of preservation in museums and on tourist lines across the country, it was the last example operating on a railroad main line with signaling and high speed operation.A cursory search of Youtube shows a number of others in various states of operation scattered around California and, until December 2020, Wisconsin.

Don’t forget the Van Ness wigwag which was also restored! (Motor was dead for 2 years, they finally fixed it a few weeks ago) pic.twitter.com/mzRrE5C4rY

— Fresno Railfan (@FresnoRailfan) March 17, 2021

If you are into technology connections, Wig Wags represent the general lag in display technology that was also seen in the audio visual world.  Electric power was limited, long life bulbs weren't very bright so electro-mechanical systems that moved a thing were the best way to get people attention in daylight.  From a time where any grade crossing protection that wasn't some dude with a flag was cutting edge technology, the Wing Wag has joined other vintage railroad technologies that today live on only in museums or literal backwaters.