GRESHAM JCT's Sequence Switches Explained

 Years ago I wrote up a profile of METRA's GRESHAM JUNCTION tower on the Rock Island division south of Chicago.  Not only had GRESHAM JUNCTION managed to stay open into the 21st Century, it was a unique North American example of a sequence switch interlocking. Supplied by the Standard Telephone and Cables Company of London, the interlocking used telecom grade sequence switches to carry out the interlocking functions instead of relays.

In my original post I provide photos of the equipment as well as a general concept of how sequence switches work and some sequence switch interlocking circuit diagrams from the UK, but without time and access to the equipment or someone who was intimately knowledgeable about how it functions, my commentary had to remain at a very high level.  Fortunately, the gang from the Connections Museum in Seattle is on the case because sequence switches is pretty much how Bell Number 1 Panel central office machines functioned (again, as opposed to later relay based technologies). I could try to go into things, but fortunately the museum's YouTube channel has video that is specifically about how sequence switches work. 

Once you see them in action at the Connections Museum, their function in the photos from GRESHAM JCT will become obvious. Of particular note is the function of the magnetic clutch mechanism that rotates the switch spindle. Perhaps if I stare at things enough I can determine what each sequence switch corresponds to in the interlocking.  Is each a complete route? An entrance? An exit? An entrance-exit combination? Let me know in the comments if you figure it out.  BTW, if you like this video take some time to watch the rest of the Museum's content.  It's top notch and does a superb job of explaining some normally opaque topics in the realm of pre-modern telephone switching technology.

CSX Bags Guilford But When to Expect Change?

CSx is set to complete its purchase of the former Guilford Rail System (currently branded pan Am Railways) on June 1, 2022.  However does this mean to immediately expect the end of NORAC Rules, searchlight signals and bracket masts? Well according to some initial reports the community will enjoy at least a slight reprieve before CSX has the opportunity to go to town on the Boston and Maine's legacy.

Guilford searchlights and the Lowell Wye.

As of now CSX plans to make no changes to former Guilford operations until October, 2022 due to the existing collective bargaining agreements and delays to the sale of the Pan Am Southern joint venture to a G&W subsidiary.  This means NORAC Rules and signal indications will remain in service until that point and it is unlikely that CSX will embark in any large scale re-signaling investments. CSX will also need to improve/signal the line between Worcester and Ayre to actually connect the former Guilford Freight main Line with its former Conrail Boston Line.

Boston Line CP-45 at Worcester

In the longer term, use of Rule 562 cab signal without fixed wayside signals on both the former MBTA territory as well as the Boston Line will likely keep the former Guilford territory under firmly under CSX's legacy "Conrail" signal rules, even if the operating rules change. How PTC is integrated into the new territory remains to be seen as MBTA lines that share the former Guilford Freight Main Line route around Lowell, Ayre and Haverhill, will be ACSES and cab signal equipped. It is entirely possible that CSX will choose to complete the look and install 562 between Worcester and Ayre and as part of any re-signaling projects on the Freight Main Line, including the Downeaster corridor north of Haverhill. 

Boston Line CP-187 with Conrail Small Target Searchlights

 As has been observed on the Boston Line, Darth Vader type signals have been slowly supplanting those of Conrail vintage, however this process is not complete after 20 years due to the young age of the vintage Conrail signaling. Fortunately the former Pan Am Southern covers both the Freight Main Line to Mechanicville, NY and the CT Valley Line used by Amtrak. The latter was recently re-signaled in the Guilford style with the remainder getting a mix of Darth Vaders and Guilford signals in any re-signaling projects.  I suspect the orphan nature of this route will further stunt investment, hopefully prolonging the life of the remaining B&M vintage searchlight equipment and US&S pulse code CTC .

Montana Rail Link Loses Its Lease

This news isn't exactly new, but I figured I should go over the signaling implications of the end of Montana Rail Link's lease of 400 miles of former BN Main Line in the state of Montana. 

Classic Northern Pacific Searchlit Cantilever Mast on MRL

MRL is fairly special in that it runs a high quality CTC main line with modern motive power such as SD70M-2's.  Like many regional railroads with signaling, changing out its legacy equipment was never a high priority, especially since it was PTC exempt and the the physical plant was leased not owned.  MRL's former Northern Pacific/Burlington Northern trackage is largely signaled with searchlights and GRS Type D color light signals with a mix of masts, small vintage gantries and cantilevers. 

BN vintage GRS Type D masts on MRL

MRL was in the process of having many of its legacy signals replaced by BNSF standard Darth Vader types with relay box mast combos being a popular replacement choice.  The reversion to BNSG is likely to accelerate the replacement process and although BNSF could in theory try and get a PTC exemption if it does not need to run TIH cargo on the line, provisions to make the route available for some potential passenger services make the prospect of government infrastructure money highly likely and with that comes a brand new bland signal system sooner rather than later.

Brand new BNSF type Darth Vader type signals newly installed on MRL.

As of this writing the lease termination appears to still be under review and if the limbo state accelerates and decelerates the existing re-signaling efforts remains to be seen. I recommend anyone in the area to get their photos now, the more the better.

Union Pacific to Abandon ATC and ACS Effective June 1, 2022

 Well after about 18 months of regulatory approval, Union Pacific is set to remove all mention of the CNW Automatic Train Control and more general Automatic Cab Signals from the rulebook effective June 1, 2022.  As explained before the legacy CNW ATC system was super clunky and was definitely not worth keeping in the face of PTC.  The ACS seems to be more of a cost cutting move as coded track circuit cab signals can compliment ETMS PTC as demonstrated by Norfolk Southern.  However Union Pacific's cab signal implementation had some shortcomings that would have likely required additional modifications to make a joint ACS/ETMS system work well. Anyway, the real loser are the Employee Timetables which are set to lose a substantial amount of their color palette.

It was mentioned that Union Pacific will still require ACS equipped lead locomotives in some areas, which I am assuming is the Hiawatha Sub as that served as Union Pacific's "Rule 562" experiment and lacks wayside signals. The Hiawatha has Aspect Change Points every 1.5 miles, in line with the PRR/Conrail/Norfolk Southern practice. It is also important to remember that in most cases the ACS codes will remain in the rails as they are used to transmit block state.  Engines will either just run over the territory with their ACS fully inoperative or simply not present. Anyway, if you want a copy of the current UP Rulebook with the ACS and ATC sections intact, download it from the official site now. If you're reading this in the future, I saved a copy of the final revision with the ACS/ATC material.

The Trials and Tribulations of Los Angeles' Closed Towers

This post fits neatly into the "old news" category as the events I am noting took place something like 4+ years ago, but it will provide some closure for anyone else who has not been paying attention. The West in general is known for its general lack of towers compared to the East and Midwest.  Certain area of California had more towers than most of the west, but the number was still rather low and from that level there was been a high level of attrition as those, largely wooden, towers were closed and demolished. Most of So Cal's surviving towers were in the general vicinity of Union Station with TERMINAL TOWER and MISSION Tower being the most well known. 

However a bit to the south were two attitudinal towers on the former ATSF Chief route, HOBART and REDONDO.  Each governed a single track diamond crossing of the busy AFST main line.

Built in 1906, REDONDO was located at the ATSF crossing of the Los Angeles and Salt Lake Railroad, that became Union Pacific's primary route into the Port of Los Angeles. The redwood frame tower was ultimately equipped with a GRS Model 2 pistol grip interlocking machine and the junction controlled the southern end of the LA passenger rain engine and car facilities. The tower was closed in 2001 when a passenger flyover was built over what would become the Alameda Rail Corridor route to the port of Long Beach that converted the sleepy UP main into a 3-track intermodal superway.

Located in a fairly isolated area the tower was generally left along for the next 15 years until some time after December 2016 the tower either caught fire or was tagged for demolition. By June 2017 the tower was a husk and by Octover 2017 it was gone. In 2001 the Alameda Corridor Transportation Authority was nice enough to commission an historical pamphlet with a selection of interior photos.

HOBART interlocking is located about a mile east of REDONDO at the west end of Hobart Yard where the UP San Pedro Branch crossed the former ATSF main line. Also equipped with a GRS Model 2 pistol grip power frame, the tower was a bit more modern than REDONDO being made of concrete. Closed in 2002, its location at a major yard and non-flammable construction gave HOBART a fighting chance of survival.

 

Unfortunately between May and December 2017, a fire started by homeless persons gutted the tower.  Although the concrete structure was still generally sound, the tower was now on the glidepath to demolition, a fate that was ultimately carried out in May of 2019.

Of course the fates can occasionally smile on old interlocking tower.  DAYTON AVE tower, located at the southern end of the Southern Pacific Taylor Yards north of Union Station, was saved by relocation not once, but TWICE.  

When Metrolink was building a new maintenance facility in the 1990's, DAYTON AVE tower was relocated from its initial site on the LA River to a site adjacent to the Metrolink Facility entrance on San Fernando Rd.

Later in ~2013 when this site was tagged for a new development, DAYTON AVE tower was moved again to a new location 3 blocks to the southwest on part of Metrolink's rail storage lot.

At the start of this article I mentioned TERMINAL TOWER and MISSION tower.  TERMINAL TOWER is currently used as some sort of MoW or signaling support base part of the greater LAUPT complex.  The long closed MISSION tower is less critical to operations, but is likely owned by a government entity and has been generally protected by local preservation groups and general governmental paralysis.  I recently found a 1980 vintage film on Youtube documenting ATSF operations at MISSION tower with its GRS Model 2 pistol grip type interlocking machine.

Enjoy.

Presenting PRR Main Line Towers in the 21st Century

Well, once again I put my hand up to do a program for an NRHS Chapter meeting and since it was for Philly Chapter instead of West Jersey I was able to partly re-cycle my 2008 presentation on Pennsylvania Railroad Interlocking towers on Amtrak's Harrisburg Line.  Of course back in 2008 ZOO, OVERBROOK, PAOLI, THORN, PARK, LEAMAN, CORK and STATE was not only open, but relatively intact.  Fast forward 14 years and only THORN, PAOLI, OVERBROOK and ZOO remain with the first two clearly on their way out. 

 My plan was to refresh the presentation with the updates and refreshed photographic content (including from my 2019 THORN visit).  The reality was that the quality of my 2008-edited photos was woefully inadequate and it took me a good 5 hours to get everything up to snuff. To avoid any awkward dead air I preformed a two hour practice session on my live stream and that is what I am now able to present to you.  There are a few hiccups here and there, but overall I am happy with the result.

Ironically the live chapter presentation had to be split into two parts because a number of Philly chapter members take SEPTA to the meetings which limits the duration to an hour. 🙄

CSX Talahassee Sub- A New Signaling Museum

CSX's habit of spinning off less profitable subdivisions to short line operators has created another signaling museum, this time in the state of Florida. Similar as to how the Lake State railroad has preserved about 130 miles of C&O era signaling and 1950's vintage code line CTC, the Florida Gulf & Atlantic Railroad has preserved about 250 miles of Seaboard signaling on the former CSX Tallahassee Sub between Baldwin, FL and Tallahassee, FL, where the line becomes DCS controlled. The lease took effect in 2019 and after three years of operation there is so far no indication that the new tenant has any plans to upgrade the signaling.  Not only would it not benefit them financially, but as a Class III operator they are exempt from the PTC requirement. 

The Tallahassee sub signaling museum is important because of CSX's effectiveness in eradicating the seaboard signaling on its S and A lines running between Richmond and Miami/Tampa as well as secondary routes such as the Abbeville Sub.  Despite using Seaboard Style (duh) Color Lights and in some cases 1980's vintage US&S elephant ear signals, CSX was relentless in its modernization efforts.  In the above street view at SE LIVE OAK we can see a US&S TR type target signal with a large type backing that was preferred by the seaboard.  The signal is in a poor man's siding exit bracket with a dwarf adjacent to the mast with a doll arm. All in all the subdivision hosts 29 controlled sidings with 32 interlockings and a large number of intermediate signals between them.  Definitely worth checking out if one happens to be on the I-10 corridor in northern Florida.