GRS and the Age of Aluminum Signals

People talk a lot about disruption and an often overlooked disruption was the North American railroad signal industry's transition from cast iron to aluminum in the 1980's. Here I am talking about the railroad signals themselves, not the entire signaling product line, but the ability for new companies to enter the market selling  new types of bulbs in a housing put a lot of pressure on the US&S / GRS duopoly. Both companies tried to respond to the new competition, but only one was successful over the long term. 

Iron melts at around 2300o F while aluminum melts at around 1200o. The former requires a foundry and expensive sand molds, the latter can be done with an electric furnace and can get away with using permanent molds made of steel. By 1980 cast iron had been the material of choice for railway signals going back almost a century with GRS and US&S operating the necessary "smokestack" industrial infrastructure to make the components at scale. However, since World War 2 aluminum had become much more common in everyday products like cars and bicycles, and investors looked at the high margin railroad signaling duopoly and wondered if their might be a better way. 

Safetran CLS-10

Safetran was the best known starting with the aluminum CLS-10 that directly competed with the cast iron GRS D Type modular color light signal. The aluminum (and solid state) Unilens was developed to go after the searchlight market and the NR went after GRS's famed G Type. About the same time both L&W and Harmon also entered the market with their own cast aluminum signal modules. The moat had been bridged and aluminum would eventually force cast iron signals out of the market entirely.

Of course both GRS and US&S were going to complete in the new aluminum signal market with US&S seeing some modest success with its clean cut modular box and CR-2 twilight. GRS on the other hand did not do so well.  In 1989 GRS was purchased by the Sasib Railway Group of Italy and they came out with a product family of aluminum signals. The better known family member was a 3-lamp monolithic signal similar to a US&S style P or R. This had some high profile sales such as the LA Union Station and Dallas Terminal re-signaling projects.

After Sasib was acquired by Alstom in 1998 this type of signal was still being sold, just with the Sasib logo scratched off.

The second offering in this family is the much rarer tri-light type intended as a G-Head replacement.  The only place I have noticed them was on the MBTA Dorchester Branch at Readville. Again, note the Sasib logo.

What I have yet to find is an aluminum D Type replacement to compete in the most popular part of the signal market, modular single lamp color lights. Of course maybe that's the point. GRS saw the market was saturated with lower cost competitors and decided not to bother. US&S did try to compete and was rewarded with lackluster sales. So why did the other two signal types fail? 1990 was a bit of an odd time in the railroad signals market. Traditional searchlights were still selling and it still made economic sense for railroads to refurbish old signals and reuse them in new signal projects. Used signals were in abundance as main line track was trimmed down from what they had been in the 1960's. It would be the better part of a decade before Safetran CLS-20 sales exploded as part of the Darth Vader boom of the 2000's.

Generic Canadian Pacific 3-stack.

In hindsight the bare bones GRS 3-lamp monolith may have simply been ahead of its time as Canadian Pacific has more recently adopted a similar no frills box as its standard new signal.

New Signals at Portland Union Station

For the last year or more, Portland (Oregon) Union Station has been involved in a slow motion re-signaling project that will unfortunately zap the last active vestiges of VC Tower, which closed in 1996 as Oregon's last active interlocking station. 

Until labor dynamic forced a change in the early 2000's it was not uncommon for railroads to splice old interlocking hardware, like switches and signals, into new control logic. VC was one such example where the eastbound signals were left untouched. 

These included a short mast signal off of passenger track #1 with a mix of GRS type E and L&W modular lamps, a modernized GRS type MF triangular dwarf, (popular with UP in the 80's and 90's) off main track #4 and two vintage GRS type MD dwarfs on track #3 and #5 that likely date back to whenever VC tower changed over from semaphore signals. 

The replacement will be an obtrusive double cantilever mast for tracks 3, 4 and 5 and a likely modern type mast on track #1. 

The current two lamp dwarf signals appear to consist of a red lamp over a yellow lamp, which would provide for Y Approach, R/Y Diverging Approach and *R* Restricting, although was not able to observe actual operations. The new signals seem to bring Y/Y Approach Diverging to the table. 

The changes aren't limited to the east side of the terminal. For some time passenger tracks 1 through 4 have been un-signaled with the west end of of those tracks being reached via non-interlocked M23 powered switches. Based on bagged station track signals and a bagged through track mast it appears the west end will also be interlocked, including the presently hand throw station track #1.

This will hopefully cut a couple of minutes off the run time, with trains possibly able to make hotter stops, instead of creeping down the super long platforms. 

Lock It Up! Electrically Locked Points

 Electrically locked switches are the red headed stepchildren of the interlocking world. Not nearly as glamorous as their powered brethren, and rarely ensconced within the safe confined of interlocking limits, electrically locked switches help make North America's efficient bi-directional main tracks possible. For the uninitiated let me clarify that while powered points are also "locked" by something involving "electricity", when I say electrically locked switch, I am referring to a hand throw switch that has some sort of electro-mechanical interlock that prevents operation in the face of an unsafe condition.. E-locked switch hardware is provided by both major North American signaling lineages (US&S and GRS) and in today's post I am going to provide a quick overview of the broad e-locked switch families and how they work. 

In the beginning if a railroad didn't want the expense of interlocking a switch with signals via a staffed tower their choices were to assume the risk of trains not being able to get stopped by an improperly set hand throw switch or ensure that all hand throw switches were in the trailing configuration, something that required at least two single direction main tracks. As track circuiting became the norm, operating a hand throw switch could shunt the circuit like any other obstruction, but this wouldn't be much help if an approaching train had already passed the previous block signal. 

Unprotected hand throw switch equipped with a track circuit interrupter.

The easiest solution is procedural control where the employee shunts the track circuit, waits a proscribed period of time, then throws the switch.  However where the railroad desires a bit more assurance than a padlock and watch, the electric switch lock comes into play. The concept is simple, use a solenoid mechanism to prevent switch operation until allowed by the signaling system. This can include direct dispatcher/operator control, like from a lever on an interlocking machine, or conditions such as track circuit occupancy or a rundown timer. In general direct control is the less common of the two as within interlocking limits railroads tend to just pay a bit more for power operated switch machines.

US&S TM-20 switch stand without an electric lock.

At this point I want to take the time to clear up a misconception regarding electrically locked switches. Above is the US&S TM-20 hand throw switch stand. It kind of looks like a miniature point machine with wires going into it, a mechanism to work a pipeline connected derail and an extra locking bar. For years I thought this was an electrically locked point machine because it appears on main lines that tend to benefit from electrically locked points. However there is nothing in a TM-20 that provides for locking functionality. The cover on the end is just houses an integrated make/break circuit controller.  So while this type of switch stand might look the part, the real e-lock is a bolt on component.

Abandoned GRS electric lock unit.

The E-Locks themselves come in two general forms, the plunger style and the pedal style.
Each style is available from both vendor lines, but I want to discuss the pedal style first since it is the one paired with those TM-20 machines I just mentioned. The pedal style consists of a small box, separate from the hand throw point machine, which locks the hand throw switch arm in the desired position. The train crew's padlock holds down a small pedal. Removing the lock allowed the pedal to raise up, energizing the mechanism. In this state a small window displays either a green lamp if the switch is free to move or a red lamp if it is not. If a timer needs to be run, releasing the pedal starts it. Any timers and signaling relays are located in a trackside cabinet. When the lamp is green a second pedal can be depressed to unlatch the hand throw switch arm. Below is an example from the old CP-VO on the former Conrail Selkirk Branch where a direct control pedal type e-lock locks the throw arm of a basic dome type hand throw switch stand. 

Interlocked e-lock hand throw switch stand within CP-VO.

Here we see a low profile US&S style lock device. Here we see a TM-20 with an SL-25 electric lock attached.

The SL-25 can be even located between the rails in a stand alone configuration and in this case uses a pipeline to lock two TM-20 point mechanisms on either end of an e-locked turnout.

Here we see the GRS answer to the TM-20 with an attached e-lock box. This example is located within the limits of CP-89 on the former Conrail Hudson Line and is released by a "lever" on the dispatcher's interface. 

The plunger style is a bit more recognizable due to its more prominent form factor. The plunger lock consists of a little housing, sometimes on a raised pedestal, mounted adjacent to any type of hand throw switch stand. The trainman opens the little door and requests a release by moving a crank type lever from the lock to unlock-request position, similar to a US&S table interlocking machine. This engages the relays and timers in the cabinet and when conditions are safe, a solenoid releases and the crank is able to complete its travel, raising a metal plunger that is physically blocking movement of the switch point rodding in the process. The plunger is either directly below the housing or below the hollow pedestal, if present.

It is common to have both a short and long duration timer with short time (~30 seconds) applying when the main track is unoccupied and the long time (5-13min) applying when a main track train movement is possible. While short and long timers are not exclusive to the plunger type, the plunger type user interface makes them more apparent.

Another feature on the plunger type is the presence of a sealed emergency release button in case something goes wrong with the release logic. Breaking the seal and pressing the button allows for immediate release of the points. On the pedal type e-locks this functionality can be provided by an optional key switch.

Pedistal mounted plunger lock. Note the housing's similarity to a semaphore signal's.

These two types of e-locks are the bulk of what one will encounter in North America with the US&S and GRS equipment lines offering both form factors. It's actually pretty simple if you think about it, but if you don't want to take my word for it, here is a video from Mark Clay McGowan that describes the operation of each type in far more detail.

I hope you all found this interesting. I didn't get into the nitty gritty of identifying every exact model of lock, but now that you know what to look for, see if you can spot the slight differences out in the field.

Hoosac to Hudson: The State of Western B&M Signaling

For years the western end of the old Boston and Maine main line between the Hoosac Tunnel and Mechanicville, NY has been subjected to a highly inconsistent re-signaling programme by the NS-Guilford joint venture "Pan Am Southern". After a recent visitation and Google Earth survey I believe I have determined the exact disposition of B&M signaling between those two locations. 

Starting at the Hoosac Tunnel, both CPF-414 and CPF-415 are retain their B&M signaling with tri-lamp searchlights and pulse-code based block state transmission. 

Inside the tunnel both ABS signal locations have had their signal heads replaced by modular square LED color lights, but appear to use the same mounting and relay infrastructure. 

At the west end of the tunnel CPF-421 is still searchlit and also features an old school intra-interlocking pole line cable bundle as CPF-421 appears to have been a larger pre-CTC interlocking plant. 

CPF-423 at the west end of the North Adams CTC siding was unfortunately re-signaled in 2022. This was part of a protracted re-signaling project that was probably cut short by the CSX purchase of the east end of Guilford and the uncertainty about the long term future of the west end. 

The split intermediate signals at mileposts 424 and 425 (numbered 144 and 145) were removed and replaced by a single bi-directional mast at the Ashton Ave crossing near MP 425.44. Signal hardware is branded as GE, which is associated with the Landsay company that seems to have taken over the lines of GE/Harmon. The new 425 intermediate may have been intended to replace the holdout signal at CPF-428 as the westbound direction has a fixed lower red lamp, however someone may have thought better of this between when the signal was installed c. 2017 and when it went into service some 5 years later. 

The MP 430 intermediate at the old Taconic racetrack along with the MP 432 intermediate were both replaced by a single new mast around MP 431.

This is where things get strange as the next 4 intermediate signal locations at mileposts 435, 438, 440 and 443, are are still B&M searchlit. 

At the CPF-445 junction with the Vermont Rail System, the interlocking has been re-signaled and B&M searchlights have been replaced with Unilens searchlights and a Safetran color light dwarf.

However at CPF-448 in Eagle Bridge, the B&M searchlights and signal bridge were decommissioned in favor of LED color lights around 2017. Because the Guilford rail system's particular tastes the project included a westbound bracket mast although the B&M signal bridge was abandoned in place.

Between Eagle Bridge and CPF-464, all the B&M searchlights were removed around 2017 including locations at mileposts 450, 452, 455, 458 and 462. However CPF-464 remains in a 2-head searchlit configuration. 

At the other end of the siding CPF-466 also remains searchlit in a 2-head configuration, however the new holdout signal at CPF-467 consists of LED color light masts. At this point the Guilford main line hits the CP searchlights at CPF-468.

I hope this makes things a little clearer for those looking to explore the area. I am kicking myself for not conducting additional expeditions between 2017 when the new masts appeared between MP 423 and 435. I assumed that by 2018 the route would have been re-signaled and rather than risk a wasted road trip I diverted my attention to the Amtrak Hudson Line. This just goes to show that one should verify signal removals instead of mentally writing them off. 

The Several Faces of GRS Products

Like the other major North American railroad signaling supplier, General Railway Signaling of Rochester, NY went through a number of corporate ownership changes over the years, eventually becoming part of Alstom in 1998.  Unlike the other brand, GRS actually made an effort to update is corporate branding over the years and in many cases the logo was cast into the metal housings of its products. 

 The classic GRS logo was  born in the early 20th century and was consisted of a script monogram type inside a circle, similar in concept to General Electric's logo. Along with the plain text "General Railway Signal" that was used on signal housings, this served GRS well up until the 1970's.

At this point the script logo was decidedly old fashioned and was replaced by a sans serif boxy stylized monogram type.  This would be used on documentation up to the Alstom buyout and switch machine castings up through about 2010. 

After being purchased by the Sasib Railways Group of Italy in 1989, an updated logo appeared on its new mono-block color light signal that gave the "GRS" monogram some 90's style and included the Sasib logo as well.

After purchase by Alston, the Sasib bit was removed from the molds, but a ghost impression remained.

Ultimately, Alstom felt there was very little value left in the GRS brand and finally has the casting holds changed to read Alstom.  However because switch parts are durable and able to be reconditioned, the older logos still show up on motors or reconditioned housings on "new" point machines.

While US&S's many parents have still found no reason to update their castings, there have been all sorts of off brand knockoffs of the venerable M3 point machine, but that is a story for another day.

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.