Caught on Camera: The US&S M22

The Union Switch and Signal M3 series of switch machines (including the M3, M23 and A and B models of both) is so ubiquitous and has been around for so long that one might assume the model spring fully formed from the head of George Westinghouse. However it is important to remember that the "M" is the family, not M3 and unlike General Railway Signal, where their switch machines Models 1 through 4 were radically different than the Model 5, the US&S Style M has remained fairly consistent since its introduction in 1918. In fact one of the reasons its easy to assume that the M3 (or M23) has been around far longer than its actual introduction date of 1951, is because the M22 is similar enough that both times I encountered one in the wild, I only noticed the machine was actually an M22 when I was performing unrelated photo research years later. 

To review, above is an US&S M23 switch machine as previously installed on the former C&O Washington Sub near Charlottesville, VA. Below is an M22 switch machine as previously installed about 10 miles to the east in Gordonsville, VA.

I'm not going to go into all the technical details as to how they differ, there's already a page for that, but the big giveaway for an M22 vs an M23 is the non-concentric selector lever that swaps the machine between manual and power operation. The second giveaway is the bolt pattern on the top of the central gearbox with the M23 having 2 large bolts and the M2 4 smaller bolts and a more bulbous cover. Unfortunately I have yet to encounter an M2 in the wild and from the few photos online I cannot determine an easy way to differentiate it from an M3. Anyway, these and any other M22's along the former C&O Cardinal Route (now operated by the Buckingham Branch shortline) were removed in a 2013/2014 re-signaling project.  However there is another M22 I just discovered situated about 5 feet from a busy public right of way.

It's this fellow, the northern end of the #1 crossover at CP-ASH in sunny downtown San Diego. In fact its directly adjacent to the Little Italy light rail station.

Although my photo is from 2015, a quick check of Google Street View shows that it is still in place as of October, 2022.

So if you happen to be in San Diego or out and around some rail line that hasn't seen a switch replacement since 1951, know how to spot an M22 and make sure you take plenty of photos if you come across one.

The Ongoing Saga of D&H Main Line Signaling

Last we checked in on the former D&H Main Line between Albany and Sunbury/Scranton, NS had reversed its decision to abandon all of the signaling below Binghamton. Since that time NS has made some alterations to the signaling it had inherited from Canadian Pacific and after a couple of field trips and Google street view surveys I can offer up a summary of the goings on. 

First we need to dive into the crazy quilt of signaling on the old Delaware and Hudson main line that is under the control of NS after purchasing the route from CP in order to access New Englande markets via the Boston and Maine route. I previously discussed the complex ownership history of the D&H in an article on D&H interlocking naming conventions.

The D&H currently exhibits 6 different generations of signals in the 200 or so odd miles between the NS Buffalo Line in Sunbury and the Boston and Main division post in Mechanicville, NY. They can be broken down as follows:

Generation 1 includes the legacy D&H with GRS SA searchlights, relay based logic and iron/steel mounting hardware including masts, cantilevers and brackets. 

Generation 2 covers the early CP era in the 1990's with SA searchlights and relay based logic using modern aluminum structures.

Generation 3 is the Unilens Era where CP applied a solid state upgrade of its older SA searchlights, primarily at automatic block locations as those present less of a testing burden than interlockings. I believe this began in the late 90's and overlapped with some Gen 2 signals being installed at interlockings. By 2005 end of life Gen 1 interlockings were being actively replaced by Gen 3.

Generation 4, the Mystery Searchlight era, is the shortest, taking place from around 2009 through 2011. This represented CP souring on its Unilens solution and falling back on older SA searchlight guts in a custom housing. 

Generation 5, starting around 2011, is the great CP resigning that have up on searchlights entirely looked to replace Gen 1 signals at relay-based interlockings north of Binghampton with typical Safetran CL-20 type Darth Vaders.

Generation 6 is modern day with NS type Darth Vaders going in to replace both Gen 1 signals select relay plants, but also to replace Gen 3 signals at newer 2005 vintage interlockings. On the remaining CP territory this included the use of mystery N-type signals in place of CL-20's.

So how do things stand today? The CP re-signaling of the 2010's zapped pretty much all of the old D&H signaling north of Binghamton except CPF-499 and the Afton siding beginning at CPF-587.

In fact CPF-587 is seeing NS replace its southbound D&H Cantilever with a leftover CP mystery searchlight!

South of Binghampton D&H signals are holding on at CPF-648, CPF-650 and CPF-679.

CPF-650, still original D&H.

However Gen 3 Unilens signals have been replaced by NS Darth Vaders at CPF-630, CPF-631, CPF-659, CPF-661, CPF-714 and CPF-716.

CPF-716, Unilens signals replaced by Vader masts in 2022.

Interestingly enough, the intact Unilens masts have been gathered at the NS Scranton yard and the adjacent CPF-673 and CPF-672 were in their Unilens (or SA?) configuration as of November 2022. Nevertheless, almost all of the intermediate signals remain as Unilens, with just a handful having been converted by CP to CL-20 Vaders.

It will be interesting to see what the future holds, especially if NS extends between Scranton and Sunbury or if the need to replace the Unilens intermediates prompts an expansion of cab signaling.

CP-SK Changes Its Spots

In 2020 I reported on some unsettling activity at CP-SK on the former Conrail Selkirk branch with new Darth Vader masts going up to replace the Conrail style target signals. CP-SK had been able to avoid the general Selkirk Branch and Chicago Line re-signaling efforts due to a very late 90's re-signaling and the ambient environment of both the former River Line and Boston Line territories holding onto Conrail type signal rules as opposed to Seaboard rules.  In fact the change point was just west of CP-SK at the western limits of the CSX era CP-12.

Well as I feared CP-SK was completely re-signaled and to make matters worse the previous western extent of Seaboard signaling has been moved east to the southern limits of CP-SK on the River Line and the Milepost 9 intermediate signal on the former Selkirk Branch, just east of the Alfred Smith Bridge.

 Although the Milepost 9 intermediate signal has been changed many years prior, it was "future proofed" through the use of Seaboard compatible Y/R/G Approach Slow instead of the NORAC exclusive Y/Y.

The old CP-12 was also made Seaboard ready through the use of R/Y/R Approach Medium (instead of R/*Y*) and extra lamp spaces in which to fit lunar lamps for Seaboard restricting.

In fact the northbound River Line mast at CP-12 seen here displaying a NORAC style R/R/Y Restricting, has that lamp color filter replaced by Lunar White (as visible in this article's first photo). An empty space on the signals lowest head indicates planning for use of Seaboard R/R/Y Slow Approach due to a short signal distance, but it looks like this upgrade was never carried out.

Likely as part of the same re-signaling project, the Conrail style small target searchlight intermediate on the Carman Branch was also undergoing replacement as of August 2022..

In related news CP-153 in Quincy, OH on the former Conrail Indianapolis Line has also seen new CSX signals go up.  The Indy Line has a crazy quilt of new and old signals so this is more of an FYI than a warning of a wide area replacement plan.

Last SP Donner Pass Signals Retired

This definitely falls into the category of a news story that fell through the cracks, but after a bit of uncertainty I can confirm that all of the remaining Southern Pacific vintage signals on the Union Pacific Donner Pass route (Roseville Sub) between SHED 10 and and WEST NORDEN have been retired and replaced by extra height aluminum signal bridges of the same type already seen between SWITCH 9 and SHED 10 and east of EAST NORDEN. This  change took place sometime in the 2020-2022 time frame with the searchlights at WEST NORDEN being the last converted.

Donner Pass Phase 1 replacement gantry at MP 173 in 2017

Although this development was not entirely surprising, the surviving SP signal locations, with the exception of WEST NORDEN, used Safetran CL-20 modules in a target configuration and had PTC antennas mounted on the steel lattice signal bridges. Although not part of a PTC project, it is likely that UP desired to replace the relay based signal logic and simplify maintainer access. In total 5 automatic locations and WEST NORDEN interlocking were affected.

WEST NORDEN was the former location where the old 1860's main track #1 split from the later main track #2 with the interlocking being completely covered in a snow shed. After the completion of the first phase of Donner Pass re-signaling in 2017 it was the only remaining set of searchlights on the entire Donner Pass route (US&S H-2's)

If there can be any consolation it is that the steel lattice signal bridges themselves have remained in place due to the inaccessibility by road cranes. In face, some of the phase 1 locations left the searchlight heads turned in place.  

Unlike phase 1, phase 2 replaced the old SP locations on a 1 for 1 basis with most locations remaining the same except for the Milepost 181 automatics which have been removed in their entirety, creating a single 3.2 mile block where a 2.0 mike and a 1.2 mile block had existed before. In addition the the Vader type signals were moved off the westbound SHED 10 lattice gantry and replaced with masts at the mouth of the snow shed 450 feet to the west.

I finally got confirmation of this sad development due to media posted of the 2023 Donner Pass rotary plough training run so if you search out media of that event you can likely catch sight of some of the converted signal locations..

Limited Triangles!

 A little while ago I mentioned NORAC Rule 280b Approach Normal, a signal indication that has been effectively extinct in the wild for over two decades. However we will look at another marker type signal indication that used to be fairly widespread, but as far as I can tell, has now been reduced in the United States to just a pair of locations on the former PRR Main Line. Of course I am referring to the limited speed triangle.

Introduced sometime around the 1940's, the bright yellow Limited Speed Triangle was deployed on speed signaled railroads in conjunction with the introduction of the #20, Limited Speed turnout. For the uninitiated this translates to speeds of about 40-45mph. Prior to this speed signaled railroads tended to have a main line Normal (Maximum Authorized) speed of  50-70mph, a Medium (aka Reduced) speed of 30mph and a Slow speed of 15mph. The system worked from both a track engineering standpoint given the speeds involved and logical standpoint in terms of full speed, half speed and quarter speed. As equipment improved throughout the 1920's and 30's, the gap between the maximum speed trains could regularly achieve and the 30mph Medium Speed began to grow. Because its easier to decrease running time by not going slow as opposed to just going fast, a number of Eastern railroads invented both faster turnouts and the concept of Limited speed. 

#20 Limited Speed turnout at BRYN MAWR interlocking.

Just like in the 1980's when High Speed 60 and 80mph turnouts were invented, railroads suddenly had to fit the round peg of a new speed into the square hole of their existing signaling system. In a time when flashing signal relays were generally shunned as unreliable the solution was the Limited Speed Triangle. The black bordered yellow triangle would upgrade Approach Medium and Medium Clear indications to Approach Limited and Limited Clear. In cases where a #15 turnout was being replaced by a #20, the signaling change would involve change to interlocking wiring or logic. 

Although some railroads including the Reading, did invent new non-flashing limited speed color light signal like Y/G/G or R/G/G, limited speed triangles were embraced by the PRR, B&O, L&N, ACL/SAL and Southern. They also appeared in Canada with the addition of the letter L inside the triangle. Of course one of the biggest users of the triangles was the PRR, which would employ them at select junctions and along its 4 track main lines that features frequent non-reverse running crossover movements.  More specifically the PRR deployed limited speed upgrades (and triangles) to places where its 4-track lines would shift orientation from ⏬⏬⏫⏫ to ⏬⏫⏬⏫ and also as part of its general World War 2 era NEC re-signaling effort.

DV Interlocking with a mix of Limited and Slow speed diverging routes.

Starting in the 1950s flashing signals became more accepted and the Limited Speed Triangle began its slow decline. The main downsides was the inability to mix Limited and Medium speed routes, the issue of Approach Limited indications proceeding Medium Approach and the reduced visibility of the triangle vs a color light, especially at night. By the dawn of 21st century I was only aware of two remaining installations of limited speed triangles. The first was at COUNTY interlocking on Amtrak's NEC in New Brunswick, NJ with a full set of four triangles at the interlocking itself and the milepost 31 and 34 automatic locations adjacent to it. These were unfortunately replaced in the early 2010's as part of the larger 562 re-signaling effort between COUNTY and FAIR near Trenton.

 

The other use of limited speed triangles, and the only one still in service today, were the milepost 8 and 11 automatic signal locations adjacent to BRWN MAWR interlocking on the name brand "Main Line" portion of the Amtrak Harrisburg Line. These two signal locations are adjacent to the Ardmore and Villanova stations respectively and easily photographed. The reason BRWN MAWR itself lacks the triangles is because the tower caught fire in 1994 and the interlocking redone with modern hardware including flashing relays. The two distant locations will certainly keep their triangles until the Main Line between ZOO and PAOLI is slowly re-signaled over the next 10-20 years.

 

Note I have been invoking the United States instead of North America in terms of the endangered nature of these signals.  That is because Canada still retains quite a few of its Limited triangles generally on its western transcontinental routes at the ends of single track passing sidings. Highly ironic that the land that hasn't seen a flashing signal indication it doesn't love, has become the final refuge for a hack intended to avoid flashing signals.

MBTA Re-Signaling Project Reaches Lowell

An update for my previous reports on MBTA's re-signaling efforts on Boston's north side commuter lines.This project consists of installing cab signals and Rule 562 operation on all or part of the North Side lines as well as the general replacement of GRS SA-type searchlight signals. In fall of 2020 the project had already commenced, but there was no sign of it at CPF-BY in Lowell when I stopped by for a visit. 

In fact I even documented ongoing maintenance work on what appeared to be brand new replacement SA heads.

Well recent photos indicate that the re-signaling work has no only reached CPF-BY, but also also replaced the GRA SA searchlight dwarfs with L&W LED searchlight dwarfs, which I guess is better than Safetran cube stacks.

At this point there is no information about CPF-LO, CPF-WA and CPF-NC located beyond the end of MBTA operations at Lowell, but before the end of MBTA ownership at CPF-NC. I suspect this might become a signaling sanctuary as CSX would want to avoid needing to run cab signal or ACSES equipped leaders here and the MBTA would want to hold out for Federal rebuild money to extend service to Nashua.

CPF-NC in late 2021 showing no signs of change.

Additional reports indicate that CSX has dropped new signals at CPF-309 and/or CPF-307 which would be in line with their plans to assimilate the old Guilford territory.  No word if the new signals are CSX standard hoods or Guilford/MBTA targets and also if CSX is planning to run Rule 562 as all Boston Line locomotives will be cab signal equipped and multiple sections of the old Freight Main Line will have MBTA cab signals.

SEPTA Suburban Trolley Signaling: Past and Future

Light rail is currently the locus of signaling innovation in North America due to its mix of limited regulation, low budgets and legacy systems.  For example I have previously written about DART's three different signaling methods in use on its light rail network. In Philadelphia, one such legacy system is the suburban trolley lines running out of  69th Street terminal on the western Philadelphia border. Similar to Pittsburgh's south hills light rail lines in concept, the method of operation is currently being converted from a basic trolley era ABS system, to a hybrid CBTC system.  As I just managed to pick up a bunch of new photos, I figured it was a good time to cover both systems while they are still in the transition period. 

Route 101/102 block signals at 69th St

The ABS system inherited by and later updated by SEPTA as necessary, was a 2-block affair with signals displaying proceed (green) or stop (red). Although there was one location, Drexel Hill Jct, that could be described as an interlocking with full signal protection and a power operated facing point switch, the entirety of the Routes 101 (Media) and 102 (Sharon Hill) were run under traditional ABS rules with hand throw crossovers and spring switches entering sections of single track. 

Two aspect ABS signals at a Route 101 hand throw crossover including operator hut.

 
The single track segments were handled with an automatic tumbledown scheme and the one junction was fitted with a three lamp signal and a route selection punch box. Where a diverging move was encountered a yellow signal indication would be displayed. There was also no ATS or ATC enforcement of signals or speeds. 

Legacy yellow diverging aspect at east end of Route 101 single track segment.

Due to the sections of street running and close spacing of stops, the Suburban trolley LRV's are considered to have sufficient braking performance to dispense with an Approach type indication. Signals are approached prepared to stop and when the next block is cleared, the following movement will get a clear signal to proceed. Not all of the route miles are protected by signal indication with the street running and other slow areas working on sight. These sections are partly defined by "end of block" signs. 

Route 102 switch protection signal paired with a single track block entrance signal.

In addition to the two lamp ABS signals, there are/were switch position indicators and reverse direction protection for the single track sections and Drexel Hill Jct. When entering single track and exit signal would follow the spring switch to protect against a race condition if two opposing trolleys were to attempt to "seize" the single block at the same time. 

Route 101 single track switch signal with block entrance signal in distance.

Starting in 2019 work started on a new CBTC based signal system that would also make use of sizable number of interlockings to replace hand throw crossovers and single track spring switches. As of early 2022 the CBTC system had not yet entered service so the interlockings were used to supplement the existing ABS signal system. 

New SEPTA Suburban Trolley cab display unit with CBTC disengaged.

In fact on the combined section between 69th St and Drexel Hill Jct there were sufficient interlocked crossovers to supplant all of the ABS signal locations! As many of the ABS block signals have so far remained on the routes past Drexel Hill Jct during the transition period, it is anticipated that the CBTC will provide full block separation, not just a safety overlay.

New Route 101/102 combined trunk interlocked crossover and block section signal.

All in all the project involved the addition of 10(!) new interlockings, three crossovers on the combined Rt 101/102 trunk, Drexel Hill Jct, one crossover on each Rt 101/102 branch, three Route 101 single track endpoints and one Route 102 single track endpoint. In addition to these interlockings, three additional holdout signal locations were installed in proximity to an interlocking.

New interlocked holdout signal at entrance to Rt 101 single track territory to accommodate short turns

Another interesting new feature is the provision of a yellow fixed ATS transponder adjacent to each fixed absolute signal.

Yellow ATS transponder located between mast base and rail.

Although I was unable to observe every detail of the current operation it appeared that the new wayside interlocking signals were backwards compatible with the old ABS system displaying R - Stop, G - Clear, Y -Diverge. The presence of a 4th lamp hints at at the presence of a lunar white indication that will either be used for a "cab speed" (most likely) or an absolute block / restricting signal.

Same location as above prior to rebuild with spring switch and yellow "end of block" sign indicating start of line of sight operations.

Although the new CBTC/CTC system is modern and high tech, it never the less exhibits the limits of technology to deliver substantive performance gains. Ten new interlockings along with 20 or so miles of CBTC will cost more to maintain than the legacy ABS system. Furthermore, the speed control function will almost certainly decrease performance from current standards. On the other hand contingency operations will be greatly improved with track work becoming possible during operating hours and vehicle/overhead line failures now able to be worked around without the need for temporary block operators hand throwing switches. In theory the capacity of the system will improve, especially on the route 101/102 combined trunk, however the decision to run more frequent service has always been limited by the budgets and political will of both SEPTA and various levels of government. My assessment is that operations will say the same, liability will decrease along with speed and the impact/cost of contingency operations will decrease enough to offset the high cost of the new signaling system, at least until the point that the technology becomes unreliable.