Asymmetric Tri-Lights

 When one thinks of the North American tri-light signal configuration (circular target with the lamps clustered in a triangle) one might assume that if the lamps are not set in a single large housing they would consist of single lamp modules kit bashed into a triangle instead of a vertical stack. For the most popular color light signal modules, the Safetran CLS-20, this is the case, however over the years the industry has produced some modular tri-light designs that don't use a common lamp module.

Of course I was prompted to write this post after being confronted by a tri-light product from our old friends at L&W. Purchased by Amtrak for its New Haven to Boston "Shore Line", this tri light has a single lamp module at the bottom with a double lamp cast aluminum housing above. From the front it looks like three singles due to the characteristic gap in the middle, but closer inspection reveals the true configuration.

 

 

The second example is from Transcontrol, a company typically associated with active grade crossing equipment. Somehow they were part of the contract to re-signal Hoboken Terminal around 1984 and their tri-light solution involves two standard lamp modules above an extra large one, which I assume serves as a junction box for the whole assembly. (Note, until this post I was unaware that Transcontrol made signal hardware and I might follow up with them in the future if more information presents itself.) 

One might consider the crop of asymmetric tri-lights to be offshoots of the original US&S style "TR", which features a single cast iron housing with three individual lamp sockets. Signals need terminal blocks to connect the interior wiring to the external wiring and terminal blocks take up space.

If you're wondering how the CLS-20 does it, there are openings on top at the 11 and 1 o'clock positions that match with other openings at the 7 and 4 o'clock positions. For a tri-light configuration the lamp modules are mounted 4 to 11 and 7 to 1. A supplier who can handle both vertical and tri-lights with a single SKU is naturally at an advantage so as a result the asymmetric tri-light has faded into history.

Amtrak PORTAL Bridge Re-Labeling

The requirements of safety and signaling made railroads some of the first organizations to manage systems of unique identifiers and all their associated corner cases. Today we will explore how Amtrak is handling some of these corner cases as they replace the historic PORTAL swing bridge on the Pennsylvania Tunnel extension in the New Jersey Meadowlands.   

1910 vintage PORTAL swing bridge.

Let's first discuss names. Originally "W" cabin, PORTAL's current name emerged around the 1930's when increased use of voice-based telecommunications prompted the PRR to switch many of its interlocking identifiers from telegraph letter codes to names evocative of their local surroundings. At the time the swing bridge and its crossovers were the last interlocking station before the western portal of the North River Tunnels, thus PORTAL. In the mid-1990's Amtrak and New Jersey Transit implemented a connection between the DL&W main line and the Penn Station tunnel route immediately west of the PORTAL bridge. Branded Mid-Town Direct, this service would drastically decrease trip times compared to the 2-sear ride via Hoboken and someone came up with the name SWIFT for the new junction. 

"New" Eastbound PORTAL signal gantry over PRR era gantry.

 

Westbound gantry at SWIFT with route indicators.

The other important labeling system is for the universe of railroad tracks. It might seem straightforward to just start at 1 (or A) and advance upward, but on which side of the right of way does one start counting? What if you need to add a track on the "below" 1? I'll make a post about track numbering at some point, but in this case the PRR was forward looking and went with track #2 (eastbound) and #3 (westbound) since in 1910 it was foreseeable that traffic growth would require tracks #1 and #4 at some point in the future. When the Secaucus Transfer opened, the layout placed slower station tracks between main tracks #2 and #3. These were given letter designations with tracks A and B. PORTAL interlocking was even expanded to include switches into the western end of track A.  

1990's PORTAL extension to support new Track A with 80mph turnouts.

Fast forward to now and Amtrak is building a brand new PORTAL replacement bridge that will also replace most or all of the current PORTAL and SWIFT interlockings. However for the better part of a year both old and new bridges and tracks will be in service and keeping the names the same might result in safety critical confusion. As a result Amtrak proactively renamed the old tracks and interlockings in December, 2025 with PORTAL becoming OLD PORTAL, SWIFT becoming and OLD SWIFT, track #2 becoming track #22 and track #3 becoming #33.

It gets better because Amtrak employs a track number based labeling system for signals and interlocking appliances. This made signals like 2E and 3E into 22E and 33E. Likewise switches like #23 and #32 became #2233 and #3322. Note that lettered tracks are just assigned a number for the purposes of switch and signal labeling with 7 standing in for A, but because track A doesn't cross the bridge there was no need for it to participate in the renaming. 

The now renamed 2233 crossover and 227 turnout at SWIFT.

Like automatic signal number plates and interlocking station signs, track numbering is a fascinating topic that I will dive into at some point, but for now I'll leave things in the context of a topical news item. 

Hoboken Terminal's Suspended Signals

Stations with large terminal fans often exhibit a problem at one or both of edge tracks. Because rail vehicles can't generally make hard right turns, one needs a longer series of switches to reach the highest and/or lowest track. Unfortunately terminals often abut a fixed location like a river or street or public square and to avoid having those extreme tracks things can get a little squished. In the early 1980s, New Jersey Transit engaged in a near total reconstruction of the former Delaware, Lackawanna and Western electrified suburban network. Not only was the 3kv DC traction power system under powered and on its last legs, but the signaling system was firmly rooted in the 1920's. In the re-signaling project that followed, NJT built the last great North American interlocking tower, TERMINAL TOWER and replaced most vestiges of the former DL&W plant.

New (frame left) and old HOBOKEN TERMINAL TOWERs shortly before cutover.

In the late DL&W era Hoboken Terminal signals consisted largely of two head, small target searchlight signals displaying the DL&W's unique mix of color light signal indications. Long platforms in the center of the terminal had these mounted on signal gantries in the normal way, while tracks towards the edge of the low 1908 train shed saw signals mounted below the gantries under the shed itself. Moreover, while center tracks could get a "straight" clear out of town, tracks towards the edges had to make do with a Restricting indication as the DL&W lacked Slow Clear and Slow Approach options, even on dwarfs. 

When NJT rebuilt the signaling there appears to be a time when the new signals were wired into the old HOBOKEN TERMINAL tower's old US&S 1908 Electro-Pneumatic interlocking machine. To make the cutover process easier, signal locations were largely kept the same, but NJT had no desire to keep the old handicap of trains of edge tracks departing under a Restricting signal indication. This meant that the replacement "high" signals had to display R/R/G Slow Clear as opposed to the G and G/G on a dwarf. In most locations this wasn't a big deal as the signal gantries could easily support three tri-light heads, however on tracks 2, 3, 12 and 13, the need to suspend signals under the trainshed due to the closeness of the first switches presented a bit of a problem.

TERMINAL TOWER 36W2 and 36W1 suspended signals governing tracks 3 and 2 respectively.

TERMINAL TOWER 88W and 92W suspended signals governing tracks 13 and 12 respectively.

The solution was somewhat akin to a Penn Station signal, just with three "heads" instead of two. To display R/R/G, R/R/*Y* and R/R/Y, two fixed Safetran modular dwarf cubes were mounted close above an additional three-unit cluster of modular dwarf cubes. These were then mounted close under the roof at the westernmost end of the trainshed.

36W2 signal governing track #3.

 

Although a bit inelegant compared to a dwarf or today's compact LED searchlights, they are a unique solution in today's largely homogeneous signaling environment and are likely to persist for many years to come. 

Amtrak's Secaucus High Density Cab Signaling in Action

When the Secaucus transfer was being designed and built around the year 2000, Amtrak implemented a new "High Density Cab Signaling" concept with shorter blocks and additional cab signal codes in order to increase the capacity of the approach into Penn Station especially with all the NJT Corridor and Midtown Direct trains stopping at Secaucus. This would replace the PRR era Rule 261 signaling with mile long blocks. Below we see the 2E signal at ERIE interlocking cycle through its indications after an eastbound NJT push-pull takes a Clear signal upon departing the track 2 station platform. 2E was fleeted for a normal route and immediately went to Stop and Proceed, then Slow Approach, Approach, Approach Limited and  finally Cab Speed (which could represent both 60 and 80mph speed codes). The horn at the end was an approaching Amtrak Regional which ultimately took 2E at Clear (not captured on video).

Unfortunately this was just in time for NJT to lean into Push-Pull service which lacked the acceleration to and braking systems to take advantage of the rapidly changing speed codes. On push-pull sets with traditional air brakes, crews would often target one speed below the one being displayed to avoid jerky train handling and the risk of penalty brake applications in the face of frequent cab signal drops.This negated much of the intended speed benefits from the high density cab signals. For whatever reason, similar High Density Cab Signals could be found on the 2005 era western Harrisburg Line re-signaling, however due to the low traffic density, Amtrak has taken to disabling some of these extra code change points.

Inside WINSLOW Tower: Then and Now

If there was a moment where I got into railroad signaling, it would be in the fall of 1998 when I quite literally got "into" railroad signaling. While being dropped off at South Jersey's Winslow Jct for the purpose of completing a 20 mile hike for a Boy Scout merit badge requirement, I noticed that one of the omnipresent plywood panels securing the lower level of WINSLOW tower had been removed. Scrambling inside I was presented with a trove of wonders that forever whet my appetite for the age of relay technology. I luckily had a 35mm film camera with me and was able to take a few photographs, but with my plan for the day already set, I only had about 10 minutes to get my fill. Although I had the motivation and opportunity to return, I as busy with school and kid stuff and by whatever time I did go back the tower had been re-secured. 

For the next two decades I would periodically check up on the tower, waiting for locals to break back in so I could follow up with more photos. It was only in 2023 that I was provided with a do over and lets just say, things were quite different. While I've covered South Jersey's WINSLOW tower and the ghostly remains of the interlocking plant on this blog before, today we will explore the interior with two groups of my own photos photos taken 25 years apart, with some additional insights provided from a 2003 urbex visit and photos from when the tower was still in service. 

If you are not familiar with WINSLOW (aka WINSLOW JCT), please check out my previous coverage to get a better idea of its history and layout. to summarize, WINSLOW was built in 1934 as part of the Pennsylvania-Reading Seashore Lines merger to PRR specifications with a brick tower, bay window and a US&S Model 14 electro-pneumatic interlocking plant. The tower was in service until 1983 when the NJDoT seashore services, run under contract by Conrail, were discontinued due to lower ridership and rapidly declining track conditions. The final service level consisted of 3 peak direction round trips to Atlantic City and 1-2 round trips to Ocean City and Cape May. When the tower closed the signals were turned and remained in place until Amtrak showed up to rebuild the line about 5 years later. 

When I first got into WINSLOW it was about a decade into its second act as a radio repeater base for NJT operations on the line. A small lattice radio mast had been build against the north side of the tower and the upper story windows were still intact and letting in light. Towers serving in useful capacities as relay huts or crew bases is one of the more common factors behind their not getting demolished. 

 
On the ground floor, the relay racks and associated relays had been removed, however the cabling that fed the US&S Model 14 interlocking machine on the operator's floor was largely still in place. From the look of it, one can see why so many old tower had their own regular maintainer that under the old system of inefficient railroad employment, could be in the position for many years.

When I visited in 1998 I don't remember much of anything in the ground floor, but in the 2003 urbex photo we can see that it was being used for general storage. I recall being informed by a Southern Railway of NJ employee mentioned that they had access to the tower, but I can't confirm if the items being stored were theirs or not.

There is a single flight of stairs along the rear wall connecting the relay room to the operator's floor. I could not tell if the relays were caged off or not as this was the typical practice to prevent operators from being tempted to tamper with the interlocking equipment to "fix" certain problems. In the 2003 photos we can see shelf style relays on the stairs, but I did not recall seeing any in 1998.

Heading up the single flight of stairs to the operator's level revealed something unexpected, a false wall built lengthwise across the room with a door in it. 

The false wall had the unfortunate effect of blocking the view of the original PRR pattern model board, expect for a small bit at the top. I also managed to get a tight angle photo in from the side that came out pretty well all things considered. 

The model board matches its final appearance from the mid-1960's through to 1983 where the main lines to Atlantic and Ocean cities were both single track manual block. 

What really blew my mind back in the day was the presence of WINSLOW's 27 lever US&S Model 14 interlocking machine. Until this point I had never physically seen one or even known what one was. While some of my railroad books had contained pictures of specifically PRSL Model 14's, the fact that they didn't look like the classic armstrong type lever frame made it hard to intuit what that strange box thing in the photo was until I literally stumbled upon one and it all clicked, despite the lever cranks had all been removed.

Here is the WINSLOW machine as it appeared in service. 

Amtrak FAIR Interlocking Loses Its Quirks

 A little while back I discussed the evolution of NORTH PHILADELPHIA interlocking from its construction in 1914 to its disestablishment in 2005. Early urban interlockings such as NORTH PHILADELPHIA were colorful characters with all sorts of extra infrastructure to handle not only the main line traffic, but also stuff like industrial switching, yard and light engine moves. FAIR tower in Trenton, NJ is not only NORTH PHILADELPHIA's sibling in appearance, but also in its arc through history. While I don't want to get too deep into the history and evolution of FAIR, I will say that it was drastically expanded in the 1930's, then entered a series of successive diets in the late PRR, Penn Central and Amtrak eras before the tower was closed around 1994.

In its second to last iteration that lasted from around 1990 to about 2020, FAIR had lost all of the double slips and freight support it had maintains up through the end of mineral traffic on the Belvidere and Delaware line. It's primary function was that of a passenger terminal for the Philly and New York area commuter services that terminated there. The two remaining quirky features were two additional tracks at the far northern and northerner limits of the right of way. Track 7 was used to store SEPTA equipment, while "North Low Track" served as an extra place to stash New York bound peak period trains overnight. Below you can see how the plant changes from its late PRR configuration to post CTEC configuration.

The area of interest is the North Low and Hill Tracks. The Hill Track used to connect with the Bordentown Secondary to Camden which saw limited passenger service like the famed Nelly Bly NYC to Atlantic City express train. In the commuter era that was used as precious storage space, keeping alive the old configuration that used to serve Doodlebugs that would run into Trenton from rural South Jersey.

 

While eastbound movements out of North Low could be made via the "Wall Track" past the tower, this involved a Restricted speed signal. The preferred option was the 86 switch protected by the 6BE and 8BE signals. This was located at the eastern end of the platform with 4 dwarf signals protecting the single low speed switch. One of the dwarfs was mounted on a striped stick for better visibility.

At the west end of the platform was another left-hand turnout, the 86W switch and associated 6BW and 8BW dwarf signals. You are seeing things right in this only allowed for North Low access from the hill track. This became an issue when around 2005 NJT opened up its Morrisville Yard west of Trenton in Pennsylvania, turning all of the terminal traffic that needed to be shuffled about into run-through traffic. Trains arriving from Morrisville could not access the North Low and as you can see from the rust, it became disused. 

Starting in 2019, Amtrak brought the rationalization hammer down on this legacy configuration. The 86W switch was reversed, the Hill Track was removed and the 16 switch from Main Track 1 was fixed up for higher speeds. Now trains from Morrisville can access the North Low, making it potentially useful again. Unfortunately the next step came with the same interlocking refresh that removed all of FAIR's pneumatic point machines. The 86 switch and its associated signals were completely removed.

Trains using North Low will now have to take the slow route past FAIR tower and them on 0 Track to HAM interlocking, but as you can see from the grass, it is unlikely there will be a need for North Low any time soon. While this all makes sense, especially in the age where efficiency is more and more important, the 86 switch and its dwarf signals are still a loss worth noting.

NJT's Speed Enforcement System: A Thing That Existed

You might have heard me reference the Northeast's preferred transponder based PTC system ACSES, or the Advanced Civil Speed Enforcement System. In most cases when something called itself "Advanced" its usually a bit of marketing speak, but in this case the basic Speed Enforcement System was a thing that actually existed for a brief period of time on New Jersey Transit's Pascack Valley Line. However because of the rapid pivot to more "Advanced" systems and the 2008 PTC mandate, information on the SES pilot is remarkably hard to come by, however I have been able to piece together a few bits of information that can hopefully shed some light on the technology.

In 1996 NJT suffered its worst accident as of the time of this writing when two trains collated at WEST END interlocking where the diesel Bergen County and Main Lines diverge from the electrified Morris and Essex lines. The cause was a veteran engineer who had been hiding a medical condition that had severely impacted his visual acuity mistaking a Stop signal for a R/R/Y Restricting. In the aftermath NJT began an effort to implement what they called "Positive Train Stop" functionality across its system, which came on the heels of a near system-wide adoption of cab signals and automatic train control (ATC). At the same time Amtrak was completing implementation of its ACSES speed control and PTC system on parts of the NEC in conjunction with the new 150mph Acela rollout. This is where things get a bit murky, but going into the 2000's, both Amtrak and NJT had two different yet compatible transponder systems for "civil" (aka track) speed control, however Amtrak "Advanced" system was integrated with cab signals where as NJT left SES as an intermittent system.

The location for NJT's SES pilot was the Pascack Valley Line, a stepchild service that ran some 30 miles north from the old Erie Main Line to dip its toe into New York State. The single track line offered only weekday single direction peak service and, like the similar old Boonton Line, the PVL was essentially unre-signaled since the Erie days. This signaling came in the form of an Automatic Permissive Block-like bi-directional ABS with occasional non-number plated (ie absolute) automatic signals that would have once appeared at the ends of hand operated passing sidings. Without any actual interlockings and only a single block of cab signaling on approach to Pascack Jct, the limited service PVL was an ideal test bed. 

 

Reading through the SES special instructions in a 2004 NJT Employee Timetable (posted below) we can gain some insight into how the system worked. The evidence points towards SES was an intermittent transponder based system that would convey track speed information in a manner compatible with Amtrak's ACSES, but also fixed signal indications. A positive stop was enforced for Stop, Stop and Proceed and Restricting indications, with the positive stop zone extending 500 feet in advance of the signal. Stop and Proceed, and Restricting could then be passed after an acknowledgement, while Stop needed the dispatcher to provide a numerical override code in addition to the verbal Rule 241 instructions. This would have come into play at the non-plated automatics and the home signal at Pascack Jct. Special instructions about cab signal upgrades and other rules not applying in SES territory further strengthen the intermittent use case. 

 

This of course begs the question about how the system would account for signal upgrades after passing an Approach signal if the associated transponder flags a positive stop point like it does in ACSES. As easy solution would be to place additional active transponder at the start of the stop zone 500 feet from each signal, but I have nothing to confirm this theory. An additional feature of the PVL that made it attractive for the SES pilot and that was the presence of signal overlaps. From what I can tell from 2007 era photos, each set of ABS signals had several car lengths between them which would provide sufficient distance for a train running at reduced speed to get stopped before it might encounter an obstruction. This would explain why the SES stop zone is 500 feet vs 1500 for the ACES zone.

PVL automatic signal location with overlap in 2007 with what might be SES transponders (or grade crossing impedance bonds).

SES was always intended to be a temporary pilot and by 2002 NJT had let a contract for its own Advanced SES that integrated cab signals similar to Amtrak, but without the finicky data radio capability for temporary speed restrictions and stop release. Interestingly the $2 million contract with Union Switch and Signal would have outfitted the entire NJT system with PTS and track speed control by 2008! The wireless data free ASES vs off the shelf ACSES debate would extend into the post-2008 PTC era with the ASES plans eventually morphing into ACSES, but perhaps the original SES hints at what NJT's solution would have looked like. Version 1 ACSES also lacked data radios and needed temporary physical transponders for TSR's and use of the stop release procedure to pass certain signals with a proceed indication. Active SES-style transponder could have solved some of those issues without wireless data.

Unfortunately I have been unable to determine the exact timeline of the ABS SES system on the PVL. I know it was in service in 2004 with the CNJ vintage GP40PH locomotives operating in a dedicated pool. I know that SES was still in service as of Jan 1, 2006, however by the fall of 2007, the line had been re-signaled with Rule 562 cab signaling and upgraded with passing sidings to allow for all-day bi-directional service. Unfortunately, starting in August 2006, all PVL physical characteristics and rule changes were put into a separate supplementary bulletin order that I do not have any examples of. Interestingly, the 300 section of NJT special instructions covering SES were left in place with slight modifications likely to cover the upcoming ASES or ACSES installations due to the 2008 PTC mandate probably resulting in some savings in crew re-training. 

If anyone has any additional information on NJT's SES please let me know so I can update this post or make a new one. I've heard a bunch of other stories regarding issues with hair trigger penalty brake applications, but not much more than anecdotes and speculation.