A blog devoted to explaining the ins and outs of North American railroad signaling, past, present and future. This blog seeks to preserve through photo documentation the great diversity and technical ingenuity of 20th century signaling and interlocking hardware and technology. Related topics cover interlocking towers and railroad communications infrastructure.
Note, due to a web hosting failure some of the photos and links may be unavailable.
We all learn about traffic lights in elementary school. Red means stop, green means go and yellow means slow or caution. These are the basics of automatic block signaling that also tend to get taught in entry level railroading books. Now its pretty logical that a signal might lack the ability to display a clear indication. A permanent stop condition or the end of automatic block territory are both situations where a Clear signal would not ever apply. However there are a few situations where signals in North America can display Stop or Clear, but not Approach on the full speed head.
The first is at interlockings outside of automatic block territory like a diamond crossing or drawbridge. The signal provides movement authority through the interlocking and without track circuits outside of the interlocking limits there is no "prepare to stop" points an Approach type signal would apply to. Trains will have their own movement authority like a track warrant so a clear signal is basically the interlocking telling the train "you do you". One might expect signals in this case to display a Restricting indication, instead of a clear, and sometimes they do, but that is going to come with a 20mph speed restriction, or less, which can be a time hit on unsignaled lines with higher track speeds.
The next situation, Manual Block territory, would be very familiar to those in other parts of the world. Although almost extinct in the US, there remains a bit of manual block still in service on the LIRR and the way to identify a manual block signal is the lack of an approach indication. (This also applies in general to historic PRR signaling charts.) Signals will display Stop or Clear Block with any Approach functionality handled by a separate distant signal towards the end of the manual block. The PRR even went one further sometimes substituting the \ "Caution" indication in place of / Approach.
Sometimes its really not good to have locomotives stopped and waiting at a specific signal, Maybe there's an issue with a grade crossing, or noise, or diesel exhaust. In this case it would not be desirable for trains to approach that signal prepared to stop, so a preceding signal will either hold trains short or allow them to approach a signal with some sort of proceed indication. The most notable of these is at the entrance to Washington Union Stations 1st St tunnel that the currently diesel hauled northbound trains cannot enter without having a signal displayed further on that allows them to leave said tunnel. Another nearby signal location at CSX's LENFANT interlocking might lack southbound approach signals for a similar reason due to an overbuild.
One somewhat PRR-specific situation is where interlockings are provided with exit signals and because of the short distance between the interlocking's entrance signal and exit signal, Slow Approach is used instead of Approach. This creates an upper head that can only display --- Stop or | Clear. The C&O also made frequent use of exit signals, but seemed to keep their upper head Approach indication, although Medium Clear to exit Approach allowed the C&O to minimize the use of R/Y/Y/ Medium Clear.
A fairly new situation where Approach has been "omitted" involves high speed turnouts. At certain points on the NEC, Amtrak has decided to combine a flashing green "Cab Speed" signal indication with R/*Y* Medium Approach. At the end of a main track that converges into another via a high speed turnout, the result will be an upper head with green and red lamps/positions and no yellow lamp/position.
The rather secretive nature of the LIRR has always made it somewhat difficult to find information about its signaling infrastructure and interlocking towers. However over the past past 26 years Steven Lynch's decidedly web 1.0 LIRR Archive on trainsarefun.com has ballooned into an absolute juggernaut of quality information. In particular the page devoted to interlocking towers covers not only the current stuff, not only the recently closed stuff, but the towers that were displaced by the modernizations of the 1950's, 60's and 70's as well as the old block stations that were displaced by automatic signaling. While the layout is a bit haphazard, you will not find all sorts of reference material that is still relevant today like photos of now out of service interlocking machines in towers such as VAN and BABYLON.
If you are unaware of this archive check it out, especially if you are doing any sort of LIRR tower writeups, like several I have planned for the future.
While trying to gather information for my recent SEPTA Unilens post, I discovered a newish railfan video channel with a large amount of up to date of front facing video content that can help with signaling research. Retired Railfan Horn Guy has been crisscrossing the country shooting a mix of front window and standard videos with special emphasis on SEPTA and, more recently, Caltrain. The latter is particularly useful given the impending demise of forward facing views on that line.
The guy is based on Long Island so naturally there is LIRR content, but he doesn't seem to have the same level of access as some of the other LIRR specific video channels that I suspect have insider access. Anyway, its a fantastic channel and good resource to bookmark.
Although I did not get confirmation about where the control was passed to, I suspect that it will follow QUEENS, and NASSAU with the territories being remote to the dispatch center at the Jamaica offices. It is unknown if installed panel or VDU interface was removed or if they remain available for emergency restoration.
In addition to the closure of VALLEY, I was informed that BABYLON and BROOK previously saw their operators relocated to nearby yard offices and DIVIDE was also closed in 2021 in conjunction with the opening of the Main Line Third Track. This means that VALLEY was the last full time, stand alone interlocking tower on the LIRR with LEAD technically being in the bridge cabin format. It seems that the LIRR has just witnesses the same collapse of interlocking stations that SEPTA saw in 2003.
In other news, L&W brand PRR pedestal signals have appeared at ROCKY interlocking on the Babylon Branch, Rocky is the last remaining position lit crossover on the branch and the LIRR uses pedestals as a precursor to re-signaling events, however the move to reduced aspect signals have made this progression less necessary and the use of new peds could be permanent in order to decommission the aging signal gantries.
I also had the opportunity to visit M CABIN that controlled the Main Line Cutoff drawbridge over the Dutch Kills in Queens. Unfortunately the cabin has been gutted of any interlocking hardware by local scrappers.
The LIRR has a number of zombie towers such as this like BLISS and HAROLD and I'll try to get definitive answers on more of them.
When the Pennsylvania Railroad needed a reduced clearance version of their brand new position light signal, they made a position light version of the semaphore dwarf signal. About a decade later when the PRR needed a compact signal that could also display the full range of signal indications they invented the pedestal.
But what if you are worried that pedestals with their pairs of plain white lamps just weren't visible enough in fog or smoke at main line speeds? Well you might need a compact position light.
If one looks at the back of a Union Switch and Signal position light setup, one will see the lamp modules are mounted on the ends of metal tubes extending out from a central tub. The backing plate, if present, is then affixed to the ends if the tubes. However you might realize that there is nothing in this setup that physically requires the lamp modules be mounted where they are mounted. They can be placed at any point along the tube. As long as there is a hole for the wire they could even be placed directly against eachother! Which is exactly what the PRR did when it needed a reduced clearance PL format.
Don't let the square targets fool you. These signals on the LIRR Main Line are completely ordinary US&S position lights, just shoved together. The compact format for the Milepost 7.6 automatics was chosen to be visible underneath an overbuild just south of the Kew Gardens station.
You can see the size difference in comparison with the full size signals on the opposite side of the signal gantry.
While these LIRR square backed compact PL's are now likely unique due to the HAROLD interlocking re-signaling project, compact PLs in general still exist in several others locations with the most accessible being DOCK interlocking in Newark, New Jersey, on Amtrak's NEC.
At the east end of the station on tracks 1 and A, the 90LA and 90LB signals were both in compact formats of varying degrees of compactness. The 90LA on track #1 even had different geometries for the upper and lower head given the unique clearance requirements.
When the LIRR's new East Side Access opened to Grand Central Terminal earlier this summer and I was expecting the signaling to follow the pattern of the LIRR's other recent projects with the new reduced aspect signals like G/L that have become the new standard. However, now that cab view videos have become available the new signaling setup came with a few surprises.
Once trains enter the ESA tunnels at HAROLD interlocking they are exclusively presented with transit style 3-lamp signals displaying single light Green, Yellow and Red aspects. Although these two videos can't necessarily reveal all possible operating conditions, the lack of anything aside from Green, Yellow and Red over both straight and diverging routes implies that those are what one gets in the ESA tunnels even with track speeds up to 45mph. It also appears that intermediate signals are provided in the few parts of the route that have significant distance between interlockings.
I suspect that the decision was made to lean on both the track speeds and speed code based cab signals to simplify the ESA wayside signaling based on the LIRR's existing practices before the implementation of the Reduced Aspect Signals. Remember, ESA has been under construction for almost 20 years and the design work was likely completed a decade before the Main Line capacity expansion projects motivated the new signals. A review of the videos shows a combination of diverging routes at the prevailing line speed (15, 30 or 45mph) or sufficient distance between the signal and the turnout for a cab signal code drop to take effect. On the outbound video there appears to be an unprotected slow speed crossover so I am not sure if that would rate Green signals over cab drops or a Yellow approaching a flashing red or what. I made some inquiries and I will post an update if those pan out.
All in all, the signaling is more interesting than an endless string of Green over Lunar and the use of US&S transit style signals is nice, but its unfortunate we didn't get a full set of LIRR "tunnel" signals similar to the Atlantic Ave branch.
As the opening day of the Long Island Rail Road's decades long East Side Access mega project approached there appeared a new hiccup. Apparently the ESA tunnels were not built to support some of the LIRR's diesel rolling stock that routinely runs to New York Penn Station. Setting aside how the LIRR managed to make their brand new tunnel more restrictive that what it typically the gold standard in limited clearance, someone somewhere noticed that a mis-routing could do a can opened job on an oversize train and demanded that the LIRR perform some mitigation.
Reverse switch to remove roof.
The typical way one would accomplish this would be to have a system of interlocked high car detectors. Tripping a detector would immediately cancel the route and the train would be stopped via both the Cab Signal ATC and ACSES PTC systems. What was so baffling about the LIRR's PTC waiver request was that they were trying to install a new "Tunnel Collision Avoidance" capability to ACSES that would allow for a positive stop at a non-absolute signal or signal indication point. The ACSES positive stop system functions via a transponder telling the on board system to enforce a positive stop in X feet if no cab signal code or radio release is received. This feature was expanded to also cover trains without functioning CSS getting a positive stop at an absolute signal not displaying Rule 280a "Clear to Next Interlocking". TCA would likely work in the same way with a transponder setting up a "positive stop unless" condition combined with a high car detector linked radio release or a cab signal code being present. In fact I think it is actually the latter because part of the aforementioned waiver notes that the ESA tunnels all use only the 250hz cab signal carrier frequency and overheight equipment (DE/.DM30's with C3 coaches) cannot detect the 250hz carrier at all. (See note below)
So my reaction to this is why the heck is the LIRR scrambling to modify ACSES when this was seemingly a solved problem. The fact a waiver is being applied for at all answers part of my question as this must have become an issue only after all of the HAROLD design and signaling work was specified and completed. My Spidey sense tells me that the LIRR's original solution was the use of the 250hz CSS carrier that would drop the cab signals of Amtrak, Metro-North and DE/DM stock to Restricting, at which point the engineer would stop the train short of the low tunnel. Regardless, the Powers That Be demanded a positive stop and instead of adding a new absolute signal at the tunnel mouths, the LIRR decided to do a software fix. I can see how trying to add an HCD system to HAROLD could result in a lot of costly testing given the number of potential routes involved. (After all, the cost of testing prevented NS from even changing the Conrail era HCD recording at CP-BANKS until the general re-signaling project in 2018!), but a couple of extra holdout signals seem pretty straightforward. Based on the general discourse of NYC project management, I suspect the cost of constructing even something "simple" in New York City made a signal-vendor supplied software fix the "better" option.
Before I wrap this up I want to complete the NYC-Region trifecta of poor public sector planning, high cost and political posturing by pointing out the letter that accompanies the FRA's granting of the rather short term PTC waiver. With everything the LIRR is doing to prevent mis-routes including route-indicating signals, rulebook rules, locked out routes, ATC enforced 15mph speeds and the 250hz fail safe cab signal code trick, I would have expected the FRA to issue a letter that states something on the order of "you have gone above and beyond to mitigate this problem". Instead the letter goes on at length about how everything I mentioned is somehow deficient and they reluctantly approve of the waiver. Here's an example.
"The Board also shares Brotherhood of Railway Signalmen’s concerns about LIRR’s existing hazard detection system not
protecting Amtrak trains operating in the Harold Interlocking from being misrouted to the GCM
tunnel. FRA notes, however, that if an Amtrak train operating with oversized rolling stock is
routed towards the GCM tunnel, a series of redundant protections exist to prevent that train from
entering the tunnel. First, if a route into the tunnel is incorrectly lined so that an Amtrak train
with oversized rolling stock is lined for movement into the tunnel, the train’s PTC system will
enforce a positive stop at either signal 11W or 65W. To proceed past either of those stop
signals, the train engineer would have to obtain dispatcher permission to by-pass the PTC
enforcement and would be held to a PTC enforced 15 miles per hour (mph) speed limit.
Second, as a train approaches the signals and diverging switch that controls the tunnel entry
track, the train crew will see routing arrows on the mast of the relevant interlocking signals (up
to three signals in advance), which will illuminate white when a route is lined from any of the
tracks to the GCM tunnel (the arrows will not illuminate if the track is not lined for the tunnel
entrance). This will provide Amtrak train crews the opportunity to stop their train, as required
by Amtrak’s special instructions. Third, in the event an oversized train passes the 11W or 65W
signals because of human error or a failure of the PTC system, and the train crew does not
notice the illuminated arrows and take appropriate action if they are operating an oversized
train, LIRR’s cab signaling and ATC systems will protect the Amtrak train, as it would any
oversized LIRR train, through the 250 Hz cab signal code which will provide an audible alarm
and enforce restricted speed."
If you don't want to read all that I can summarize in a 14 second video clip.
What's even more telling is that its the railroad signaling union that is explicitly complaining about the lack of TCA capacity. Just remember, whenever a Union is applying political pressure there is likely overtime to be had. Now, the Railroad Safety Board is a political entity and they are going to do whatever they can to cover their asses to the max and/or avoid political problems with unions that might still provide a few Democratic votes, but the waiver also includes at least 6 safety theatre-esque action items that will add more time and cost to the entire ESA enterprise. Is a mis-route possible? Absolutely, they happen all the time.Even with all the protections could we actually get the can-opener effect? Well an Amtrak Keystone did go to Cynwyd 🤷. Still, the likelihood of all these Swiss cheese holes lining up is remote, especially as there are countless locations along busy passenger tracks where a bad route can take a train into a yard or an out of service track and they aren't causing major safety problems. If rail is every going to deliver nice things, we can't have this level of of CYA virtue signaling coming from the top.
PS: The entire docket of documents related to this waiver, including that super useful HAROLD interlocking diagram, can be found here.
*Note: The PRR legacy Cab Signal System as now deployed in North America makes use of code rates in pulses per minute and one or more AC carrier frequencies in cycles per second (hertz). These can be combined to increase the number of usable codes if so desired. Railroads on Amtrak's Northeast Corridor make use of a 100hz carrier for the basic CSS codes and a 250hz carrier for additional codes that were added ~1999. The LIRR uses an expanded set of pulse code rates and therefore does not need a secondary frequency. This means they could make the EMU stock (M3's, M7's and M9's) sensitive to both a 100hz and 250hz carrier with the same code rates. All other equipment including Amtrak, Metro-North and DE/DM stock will receive a Restricting cab signal in the abstinence of a 100hz code.
The (temporary?) return of Budd M3 Metropolitans to LIRR service has resulted in a bevy of head end railfan window videos from Youtuber Mr Master 767 including the new Main Line third track arrangement between DIVIDE and QUEENS interlockings. I figured I would post some of the videos and then provide some quick commentary on the key points of interest.
On the Ronkonkoma to NY Penn segment above we can see the final result of both the Ronkonkoma double track and Main Line Third track projects. The good news is that BETH and both core and extended parts of DIVIDE interlocking remain position lit, however the new MNRR style reduced aspect signals have taken over all other portions of the route to QUEENS interlocking. At this point QUEENS is scheduled for additional re-signaling and re-configuration with BETH and DIVIDE to follow in subsequent years unless the MTA's financial situation heads this off.
In the above Atlantic Branch video we can see that DUNTON interlocking is still largely position lit, but point machines are now electric. VAN interlocking has also been converted to electric, but BROOK appears to be holding on with some remaining pneumatic.
On the Long Branch Branch LEAD interlocking has been converted to non-reduced color light (probably several years ago), no word on the status of LEAD as a manned interlocking station however.
Finally on the Port Washington Branch a reconfiguration of NECK interlocking appears ready to see the replacement of multiple position light masts, gantries and pedestal signals including the practically brand new westbound signal bridge. This is accessible from the station and is definitely on my To Do list.
I have received reports that the former LIRR POND tower has suffered a fire related incident. The extent of the damage is currently unknown, but the wooden structure would be highly vulnerable to flame. POND is located on the LIRR Montauk Branch at the west end of Fresh Pond Yard, which now serves as the base of operations for the New York and Atlantic and, by extension, rail freight for the entirety of Long and Royal islands.
Built in 1905, POND was on the LIRR end of the junction with the New Haven / New York Connecting RR's freight extension to Bay Ridge via the Hell Gate Bridge. Closed as an active interlocking station at some point in the 70's or 80's, POND outlasted its newer and more robust sibling FREEMONT tower on the Bay Ridge Branch by being repurposed as the NY&A's freight/yard office. It's location in an isolated and wooded area probably meant that transient related vandalism was inevetable. Hopefully the damage is such that repair, rather than demolition will be warranted, but I am not optimistic.
You may recall that some years ago I was sounding the alarm about the pending demolition of NASSAU tower in Mineola, Long Island. Well, New York being completely dysfunctional, the demolition to make way for the LIRR Main Line Third Track project took far longer than anticipated, eventually taking place sometime between August 2021. The demolition was just in time for the complete collapse of peak-period commuter travel in the NYC area rendering the third track capacity expansion completely unnecessary (😢).
NASSAU interlocking, sans Tower, February 2022.
Anyway as the third track megaproject continues to creep forward, someone spotted NASSAU's late model interlocking panel dumped out back near some storage containers. It was unclear that the fate of this artifact was to be, as in museum preservation, scrapping, theft or vanishing into a railroader's basement, however it is worth checking out for any signal fans who happen to live in the area (and who might own a truck and some high visibility vests, wink wink).
Apparently this panel type interface was replaced by a VDU late in the
tower's existence as plans were carried out for the transfer of
operations to the Jamaica dispatching center as was done with QUEENS
tower a few years ago. Thanks to multiple visits to the tower while it was in service along with some contributed interior photos I plan to post a more complete retrospecting on NASSAU tower in the near future, so stay tuned for that.
In other news the pneumatic movable point diamond at the NASSAU flat junction has been removed. A major maintenance headache, the diamond has been replaced by a second Oyster Bay switch onto main track one, creating a bottleneck by forcing all Oyster Bay trains to platform on the westbound local platform.
You can see the new configuration in the LIRR Main Line 3rd Track plan.
This type of 2-tracks into 1-track configuration is extremely rare as it doubles the chance of a switch failure impacting main line traffic compared with merging both branch tracks before a single main track switch. This will also end of ritual of inbound and outbound Oyster Bay train passing eachother at NASSAU to minimize impacts to Main Line service. The ideal solution would have been a two track flat junction using full turnouts and a mid-platform signal on the new eastbound track 3. That would have allow for the option to use both platforms if extended wrong running on track #1 was not available.
As 2020 winds to a close I wanted to share a few PRR Position Light related news items. The first is that the Lebanon Mason Monroe tourist railroad in Lebanon, OH, had installed a semi-functional amber PL at the end of the platform at its Lebanon, OH depot.
Next, the LIRR has started to equip its legacy amber PL's with the same type of LED lamps that SEPTA first installed a decade ago at ARSENAL and ZOO. With all of the reduced aspect signaling and tower demolitions, its nice to see that some of their PLs might have a brighter future.
Speaking of SEPTA, I reported back in May that the PRR PL's at ARSENAL and WALNUT interlockings appeared primed for replacement, however during my annual winter SEPTA trip I was able to confirm that the signals at ARSENAL, WALNUT and the MP 1.5 southbound PL automatics are all still in place, however the northbound MP 2.0 automatics have both been replaced by color lights.
MP 2.0 automatic half way through replacement in 2019.
That wraps up my 2020 season. Signal wise, it was not as bad as some other things. Stay safe and join me again in the new year.
Despite the efforts of preservationists, both the Long Island Rail Road's NASSAU interlocking tower and the adjacent 1910 substation building will soon be demolished to make way for the third track and a kiss-and-ride drop off loop. Current scuttlebutt is that this is set to take place within the next 30 days.
Built in 1923 as a mechanical plant, the flat junction between the LIRR Main Line and the Oyster Bay branch has become a major bottleneck in recent years. The new third track is being constructed south of the existing Main Line due to the divergence of the Oyster Bay branch to the north so demolition or relocation of the tower was inevitable and the MTA ultimately chose the former.
The flat junction also involves a grade crossing and is in an area of poor drainage, requiring the whole plant to be dug our and re-graded on an almost yearly basis. It will be interesting in what the final configuration will be.
As was seen with the Ronkonkoma double tracking project, the existing position light signals between QUEENS and DIVIDE will likely be removed and replaced with Reduced Aspect dwarfs.
How the interlocking will be operated is a bit less clear. It is likely that the NASSAU territory between QUEENS and DIVIDE on the Main Line and the entire Oyster Bay branch will be giver to a new dispatcher at Jamaica. However I believe that DIVIDE tower had alternate control of at least the Main Line portion of NASSAU's territory so until the dust settles with the third track, the LIRR might just wheel in a second office chair there. It is also not clear what will be done about the NASSAU train order station as orders are frequently hooped up to Osyter Bay trains for various reasons.
I was personally able to visit NASSAU in 2007 and again in 2016 and I feel confident enough in my documentation that feel no reason to brave the NYC COVID hot zone to rush back up there. The only exception is the pneumatic switch machine used for the NASSAU movable point diamond. If anyone heads out there please get as many photos as you can as a work crew thwarted my 2016 attempt.
As you can see I have some inside photos of NASSAU, but I plan to do a full interlocking write-up once the new configuration is in place so I won't need to do a followup. Until that point I'll probably work on getting QUEENS out.
At 11:38pn on January 10th, 2020, the Long Island Railroad's QUEENS tower was closed with control passing to the dispatch office at Jamaica. This is the first expansion of the Jamaica dispatch office's control beyond the Port Washington Branch and the Jamaica Terminal. QUEENS tower was built in 1924 in the style of other towers on the main line like DUNTON, JAY and HALL.
QUEENS interlocking had actually been re-signaling in the 2008 time period with the Model 14 and NX panel being replaced by a VDU system, however the LIRR had a commitment to the quality of service provided by local tower operators and the tower remained manned.
Old Model 14 machine for the local 4-track crossovers
Old N-X panel for the adjacent high speed equilateral turnouts.
While not much will change from the outside, this is likely the next step in the LIRR's change to a more Metro-North style of operation with reduced aspect dwarf signals and centralized dispatch from a single location.
Please look out for a more in depth article on the history and operation of QUEENS tower as I have a good collection of both interior and exterior photos.
With the LIRR Budd M3's on the way out and all sorts of signaling changes under way, the Long Island Rail Road should probably be one of my top priorities for photos and video. Unfortunately with only 174 M3's on the active roster (vs ~800 M7s) not only is scoring one incredibly difficult, the crews are notorious surly and not only hostile towards videography, but will also tend keep the front car closed or run with the half cab door open to physically block the forward view. Getting LIRR video requires someone local who can ride day in and day out in order to be there when the stars align. Fortunately for everyone, MrMaster767 is on the job and has assembled a comprehensive library of LIRR "Cab" videos, many in 60Hz 4k.
While many of the LIRR routes have been rendered blah due to a general lack of interlockings and wayside signals, some of his grabs are quite a bit more interesting such as the Atlantic Ave Branch showing off the current disposition of position light signals and pneumatic point machines. For example DUNTON interlocking still has a smattering of pneumatics and some new-installed position lights, while down by BROOK and VAN a number of the PL dwarfs have been replaced by color lights and some electric point machines have appeared as well.
He also has a rear facing video showing off the new Ronkonkoma Branch second track and the reduced aspect signaling that went with it :-(
As much as I might try, I can't do it all. It's nice to see that others are able to pick up the slack and cover other portions of the North American rail scene.
Back in May I wrote a post covering the LIRR's new Reduced Aspect system. Similar to Metro North's, the system uses some additional indications involving slow speeds as well as the color Lunar White to distinguish it from existing color light signals. I was somewhat puzzled why, after adopting a new color light system to replace the older position light system, the LIRR would create a brand new system from scratch as opposed to just expanding, or using its color light system. After all, NORAC has had this down for years with the "Clear to Next Interlocking" modifier or the use of a Cab Speed signal with a Restricting option for failures.
In fact, I had heard that the LIRR had been using the "Flashing Green" aspect to indicate Absolute Block Clear. It had never seen it, but it made sense. Not to mention they had Manual Block Clear as an existing option as well. A quick google search actually found a previously unknown LIRR signal rule reference.
Yeah, there you go. If you want to go to color light, just use *G*/R. A nice uniform difference from NORAC Cab Speed.
Huh? *G*/*R*? That's a bit...odd. I guess they really want to make it different from anything that might appear in the Amtrak zone? Wait a minute...what's that in the text of Rule 298B?
Absolute Medium Clear? Absolute Slow Clear? Oh no..
Yup, that is a flashing three headed signal. I mean I guess I see the logic. The LIRR doesn't use flashing signals outside of the Amtrak zone so this associates flashing with an absolute block while not duplicating any existing signal aspects.
They named a signal indication "Flashing Slow Approach". I guess the other three signal rules used up all their creativity juice. The fact that I only became aware of all this now just shows the extent to which the LIRR keeps its operating practices under wraps. To be fair, this isn't as crazy as it appears. Like I said, when this was developed in the 1970's the LIRR had avoided flashing signal aspects and also wanted to avoid conflicts with Amtrak zone signals (although there was and is no wayside-free operation in the Amtrak zone). In the relay hut logic could use a single flashing circuit applied to the entire output of a signal when an Absolute Block signal was called for AND the system avoids the odd case of a "Clear to Next Interlocking" displayed along side an Approach signal, which can happen under NORAC despite being redundant.
This here is how you do absolute block. End of discussion.
Ultimately it doesn't matter if the system makes sense when viewed at the right angle on a sunny day. In a recent Newsday article, LIRR operating personnel were complaining that the new reduced aspect signals don't give the engineer enough warning, that train handling and/or the ability to maintain a schedule will suffer. The Pennsylvania Railroad, the Long Island Rail Road's corporate parent
until 1968, SOLVED this issue in the 1940's with the 'C' marker which simply modifies an existing signal aspect. The root of today's limited aspect problem is that in the 1970's, instead of adding one extra marker light and one extra signal rule, the LIRR decided to add 4 signal rules and 13(!) different indications to implement a cab signal system without fixed wayside signals and now trying to change it over to something like the NORAC method with color lights likely would lead to confusion. 😵
Metro-North started fresh in 1983 and first choose the PRR solution.
The rank and file of the LIRR have always prized a complex rulebook that is shrouded in secrecy in order to increase job security and overtime. 40 years later the management is now having to take drastic measures, beyond a simple
color light conversion, to bring order to the chaos and unfortunately I suspect that all
the old vestiges of the train order and manual block systems are likely
to be next.
