K TOWER "Relocated" w/ N-X Panel Retired

It has been confirmed that Amtrak has relocated the train director(s) working K TOWER at Washington Union Terminal from the historic 1908 structure and into a small office in the Railway Express building adjacent to Track 29 on Union Station's lower level.

 

Unlike R Tower in Sunnyside yard, where a similar relocation immediately preceded demolition to make way for an Acela maintenance facility, the historical significance of Washington's K TOWER is well understood.  In 2017 I reported on plans to cover over the entire union station approach with some mixed use development with K Tower specifically singled out for conversion into some sort of high end bar. The culprit here is some combination of Amtrak's desire to simplify "management" and also cut costs along with some technical upgrades that were evidently completed behind the scenes.

As constructed in 1908, Washington Terminal was controlled by at least three US&S Electro-Pneumatic equipped towers, A Cabin, C Tower and K Tower. In the 1970's, K Tower had its long Electro-Pneumatic machine replaced with a then cutting edge N-X type interface and model board that drastically cut the need for staffing (and floor space) and centralized control of the entire terminal into a single location. This change likely took place around 1975 as the construction of the DC Metro's Red Line required the demolition of C Tower. Although cutting edge for the 1970's, by the 2010's the N-X machine was becoming increasingly difficult to maintain as parts were long out of production and failures could become rather nail biting in terms of getting the machine working again.

Although decorated with some LCD screens, the big old N-X panel's days were numbered and as soon as the control was converted into a video display interface, the human train director was no longer limited to being in the tower itself, especially if CCTV feeds could be provided. Although I suspect the historic K TOWER will be maintained and serve a railroad function, while active as a work site the HVAC, restrooms, etc would all need to be maintained to a higher standard. Plus there is the added benefit of management being able to "pop in" to "supervise". It is quite possible that the N-X panel was actually replaced years ago and COVID simply delayed the inevitable. K Tower would therefore be a rather extreme example of a "return to the office" policy. Still, given that computers can be installed anywhere, there is always the chance that the K TOWER staff could find themselves back in the old tower in the future, baring some redevelopment effort.

K TOWER joins the fate of many other pre-video "panel" type interlocking setups that I discussed previously in the content of Hoboken's rather short lived TERMINAL TOWER. Given the ease at which an N-X panel can be converted to a video interface, it is entirely possible that, rapid transit systems not withstanding, we  might see electro-mechanical machines outlast hard wired N-X panels in staffed towers.

British Power Signal Box Video Tours

On a British signaling forum I frequent, a signaler known as Ian Ives uploaded a number of VHS video tours he made of some London area British Power Signal Boxes (also called Panel Signal Box or PSB) back in the 1990's.  For those of you who don't know, a PSB is roughly equivalent to the type of interlocking tower that was largely passed over in North America in the evolution from single interlocking towers to dispatch offices. They are basically what the NYC Subway calls Master Towers.

Popular in the UK between the 1960's and the 1980's, they replaced most of the electro-mechanical interlocking towers in busy urban areas as well as scores of pure mechanical towers.  PBS's contained large NX style model boards with light green tiles.  Their most high tech feature was automatic train description using small LED or CRT display boxes, which in the 1960's was quite a feat indeed.   While well documented pictorially, there are relatively few video records of how these panels were worked so check out these great resources.

If you like these, make sure you visit and/or subscribe to Ian's channel here.  If you would like an official tutorial on how these panels worked, you can find it here.

PHOTOS: Amtrak LAKE ST Tower

It's been a while, but it is finally time to conclude my METRA Tower series by looking at a tower that wasn't METRA's at all, but played a large role in METRA operations.  This would be Amtrak's LAKE ST tower, situated (until recently) at the north end of Chicago's Union Station.  The tower was built by the same PRR/MILW/CBQ consortium that built the entire Chicago Union Station complex in the mid-1920's.  Despite its prominence I have not yet been able to locate any period interlocking diagrams or other information that could better inform my talk, but since when has that stopped me before ;-)

Built during the roaring 20's, LAKE ST exhibited all the opulence of the era with a tile roof, copper gutters and all brick construction.  During the Amtrak era is was actually upgraded with modern picture windows and ample exterior lighting.  LAKE ST was closed in 2005 after 80 years of service and then demolished in 2013 due to an overbuild project to cover the tracks with either condos or a park. Until then it was a fixture of the north side railfan scene, viewable from the adjacent Lake Street bridge and easy to work into all sorts of photo angles. This may seem like the typical story of a classic big city tower, but LAKE ST was something special and one tip off is the windows.

Like many Chicago area towers, LAKE ST was equipped with an emergency exit.

The south side of Chicago Union Station is far more complex and sees far more traffic.  With road bridges providing an unobstructed view of the action it is what people think of when they think about long distance passenger rail in Chicago.  That part of Chicago Union Station was controlled by HARRISON ST tower, an elevated affair that was eventually surrounded by the new post office building in the mid-1990s.  At the time Amtrak also embarked on a large scale re-signaling project on the south side replacing the old Model 14 machine in Harrison Street with modern relay logic and the PRR position light signals with B&O style CPL dwarfs and high color lights.

What main people failed to realize was that the north side interlocking controlled by LAKE ST was left completely untouched and moreover, control of the south side plant was moved to a large NX panel in LAKE ST tower.  Thus LAKE ST wasn't just a tower, but was the control facility for the entire Chicago Union Station complex. Thus, nice new lighting and big picture windows.

 In 2005 time finally caught up with LAKE ST as a $45 million, 2-year project to re-signal the north end finally came to fruition.  This saw the replacement of the PRR PL dwarfs with LED searchlights, the implementation of a new CANAL ST interlocking to replace what had been a number of hand throw crossovers north of LAKE ST interlocking proper and the consolidation of all Chicago signaling control into the CUS office complex.  This included the closure of Amtrak's 21ST interlocking at the southern gateway to the CUS complex as well.  The interior photos I have of LAKE ST were taken just before and then a few years after its closure.

Here we see a post closure photo the 95-lever US&S Model 14 interlocking machine originally installed in 1925.  The large number of white painted spare" levers is due to the rolling closure where successive parts of the interlocking plans were cut into the new vital logic.  At the time of its closure the LAKE ST Model 14 was down to 9 signal levers, 4 switch levers and one traffic lever.

The model board shows the layout as it originally was with 11 station tracks that fanned out from a three track main line.  9 of the tracks are stub end with 2 additional through station tracks and 1 bypass track.  Station tracks are given odd numbers as even numbered tracks are on the south side of the station.  The model board is 4-colored in accordance with Milwaukee Road practice and uses green lamps for track occupancy.  Displayed signals are not shown on the model board.  Alterations have been made with a combination of black tape and hand painted lines.  On the through tracks a number of signals that are controlled from the NX panel are indicated with the N/S suffix opposed to L/R.  A quick count indicates 7 doubleslip switches, 11 single turnouts and 5 crossovers.

 In this opposite view of the model board we can see the entrance to the interlocking at the grade crossing with Canal St.  Most of LAKE ST interlocking is located underground a block or two north of the tower itself.  The tower only had direct sight of a few hand throw crossovers near Canal St and the outer crossovers between Lake St and Randolph St.  One of the reasons for the rolling cutover was because the interlocking was not only resignaled, but also reconfigured.  Compare the model board above with a facing point ladder track, stub end track 5 and a non-circuited track passing close to the tower to the current layout below.

Here we see a parallel trailing point ladders, one of which employs a doubleslip, the other a scissors crossover between the two center tracks.  The non-circuited track has been removed leaving the single station bypass track.For a more complete view of the current interlocking layout please refer to this computerized model board of the Chicago Union Station area. 

Back inside the tower we see an odd blank patch on the interlocking machine where lever spaces 1 through 32  had been removed.  This does not appear to have been part of the re-signaling effort given the age and condition of the metal.  Looking at the model board I suspect there was some spare capacity at the lower end of the machine in addition to some of the northern part of the plant being made redundant through hand operated switches. Without lever positions on the frame I am unsure how the 16L, 18L, 20L, 24R, 26R and 28R holdout signals at Canal street were controlled.

 

 Closeup view of the levers looking down the frame towards the emergency exit door.  The bay window is to the left of the photo.  Last active lever is 94, but the frame has space for 95.

Another view of the levers this time showing the mix of 1920's and modern track lighting fixtures. 

Moving back in time to 2004 we see the tower towards the end of the re-signaling project.  The Model 14 machine is still in service, but most functions have been transferred to a pair of NX panels sitting over the blank section of the frame. The remaining part of the interlocking still controlled by the Model 14 is covered over on the panels.

CTA Mini-Towers

The Chicago Transit Authority has remained a strong supporter of the "tower" system of rail transportation control.  Just like the NYC Subway and the Long Island Rail Road, the CTA's traffic density still gives an edge to human eyes and judgement in place of automated routing and remote control.  Those who ride the CTA are probably aware of the currently manned towers placed at the yards and major junctions.  It is pretty hard to miss them the way the operator's cabs typically cantilever out over the tracks.

The CTA even produced this video showing its recently rehabilitated towers at TOWER 18 and CLARK JCT, which received brand new NX Panels.



However the CTA has another type of tower, one  that is almost ubiquitous, but also hard to spot.  While local control panels are a common feature in most relay rooms, the CTA steps things up one notch by placing many of these, from junctions to simple crossovers, in their own little booths.




 The most "tower" like of these mini-towers is TOWER 12 at the southeast corner of the loop where Orange and Green line trains split off to the south.  While this junction is normally remote to Tower 18, there is still a small porta-potty sized booth where a human operator takes over at peak periods.

Another form of the CTA "mini-tower" is a space built right into the trackside relay huts.  Again the giveaway are the windows placed in a manner that would allow an operator full view of arriving trains.

Here is a portable interlocking cabin set up at the Harlem and Lake Green Line terminal and again the small window for manned operation is present (also note the interlocking horn).



Finally, sometimes the operator can get his own stand-alone booth on the station platform.  One such mini-tower is located at the south end of the Damien Blue Line platform.

This mini-tower controls a small scissors crossover immediately behind it.

The interlocking is clearly remote from somewhere else, but as you can see the Damien local tower has a fully functional panel.

 It has NX buttons for the signals as well as overrides to throw the switches without a signaled route.  It also has buttons for the direction of traffic on all four exits, call-on buttons and even a button to sound the interlocking horn.  Of course there are switches to set control local, remote or automatic.

What's interesting and a touch ironic is that at the opposite end of the same platform is a classic style tower that was built, but never placed in service as the junction it was to control was eliminated.  It looks like the CTA took a second bite at the apple. :-)