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Saturday, July 27, 2013

PHOTOS: LIRR VALLEY Interlocking and Tower

VALLEY interlocking in Valley Stream, NY on the Long Island Rail Road (of iced tea fame) is one of the more important and visible towers on the LIRR. It was re-signaled in 2009 or 2010, but due to the LIRR's commitment to service quality the tower repained open converted from its original 1930's US&S Model 14 interlocking machine to new panel and video game setup. The tower is located at the quintuple junction(!) of the Montauk Branch, Long Beach Branch, Far Rockaway Branch, West Hempstead Branch and Atlantic Branch.

Now I don't have as many details as I usually do due to the retaliative opacity into LIRR operations as the labour organization is skilled at protecting the jobs of its workers, however some of the photos I have were made available by a knowledgeable individual on one of the forum's I frequent. Despite the LIRR prefix VALLEY and almost all the rest of the classic LIRR physical plant this was essentially a PRR operation as the LIRR was a wholly owned PRR subsidiary up until the mid 1960's when it was given over to the Metropolitan Transportation Authority. The tower is typical for late 1920's PRR interlocking plant with all brick construction, pneumatic switches and of course position light signals, one of which is seen here displaying a Clear indication for a move eastbound to Long Beach on the 24L signal.

Here is a side view of the tower from the Far Rockaway branch showing the air drying unit and a signal from the LIRR thanking you for riding.  Unlike many other PRR towers VALLEY lacks a bay window, but being situated in the middle of the interlocking plant VALLEY tower doesn't exactly need one.

In this view of the model board you can see VALLEY is arranged into West and East sections on what appears to be a 4-track main line.  However the 4-tracks are actually two parallel two track lines with the northern set being the Montauk Branch and the southern set the Long Beach Branch. The single island platform for the Valley Stream station serves the Long Beach tracks and also features a two track flat junction complete with diamond to the Far Rockaway Branch.  This reflects the LIRR's concept of segmented service allowing Montauk/Babylon trains to run express on their own tracks while Long Beach / Far Rockaway trains make local stops.

Despite the 2x2 setup VALLEY is not inflexible with a trailing ladder in the west end to allow any eastbound trains to access the Valley Stream station and Far Rockaway / Long Beach branches.  In the east end of the plant there is a facing point ladder to allow trains to access the West Hempstead branch.  Today this is a minor branch line reduced from a double to a single track junction and non-peak service consists of shuttle trains originating from Valley Stream, laying over in the siding track east of the tower.   This requires shuttles to tie up the entire plant crossing over the 4 main line tracks. As one might expect peak period trains do not attempt to stop at Valley Stream and use the express track to Jamaica.

There is a third section to the interlocking plant which consists of an independent crossover on the Far Rock branch to allow trains leaving or arriving at the island platform to use either Far Rockaway track in combination with any platform track.  Both the Far Rock and Long Branch are run under single direction cab signals without fixed wayside signals, although manual block signals are provided for wrong direction running.

The heart of VALLEY is a US&S Model 14 electro-pneumatic interlocking machine dating from the 1930 when this part of the LIRR was grade seperated. The machine appears to be a 34 lever frame with only about 3-4 spare spaces.   Running against typical standards the signal levers are painted black and the switch levers are painted red.  The interlocking mahcine itself has been painted a pleasant green color which is common practice on the MTA owned NYC Transit Authority.

Unlike later Model 14 setups this one relies on a large number of glass globe signal rundown timers.  This shows the wealth of the PRR since in most interlocking plants poorer railroads would only provide about 1 to 3 timers for the full compliment of signals.  Here the PRR provides a timer for what is presumably every signal pair.  Similar arrangements could be found at OVERBROOK and NORTH PHILADELPHIA towers.  In the 1930's US&S began to offer timers integrated into the Model 14 itself that would cover multiple signals. The new arrangement was not as flexible this one, but offered savings that not even the PRR could turn down.

Here is the original westbound PRR position light signal guarding the west end crossovers and trailing ladder.

Here is the westernmost signal gantry showing the eastbound signals.  While the two primary eastbound tracks are provided with high PRR Pl signals, the reverse direction track on the Atlantic Branch is provided with a dwarf PL reflecting the original single direction operation.  The Montauk was upgraded for full bi-directional operations with the inclusion of a PRR pedestal signal.

Classic interlocking plants with electro-mechanical lever frames have always had issues dealing with bi-directional operation.  Bi-directional tracks mean that there has to be a traffic control check before a route can be cleared. Adding in this logic to a plant that did not anticipate it can mean quite a bit of modification as every single route needs to have a traffic check added.  One way around this is to add in exit signals that only have to check the traffic direction.  Then you can just add in one additional check in the mechanical portion of the frame to make sure that the proper exit signal lever is cleared.  Here we can see 4 exit signals on the western eastbound signal gantry.  All four were added later and even come with the late model signal ID plates indicating they could in fact date from the late 1990;s or early 2000's.

 With the re-signaling these seemingly solid PRR gantries were replaced with new aluminum type signal bridges.  Here on the west end the westbound gantry retained the three high signals and single pedestal signal. The extra pedestals are temporary while the new signals are put in service.

The eastbound gantry lost the exit signals as the new interlocking logic can natively handle the bi-directional operation on the tracks west of VALLEY.

The East End and its ladder only has one signal gantry for westbound movements.  There is an oddity in that the eastbound Montauk track lacks an entry signal into the East End requiring trains to be held at the West End gantry when the East End ladder is fouled.  The eastern gantry has high signals for the bi-directional Montauk tracks and a pot for the reverse direction Long Beach track.  Exit signals are provided for the two Montauk Tracks and the eastbound Long Beach track with a manual block signal for the reverse direction Long Beach track.

The revamped east end gantry of course last all the exit signals except the one manual block signal for reverse running to Long Branch.  Note the position of the 10L pedestal signal for westbound moves on the Montauk.

The West Hempstead branch branches off from the east end and its home signal features a formerly two track signal gantry now serving a single track.  Once again an exit signal is provided.

The resignaling fixed the problem with missing East End entry signals with these new predistals shown here bagged.  The old 10L signal is getting moved to in line with the other eastbound East End signals.

 As I mentioned before the third section of VALLEY is a full crossover on the Far Rockaway branch with its own set of absolute signals and exit pedistals. In this case the westbound signal heading off the Far Rockaway branch is displaying an APPROACH SLOW signal for the SLOW APPROACH signal at the 15mph East End flat junction.

 Here is the East End signal coming off the Far Rockaway Branch.

Signals for the Far Rock flat junction are located on or at the east end of the station platform.  The ASC (Cab Signal) test unit is present because Valley Stream serves as a terminal for West hempstead shuttle trains.

The 18L pedestal signal was also replaced in the re-signaling, although the new pedestal was given a Train Order lamp given the tower's still active status and need for train orders for wrong direction moves down the Long Beach line.  The red train order marker is made from a surplus US&S PL-3 unit.

The 24L high signal on the eastbound Long Beach track was also being changed from a high signal to a pedestal, shown here with a departing Long Beach train.  Note that the high PRR PL itself is a modern replacement for something earlier.  Also by this point in the re-signaling the A-5 pneumatic switches have been replaced by M-23 electrics.

Closer view of the west side of the tower showing the standard black-on-white LIRR station sign.  An SRS dooglebug peeks out from one of the interlocked storage tracks.

 Closer view showing the tower door.

 Views of the east side of the tower.

Going back inside we find VALLEY has more surprises than just the Model 14 machine. VALLEY has long since had CTC control of the various spoke lines that branch out from it. It controls the Far Rockaway Branch, West Hempstead branch and co-controls the Montauk Branch with BABYLON tower between here and BABYLON interlocking. Here you can see the VALLEY panel showing the Montauk/Babylon Branch (top), the Far Rockaway Branch (middle) and the Long Beach Branch on the bottom.  The West Hempstead Branch is displayed on a more modern Video Display Unit.  VALLEY interlocking proper was included on the panel, but was never activated and is shown hiding behind the Hempstead VDU except for the westbound traffic control functions.  With technology marching on the new VALLEY interlocking would be represented on VDU screens..

Recently the terminal of the West Hempstead Branch was interlocked with new storage tracks and control was integrated into a video game system located in VALLEY tower.  I believe that for a time the branch had been run under unsignaled manual block control.

Here is the operator's desk at VALLEY showing the train describer, block phone/radio and assorted miscellany.

Well, I think that ends today's technical discussion. On that note its time to go out with some VALLEY train photos.  Here is an M-7 Hempstead Shuttle pulling out of the station and across the ladder track to the West Hempstead branch in 2008.

And a pair of M-7 express trains on the Montauk Branch passing adjacent to the Valley Stream station platform.

Here is an old photo of a train of M-1/3's pulling into Valley Stream from the Far Rockaway branch. 

And another photo of one departing with M-1 #9015 on the rear.

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