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Monday, October 22, 2012

Extinct: The US&S MT Switch Machine

Over a year ago when I posted about the demise of E 180TH ST interlocking and tower on the New York City Subway system I was unaware that we were not only losing the last main line single interlocking on the IRT or the last section of IRT signaling (including those three headed monsters).  It appears that the E 180TH ST interlocking had one more surprise, a surprise that I had noticed, but never fully comprehended. 

This mystery object was brought to my attention be a superb, yet rather invisible, signaling blog called The Has Been that took note of my E180TH report and quickly flagged the item of interest.  If you had ever viewed my photos you may have seen something that looked a bit out of place...a bit like it should belong in the London Underground instead of the NYCS.  I'll make it easy for you and just show you what I am talking about.

Well I have confirmation that yes indeed that is a Mid-Track mounted point machine produced by USTS as the model, what else, MT and according to this post on the Has Been blog it dates from the original construction of the interlocking and was manufactured sometime between 1904 and 1912, surviving about 2 or 3 re-signaling efforts...but unfortunately not 4.

The MT machine at E180TH ST was attached to a split point derail and what probably kept it in service in addition to its compact mounting, was that it is probably the only model of point machine that support staggered point blades, which were called for in this specific power derail. 

Anyway, the 100+ year old point machine had been giving the NYCTA some real headaches as of late as all repairs had to be carried out from scratch, still, it is always a same when the last of something disappears from the wild, if not the entire world.  While the three headed monsters were clearly unique, they were made from standard hardware that still exists in droves.  The MT was truly unique and something the likes of which will never be seen again.

Monday, October 8, 2012

PHOTOS: METRA TOWER A-2 (Western Ave) Part 2 - Inside

So back in Part 1 we explored the history behind TOWER A-2 and the layout of the interlocking plant.  Here in Part 2 we will venture inside the tower to see how it functions as a critical part of the Chicago area commuter rail network.  Just for a quick reference I am going to throw up the link to the original interlocking diagram again so you can open it in a second tab or window for reference.

So we will begin with another quick look outside the tower at the entry stairway which was clearly updated at some point after construction.  The PRR tended to prefer internal stairways for its late model interlocking towers, but in this case Milwaukee practice seems to have prevailed with an external stairway and door.  As is typical the relay room has been provided with its own entryway.  The upper story of the tower has been retrofitted with new siding and new replacement windows, but fortunately seems to have avoided the worst aspects of Tower Window Syndrome with none of them being boarded up.

Here we see the venerable US&S Model 14 electro-pneumatic interlocking machine.  This is an 83 lever frame that contained 69 active levers in its original configuration with 45 for switches, derails and movable point diamonds, 22 for signals and two release levers that I believe set traffic direction over the crossing.  As this tower is following Milwaukee practice the model board is of the more colourful variety with color coded track circuits whereas PRR practice used a white on black scheme with diagram symbols to indicate circuit boundaries.  The other Chicago Union Station towers, LAKE and JACKSON streets, also used this multi-colored style.  Due to the four color theorem US&S only needed pastel versions of red, green, yellow and blue to represent all the circuits without having any one color touch another of the same type.

While the model board has had all of the removed trackage blacked out, those altering it did a good job blacking out what was gone and re-painting what could not be simply blacked out.   Moreover all of the original text labels like C.&N.W. RY and C.M.S.P.&P. RY are still present along with the control city of Logansport on the since removed PRR Panhandle track.  BTW, I believe that the model board is in fact fitted with three clocks, one old analogue, one new analogue and one digital.

Builder's plate on the Model 14 machine.  Constructed in 1938 this is a fairly late model frame, although production would continue up until the 1950's.

Wider view of the Model 14 machine.  You can see that when the tower was renovated it was fitted with a drop ceiling and track lights to illuminate the model board.

Opposite side angle view of the Model 14 power frame.  You can see that the lever 83 position is still occupied to control a switch.  Of the 69 original active levers about 45 are still in service.  Those switches that do not see frequent movements are affixed with Rusty Rail tags which remind the operator that trains working over those switches may not shunt and therefore the operator should verify that the route is clear before making any conflicting actions.  Probably due to a noddle incident there is now a sign on the interlocking machine advising people not to put food or drink on top of it.

As would be expected the levers at the far right of the machine handle the position light signals and crossovers in the east end of the interlocking plant. The 77 turnout is set reverse with a blocking device applied which would imply that track #2 east is out of service at that time.

Here in a closeup of levers 29 through 49 we see the standard US&S setup with switch levers pointed upwards and signal levers pointed downwards.  Unlike PRR practice, the levers here have also been painted in the normal style with switched black, signals red and lock levers blue.  The PRR tended to leave all of its power frame levers painted black.

Saturday, October 6, 2012

Trading the Uncommon for the Rare

The MTBA owned portion of the Fitchburg Line is being re-signaled and while this will ultimately lead to the closure of Waltham Tower and its increasingly rare US&S Model 14 machine, it has created a rather interesting conundrum for the committed signal fan.  The junction of the Fitchburg Line with the Guilford Rail System's freight main line is being reconstructed to accommodate the second track being added to the MTBA portion of the line and of course the relay based interlocking plant with its Boston and Maine era signaling hardware is going to be replaced because what good is Federal money if it can't be used to help out a private for profit corporation.  The silver lining is that a pair of rather spartan B&M two track signal bridges equipped with three head US&S searchlight signal masts are being replaced by brand new target type bracket signals, similar to ones installed previously on the Haverhill Line resignaling project.

While the loss of searchlights, especially US&S H-2 units is always tragic, the truth is that the bracket mast is far more endangered on the North American rail network than the searchlight signal is, especially if Unilens and new LED searchlights are included.  Today the MBTA is the only outfit that still regularly installed bracket masts after NJT generally dumped them in favor of standard signal bridges.  So I guess I'm have to be contented with the silver lining of getting a brand new instance of something that has become increasingly rare.