Saturday, July 25, 2020

EUGENE ARRIVAL-DEPARTURE YARD TRACK CHANGE

With the sustained down-time of this Spring and Summer (no operating sessions), I finally tackled a long-planned track arrangement change in the Santa Clara Tower throat complex (Eugene Arrival-Departure Yard).  Comments made by two of my professional railroaders during the first operating session on the full mainline in June, 2015, caused me to reconsider and then redesign the throat track arrangement for Santa Clara Tower.  This throat area is the space between the RR-East end of the Eugene Depot and Classification Yard and the reverse loop staging yard which serves as the Arrival-Departure Yard. 

My original track arrangement necked down the mainline and WP Siding from the depot area to a single track main.  This single main split to access both ends of the reverse loop.  A short section of additional track provided an auxiliary "East Main" in the original formulation that accessed only the five reverse tracks closest to the wall on the "right hand" side of the loop.  


Original Santa Clara Tower track arrangement.  Only A-D Tracks 1-5 and the Halsey Branch can access the "East Main"--the right-hand track in the foreground.  All other tracks had to use the original mainline which splits at the throat switch in the middle foreground.

My professional railroader's comments about "extending the WP Siding" lit an "understanding light bulb" in my brain immediately.  I had been staring at Ed Austin's Eugene track diagram in his and Tom Dill's Southern Pacific in Oregonbook (PFM, 1987) for a couple of decades, but only by that comment did I understand what SP had done with track in the Eugene terminal.  Starting at the RR-West switch just beyond (geo-south) for the Eugene Depot, the WP Siding extended as an additional track with several crossovers all the way out to Irving--the RR-East end of the Eugene terminal.  What I had missed was the flexibility that additional track gave to the entire terminal.  Trains, switch moves, and light engines (often returning helpers) could use either track past the depot to get to their destination within the terminal complex.

Studying my existing track, I recognized I could never achieve the complete solution which would have involved two tracks accessing all tracks in my reverse loop area.  I could, however, achieve most of the benefits by providing full access to the "right-hand" switch ladder, adding A-D Tracks 6-12 to the connection to the "East Main."  This could be achieved by replacing the single switch that connected either the "throat switch" and the nominal main or the "East Main" with a double slip switch.  Continuing RR-westward toward the depot, the rest of the project requires three more double slip switches to create two "main" tracks extending from the depot to the Arrival-Departure Yard.

Double slip switches are something to be considered VERY carefully.  They are complicated bits of moving track.  Further, their routing is not intuitive, even to experienced railroaders.  They are known as "puzzle switches" for good reason.  One can think of a double slip switch as two opposite acting switches jammed together in the same space.  The points controlling the pair of routes on the right side of the switch are located on the left side of the frogs.  

I knew by the summer of 2015 that I needed to install four double slip switches to achieve the desired track rearrangement.  At the National Train Show at the end of the NMRA Convention in Portland (PDX2015) that year, I sat down with the folk from Fast Tracks to order assembly tooling for a Number 8 double slip switch.  My mainline switch standard is a Number 8 so that seemed the right way to go.  Unstated at that time, though, was that a Number 8 double slip switch needs moving frogs.  No instructions for such an arrangement were forthcoming and such an arrangement screams mechanical complexity.  When I discovered that fact a year ago as I was getting serious about this project, I decided I needed to take a fresh look at my options.  I settled on Peco SL-U8363 Number 6 double slip switches.  My track arrangement was adaptable to the sharper frog angle.

With the first of my Peco double slip switches in hand, I began laying out the revised yard tracks.  I am happy to report the Peco Number 6 fits my track arrangement very well.  I decided the overall project logically fell into two phases.  The first phase involves the installation of a single double slip switch to provide full access to the "right-hand" side of the reverse loop Arrival-Departure Yard.  As operations on my railroad have developed, this is the westbound departure end of the reverse loop.  As a consequence, all of the tracks in the throat area are being re-named to reflect their actual uses.  What had been called the "East Main" is now the "West Main."  The former "Main" becomes the "East Main."

With no operating sessions in sight and having all of the materials I needed, I began the rework by removing the old "throat" switch and the switch for the old "East Main."  I also removed the switches for tracks 6 and 7, as the new alignment would focus on Track 6 instead of 7.  For the past five years, I thought I would continue the compounding switch arrangement for Tracks 6 and 7 I originally built, but as I began removing track, I realized I had a far better option.  I could begin the switch ladder with a left-hand switch breaking off of the Track 6 alignment and then have all right-hand switches in the switch ladder.  This is what a full-sized railroad would do.  I also discovered I could add a connecting track to the engine lead, previously accessed only from the left-hand side of the reverse loop.  This new connecting track provides a West engine lead.


Removing the old track helped open my eyes to a better track arrangement than originally envisioned.   This view shows the original location and alignment of the switch for Track 7.  This switch was removed and replaced in the final design.

As I began placing the new switches, location of switch throwbars was a concern with regard to benchwork stringers under the roadbed.  I drilled exploratory holes on the prospective throwbar locations and then stuck bamboo skewers through the holes.  Sure enough, one switch needed to be moved a bit to provide adequate clearance from an underlying benchwork stringer.  


Bamboo skewers inserted in exploratory holes for throwbar locations.  The skewer and hole on the right was a bit too close for comfort to an underlying benchwork stringer.  Fortunately, I could move this switch closer to the double slip switch to clear the nearby support.


Final track arrangement.  Note the double slip switch has a straight-through route connecting the new "West Main" to the alignment of Track 6.

Wiring the new track arrangement was both straight-forward and frustrating.  First, the double slip switch was very easy to wire.  Peco provides feeders for the two frogs and the outside rails.  The outside rails are electrically connected to the correct rail segments within the switch.  A simple wiring diagram is provided on the packaging.  I re-purposed the switch machines for the former "throat" switch and the former "East Main" switch.  Similarly, I moved the switch machines for Tracks 6 and 7.  New switch machines were required for the two ends of the new West Engine Lead.  

The wiring frustration came first from trying to reuse as many track feeders as I could.  This saved on making more solder joints to the track bus wires--a process for me that requires using my resistance soldering rig.  Beyond that, it was a matter of locating the correct pair of bus wires under this very complicated throat area--lots of wires for a variety of track segments.  Finally, getting the frog polarity connections right resulted in the one for Track 6 needing to be reversed--something I discovered with the first test train.  

I rearranged toggle switches on the control panels for Santa Clara Tower.  Two toggle switches had to be moved and another one added.  The track lines were redrawn.  I chose to activate the engine lead switch closest to the engine facility as part of a crossover from the switch off the new East Main.  This saved one toggle switch.  Although the pair of toggle switches for controlling the double slip switch appear "logical" to me, I know these controls will remain a puzzle for many.  I augmented the toggle handle directions with light emitting diodes (LED) to indicate the route selected through the double slip switch.  Following color conventions on my railroad, the RR-East side uses blue LEDs and the RR-West side uses amber LEDs.  My long-term plan for this panel will replace the toggle switches with pushbuttons for two-button (Entrance and Exit) control.


Modified control panel for the "Westbound" end of the Arrival-Departure Yard.  

Finally, it was time to run the first train or cut of cars through the new switches.  This is when I discovered the reversed polarity of the frog connection for Track 6.  That was an easy fix.  This new track arrangement awaits testing by some of my regular crewmembers.  Once I pass that test, I will consider doing the second phase of this overall project, with three more double slip switches.  For now, I am happy to at last provide an alternative access to the full RR-West end of the Departure Yard.  A bonus was providing a path from this West end trackage to the engine facility.


First train (cut of cars and locomotive) crossing the new double slip switch.

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