SP Jawbone Branch (Part 28) - Laying Out the NG-SG Rail Transfer Pit

Flash back to April 2021...

My construction of the Jawbone Branch at Owenyo continues with the construction of the Rail Transfer Trestle at the north end.  For a full list of blog posts of this series check out the SP Jawbone Branch Index page.

Owenyo SG-NG ramp - Rich McCutchan  - owensvalleyhistory - slim rails63_sml

The SP narrow gauge (SPNG) was cut off from the shops at Moundhouse, north of Montgomery Pass in 193x.  There were no heavy engine rebuilding shops south of Montgomery Pass on the remaining section of line, so a transfer ramp was established to put NG engines up to the deck level of standard gauge flatcars.

SP SG-NG transfer ramp - Rich McCutchan - owensvalleyhistory.com sp_narrow_g46b_sml

Here's a close-up of the SG (southwest) side of the ramp, which is actually more of a bridge that just stops.

SP 6144 & SPNG 9 on flatcar at Bakersfield - Scott Horgan Collection - Western Narrow Gauge FB

The Narrow Gauge engines, like SPNG 9 above, once loaded on a 60ft flatcar were moved down to Bakersfield shops to be worked on.  Here SPNG 9, freshly shopped and painted is photographed with the new F7ABBA set of diesels with SP 6144 on the west end.  The shop forces have all turned out for this photograph!

SPNG 9 "Movie version" on the whisker track at Bakersfield - Inad Akeb screen grab - fair use.

The SPNG 9 was later refitted with 1890s style headlight and much more colorful paint scheme for movie filming on the SPNG.  Here is a photo of here undergoing pop valve adjustments at Bakersfield, still loaded on the flatcar, before heading back to Owenyo.

PRR F30A arriving Owenyo with SPNG 1, 1954 - owensvalleyhistory,com - dennis_burke03_spng_diesel01

In 1954, the new SPNG #1 diesel was delivered on a PRR F30A class flatcar.  The shot above is a great photo showing the F30A down in the ramp to unload at Owenyo. --- Now where is my F30A flatcar?

There's one of my F30A Bowser flats... - Ok, have a new load for you when you're done with that lumber!

Building the Model

Sub-roadbed cut marks ready, March 1, 2021.

I drilled a hole big enough for my saber saw blade to be dropped into the corner of the depressed area.  Then cut the 1/4" MDF, following the lines.

My pit at the east end of Owenyo with an F-70-10 for scale.

I cut the sub-roadbed with a sabersaw and flexed it down with a piece of 0.04" stryene slipped between the top of the ramp and the underside of the main roadbed sheet to hold it temporarily.  I glued two small scrap pieces of 1/4" MDF to make a lowered shelf, gluing it to the bottom of the top sheet.  I'll be able to add shims to adjust it to the height I need once the NG trestle is built and in place.

More Info Arrives from Alden!

SP 2335 & Two water cars Excursion Oct 1954 - Alden Armstrong photo (with permission)

Notice in the Alden Armstrong photo (above) that the closest SG track is dropping almost immediately after the switch.  This is the track dropping into the NG-SG rail transfer pit.  This photo also nicely shows how much terraforming I need to do on the MDF sheet to get the pit big enough and properly shaped.

Modifications... Cut twice... cut more!

After seeing the prototype photo showing how quickly the track drops away from the 'normal grade' of the area, I went back in with the saber saw and cut several inches farther towards the frog of the switch.  Yes, this was done after the flex track and switch were spiked in place.  On the front cut I had to drill a couple more small holes and connect them, as the under module bracing crosses the pit track here.  I already pre-relieved the brace so the pit track could drop some there.  Nice to plan ahead a bit with some flexibility in the engineering!

Looking down the spur from the house track switch.

I have not fixed the dropping road bed to this brace or the L-support lip at the far end of the spur.  So there's still room to push the pit lower or have the vertical curve happen sooner, closer to the switch.

A more normal viewing angle of the east switches at Owenyo.

I'm going to hold off on actually building and installing the Narrow Gauge sections and the transfer ramp trestle until I have the SG wired and working.  Anything sticking up too much above the layout right now would be asking to be klutzed when I flip it over for the wiring.

"Well Now You Know & I Know..." Oops...

SP 2335 East Owenyo with excursion Oct, 1954 - Alden Armstrong photo.

Just a great photo showing up after I put the rest of this and SP Jawbone (Part 27) - Finishing Up East Owenyo Switches was posted.  Thanks to Alden Armstrong sending me this photo, I now know that I layed out the switch headblocks for the east wye switch and house switch reversed in positions.  The wye switch should be slightly 'east' of the house switch headblock.  

Oh well,  One of the issues of compressing the layout and using tighter No.7 switch angles is that some small details like this need to be 'selectively compressed' to fit.  Also since I have already laid out the ties and spiked the switches down, I'm not about to tear it all out to fix a minor issue like this.

If I were to lay this out again, it would require moving the east wye switch headblock about half way closer to the main track switch and pushing the house track switch 'west' at least  3-4".  I don't really want to mess with the alignment of the "Pit" track or the rest of the compressed track alignments through the team-crane and loading platforms.  So this will remain the way it is.

In Closing - March 2022

I'm looking forward to building the ramp trestle after getting the rest of the construction back on track (oh, bad pun!).  I'll be posting SP Jawbone (Part 29) shortly, which is a recap and new progress on the lighting since Part 24, where I was working on the new lighting when I hurt my shoulder.  Then I'll move on to update to where the projects currently are at the end of March 2022.

Jason Hill

Related Articles:

SP Jawbone Index Page - Links to all posts in this thread

SP Jawbone (Part 24) - Let There Be Light - Starting LED Lighting Work

SP Jawbone Part 27 - Finishing Up East Owenyo Switches - East end of Owenyo trackwork.