SP Jawbone Branch (Part 47) - Owenyo 3rd Module Construction

In the last couple posts I've been researching and pondering the finalized design for the modeling of Bartlett.  However the next step in construction really is building the frame for the Owenyo #3 module.  I've called this module Owenyo #3 in previous posts, as I was numbering the modules from the east-end of the branch.  This module is required to start working out the door-crossing removable module.  So eventually I'll need to get the other end of the removable section sorted out, and that will require Bartlett.  Those steps are still a little way down the road.

Constructing Owenyo #3 Module

Owenyo #3 Module CAD Test Assembly with OTT - 2024-01-28 with rough plan for the foam scenery.

I've been working out structural design for several months, really since almost 9 months ago, how I will be building this module.  This week, I finally started construction of the framing for the west of the three Owenyo modules.  For the back right corner of the module, which will go into the corner of the room, I lapped the two layers of 1/4" MDF, so that neither had a full butt-joint into the other frame strip.  When construction is complete, I can also glue in a section of MDF gusset or 2x2 to support the corner.

View from above, higher than normal viewing angle, but to show rough planning of the structure.

The other challenge is that I want to model a small culvert (bridge) just about the same place that the curve spiral is and the vertical easement into the 1.25% grade is.  That's really too much to ask the sheet of 1/4" MDF to do cleanly and smoothly with just riser supports.

So for this module, I'll be switching over to "spline" roadbed construction, but retaining the top cover piece of roadbed.  I believe that the spline-construction will allow me to 'sculpt' in the vertical transition to the grade and the curve, which is also going to have to be twisting in shear so that the rails are still cross-level after going through the nearly 90 degree corner, and establishing the 1.25% grade.

The underside of the planned structure - wire frame to show shapes without the shading.

The underside rendering of the design shows where the complexity comes it.  The spline roadbed will have to notch, or 'hop' over the front frame rail.  There will also have to be some fancy spline and grade work under the spur rolling over and forming the curve to align with the Owenyo Transfer Trestle structure.  For sake of my sanity in the CAD program, I only made the CAD drawing for the critical and weird parts of the construction.  I'm sure I'll be putting in more diagonal "web" bracing and stuff under there as well.

Cut & Glue Time!

This is the rear corner with the 1/2" plate (at right) abutting to the west end of the Owenyo #2 module section.

I'm returning to the previous method of using Gorilla Glue to bond the MDF sections together.  This is an expanding epoxy-type construction adhesive.  It requires clamping and holding the pieces until they dry.  I'm using the 90-degree corner clamps to hold the angles correctly.  In the later construction steps I'll be putting in corner gussets to support the joints, and when the module's done there will be foam scenery filling most of the internal area of the module.

This is the interior joint of the front frame member bonding to the right outer frame member, forming a T-corner, against the wall. - Top view

The structure is made up of a mostly standard frame-work like my previous four modules have used.  As this will be the first corner module, plus the transition to a 1/25% down grade, I'm having to work out the supporting structure, and keeping it square.  Every time you build a section or module and induce a warp or twist into the pieces that make it up, that piece will try, in return, twist the rest of the structure until the whole structure finds an equilibrium.  So all of that will have to be planned into the design, while at the same time correctly allowing the track supporting roadbed to twist and change to the grade, while on a 48" radius curve.

Back right corner, two layers of 1/4" MDF lapped and glued.

This back corner will also have to be secured vertically to the rear support bracket of the staging yard, while I still plan to have another bracket between the window and the door supporting the right wing of the corner module, I'd rather have it extra secure.  I also did the same thing, attaching the Owenyo #1 module to the wall, because of the weight of the extra supports and the cantilevered wye that can be attached.

The completed T-joint forming the front strip (left) and the right wall (right) - This is the bottom view.

This completes the basic four cornered 'box' frame which will be supported from below, as on the other Owenyo modules, and fit over the top of the Mojave staging yard below.

Always Planning Ahead

The frame of the new module is still rather fragile, without even any cross-members.

On the east end of Owenyo #3, I'm adding these small 1/4" MDF gussets to support the corner.

The final front strip will lap over the outside of the heavy 1/2" MDF mating plate to the Owenyo #2 module.  I can't really fit that strip, as it will be forming the front fascia of the whole module, curving and changing grade and also forming the terrain profile.  So I'd rather wait until much closer to the end of construction to install that piece.

Before I glued up the rest of the frame, I cut these slots for the future spline roadbed to mount to the end plate.

I'm planning to build the spline roadbed out of multiple pieces of 1/4" strips, so I made a set of 1/4" slots in the end plate for the spline ends to lock into.  Then I should be able to bend the strips into the desired spline shape with a couple other pieces to hold the shape I want.  There'll be a fairly short straight section, before the transition to the curve.  That should allow the bond between the splines and the end plate to be strong.

Mocking Up in Place

At this point I realized that the room is about 1/4" out of square at the long-wall window joint, so it introduces about 1/8" skew into this module's frame, which while annoying, isn't going to be a problem if I glue up the rest of the diagonals to hold it in this alignment.  Notice the clamp at the front edge of the mating plates at left.

For now an extra 3/4" plywood bracket arm is clamped to the right frame strip.

The clamp at the right side here is to help hold the module level and in proper position to start building the rest of the diagonal supports into.  

In Closing - For Now...

The outer framework over Mojave staging yard mocked up.

I think I'll leave the blog post at this point for now, and when I post on this again, hopefully I'll have more of the frame's diagonal supports and outer frame around the corner with the 0.65" grade change by the end of the module worked into it.

Jason Hill

Related Articles:

Jawbone Branch Layout Build Index - Master list of previous blog posts on my Jawbone layout.

SP Jawbone Branch (Part 46) - Printing Full-size Bartlett Template - Previous post in the series...

SP Jawbone Branch (Part 35) - Cutting Out Owenyo #3 Module - Last post on Owenyo #3 from 2022, on Aug 30!  Wow, that seems like such a long time ago.

SP Jawbone Branch (Part 46) - Printing Full-size Bartlett Template

So I've been looking at the Bartlett plant in more detail, working on the selective compression ratios, researching traffic patterns, looking at all the photos I can get my hands on for a couple of months now.  I covered more of the Bartlett Plant research in a new deep dive series: Owens Valley Mining (Part 2) - Bartlett Plant - Columbia-Southern Chemical Corp - Soda Ash, Trona, & Boron, but now it's time to come back to what am I going to do with the model of Bartlett, and how am I going to progress with building it?

Revised Bartlett track plan from 2024-05-05 with the inner tracks rotated about 5deg CW.

One of the minor changes I made since earlier this year, was the possibility of just rotating the plant's tracks about 5 degrees clock-wise to create the curve between the main track switch and the west (south) run around switch.  This requires moving the main track switch a bit more to the right on the track plan.

A Paper Layout?

Who wants a Bartlett puzzle?  That's a lot of pieces to jig-saw together!

The next step was to take a screen-print of the current drawing (unfortunately not the rotated version) and slice it up into 26 images that could be printed on standard 8.5x11 sheets, then taped together.  I want to get a feel for how big this is, how the switching will be, how the elevation of the modules will come into play with the size of the warehouse, which is between me and the loading spur.

Paper Bartlett plan layed out on foam over Owenyo modules.  It's big and a different shape, so hard to get a feel for in this spot.

In some ways the life-size print out is showing me how much 'extra' space that my CAD drawing 'baked' into the design.  I allowed 'rounding up' of certain measurements, length of runaround, placement of road, etc to be "worked out later" and "It'll go about there somewhere" because of all the selective compression that I'm dealing with.  For example with the more careful measurements of the photos, the tail spur at Bartlett, where I believe the loading was done, is actually more like 7 cars long with at least one extra car length of tail beyond (north) of the warehouse.  I've currently got the plan to handle about 4 cars past the headblock of the north runaround switch.

Oddly, the prototype photos don't back up this much traffic (which I cover in Owens Valley Mining (Part 2) - Bartlett Plant - Columbia-Southern Chemical Corp - Soda Ash, Trona, & Boron blog post).  I'm still not sure why that is... if the dates that the aerial photos were taken really were just dumb luck to not have picked up the boxcars being on-spot for loading, and the plant was shut down for work, it certainly is odd.

Extra 3237 West rolls to a stop at Bartlett with a string of GS gondolas from Owenyo.

Given that I think the production rates could have been as high as 7-8 cars per respot by the SP, having the spotting positions being more like 4-5 cars is reasonable.  Then the out-bound Mojave trip respotting could make since on the way to Lone Pine and Owenyo, with 3 cars or even more spotted in the run around allowing the north bound train to respot the whole warehouse each day.

Paper & Foam Core Warehouse?

In the past I've used foam core or foam-board to make structure mock-ups. So it's always handy to have some on-hand!

My next step is to draw a mock-up of the warehouse loading building, which I can put on the full-sized printed footprint of Bartlett.  I want to put them up at the planned height of the future Bartlett station and see how I'll do being able to switch the plant, lines of sight, views of the plant, etc.  I don't want to build it and then realize that I can't see anything, it is too awkward to reach around the warehouse to switch it, etc.  I think there will be some possible solutions to that, but I want to see if they'll work before starting to actually cut any roadbed.

Here's an aerial photo of Bartlett dated 9-10-1955... Look at the large silo casting the shadow at center. 

Once I've answered the questions, I'll consider foam-core mock-up of the warehouse until I can build a scratch-built proper model for it.  There's still questions about exactly which configuration I'll build. 

Bartlett warehouse on 3-7-1954, notice there's no large silo mid-photograph yet.

The 1954 version with no large silos, or maybe the 1955 version where large silos were put near the mid-southern end of the warehouse... I think possibly to load covered hoppers, as the plant was starting to be upgraded for the 1958 tripling of production rates.  Unfortunately, I still don't know much about the timeline of how that happened and what exactly was done when.

Covered Hoppers at Bartlett?

I don't have many other uses on the Jawbone Branch for the covered hoppers I do own.  So it might be fun to have a reason to run a couple of them up to Bartlett if I have the ability to load them there.  I believe most of the cars I own would have been in cement service at Monolith for cement or for North American Potash and Chemical leasing service out of Trona and West End, which is not the part of the Jawbone Branch I'm modeling!

American Potash & Chemical Corp owned the plants at Trona and West End during the 1950s, but I doubt this car would have come to Bartlett to be loaded.  This PS-2 is a little too new for me with 1-55 built date.

If there was covered hopper traffic to Bartlett, I'm not sure if they'd have been general leasing covered hoppers from SHPX, GACX or NAHX reporting marks, or if SP cars could have been supplied, although I think most of those were used by other companies involved with shipping cement, etc. and a company like Columbia-Southern Chemical, a division of Pittsburgh Plate Glass would have been using a leased fleet of cars assigned just for their use.  See Tony Thompson's blogs on leased covered hoppers: "Updating the car fleet plan: covered hoppers" or "Small project: repurposing a covered hopper"

One advantage of using covered hoppers would be that they could carry bulk product and 70-tons at a time, in less spur length than standard 40ft boxcars, which could only take 40-50 tons at full loading.  One problem with this theory is that I have no photographic evidence of covered hoppers before ~1958 at Bartlett or even the Owenyo Branch north of Searles, which is more than four years after my cutoff date.

I dive a bit deeper into the NAHX covered hoppers in my NightOwlModeler blog post: NAHX Leased Covered Hoppers - Pullman PS-2 & Greenville Prototype.  In short, I decided that the Kadee PS-2 pushes too late compared to my 1954 cutoff year.  Also the American Potash & Chemical Corp really isn't related positively in the Owens Valley soda ash processing plants, I believe they were more competitors from the Searles Valley.  So unless there was an NAHX or other leasing company sample covered hopper was sent over for mechanical considerations of how they would load one in the Bartlett's 1955-58 upgrades, but I don't see them being a regular car that could show up daily or even weekly.

In Closing

SP 3237 pointed east Bartlett on the Jawbone branch - Leo Barusch photo, my collection

I'm still looking forward to replicating this photo on my layout.  I was able to pick up an F&C XM-1 boxcar kit, and will be looking into kitbashing it to be a Seaboard boxcar, as in this photo.  I think this shot is also evidence that the SP was at least respotting Bartlett on the way north, and then doing most of the work on the way back to Mojave.

Paper full-size printout of Bartlett track plan with an Owenyo Local lead west with SP 3237 and some cars in the Bartlett Plant.

So there's still much to do, but at least I'm nailing down the large silo and several other aspects of what the Bartlett model will consist of.  It seems clear that the addition of the large silo would have been visually interesting to have in the foreground of the complex, it wasn't built until at least sometime in mid-1954 or 1955, which really puts it beyond my modeling era.  At least I won't have to deal with building covered hoppers!

Jason Hill

Related Articles:

Jawbone Branch Layout Build Index

Owens Valley Mining (Part 2) - Bartlett Plant - Columbia-Southern Chemical Corp - Soda Ash, Trona, & Boron

Tony Thompson blog posts:
Updating the car fleet plan: covered hoppers

Small project: repurposing a covered hopper