SP Jawbone Branch (Part 56) - Rough Foam Scenery for Owenyo#3 (Sept 14)

This blog post might just like the plains of pink foam without much happening... but there will be some basic changes and sculpting of the foam going on.

SP 3203 mocked-up working the trestle spur with some GS gondolas.

This is where I'm really starting to focus the construction of the layout module to match or at least capture the look of the prototype, compressed into my 48" radius 90 degree curved corner.

September 14, 2024

So I took most of a week away from the construction, allowing the layout construction and gluing to cure well.  Construction resumed at about 7pm on the 14th.  I put in more foam between the mainline roadbed and the spur pit roadbed.

Gluing down the roadbed.

In this photo, I'm applying the weight of the water-bottle to help keep the Gorilla Glue from swelling up, and lifting the foam in unexpected ways.  The yellow cheese-grader looking "Sur-Form" tool is handy for trimming down the foam and shaping it as well.  I used it to rough in some details over near the ballast deck bridge, and also shape down some of the foam form a bit during the course of the night.

The larger foam sections are installed, but at this point I'm gluing in the smaller sections and pieces of foam to complete a good solid surface.

At this point I'm cutting the 45 degree chamfers along the pit-track.

The many little scraps from cutting up the foam sheet provided plenty of pieces to stuff in all the little holes.  Several square or rectangular pieces were cut at roughly a 45 degree slope, to then glue in along the square edges of the foam and spur pit edges.

Checking a low-angle view with the trestle.

Again, the main concern with the trestle pit track is how far below the "natural" ground level it should be.  The main measuring point for this is the height of SP 1948/49 GS Gondolas and the trestle's bents.

At this point I dropped the trestle mock-up 3d print in place.

The main track really cuts across this view of the trestle, showing how much of the mound of dirt between the main track and the tighter radius spur's curve has been compressed.

More of a side-view of the trestle.

It's hard to get the camera's point of view low enough to replicate the "standing" view of a person walking around on the natural ground level, yet still see the details of the terrain.  About this point, I was coming to the conclusion that I would have to continue the climbing slope up to the backdrop, which will match the prototype.  In real life, nothing is flat, nothing is smooth... you might think it's flat, but it could be the whole field or area of the terrain is actually on a 2-3% grade.  I believe that's what subconsciously is going on in Owenyo.  It should be able to blend into the backdrop as the erosion terrain blends into the Owens Mountain Range to the east.

Here's a side view with a GS gondola.

I want the foam to be roughly at the bottom of the side-sheets of a standard GS gondola.  The foam surface will be a bit below what the final scenery level will be, once I add the Sculpt-a-Mold and dirt to the top.

A bit of wetted MDF roadbed from gluing in the last sections of foam.

This last section of foam was a trick to put in, as it has to transition from on top of the spur's roadbed near the trestle, to under it near the switch.  This resulted in some openings in the foam, and I filled those with some Gorilla Glue soaked paper-towel.  Effectively "Gorilla Glue Hard-shell", for those familiar with standard plaster 'hard-shell' scenery.  As this module will be movable, I don't want to have anything at this level of the structure being standard plaster, which I've all too often seen come unattached from the layout structure and sub-roadbed.  I want this glue-joint between the foam and the MDF structure to be very secure.

Nearly the end-view that I'll have if you eye-ball the scene with the door module out.

The white "snow" in the background is actually more paper-towel "Gorilla hard shell." stuffed into a few other cracks, along with some of the expanded Gorilla Glue foam, which will be Sur-Formed down later.

Checking how it looks with four GS gondolas spotted.

The last section of bents on the trestle don't have any dump chutes, so the standard gauge cars have to be shoved about half a car length under the trestle to be filled to the end of the car.  It's about 2-car lengths to the overhead tell-tales.  Often the photos of the real trestle show 4-5 cars spotted on the spur, which would basically be a second full spot of the trestle.  Thankfully I've been able to work in the spur to be able to hold the four cars at the trestle and another four "off-spot" on the spur between the last dump chute of the trestle and the fouling point of the spur switch.  Actually I've planned it now so the total of 8 cars on the spur will clear the lift-out section across the door.  I don't want to disturb the spotted cars in the spur to open or close the door. 

Higher view of the spur in place.

Sadly, there will only be room for four GS gondolas instead of the prototype's five cars.  It won't really matter in the operations of the trestle-dump.  It may mean that the trains will be a couple cars shorter, however there's some thoughts that have come up discussing the multiple different ores and minerals that were loaded here.  

Overview of the whole module with the 4 GS gondolas and trestle mock-up.

I'm starting to think the reason there's often photos of more cars than can fit, is that they were swapping out which standard gauge cars were loading what into them.  If dolomite was being loaded, then they needed the dolomite GS cars, if they're loading something else, then they'd need those SG cars.  Also added into this the fact that the smaller ~20-ton Narrow Gauge cars would take several carloads to fill a standard gauge GS gondola.

This is my plan around the end of the spur

Eventually there'll be a timber retaining-abutment wall at the end of the spur, where the trestle transitions to the ramp sections.  I set this in with a single small piece of foam, then back-filled it with another larger scrap.

Higher view of the spur and main track with the 45 degree pit foam in place.

Off-level curve in the foreground is starting to be marked in red.

By this point I'd sanded down the roadbed and taken the warp out of it.  Then I came back and re-marked the 48" radius centerline for the main track.

September 15, 2024

Midnight came and went... The planning and work on the module continues.

Overview of the whole corner of the layout.

There's still plenty to do to get this module finished.  Several times during this construction, I took the module off from the wall brackets and pin/bolts to the #2 Module, allowing me to see how heavy the structure is.  Now that it has foam glued in, the whole module is very rigid, yet quite light.  I need to get a bathroom scale out sometime and weigh it.

Another overview of the whole module.

There's obviously still track-work to apply, drill and solder on feeders, and then run all the under-module bus-wiring to install.  The staging yard will also require a string of LED lights along the front frame to light the yard.

A view at the door with the two roadbeds and foam cut off even at the end of the module.

I'll still need to drill and mount the alignment pins and bolts for the section across the door, but for now the end of the module is looking good.  The foam scenery is roughed in as well, with a nice subtle taper down to the inside of the spur switch.

In Closing

This brings us to the point where I had to stop construction and focus on the preparation for the Southern Pacific Historical & Technical Society 2024 Convention in Sparks, NV.  There will still be more carving of the foam on this module.  I'll probably be doing more direct photo comparison against the photos I've collected of this area around the trestle.  The foam beyond the trestle spur, probably will be on a slightly steeper slope, and I may work in a section of the SP Narrow Gauge mainline.  I've also marked out a couple of radii options for the curved backdrop that will be built in the corner.  I'm considering as tight as 12" Radius and as high as 18-24".  I'll probably work on a card-stock sheet mock-up of the options, take some photos, and see what works.

Staging how SP 3203 will look switching the trestle spur.

The next big step before I should get the track layed in place will be construction of the bridge section across the door, and I'll need to actually start building the Bartlett module to provide the opposite end of the bridge section.  The spur's switch will be on the door section.

Side Note: The Code 70 ME track I ordered arrived.  This will be to replace all the main-line track.  So around this time, I removed the spikes holding down the main track on Owenyo #1 & 2 Modules, disconnected the bus-wire feeders and disassembled the west wye switch (which is on the main track).  These 3-4 sections of Code 55 flex track will be swapped out with the new Code 70 track.  I still need to get the new Code 70 Points and Frogs made, but hopefully by the end of the year that can happen too.

The west end of Owenyo's siding switches are also a point of decision which I'm still pondering.  I need to look at it carefully to decide exactly where I'll be building the two switches in relation to the Owenyo #3 Module's curve and spiral easement.

Jason Hill

Related Articles:

Jawbone Branch Layout Build Index - All articles in the construction of the Jawbone Branch layout.

SP Jawbone Branch (Part 55) - Installing Spur and Foam Scenery for Owenyo#3 - Previous blog post

SP Jawbone Branch (Part 54) - Roadbed & Rough Scenery Foam - 2nd oldest blog post on this module.

SP Jawbone Branch (Part 55) - Installing Spur and Foam Scenery for Owenyo#3

I've been away from the layout for most of a month... so let's get caught up with a series of photo-blog... Pblog... plog?... anyway... This is just a smattering of my pictures I took in order.  There will probably be several posts in this series of photos.  Mostly you'll see lots of clamp pictures - but that's what you get when you're assembling the layout!

Sept 8th Photos Starting at Midnight

Time to make the decision by starting to work on the trestle spur roadbed.

I'm using the 3ft bubble-level as a straight-edge to clamp the spur's inner vertical frame to before gluing.  This will keep the frame straight, so it won't be wavy.

Looking towards the window, more clamps.

The transition to the spur's curve also clamped straight.  The front edge will be bent around to match the layout "cookie cutter" top sheet shape.

Planting more clamps to hold the pieces where I want them.

Notching of the vertical frame member over the cross span frames, which connect the main frame and the main track spline roadbed.

Time for more clamps on the diagonal brace frame.

Everything clamped together for the glue to dry.  I didn't want the spur's frame moving, so the lower clamp is holding the spur's frame at the right distance along the diagonal sub-frame.

Back checking where the front spur frame lands on the wall.

I use water to pre-wet the structure before I put the glue on.  There's an area of "wetted" rear frame still showing, as the applied Gorilla Glue is about to start expanding over the later photos.

Lots of drop-clothes in the form of paper towels to keep the drips from causing trouble.

Small amounts of Gorilla Glue is starting to expand from the first angled joint.

Starting to clamp around the curve.

Again, wetted MDF for the bonding with the Gorilla Glue at the start of the spur's curve.

Main cross brace on the primary direction of the #3 Module frame.

Expanding Gorilla Glue filling in vertical gap, but I was still concerned how strong this joint would be, given that I made square-cut notching in the frame-strip.

Back Frame joint.

The glue filled in around the rear frame joint.  The notches in the frame make it level, to my pre-glue dry fitting.

Filling in frame joint with glue.

I applied a good amount of extra glue around this joint, and used some plastic bag material between the module frame and the wall-bracket, so the module won't get glued to the wall!  I don't mind the glue squeezing out, or expanding, but I don't want to break it off of the bracket later.

Time to Work on the Top and Rear Frame

Time to start putting in the cookie-cutter roadbed top, which required ~1/4" shims underneath.

Overview of the end of the standard gauge spur, which will be under the trestle.  I placed some shim material under the top-surface roadbed to hold it at the right level while the rear frame is glued in place.  At this stage I am dry-fitting everything.

Box-section rear frame being glued in place.

This type of dry fitting is good, as I need to practice how I'm going to clamp it when I have glue on the parts.

Waiting for the glue to dry on the straight portion of the spur roadbed.

I'm cross checking the way everything fits at this point.

How much more can I do while the glue dries?

And, what's it like with the piece of flex track in there?

Still waiting for the glue to dry.

Checking the view down the curve.

16 Adding shim along short-wall support for the spur's curved roadbed.

Let's add a bit of shim to support the edge of the roadbed curve against the rear-frame, along the right wall.

Looking down at the right end of the #3 Module.

Downward view of the wall between the window and doorway.  Marks in place to show where I'll be cutting it of.  This allowed me to move the spur radially around the main track.  The extra material would then be cut off.

Time to Glue

Ok, now to the rear Spur Frame.

Level-bar checking that the spur is on the correct level and the spur is "flat" without any humps and dips.  It will need to be, as the future trestle will want to be on a constant surface.

I wanted to use the level to keep checking the flatness of the roadbed.

And now the forest of clamps comes into play again.

Wow, that's a lots of clamps!

Another view of the clamp forest.

Time to Mock it Up

Now that the spur roadbed is stable, time to see if everything fits.

I make a number of test fittings to check everything, evaluate how the views of the layout look, etc.

Let's check from the doorway, lift-out area.

Backing up a bit to see how the curve comes into the main track.

More views

The "reverse" view checking how everything looks.

Close-up of the joints under the trestle roadbed.

Detail view of the footings of the trestle and how the front frame glue is bonded.

"Doped" Paper Towels?

On old balsa wood airplane kits, the final skin of the model used to be made with tissue and "dope" which was a varnish, which would tighten the tissue as it dries.  I've also used techniques like this to make 'tar paper' on roofs of cars and buildings.  I decided that I wanted to do something like this to contain the glue drips and provide more bonding area around the weird angled joints in this module.

Front main frame and front spur frame.

Close-up of the application of paper-towels to form both a bag around the wet Gorilla Glue, keeping it from dripping, and also to provide effectively a "fiber-glued" structure around the joint, adding strength.

Cross brace near the left end of the spur's roadbed.

Close-up on another example of cut paper-towel filling in square-cut joint, and allowing the glue to fill the void.

After Midnight (Sept 9)

Another Midnight Mockup!

Another overview of the whole module with train posed as a mockup.

Time to Lay in the Foam

This is a dry fitted piece of foam for the rear section.

Now that the basic parts of the spur's roadbed has dried, it's time to start installing the rear foam pieces into the rear portion of the module.  I made sure not to let the left end of this foam get too low into the pin and bolt connection to the #2 Module.

Dry fitting the rear foam panel.

The next section I worked on was the rear piece that would fill in the rear corner of the module.  This section will wedge in well, but also have some glue to secure it.

The edge of the rear foam block will be cut down later.

It's good to finally see the module filling in for the first time.

A nice high view of the foam and positions of the relevant pieces of foam.

Starting to lay in the foam between the main track and the trestle spur pit's roadbed.

Back to a track-level view of the whole spur and trestle area.

The foam is now filled in from the rear piece along the right wall, following the edge of the spur.

A view of the trestle with the various pieces of foam filling in.

I like coming back and taking photos to check against the prototype photos to see how the layout is coming together.

In Closing

Time to see what the local with a 2-8-0 will look like switching this part of the layout.

Let's have another mockup!  Sadly, being a "nightowl", my work on the layout during these late summer days starts at about 9-11pm and stops somewhere around 3-4am.

Next time we'll look at Sept 14th, nearly a week later, as I continued to work on the smaller pieces of foam being put in.

Jason Hill

Related Articles:

SP Jawbone Branch (Part 54) - Roadbed & Rough Scenery for Owenyo#3 (Aug 31-Sept 6)

Jawbone Branch Layout Build Index