HO SCALE DELAIR BRIDGE - A Bridge too far?

 Our HO scale Free-mo ambitions have grown.  The three section module (considered a single module in Freemo as we only have two Free-mo end plates) is set up and fully operational in Jimmy’s basement.   We are working on basic scenery and building structures.  

This module semi represents an industrial section of South Philadelphia, with a chemical plant, replaced by a Corn Syrup plant, loosely based on a prototype facility in Morrisville, PA.   It’s full of switches and passing sidings, and all the associated electronics and switch machines.    A discussion about a simpler mainline only, no turnout, scenery module, morphed into a module with a bridge.   Now here is where I went down the rabbit hole - instead of a pretty straightforward Walthers, Central Valley, or Micro Engineering bridge, I decided to ATTEMPT to build the Delair Bridge from scratch. 

The double track,  Delair Bridge was built in 1896 between Philadelphia and New Jersey, spanning the Delaware River.  Prior to this, any freight between Philadelphia and New Jersey moved on ferries, or via a long rail route through Trenton, NJ.  The bridge originally was three fixed, 533 foot Petit through truss bridges, with a 323 foot center pivot swing bridge, also a Petit through truss (also known as a Pennsylvania Truss).    Additionally there are steel approach trestles on both the New Jersey and Pennsylvania sides of the bridge - the New Jersey is 324 feet and the PA is 2,129 feet.   To make matters more complicated, the construction of the US Steel Fairless works upstream, in the 1950s required a wider channel than the existing swing bridge provided for their ocean-going ore ships.   The Pennsylvania Railroad rebuilt the bridge.  They kept the New Jersey fixed span as is, permanently locked the swing span in place, shortened the existing Philadelphia side fixed span by 100 feet, and built a new, 542 foot vertical lift bridge.  

We are modeling the present day bridge, which includes the 1950s modifications, making designing and scratchbuilding a bit more difficult.  All four spans are mostly different, although the PA and NJ fixed sections are mostly the same, except for modifications to the PA side to shorten it.   In my opinion, selective compression doesn’t really look good when it comes to HO bridges, and this is where we are getting into crazy land territory - the module will be around 32 feet long to fit the four bridge spans, the New Jersey approach trestle, and an abbreviated PA approach trestle (the real one is almost a half mile long).  

These structures are very complicated, and big, and honestly I might throw in the towel if it begins to look impossible.   I’m starting with the New Jersey fixed span.  If this goes well I can build the PA fixed span next as it is mostly the same, and then probably the original swing span, followed by the big vertical lift span last.  

Here is where we are at - the deck girders were fabricated from acrylic and .020 styrene.   Now I am starting to design, cut and build the vertical columns.  As the top of the bridge is arched, each of these is a different size, and they can’t be simply cut to fix, but rather, need to be designed specifically to fix each position.  The bridge has sixteen sections and the verticals installed are the center and two immediately adjacent to the center on each side   Just keep in mind, this is only a single span - works out to be a bit over 6’ long.  There are three more to add to this.  More on the details in the next installment.  

OUT OF COMMISSION FOR A FEW MONTHS, BUT PLENTY O’MODEL RAILROADING WAS DONE

A surgery, and caring for a seriously ill family member has kept me away from updating for a few months.    I had also been considering switching to a video blog on Youtube.  I put together a few, but decided not to go that way as there is more work involved than this format.   I will however probably put up videos from train shows, railfanning, and instructional videos if I ever make some of my O Scale freight car parts available.   When I do, I will link from here.

Strangely, with everything going on, I was a very productive model railroader.  It’s easier to just list what I’ve been up to: 

• Proto:48 layout - installed most of wood ties.  Designing crossover track assembly in Fusion360.  There are none commercially available for Code 125 rail.  The plan is to print in resin.  The design is for several different sub assemblies that will be glued to metal rail segments, while also acting to gauge the track, and insulate the rails from each other.  
• Free-Mo - Yes, you heard that right.  I’m back in the Free-mo world.  We (Jimmy) are building three 2x6 modules.  They will serve as Jimmy’s home, basement layout, between shows.  There will be posts on this.  Our theme is modern era, South Philadelphia.  Mostly scratchbuilt prototype, or prototypical structures.  
• HO Structures - related to Free-mo,  I’m back building in HO scale.  Mostly scratchbuilding, with some commercial parts, or components.  Lot’s of digital fabrication to augment this building.  Laser cut building parts, and 3d printed details.   First up - trash to rail metal warehouse type building - a brick food warehouse - and a corn syrup plant.  
• O Structures - Scratchbuilding a freight house, based on an Erie prototype that was located in Manhattan (Not the huge four story one).   Also, finishing up some parts for the Tidewater Grain Elevator.  All these models will end up on the Cherry Valley MR Club O Scale 2 Rail Layout. 
• HO Freight Cars - I pulled out some of my circa 1980s “modern” era freight cars for the Free-mo layout, and have started weathering, and “modernizing” them with patch jobs, rust, and heavy weathering.  
• O Freight Cars - In the design/preliminary phase of a Norfolk and Western  G72,73,74  gondola.  

Updates to begin again soon.

Jim

PROTO 48 LAYOUT #6 - FASCIA AND BACKDROP

 Before adding any thing to the roadbed or foam surface of the layout, I wanted to get the backdrop and fascia squared away.  I imagine that both will have to be repainted or touched up during the construction of the layout, however, installed, with a base coat, it shouldn’t be a hassle to do this.  

The layout isn’t independent, but rather, attached to the wall of my shop.  The wall is 1/2” OSB.  This was both a cost savings measure and a convenience for attaching shelves ,tool holders, etc. on the work bench. OSB has too much texture to serve as a backdrop, and I wanted radius corners.   I applied 1/8” masonite over the OSB.  This material will curve into a pretty tight, maybe 8” or so radius at the corners with a little work.  It was attached to the OSB with drywall screws.  Care was taken to place the screws on studs, and a countersink drill was used to “prep” the holes so the screw heads sit flush.   There were two seams between sheets, and a lot of screw heads to disappear.  I used a two part resin body filler, like Bondo for this work.  It’s easy to sand and tends to fill nicer than the putties or drywall compound that most folks use.   We use this in our cabinet shop for almost all painted cabinetry.   When the heat and humidity return in the spring, we will have to see how the seams behave, but for now, they are invisible.  

After sanding and refilling as needed, the backdrop, and fascia, which was installed in same way with same material, was primed and painted.    I’m on the fence with having the sky color on the soffit, and might change to black, although that would add a third color into the mix.  

TOOLS - CLAMPS

As a professional woodworker, I’ve found that you never can have enough clamps.  As many as I’ve bought over the years and sit at the ready on racks in my shop, I always seem not to have enough or not enough of the right size.  The same goes for my hobby workbench.  Two of the clamps I use most often in model railroading are spring clamps, and quick-clamps.   Both are basically miniature versions of what I would use in my commercial shop.    Home Depot used to, and maybe still does, sell a bag of cheap, plastic spring clamps.  They were black with yellow jaws, and there were a variety of sizes in the bags.  The most useful for model railroading, were the four smallest ones, although occasionally the larger ones are used.   In the quick-clamp department, both Irwin, and DeWalt made miniature version of this type of clamp.  Both are very decent, with the DeWalt being slightly larger and beefier.  

While shopping at a Woodcraft Store, I recently came across both miniature spring and quick-clamps.  The spring clamps are made by Bora Portamate.  They come in a box of 20 for around $15.  They are superior to the Home Depot versions, in terms of quality of manufacturing; operation; and larger jaw clearance.  They also are all the small size you need.    The quick-clamps are made by WoodRiver, which is the Woodcraft in-house brand.  Sold in a pair, for $13, they are as good, if not better than both the Irwin and DeWalt versions, and may be cheaper too.   The jaw pads are the largest of the three and the metal shaft is heavier.  The release is between the handles, which is awkward, only because I’m used to it being in front of the handles.  It works fine.  

The Quick Clamps - Wood River is at the bottom.  

The Bora spring clamps.  Easy to store at workbench

MORE HOUSEKEEPING - UPDATED LINKS

 I added the links section when I first started this page, and probably haven’t updated it since.   About half were dead links, so sorry about that if you were trying them.   Some haven’t been updated for many years, but still exist, and still have good photos and info on them, so I didn’t take them down.  

I only got around to adding one new link - Steel Mill Modelers Supply.   If you are looking to heavily upgrade your Walthers Steel Mill kit, or if you are scratchbuilding a mill, this is the place to go.   Steel mill modeler, Kevin Tully started this business some years ago using 3d printing technology,  when most of us were still working with molds and resin casts to sporadically make parts for steel mill modeling.   His products are well researched, well drawn in 3dCAD (not an easy task),  and printed using high quality printers (ie expensive).   

I tried to post a link to the Facebook Steel Mill Modelers group that Donald Dunn moderates, to no avail.   Maybe I can’t post Facebook links on here.   If you are on Facebook, you should be able to find it - just make sure the moderator is Donald Dunn.   He also has two associated groups on real steel mills and selling steel mill stuff, which you should also be able to find.   Donald does an excellent job at keeping these sites focused on their subject matter.  He also puts out a quarterly steel mill modeling ezine (is that even something anymore)  which has excellent articles.  I will try to find a link for that an post.   

I’m also going to add a bunch of links for O Scale and PROTO 48, but I’ll see if I can organize these things better.  

Jim

PROTO 48 LAYOUT #5 - THE SAWMILL

 There is still work to be done sanding, priming, and painting the backdrop, prior to installing ties, but I figured it couldn’t hurt to get them cut.  

The bag on left has the “standard ties”, with the enough turnout ties in the right bag for six #6 turnouts.    

Just to refresh - I’m using basswood, as opposed to white pine.  I buy basswood in roughly 5”x8” blocks, 8-10’ long.  They are rough cut, so you need a jointer to flatten and square up two sides prior to any ripping operations.    A single block will last me a decade in model trains, even with this tie cutting operation.  My many years as a professional woodworker has taught me that, the lighter and smaller the piece, the more dangerous it can be to cut.  There is a lot more to ripping and cutting this material than a table saw and a chop saw.  You need to make jigs and temporary fences to keep the material supported, and your hands away from the blades.  

PROTO 48 LAYOUT #4 - BENCHWORK

 This layout resides over my workbench at a height of about 55” from floor to railhead.   I wanted all 20’ linear feet of the workbench to be accessible by a rolling chair, as I have different stations along it - painting, electronics, assembly and build area, machining, parts storage,…etc..   This meant no legs to impeded my lateral movement.  Additionally, I didn’t want any vertical supports between the layout and the workbench to obstruct the work space.   The bench and the layout would have to be cantilevered off the wall.   

You can see the framing for the layout and workbench on the left.  They are both supported by the same vertical “legs” spaced about 4’ apart.   The radius arch horizontals don’t interfere with legs, while moving back and forth, and also don’t interfere with the work area.  They are actually handy for storing clamps.

As you can see from the photo, there are plywood stringers, with a L front assembly to strengthen the edge.  Everything is made from 3/4” maple plywood.   The work bench has steel Unistrut stringers for sturdy support without sacrificing leg room.  

The “sandwich”    Unfortunately the seam fell just at the end of a piece of roadbed and the chunk of homasote on the right is only a 1” triangle.  

The layout surface is a sandwich of 3/4” foam core maple plywood,  two layers of 1” foam, and 1/2” homasote.    The whole thing is an effort to keep the weight down on the layout.  Everything put together, including the homasote was probably around 30-40 pounds.  

Foam inlay cutouts for homasote roadbed.

The maple foam core plywood was secured to the framing with washer head cabinet screws from underneath.    While it would have been more economical from a material standpoint to utilize full sheets of plywood and foam, I cut all the layers in three equal length sections.   The idea is that someday, it would be easy to remove the sections, by just cutting the rail at the seams between.   Since this is as much a diorama as a train layout, I sort of intend on changing it in the future and building an entirely different scene.   

Homasote roadbed pressed into foam

Since the layout was drawn full scale in CAD, I used this and a CAM program, to create cut files for a CNC machine, and everything was cut out on that for accuracy.  If I was using flex track, I could have attached directly to the foam, but since I’m hand laying the track, and based on experience doing this as a teenager, Homasote is an excellent base for this, and holds the spikes well.  Again, with keeping the weight down, I figured on only placing the Homasote exactly where I needed it.  Fortunately my CAM program has an inlay feature.  This feature generates the cut file for the pocket in the foam, and the file that cuts out the Homasote.  It’s actually more complex than it seems.  Since the CNC machine cuts with a round bit (1/4” in this case) the cut in the foam would leave a 1/8” radius on the inside corners, but this same corner on the Homasote, would be an outside corner, and would be cut sharp.   The program figures all this out, so you get a perfect fit.  I programmed in a 0.020 allowance on the cut, and everything fit perfect but I had to tap them in slightly.  Doing it again, I would have gone with 0.030.   I could have set this pocket to any depth, but since I’m modeling well used industrial track, I wanted the bed almost flush with the surface.   Another nice feature of using the CNC - I used a v shaped bit to cut a barely visible centerline in the roadbed.