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.
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