# New bridge for Belden Falls Railway



## llynrice (Jan 2, 2008)

Larry Green has just finished building a truss bridge which he'll install on his railway this spring. I've posted the pictures for him and he'll follow up with posts detailing the design and build process he followed.














































Be sure to press him to tell you how he is making builder's plates with raised lettering. It's really clever.


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## NTCGRR (Jan 2, 2008)

VERY NICE 
I'd like to know where I could get the materials from??


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## SE18 (Feb 21, 2008)

The angle alum can be obtained from Lowe's or home depot or made from scrap. The bolts are from MicroFastener. Just a guess  

What I'd really like to know is how the builder plate was made!!! 

Can't Larry Green come on the forum? 

Great job on the bridge, btw 

Dave V


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## Larry Green (Jan 2, 2008)

Yes, I'm here, but since Llyn is the official BF RY photographer, he gets the first post. 

This is a Pinned Lattice Truss, based on the designs of the former Phoenix Bridge Co. of Phoenixville, PA. It is 42 1/2" long, 10 1/2" wide with 6" high trusses, representing a 72 foot bridge in 1:20 scale. All structural members are of aluminum and are from McMaster-Carr. The T's and some channel sections for floor beams and stringers were used as purchased, but those for the truss uprights and the angles were milled down to size as necessary. Gussets were formed from 1/16" aluminum sheet. All truss hardware is brass. The truss pins are 5-40 scale bolts and nuts from Coles Power Models. The prototypes had pin bolts up to 4 1/2" diameter or more. In pre-CNC machining days, that must have kept some lathe hands pretty busy. Other hardware is stainless from MM-C. Before mounting the deck structure, everything was cleaned, given a phosphoric acid wash, primed and finished with Krylon aluminum, from their industrial finishes line. 

The deck is red cedar, coated with latex house stain to simulate creosote. This 1:20 scale lumber is available from Ozark Miniatures; the bridge ties scale to 8 x14 and have been notched underneath for the stringers. They are attached to the stringers with Walthers' Goo,(same as Pliobond) flexible adhesive, which I have found to last indefinitely outdoors fastening wood to metal and glass. Brass bolts inserted in the ties represent the bolts and J-clips that were used on the prototype. 

The rails are code 250 Lllagas Creek, painted with Rustoleum camo brown. The fasteners are #2 brass miniature lag screws from Micro-Fasteners, with brass clips which I made from sheet stock. 

My steam track is elevated about 4 feet above the ground where the bridge will be installed and, in theory, the Otter Creek flows underneath on its way to the Belden Falls.. Since winter had arrived here in Vermont by the time it was finished, I am waiting for warmer weather to install the abutment brackets and realign the approaching track. We had been steaming across a temporary plank this past summer after the opening had been prepared. 

Now, about the "cast iron" builders plates, which just about all bridges of the era had. The idea is not mine, but something that was recently mentioned at the 7/8ths scale site SE Lounge forum. Unmounted rubber stamps, mirror imaged from normal! I found an online company that had a menu-type order system, and they were very reasonable. Of course, I had to order them twice, because I neglected to specify "mirror image" the first time. The material is natural gum rubber, so I am going to experiment with finishes on the wrong ones, but my idea is to attach the rubber to a thin brass backing plate with JB Weld, then paint with the Krylon aluminum and UV-stabilized clear coat. If that attacks the rubber, some latex finish will be tried. 

When first deciding to build a bridge, I thought of a riveted truss. All those holes that had to be aligned wasn't much of a problem with a milling machine, but doing the actual riveting was going to be monotonous. I found that out years ago when building a GE electric engine in 1-1/2" scale that had over 2200 1/16" rivets in the carbody, all hand set. Seeing the Phoenix pin design finally got me going on the project, and I think it is a good representation of a past technology that still is in railroad service. An example is on the NS Lehigh Line over the Delaware River between Easton PA and Phillipsburg NJ. 

And before anyone asks, I have no plans of the model. Aside from a few little scribbles on a pad, it was designed on the go while measuring a scale drawing in the book "Without Fitting, Filing, or Chipping", a history of the Phoenix company by T R Winpenny. 

Larry


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## xo18thfa (Jan 2, 2008)

I am not a big fan of metal bridges, but this one looks very nice. It looks very realistic, without going way overboard on the detail. I particularly like the way the track is laid directly on the ties without the use those ugly plastic ties strips.

Great job Larry.


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