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The Mainline => Scratchbuilding => Topic started by: Yannis on May 12, 2026, 10:34:54 AM

Title: Question on material for ATSF LA River Bridge
Post by: Yannis on May 12, 2026, 10:34:54 AM
Hi everyone,

I don't know if this is the right sub-forum to ask, but since it is going to be a sort-of scratchbuild bridge, it might be.

I want to build the ATSF Los Angeles river bridge as it used to stand near the Elysian park in 1969. The bridge no longer exists, it got replaced by a more modern construction. My main concern is the three skewed Truss Bridge spans.

To cut a long story short, there is no kit that would approach it's construction, so i ll need to kitbash/scratchbuild most of it.

For the deck and core components that will bear loads i ll design everything and 3d print it. But i ll need to dress the core with styrene piece that accurately reflect the girders and the lacing pattern they had (Z pattern and gusseted depending on the part of the bridge). For that i think i ll need to obtain a few kits or pieces-sets from Central Valley, or re-purpose pieces from the Micro-Engineering Steel Viaduct kit that i got leftover.

Since i am not familiar with Central Valley kits... do you reckon they ll do the job? I had my eyes on the 1902 bridge kit and the following extra pieces:
https://www.walthers.com/gusseted-bridge-girders-kit-5-7-8-14-9cm-long-pkg-10
https://www.walthers.com/classic-laced-bridge-girders-kit-5-7-8-14-9cm-long-pkg-10

I ll need to build 3 spans roughly 3' 2" each in length.

Looking forward to hearing from you on this and thanks in advance for your time and replies.
All the best
Yannis
Title: Re: Question on material for ATSF LA River Bridge
Post by: jbvb on May 12, 2026, 10:16:57 PM
Checking photos in a Santa Fe Pasadena Subdivision page on Flickr, I see there was one short span and two longer spans. One long span and the short span are pin-connected, using eyebars for members under tension only.  The westerly (towards LAUPT IIRC, I only crossed it a couple of times) span appears to be the same length as the longer pin-connected span, but it's plate-connected. Was the LA River's concrete trough widened at some time after about 1900-10?  Or did one span get wrecked by a flood? AFAIK that's the period when calculus got good enough to allow design of fully plate-connected bridges.

If I ever saw a more-skewed bridge, I don't remember it.  The lattice crossbracing on each end of the pin-connected spans appears identical, and the pin-connected spans will be where you use the Classic Laced Bridge Girders, the plate-connected span uses Gusseted Bridge Girders.  But I can't say how the scaled size of each will compare with the look of the prototype.  A 270 foot loong through truss is pretty big. The CV bridge is 153 scale feet long, so its parts might look a little light and the portals a little low in a model of a much longer prototype.
Title: Re: Question on material for ATSF LA River Bridge
Post by: Yannis on May 13, 2026, 12:52:41 AM
James many thanks for the reply!

It is actually three truss bridges plus 2-3 plate girder ones making up the whole "bridge". So if a kit was suitable i would be needing 3 of them (or 1 plus extra add-on pieces to basically use the kit as a donor for girder parts).

The bridge got rebuilt at some point after a flood in 1939 if i am not mistaken.