Question about Atlas O scale truss bridge

[keystonefarm]

Have a few questions about the Atlas O scale truss bridge. I'm a HO modeler and another modeler in my area used one of the Atlas O scale single track truss bridges for a double track HO scale bridge. It really looks good as a very heavy duty high Cooper rating bridge in HO. I see Atlas offers a single track version and a double track version they also offer a kit to convert the single track to double. Trying to determine which one I need to get for my bridge project in HO. Are there any differences between the 2 rail and 3 rail version other than the track ? This would be for double track in HO. Thanks , Ken

[big train james]

Hi Ken,
I'll try to answer your questions. I had both single and double track Atlas truss bridges at one time, but I sold them on as they were simply to long to be practical for any application I could come up with. So I can only offer impressions based on memories at this point, but hopefully I can still offer something useful.

I'll answer the easy questions first. There isn't any appreciable difference between the 2-rail and 3-rail versions other than the track. The other easy one is that I don't believe you will find any value in purchasing the conversion kit. I've never seen one first person, buy I believe the kit only includes the double track deck assembly and the longer lattice bracing that spans between the two side trusses. It does not include the trusses them selves.

It might make sense to describe the bridge kits at this point. Whether 2R or 3R or single or double track, each kit includes two assembled trusses, and assembled girder/deck, a walkway for the double track versions, and various lattice bracing parts to connect the two trusses together. The track is already attached to the girder base, I don't know how easy it is to remove as I never had reason to try. It's actually a fairly simple kit to assemble as there just aren't that many parts that aren't already pre-assembled as sold.

Returning to the single versus double track question, I'm going to take a guess and say that the single track deck is about 3" wide, and the double track deck width is about 6½" wide. I think that makes the single track bridge too narrow for a double track HO bridge while the double track version is too wide.

I'm not sure you can practically use either of the Atlas bridges for an HO version, directly out of the box. I do think you can utilize the truss assemblies, but I think you will need to use something else for the cross bracing and deck, unless you want to modify the Atlas parts. I suppose you could rip the deck down the middle (be aware, there's metal inside for strength) and remove enough to get the desired width. I suspect the cross bracing won't be as simple given it's geometry.

There's a modeler named Bill Neale in the Detroit area, that models the PRR Panhandle just west of Pittsburgh, including the Ohio River bridge at Steubenville. He used parts from three Atlas O scale truss bridges along with a Micro Engineering parts to construct the bridge. I presume a heavy truss bridge like this is similar to what you want to build. Unfortunately Bill passed away at the end of last month, otherwise I feel confident he would have been happy to discuss his build with you. There are photos and videos of his layout available on line, I suggest you check them to get a sense of what he did to get the finished model.

Here's a video with a decent description of his layout including some imagery of the bridge.  The bridge content starts at about the 46:50 mark.



Hope that helps,
Jim

[lvrr325]

I picked up a single track bridge at an auction last year. So far no takers at shows, I haven't tried the internet yet because it's so big the shipping will be absurd.