Ballast bridge track?

kasskaboose · June 21, 2016, 10:05pm

Should I bother ballasting track over a bridge? I got a bridge from a friend that looks similar to the below pic: https://s-media-cache-ak0.pinimg.com/236x/67/04/37/670437e663787fff57604a90ade23266.jpg

Should I bother to ballast this area of track? To do that, I would need to put stryene under the track to prevent the ballast from falling through the bridge. Based on a search online, it appears that ballasting track on this structure isn’t common.

doctorwayne · June 22, 2016, 12:00am

On a bridge of that type, the track would not normally be ballasted, although some railways do alter the bridge by adding a deck under the track. The photos which I’ve seen show concrete, and it’s done as a trough in order to contain the ballast. On such bridges, the more closely-spaced bridge ties would not be used, as the track functions in the same manner as regular track.

Here’s a bridge similar to that in your photo. The closely-spaced bridge ties require no ballast (and there’s little under them to support ballast).

Here’s a link to some photos of ballasted-deck bridges.

Wayne

gmpullman · June 22, 2016, 12:02am

You’re correct that a steel truss bridge wouldn’t have a ballasted deck. A through girder or plate girder type bridge might be designed to have a ballasted deck.

https://www.arema.org/publications/pgre/Practical_Guide/PGChapter8.pdf

There was normally blocking or part of the abutment was formed to keep the ballast held back at the approaches to either end of the bridge.

Have Fun! Ed

kasskaboose · June 22, 2016, 9:46am

Thanks all for this useful information. I didn’t know so much about railroad bridges until exploring this topic further. Given that the bridge is in the back, I still wanted to replicate a protypical scene.