Hello all. I am needing to install a bridge and would like your help. Here a few pics of what I am working with;
First off this is N scale. I have a river bank that is solid rock on one side and a dirt/rocky bank on the other side, Would a double track truss bridge be OK setting on the solid rock or should I build some kind of footing? On the other side where the dirt and rocks are what should I have there to support the bridge?
I hope this is clear enough for you to follow, if not I will try to explain it in another way.
Thanks for any advice. Mike
I’d put some sort of wall to support the bridge and stop erosion… not that a layout landscape erodes (hopefully).
I can’t find any really good pictures of what I’m talking about at the moment. This small one of Elmer McKay’s layout kind of shows what I’m talking about in the upper right hand corner:
There is always some kind of abutment under the end of a bridge, even if it is resting on solid rock. It may only be a cast-in-place block of reinforced concrete, but it will be there. Natural rock may have small flaws, not easy to detect, that would cause it to break away under the concentrated stress of a bridge shoe - possibly when the bridge is loaded with a heavy train.
On the less-stable end, the abutment would take the form of a retaining wall - poured concrete from the 1920’s (or possibly earlier) or large-block masonry. There would be a step to accommodate the height of the bridge floor and shoe. The flexible shoes would probably be on the less stable end, while the solid rock end would have fixed shoes.
(There was a forum thread about bridge shoes a short time ago. Enter bridge shoes in the search block to find it.)
Chuck (modeling Central Japan in Septmeber, 1964 - with LOTS of steel bridges)