My road bed is down. I have bridge track that I intend to use on 3 bridges. One bridge is for double track and 2 are for single track. My biggest questions are: How much over hang or where do the approaching rails meet the bridge rails? When and how are the bridge rails attached to the bridge? Is there anything to really watch out for? My layout is predominantly styrofoam. Thanks for any assistance. Jim
Bridge track, i.e. with closely spaced ties often cut to a length suitable for the bridge structure, starts at the abutments.
You didn't mention anything about abutments, but they are very necessary as they support the weight of the bridge and what passes over it while holding back fill or whatever is used on the approach to the bridge.
Abutments come in many forms. Wood, stone, brick, concrete, and steel are all used, but practice varied depending on era, engineering, and finances.
Abutments are readily available from different sources, but are also very easy to build yourself.
Mike Lehman
Urbana, IL
And because abutments can sometimes (even with the most careful work and measurement) cause a slight "lurch" or bump, it might be a good idea to take the bridge track and modify the ties at the ends that would extend beyond the abutment so that those ties have the length and spacing of regular track. That way you don't have the double problem of both the rail joints and the possible bump from the abutment at the exact same point.
Dave Nelson
I extend mine past the lip of the bridge right onto the roadbed...You will see where the guide rails form a point is on normally spaced ties. The abutment is where the land and bridge meet, In this case it is a double track swing bridge that works. So it is imperative that all parts are perfectly level. I do not glue the bridge track or the approach track to the bridge. It is screwed in place with Perfect#0/3/8'' Round head black wood screws at the lip of the bridge and the roadbed, also at mid-point on the track in the center of the bridge. Holes drilled thru the ties and into the girder structure of the bridge. I used Walthers code 83 bridge track, which turned out to be quite expensive for a 27" long bridge.......but it was worth the money in My case because it has worked flawlessly for the past 15yrs.
Photos may be clicked on for a larger view:
I am in the process of redoing the whole area, but the swing bridge will remain in the same place. I scratch/bashed another bridge that will go where the other tunnel portal is...also double track. Used ME bridge track, which has to be assembled, unlike the Walthers which comes assembled. The ME is a lot cheaper though and can be assembled with a good CA. I used Zap-A-Gap Medium CA.
Take Care!
Frank
zstripe I extend mine past the lip of the bridge right onto the roadbed...You will see where the guide rails form a point is on normally spaced ties. The abutment is where the land and bridge meet, In this case it is a double track swing bridge that works. So it is imperative that all parts are perfectly level. I do not glue the bridge track or the approach track to the bridge. It is screwed in place with Perfect#0/3/8'' Round head black wood screws at the lip of the bridge and the roadbed, also at mid-point on the track in the center of the bridge. Holes drilled thru the ties and into the girder structure of the bridge. I used Walthers code 83 bridge track, which turned out to be quite expensive for a 27" long bridge.......but it was worth the money in My case because it has worked flawlessly for the past 15yrs. Photos may be clicked on for a larger view: I am in the process of redoing the whole area, but the swing bridge will remain in the same place. I scratch/bashed another bridge that will go where the other tunnel portal is...also double track. Used ME bridge track, which has to be assembled, unlike the Walthers which comes assembled. The ME is a lot cheaper though and can be assembled with a good CA. I used Zap-A-Gap Medium CA.
yellow_cadHow did you attach the bridge to the abutments?
Well in the case of the swing bridge...they are not attached to the abutments. The bottom girder of the bridge slides along the top. The other bridge will not be attached to the abutment either........the abutment will be glued in place.....the bridge will rest on top of it and the track will hold it in place. Everything I have on the layout is meant to be removeable so almost nothing is glued in place. Buildings base is screwed to foundation cut-out so they don't look like they are floating on top of scenery, which I see a lot of modelers doing. All My structure roofs are removeable, to get at interior/screws. My layout construction is 1/2'' ply with 1/2'' Homasote on top so it is easy to screw anything to it or even drill a hole and stick something in it and it will stay. I don't believe in using foam for a layout top. I use foam only for scenery purposes.
This fence, all scale 500 ft of it is, removeable. Its set in holes drilled into the Homasote and the sliding gate, actually works......
The gate started out scratched from brass rod and shapes all soldered together:
On my previous HO layout I had a long single track bridge (cornerstone kit) and put in bridge guard rails using code 83 (layout was 100) and put in place with AC cement. Amazingly, that held nicely for the life of the layout - 1994 to 2008.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central