I'm looking to add an HO scale highway overpass (over a double track mainline) that curves and inclines before going over the tracks.
This quick sketch should give you an idea of what I'm trying to accomplish (black lines are the train tracks):
I'd like to use Rix Products Wrought Iron overpass for this.
However I'm having a hard time finding any photos of Rix Products overpasses in use with an incline. Every photo I've found online thus far show mostly a flat overpass. So I'm not sure if they can be inclined or not.
Can Rix Products overpasses be inclined?
Also what is the width of just the roadway (excluding the railings) that comes with Rix Products overpasses? I'm redoing my 2 lane highway so I'd like to make it match the width of the overpass.
The curve part will have to be scratch built. So I'm wondering if I should just scratch build the whole thing. Maybe using some of Rix Products parts.
Thanks for any input.
Matt from Anaheim, CA and Bayfield, COClick Here for my model train photo website
Well, Matt, any free standing, inclined, portion of the Rix overpass won't look quite right since the concrete uprights for the railings won't be in a fully vertical position any longer.
You might want to create some sort of inclined embankment leading upwards, then curving around and having the Rix overpass spanning just the tracks. That approach would probably look the most realistic. That was the arrangement I used, as illustrated below.
CNJ831
To answer some of your questions, the instructions that come with that kit indicate that it makes a bridge 150 feet and consists of 3 spans. Each span is supposed to be 50 feet long by 25 feet wide. Oh, and we are talking HO, correct?
I believe that Rix uses the same roadway pieces for all of their bridges of this type. Measuring the actual roadway piece, I measure 50 feet long not including the little lip at one end which connects to the next span. However, the width of the piece measures 22 scale feet. So, I have to assume that the 25 feet refers to the overall width across the railings. (I have a section of the more modern bridge in front of me and that actually measures 24 feet across, but I don't remember what that package for that item said it was supposed to be.)
However, the construction of the model incorporates the railing supports which are designed to overlap the edge of the roadway. This overlap sort of forms a curb that decreases the roadway width by the amount of two curbs. The amount of this overlap measuring quickly is about 6 scale inches, so the roadway ends up being about 23 feet wide between the curbs.
So far as your incline question goes, you sort of show the ramp to horizontal bridge connection as what would be a hump. But I'm pretty sure that the hump was more as a result of your trying to depict what you want than what you might really intend. Are you asking if the bridge kit can be somehow flexed into a horizontal curve to join or form the ramp? If that's the case, I'd say that the answer is no unless you are going to do a lot of kit bashing. The kit is designed such that each section or 50 foot span winds up being a pretty ridgid assembly. There is some flexibility at the joints between the three spans so you could kink these joints to a certain degree, but you would end up with three tangent sections, not a smooth curve such as what you get when you look at a real highway ramp. Plus there would be vertical gaps between the railing sections at the end of each span.
In case you didn't know, you can buy the pier assemblies separately. And these can be adjusted for height by just cutting the vertical posts to suit your needs. Possibly the way to go would be to use the kit to make a flat bridge, and then use the pier assemblies (or scratch build your own piers) with a scratchbuilt ramp.
Hope this information is helpful.
Regards
Nice scene
Embankment is a great idea. Now that I'm looking more at prototype photos online, an embankment seems to be the way to go:
Now I'm wondering which style of overpass would be best for our setup. Maybe the vintage style would look better.
Our layout is circa 1958 and the highway is Route 66.
In this photo, the curved approach to the overpass will start where that old dead tree is at the end of the highway:
The width of the road without the railings is 3 and 1/16 inches wide.
The support piers are adjustable in height so you can make them different heights. If you put them under a roadway that is inclined, you may have to shim one side to compensate.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.