first let me say that I have been one of those people who have been doing alot of reading and not replying.
I really appreciate all the help that I have recieved through this forum. Now for my question. I am building in
H.O. and in the layout two tracks cross each other. One will be 3inches above the other and each is on a curve.
Is there a way to build a curving bridge? The radius of the upper curve will be about 20inches. All the bridges
that I can find appear to be only built for straight track. Thanks for your input
Only thing I can think of is to scratch build the bridge or check out a double track bridge and see if it will allow enough clearance with your curved track in it. Ken
Welcome to the forum Buzzsaw, good to have you aboard.
Here are four threads that should lead you to all the info you need, all threads are related to curved trestles and/or bridges.
http://www.trains.com/TRC/CS/forums/8762/ShowPost.aspx
http://www.trains.com/TRC/CS/forums/13232/ShowPost.aspx
http://www.trains.com/TRC/CS/forums/126905/ShowPost.aspx
http://www.trains.com/TRC/CS/forums/760689/ShowPost.aspx
Have fun & be safe
Karl.
You may have another problem . . . 3 inches isn’t enough clearance!
Depending on just how you’re measuring it (rail head to rail head, or actual clearance between the lower rail head and the support for the upper track), you might get 3 1/2 inches to work, just barely.
All American RR bridges I’ve seen may contain a curved track but are made from straight sections - including trestles… Exceptions may be those built from stone (Europe) or concrete (Mexico). Cobre Canyon comes to mind.
I would figure a bit more than 3" clearance. and maybe a curved trestle for 20"R. Others may have better ideas to offer…
I’ve seen curved trestle kits:
thanks for all the great info. this is what makes this forum so great!
I don’t know how to reply to all that answered. like I said I’m a newbie
PLEASE DON’T STOP SENDING INFO. Theres no such thing as
too much information!
Yes, 3 inches is not enough. If you have an NMRA guage (and if you dont, get one) and place it on the railheads of the lower rail, ideally the top of the guage should be able to fit under your bridge. You dont have to have it quite this tall, but if you go shorter you will limit what you can run under the bridge. I have a similar situation on my layout, and I made a simple but convincing curved bridge from scratch. The bridge is just a piece of 1/2" plywood cut to shape with a jigsaw, but I covered the sides with styrene that looks like ribbed steel material and put a couple of concrete legs underneath.You cant see the bridge from above, its near the wall and my layout is a shelf style at eye level so the plywood doesnt even need to be painted behind the raised “steel” sides. It is a very nice looking steel bridge and the most advanced skill you need is how to use a jigsaw.
I must respectfully disagree with the concern over three inches of clearance. I have just run my Challenger around my new layout for the first time. It must manage four tunnel portals, and two of them are only 2.75" at the apex measured from the rail top. The engine has no problem with that clearance, and looks okay doing it…not prototypical perhaps, but it doesn’t look like a squeaker, either. With the cab roof vent lifted, the clearance is still nearly 3/8".
What we should be watching for is the total distance between the two sets of rail tops while still providing room for the necessary supporting structure that will carry the upper trackbed and rail system while affording the minimum clearance necessary to allow the highest rolling item to pass below. So, while the recommended clearance may be a full 3-3.5", you can get by with considerably less if must needs, as long as the overhead track can still get its bridge under it.