Bridges-which to use?

[Anonymous]

Hey guys, another newbie question for you: When using bridges on a layout, how do I know which one to use? For example, I'm going to have one bridge going over another track(or two)--is there a specific bridge style for this, or is it personal preference? I'm also going to have a bridge passing over a small river/stream--is there a specific bridge for this? If so, does it vary based on height?

I've flipped through a bunch of MR magazines and I see so many different styles and uses, but I couldn't really see a standard.

Thanks in advance for both your answers and your patience with a rookie
JASON

[cwclark]

Kalmbach has a publication called "Bridges and threstles" that will show you how to build them...most commercial bridges are too large or just don't look right on the layout...you might want to try scratch building your bridges..they will really enhance your layout and don't take that long to build...i scratch built my last bridge in less than 3 weeks using plastruct beams, styrene plastic, some rail, campbell railroad ties, and rail spikes...the only thing that was a kit was the bridge girders and i used the "Atlas" N scale version for an ho bridge...it came out good and looks more prototype then the commercial bridges...even simple bridges like wooden truss bridges can be built with dowel rod and balsa or basswood and they look great once you build them and they are installed...Chuck[:D]

[eastcoast]

You have found the KING of bridges pal.
You need ask two questions:
HOW LONG ? HOW HIGH ?
Then you can worry with all other questions.
I have many bridges on my 3 track ,around-the -room layout.
If you are going short, say, over a stream, use a flat plate girder.
If you are going long, like over a canyon or train yard, a truss type.
The other is height, how much support will you have to hold it up?
A plate bridge, mainly flat with flat steel siding, will need alot of support.
A truss bridge, supported by itself by steel triangular girders can travel a
further distance with less under support.
Now, becuase we work with "plastics" most of the time, unless you build
by scratch with another material, you will need support anyway.
I needed a bridge to go 3 feet,real life, and had to put a peice of 1 by 3 under
the entire model to keep it from sagging over time.
I have put many bridges together and also mixed styles as in real life to get
my desired effect. Real bridges mix styles all the time to achieve function.
I hope to have helped even a little. Good luck. Any other questions, feel free
to ask and I can try to get you out of the jam.

[Anonymous]

Thank you very much for the quick and helpful replies. Eastcoast, that's exactly the information I was looking for--I'm actually just drawing my layout on the table right now so I have a feeling length and height are going to change before I'm done, but at least I have a rule of thumb to go by for now. Once I've finalized my gaps for the bridges I'll pop back in and give you some real measurements, so you can keep me moving in the right direction.

Thanks again
JASON

[oryan_dunn]

QUOTE: Originally posted by MrClark

Thank you very much for the quick and helpful replies. Eastcoast, that's exactly the information I was looking for--I'm actually just drawing my layout on the table right now so I have a feeling length and height are going to change before I'm done, but at least I have a rule of thumb to go by for now. Once I've finalized my gaps for the bridges I'll pop back in and give you some real measurements, so you can keep me moving in the right direction.

Thanks again
JASON

The latest MR has an article about plate girder bridges with different styles and their uses. I found that helped me decide on the bridges that I will use on my next layout.

[Anonymous]

RMC ran a series of articles on bridges within the past year or so.

Another great place to research types of bridges for particular circumstances is the web. As part of a Cub Scout requirement I was researching different bridge types for suitable pictures to show the boys. I ran across many web sites aimed towards high school and college students. Lots of really great information and pictures.

Actually, often times the pictures are better determinants of what type of bridge to use in a given situation than just text. If there is a picture of a girder bridge used by a railroad to cross a small stream . . . well, you just got proof that such a bridge is appropriate!

[RedLeader]

Jason, this will help you a lot :
http://www.pghbridges.com/basics.htm

[Anonymous]

In the way of kits, you should look at Central Valley's products as well as micro engineering. Because both of these companies lack websites, you can just go to www.walthers.com and search their names using Walther's "advance search" tool. Just use "bridge" as the keyword and "central valley" or "micro engineering" for the company name. Good luck![:)]

[cjcrescent]

If you want the best reference (at least in my mind) on bridges and trestles, try to get a copy of the late Paul Mallery's "Bridge and Trestle Handbook". He not only shows what bridges goes where, but also explains the why and the what of the bridge in a way even the non-engineering types, (like me), can understand. It 's a Cartsen's publication and may be out of print. I've seen them at train shows and at some used bookdealers.

[Anonymous]

I think Carsten's still advertises it in RMC for sale.