Curved Bridges

[tomytuna]

My layout extention is going to require me to purchase curved ho track bridge....can onyone advse a mfg that they have had good luck with on their layout?...Walthers catalog shows european mfgs..but radious is in cm..not inches...and i don't want to buy bridge that does not fit....i know that this is not prototypicle....but to complete extention...i'm afraid i have no choice...thank s for any help....Tom

[lupo]

if you use flextrack for your bridge there will be no difficulty in using a metric bridge
you fit the curve of your flextrack to the bridge

I presume you know that 1 inch is app. 25,36 mm or 2,536 centimeter
good luck
LUPO

[cacole]

I went through a similar search a few years ago and wound up having to scratch build the bridge because no one makes a curved bridge in the right degree of curvature or length that I needed. I wanted something like 20 inch radius, and that curved bridge from Germany is less than a 9 inch radius.

[Anonymous]

Curved bridges are actually very rare. Trestles can be curved, and masonry viaducts can be curved. Steel or iron bridges that are curved are usually made up of several shorter straight sections, with a slight angle between the sections where they meet on a pier.

If you take this last approach, it is relatively easy to kitbash some of the inexpensive Atlas bridges into what you need. Creating a ballasted deck means you can lay regular curved track right across. You might wishto add guard rails to the track crossing the bridge.

Andrew

[Anonymous]

Hi Tom
[2c]
I'm assuming you are modeling a modern era railroad because JV Models makes a curved wood tressle bridge but I'm thinking wood's not your thing
I saw a video of Rick Rideout's L&N layout and he had a super long girder deck bridge sitting on a wide curve. What he had done was attach plate girder sections to the sides of the sub roadbed. For the piers, he wraped thin styrene, painted a concrete color, around the front (outward facing) of 2" x 4" wood risers. It looked very convincing. If you want more detail you can dress the underside with styrene "I- beams" and ballast the deck.

Anyway, it looked good, didn't cost a fortune and seemed easy to build. If you can rent Allen Keller tapes from your L.H.S., check out volume #9 RickRideout's L&N Henderson Subdivision. Of course it's the only video that "SOLD OUT". Maybe if enough people ask, they'll make more copies.

[vsmith]

I have the same problem but in a different scale, I'm doing large scale and I only have two choices, one supplier or scratchbuilding, and I consider myself lucky i have the one supplier, but it is a little pricey. $79 for a 36" prebuilt curved trestle and I need a 60" curved trestle, so its penny saving time!

I would agree with buying the euro bridges and flextracking the raodbed. Make sure if you buy the euro bridges to get the right peirs specific to that manufacturer, they are all a little different from US makers. A little metric conversion math and you can determine which spans are closest to your needs. If the euro bridges are too expensive then you might try the other method described above. Cutting the plywood stringer close to the roadbed then bending those girders around the plywood is a good cheap way to build a curved bridge, just more labor on your part.

[Anonymous]

QUOTE: Originally posted by vsmith

.....bending those girders around the plywood ......

Just a note to clariify (like mud) that the plate girders aren't bent around a "curved" sub-roadbed. Instead, the sub-roadbed (which is also the roadbed) is cut in angles in equal lengths, like a stop sign, to make a curve.
The track doesn't go straight through the center of each bridge section but curves. The roadbed has to be wide enough so that rolling stock doesn't hit the plate girders on the outside curve .

[vsmith]

Thats one way, but if your talking about a bridge where the girders are above the track like a typical girder bridge, then you'de have to keep the radius pretty large to get a bridge that wasnt too wide. If you are planning a tighter curve the bridge will get really wide to acomodate that curve. I'd then suggest building the bridge with the girgers below (like a deck girder bridge) the track otherwise by the time you take clearences into account the bridge can get really really wide on a tighter curve. With the girders below, car overhang doesnt become a problem.

[tomytuna]

WOW...thanks for all of your responses.....i guess i kinda knew the answers...thanks again for all the input.....guess i gotta buy a bigger house.....lol....Tom
p.s. to: LUPO....No! i did not know the conversion of inches to centermeters.....thanks anyway.....i think the USA should have converted to metric back in 80's when they originally wanted to...im an old dog now...to late to bother.....thanks again to all Tom

[Fergmiester]

I picked up an Atlas Arch bridge without the deck for a couple of bucks at a train show several years ago. I had a span of track crossing a valley for which the bridge was the perfect length. Problem was the track had a curve in it. I made a deck to cross the valley and it fit the contours of the curve. I then fitted the side arches onto the deck. Though I don't know if it structuraly feasible in real life it works well and looks good and can handle my largest locos without sagging.

[Anonymous]

QUOTE: Originally posted by vsmith

I have the same problem but in a different scale, I'm doing large scale and I only have two choices, one supplier or scratchbuilding, and I consider myself lucky i have the one supplier, but it is a little pricey. $79 for a 36" prebuilt curved trestle and I need a 60" curved trestle, so its penny saving time!

vsmith: Is that a commercial supplier, or a custom builder ?
The reason I ask is that I also build custom trestles, in several scales, G, O, O-Tinplate, and HO, and depending on height and level of detail, that $79 for a prebuilt 36" curved trestle sounds like a pretty low price.
thanks; Mike

[vsmith]

Hey Mike,

Yeah its a good price except when you got no cash, the company is called BridgeMasters, they are located here in Southern California and are pretty well known in the largescale community, they make the only curved trestles that I knowof, and they make it for 3 different diameter tracks at 10 1/2 " high.

www.bridge-masters.com

another good company that produces bridge kits is Garden Texture but they do not have a curved trestle hence my "one source" comment.

www.gardentexture.com

There are a couple of other suppliers that make straight bridges but these two are the most well known.