Straight Talk on Curved Bridges

"Curved" bridges are actually short sections of straight stringers.
Here's an example of a low trestle I built for an N scale Free-moN module.
Start by laying out the stringers on a trace of the curve you want:

I used thin strips of double-sided tape to hold stringers in place.

Using woodglue, arrange planking along the entire span:

It's a bit tedious, but having a game on helps.
Notice that PC board ties are superglued every 1" or so.
You don't need to use PC board ties if you Pliobond the rails directly to the wood.

For the bents, it's easier to build a jig:

After you build the first bent, use it as a template for the jig.
I just CA'ed some wood to a scrap piece of plexiglass (helps prevent bent from getting stuck in jig if excess glue leaks out).

This is a low trestle with very straight / vertical bents.
You can built them with angled piles if you want.

Once you get all your decks and supports built, stain / paint them:

[Most times it's better to stain everything before gluing, so there's no splotchy glue stains]

Then glue the bents to the deck:

Notice that there are a pair of bents at the "joint" where pairs of stringers come together, but only singles mid-stringer.

I used pink foam in on the modules, so it was easy to just press down on the trestle to make marks on the ground, then used a spare round pier in the Dremel to "carve" out spaces:

I strongly recommend scenicking the ground (dirt, ground foam, static grass, etc.) BEFORE you secure the trestle, but depends on the height.

I used clear caulk, then put weights on a thick metal ruler to keep trestle even while caulk cured:

Solder the rail to the PC board ties, using 3-point gauges to hold rails in position:

Paint track & PC board ties to match stained wood, use a white colored pencil to add some weathering, and you're pretty much done:

I added guard rails (smaller Code 40 rail) after everything was done. Just CA'ed them on the inside equidistant from the rails.

Many trestles also have horizontal supports, and you can also add a walkway, escape platforms, nut-bolt-washer details, etc., like I did on this other N-scale curved trestle:

Hope this helps.

Better Trestle Tutorial

The late, great Wolfgang Dudler has a step-by-step tutorial on his Westport Terminal website.

Very similar, and his is in HO.

Hope this helps.

There are bridges with real

There are bridges with real curved girders, however, they are a newer construction, and the exception. 

Otherwise, its small, straight sections. Hopefully these answer your questions-

"There are bridges with real

 Do you know where they are used? I can't think of any reason to use curved girders in a railroad bridge ? .....DaveB

 Would this be a good enough

Would this be a good enough reason?

 "Would this be a good enough

No, a railroad should be able to come up with a better solution for the problem than that ....DaveB

Curved Concrete

In Richmond, CA there are two legs of a wye that elevate & curve over the freeway, connecting the Richmond Pacific to the BNSF/UP.

Go to street view on the 580 & look up & you'll see the concrete sections are curved.

I haven't yet seen the bridge referenced by the OP, so don't know if wooden trestle, open girder, or concrete.

...

It seems like a perfectly acceptable solution to me...but then maybe I actually believe in Advancement in Engineering...

... a better solution ... / ... Advanced Engineering...

The B&O came up with a better solution and engineering in 1833 with the Thomas Viaduct. Yes it is made of stone and mortar and not wooden bents, but it is still in use.

"but then maybe I actually

    Easy to say when it's other people's money they are spending, but gold plated toilets are not advancement in engineering ,they just dazzle the masses. A little re-alignment might cut the costs in half but would not be so "impressive" .....DaveB 

Wow...

...Fighting over a curved bridge....Get a life!!

"Fighting over a curved

    If you have no opinion on the engineering the polite thing would be to leave the discussion  to those who do? ......DaveB 

If you've ever been to

If you've ever been to Cincinnati, there's a bridge over the Ohio from Kentucky just west of the football stadium. A line off the bridge descends to street level over a couple blocks, all on curves. The bridge sections are curved to match the tangent of the track.

Benny, is that bridge in..............

..........Australia?  I notice the cars are on the "wrong side" of the road and it sure doesn't look like England.

Peter

...

Dunno.  I found online - I dare say it might even be japanese.

Curved Trestle

In Colorado it's hard to find a straight trestle. A lot of them followed the contour of the mountain side or curve of the stream.

Not all railroads are built over flat land. Sometimes the design is dictated by the right-of-way or natural obstacles, it's not good to fight mother nature.

--Bill B. 

The curved trestle is

the Keiyo Line Yumenoshima Railway Bridge in  Yumenoshima Japan.  

Andrew

"Sometimes the design is

   That's why most curved trestles are actually a bunch of straight trestles joined together at angle points. Curving the support beams adds a torsional component which is not an efficient way to carry a load. The further the load is applied outside of the beams the worse the situation. Since railroad curves are so broad it's almost always possible to design straight beams to support the load and just apply a cosmetic curved deck for trainmen to walk on....DaveB

Frankenstein Trestle

Of course there is always the Frankenstein Trestle curving above Crawford Notch, NH. It violates a couple of engineering norms: It is curved and it is built with significant grade (average grade up to the notch is 2.2%). The original structure was completed in 1875 but has been rebuilt several times with mostly straight steel pieces but some curved sections.

A great view while riding the Conway Scenic Railroad. It also confounds those who doubt that there are high broad perspectives for Appalachian modelers to include on the backdrops of their layouts.

Frankenstein Trestle... 2016

I hope to get to the upper deck of my layout and specifically scratch-building Frankenstein Trestle to scale sometime next year.  Unfortunately, none of the photos I have or have found show the steel supports under the center of the bridge.  At the ends they are looking straight to me.  I may go with all straight sections lacking anything definitive.  The Trestle structure seems pretty unique anyway, so I doubt anyone will look up underneath at those.  And in N scale it will be quite a project even without trying to do curved supports.

-Ed

Thank you all!

I appreciate the good advice.

Geof

Another Curved Trestle Build Post for Reference

You may also want to check out Michael Rose's Georgetown & Allen Mountain Railroad post starting at page 106 ( The railroad wouldn't be) and running through abut page 110. His curved timber trestle looks like it is going to be spectacular when he gets the mountain and scenery done.

My trestle is a JL Innovative

My trestle is a JL Innovative that I assembled.

Another example

Geof - Hope this helps with a view of the supports below:

neil