# Curved bridge overpass confusion



## joed2323 (Oct 17, 2010)

Im working on the tracks leading into my staging, but i have alight problem.

The track here is 4 inches high and its on a 29 inch radius curve and the staging lead will be going underneath this curve. 

As most of you know they dont make much for curved bridges so i was looking at using the micro engineering 210 foot long viaduct bridge to support the curved section going over the staging lead.

Now the staging lead is also on a curve going under the mainline, but i need the bridge to be roughly no shorter then 150 scale feet long. With the track going under the bridge, how am i going to position the supports correctly with the staging lead track being under this??? 

Thats plan a, plan b would be the easy way out, and make a tunnel entrance before the planned crossing so i wouldnt have to worry about making it look nice, i could make side supports to support the top track while the bottom track is covered up in the mountain.

lol, it looks like my staging leads to the side of doom, but i will be adding on a section here, no worries, it will be hidden


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## Big Ed (Jun 16, 2009)

Have David Stockwell make you a custom bridge?

http://www.modeltrainforum.com/member.php?u=3233


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## joed2323 (Oct 17, 2010)

Im not sure he builds modern, i do not want a old style bridge here


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## NIMT (Jan 6, 2011)

Yes I think he has done some more modern bridges too. Just ask him.


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## sawgunner (Mar 3, 2012)

I had a similar problem with my first large layout i did. I had an elevated curve going to my staging area and crossing the double main below. if you can find them I think they are the model power plate girder bridges. they don't have any track on them so you can chop the ends off at the angles you need then somehow mold them together to make the curve. and it would also be a ballasted deck as those types are on the prototype


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## joed2323 (Oct 17, 2010)

I will have to check that model power out. Usually though model power stuff looks very toy like unless im crossing this with a different manufacturer.


I think i will try to cobble something together and if im not happy with the outcome i will rip it out and try again.

I wanted to make a nice bridge crossing but i may just hide the staging lead with a tunnel entrance instead


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## sawgunner (Mar 3, 2012)

these are the ones i was referring too, they look real enough on the sides but the floors were a bit lacking (but those will be covered)

http://www.ebay.com/itm/HO-Scale-Mo...551157?pt=Model_RR_Trains&hash=item1e789ca6f5


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## Pfunmo (Feb 21, 2013)

I would suggest looking to the net for pictures. Mountain areas would be my first thought as they often require more congested trackwork. From there I would have to go with designing what the proto folks might have used. Scratchbuild will likely be required. 

I have lost the pictures now but there was a stone trestle West of St.Louis, Mo. that had something like what you are doing. Keep an open mind on what form the support may take as they were built to do the job and many times were not built to fit squarely under the tracks. Give me a few minutes to draw up what I might see for your situation.


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## Pfunmo (Feb 21, 2013)

Something like this? 











The blue being stone columns built to fit the space. The dashed lines being heavy beams to support the grey bridges. Set it all into place to make it look like it will work and most people will not question if ,in fact, it would pass an engineers eyes.


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## Pfunmo (Feb 21, 2013)

Sorry! New here and picture posting is different??


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## joed2323 (Oct 17, 2010)

Thanks guys.

Pfunmo- i cant see your picture.
Can you copy/paste the img code?

Your suggestion sounds good, hope you can get that picture to work


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## Pfunmo (Feb 21, 2013)

Yes. I do have a problem with posting that I've not figured out yet. Will try this way???


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## Pfunmo (Feb 21, 2013)

No good, huh? 

http://s990.photobucket.com/user/Pfunmo/library/

I may need help!!!


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## sawgunner (Mar 3, 2012)

Pfunmo added it for ya


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## Pfunmo (Feb 21, 2013)

Something has changed either at Photobucket. They have a new screen setup since I last visited their site. Or it is quite possible I'm not using this site correctly. Hope you can see the tiny little picute well enough to see my thinking. It sounds pretty offbeat but I've seen several spots where they have done this. First time I was in Roanoke, Va. chasing trains when I came to the setup. It really looked shaky but they were moving trains!


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## Pfunmo (Feb 21, 2013)

Thanks for the help!


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## sawgunner (Mar 3, 2012)

photobucket did change their site. what you have to look for in the links option to shre your pic is the IMG code it'll be the bottom one everytime


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## Pfunmo (Feb 21, 2013)

They may be going through yet another change. Under links, I get a new feature for a slideshow as the last link. I was expecting to copy the IM link, click the "insert image" link above and paste the IM link in but that gives me the big red "X"...... 

That gets into a whole new topic so, THANKS!


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## Southern (Nov 17, 2008)

`I do not know if this will help. 
https://maps.google.com/maps?q=old+pineville+and+griffith+st&ll=35.160657,-80.877645&spn=0.000819,0.000857&oe=UTF-8&hnear=Old+Pineville+Rd+%26+Griffith+Rd,+Charlotte,+Mecklenburg,+North+Carolina+28217&gl=us&t=h&z=20


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## Pfunmo (Feb 21, 2013)

That is exactly the type item I was trying to draw!!

It is also an amazing job of layout building. So well detailed it almost looks real. Great job.


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## Southern (Nov 17, 2008)

lol Thanks

I had to drive the pillons down 65 feet to the bed rock. the top track is the Charlotte light rail, the lower is the NS main line.


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## joed2323 (Oct 17, 2010)

This picture southern posted is real. That is awesome. Ive never seen that design before.
It just goes to show you sometimes the engineers have to be creative.
From the design/picture i wonder if this works easier with the bridge being a double track?


This definitely gives me some ideas which i didnt previously have.
From the picture though it looks like the track underneath the bridge is very curved at all,
On my layout i have the mainline radius at 29 inch and the bottom track radius at 27 and the bottom track is more offset so the curves dont match up exactly.e


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## Southern (Nov 17, 2008)

If you zoom out of the photo it makes a little more sense. The lower track was there first. the upper tracks can have some tight turns and steep grades as it is a light rail line. Take a look at it from the steetview.


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## Pfunmo (Feb 21, 2013)

This is more for the general idea than as a specific way to do the job. What it shows is that building a real railroad takes some major thinking to get the plan right. 
We are lucky in that we don't have to worry very much about the weight and pounding from an HO train. What I would encourage doing is looking at your own setup and ask yourself where support would need to be to make a more or less even looking set of piers. The piers do need to have plenty of clearance for the lower track but they can be set at any angle or place that seems right since they are more for appearance than actual support. 
For a modern look as if it had been built in the last 10-20 years, I favor round concrete columns. But then there are many which are much older so it just depends how you want your railroad to show the time modeled. Are you into modeling structures with plaster? I find it one of the really handy things to use to make all kinds of things that I need which will never be marketed. 
Since I find myself in an area that has no hobby supplies beyond the very basic, I find plaster is becoming one of my most used items for scratch.


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## joed2323 (Oct 17, 2010)

Man, a side view picture of that bridge or one like it would be awesome guys...


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## dannyrandomstate (Jan 1, 2012)

http://www.ebay.com/itm/HO-Scenery-Train-Trestle-overpass-made-on-a-curve-/251248122180?pt=Model_RR_Trains&hash=item3a7f8e1944


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## joed2323 (Oct 17, 2010)

Thanks southern, the picture helps put alot, especially when you go down to street view, you can see alot that way.

My curve radius is alot tighter then that, but i should be able to replicate something like this...:thumbsup:


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## Pfunmo (Feb 21, 2013)

You've got a tough one but then that is what makes us get better, right? I've found also that the upper deck does not have to be of a sort that has ballast. Ballast is used to hold the ties when on ground but on trestles and various bridges there is no ballast. Just a small thing to let your mind work a bit easier if it helps.


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