Truss Bridges

I built a bridge on my 1 sq ft diaroma, and thought I was building a Warren Truss bridge. It seems, however, I left off the vertical support
members (perpendicular to the bridge deck.) How critical are they to the Warren Truss style? Is there another style that doesn't use them?
I have: _____________________ / \ / \ / \ / \ / \ / \ -----------------------
I should have: _____________________ /|\|/|\|/|\|/|\|/|\|/|\ -----------------------
Structurally speaking, how imporant are the vertical supports?
Puckdropper
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Puckdropper wrote:

Pd:
You're in luck. In its simplest form, which can be seen in common house roof trusses, the Warren truss has no vertical members:
http://www.bergen.org/AAST/Projects/Engineering_Graphics/2004/Bridge2/types.htm
The vertical members exist to support the bridge deck and subdivide the truss panels. If they are left off, the top and bottom chords of the bridge should be made thicker than on a bridge that has these vertical parts.
Here is a prototype Warren truss railroad bridge with no vertical supports:
http://www.brantacan.org.uk/WorcsR6.jpg
Do you have a picture of this bridge available?
Cordially yours: Gerard P. President, a box of track and some plans.
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snipped-for-privacy@gannon.edu wrote in

Thanks for the information. I don't have pictures available, but I'll post a link to r.m.r if I take any.
I'm so glad I don't have to worry about the bridge being wrong, building another bridge isn't difficult, putting it on the diorama with the hand laid track is!
I do have "plates" on the sides of the angled structural members, it was a way of tieing the whole thing together.
Puckdropper
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Please do not spam this newsgroup with your links.
ET
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On Mar 22, 11:14 pm, El Trauco <naughtynaughtynaughty> wrote:

A link to a picture is hardly spam. The guy isn't selling anything.
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El Trauco <naughtynaughtynaughty> wrote in

I'll tell you what. I'll use a descriptive subject line, and if you don't want to look at the message you don't have to. Sound good?
Puckdropper
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Wise is the man who attempts to answer his question before asking it.

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PD --
Your link postings -- like the Royal Gorge slide fnce link -- are fine. Don't let anyone dissuade you frm contributing them.
Puckdropper wrote:

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Don't waste any time with the idiot. He went straight to my killfile. Didn't deserve so much as a *PLONK*. -- Excuse me, I'll be right back. I have to log onto a server in Romania and verify all of my EBay, PayPal, bank and Social Security information before they suspend my accounts.
Working the rockie road of the G&PX
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snipped-for-privacy@pimin.wan.vpn (Paul Newhouse) wrote in writes:
*trim*

Don't worry, I don't plan on wasting more time with him. Every once in a while, though, a reminder of how Usenet works is a good thing.
Puckdropper
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Wise is the man who attempts to answer his question before asking it.

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Speaking a structural engineer who has been designing highway and railroad structures for over twenty years: The answer depends upon where the floor beams are located. The floor beams are beams that run crosswise to the track, located below the ties. There should be a vertical or diagonal truss member located at every point where a floor beam is connected. These vertical or diagonal truss members give the upward "pull" to counteract the weight of the train on the floor beam.
But at this point you gotta ask yourself, even if floor beams are located where there isn't any vertical member in your model, is it really worth the effort of messing up your hand laid track? I doubt it. Gerard gives a good example of a Warren truss without verticals*, so unless your model is a nitpicker for proper floor beam framing (or your intended audience for the diorama is a bunch of structural engineers), it won't be that big of a deal.
* In the case of Gerard's example, the transverse floor beams occur at the locations where two diagonal members come together.
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It's still a Warren without the vertical members. For a primer on bridge types, see: http://pghbridges.com/basics.htm
-- Bill McC.
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