MTH Arch Bridge...Center Support Needed???...Other question added.

Middle pier is required per the owners manual.  You MIGHT be able to make modification to the bridge by installing aluminum channel material under the decking and having that provide the load bearing element.  This is not how the bridge was intended to be set up/used.

Are you talking about this bridge?

 I have 2 on my layout in which a challenger and 2 double headed y-6s where all three on it at once  many a times.I even removed the middle sidewalks and without the middle support.So i would say its not gonna be a problem unless you plan on standing on it.

I also have two of the MTH bridges, 1 single track, the other double.  I don't use, nor need, the center support.

It is indeed the bridge posted above.

That's a lot of heavy metal at one time Patrick.

Thank you for the responses everyone.

The prototype would not have a center support. That defeats the purpose for the span.

I have one on my layout.  Two track with Gargraves.  Not a hint of sag with a Premier Dreyfus Hudson on one track and a Premier K4 on the other.  

Here is mine. It isn't on my layout yet, but I have had my Williams scale Hudson on it and it didn't sag at all. The track takes a bit of the load and the bridge is fairly stiff,so there isn't any reason to be concerned.

Very good point.  Look at the MTH picture of the bridge with the center support and ask yourself, What's wrong with this picture?  No prototype bridge would be designed or built that way.  Two span yes, one span with a pier under the middle, no way. Then look at Mike's picture above: the way it should be, yes?  Can't believe somebody at MTH didn't catch this.

Purrrrrrrrrrty!

I have 2 of the double track bridges and i park my challenger on it and its fine with out the center support...

I have three of the double track arch bridges, each separated by a 10" girder bridge.  I have the piers only where the bridges meet.  I haven't had anything supporting the center of bridges some five years now with no issues.  At the moment, there is a consist of ten k-line diecast hoppers sitting on one track.  Trains run by on the other track and the bridges seem solid as a rock.   I'd say you  don't need the center piers.

Nick

I think that MTH is almost obligated to error on the side of caution on this. Think of how this Forum would be ripping them apart if it flexed even once. I have the bridge and I don't use the center support and it is one sturdy built bridge, handles my Premier Class A with no problems. I have leaned on it while doing scenery around it it will handle any train you have believe me.

Want to bet??   

Thanks for all the comments fellas.

How about stack cars? Is there clearance for MTH and/or K-Line Double Stacks?

No center support required here either and this is 4 feet in length.

jim r from bridgeboss.com

I did not use it as it takes away the purpose of a span like that. No issues or problems to report.

As you can see by comparing these 2 pictures, the end piers do NOT have to be on the extreme end of the bridge.  You can 'cheat' and move them closer to the center.

the bridge's design offers a lot of options.

- walt

On extreme ends:

Pinched in:

Take a look at this picture of our club's layout. We modified the three bridges by inserting "L" shaped aluminum angles under the walkways.

I am with the others, no center support required for the Eastern District.

Donald

I have mine (2 track) as a Lift out to eliminate the duck under.

No supports at all. I run My Big Boy and the Add on Die Cast tender over it all the time, no problems. Doesn't matter what consist I'm pulling.

The ends sink along with the approach track as it bears weight but the span does not sag.

The Big Boy makes the track sink in a bit everywhere on the layout, the bridge is the stiffest part !!!

Yowza. Any chance we can see a picture of that?

FWIW, this is not an arch bridge.  The proper name for this bridge is a CHORD TRUSS.

The former PRR Rockville Bridge is an arch bridge.

Fred

Hmmm... I'll believe it when I see it. 

Here you are.  Sorry it's not a better photo, but it's hard to get the whole thing in the frame.

Nick

nick b, very nicely done sir.  blended together so it looks like it was designed and built as one bridge by someone who knew what they were doing.  that must be 8 feet of bridge.  impressive.  makes sense at the back of the layout too, improves visibility of the trains crossing it.  i like.

dave

Thank you, Dave.  It's actually 11+ feet of bridge. ((3x31")+(4x10")=133"=11'1")  Initially i tried it with out the girder bridges and had four of the steel arch bridges together.  But it looked weird to me so i returned one bridge and tried the girder bridges in between.  Obviously, that's what i decided to go with.  There's no reason for a bridge like that to be there, other than my favorite reason: i think it looks cool.

Nick