Another interesting bridge 1

[spsalso]

We've talked about the railroad bridge over Highway 101 at Ventura CA, and the addition of unnecessary steelwork thereon.

Here's another one, but I doubt there's anything unnecessary. In fact, it visually feels like something is missing.

The bridge is at Cuttingsville, Vermont.

Here's an exceptionally artsy picture:

https://www.railpictures.net/images/d2/2/4/4/3244.1514383860.jpg

Of interest to me is that the outer two spans are cantilevered off of the center span. I believe that is highly unusual, perhaps unique.

Here's another shot:

https://external-preview.redd.it/UN...bp&s=28f1b14450cd8a3348a328fdc1536fd707a1c5b3

I'm interested in opinions of why this unusual design was chosen. If it was a good idea, why is it so unusual. If it was a bad idea, why? Note that the bridge has been around for awhile (as opposed to, say, a certain bridge in Genoa), so it probably actually does work.


What say you?



spsalso

 

[BridgeSmith]

It's a mirror image of the Ventura 101 bridge we discussed earlier, without the faux chords.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[spsalso]

The Ventura 101 bridge is two spans, each of which is structurally independent. Just two through girder bridges in series. Removal of one span will not cause the other to fall.

The Cuttsville bridge is three spans which are not structurally independent. The center span is used to support the inner ends of the outer spans. They are definitely NOT independently supported.

That is hardly a "mirror".


spsalso

 

[BridgeSmith]

Obviously, since the load direction is still downward, but the truss is 'upside down' relative to the Ventura bridge, it's not an exact mirror. However, take out the faux chords of the Ventura bridge and it would look like this one.

Anyway, my point is that the only thing somewhat unique about the configuration of this truss, is that it doesn't have the unnecessary pieces that are often added to trusses to make them look 'complete'.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[spsalso]

Even if you turned the Ventura spans upside down to make a deck truss bridge (which would make adding the faux chords quite the challenge!), there would still be the fact that each end of the Ventura spans would rest on abutments/piers.

That is NOT the case for the Cuttsville bridge. And that makes this bridge quite different than the Ventura bridge and probably all railroad truss bridges. It IS an interesting point that the Cuttsville bridge could be viewed as a cantilever bridge. If so, it is DRAMATICALLY different than the Ventura bridge. Which is not a cantilever.


spsalso

 

[kevinsnn]

Could the highway be newer than orignal bridge and this pier was origanally a abutment so they could add a new span.

 

[spsalso]

I find no mention of major modifications to this bridge since construction in 1895.

I earlier mistakenly called this bridge the Cuttsville bridge. It is the Cuttinsville bridge.


spsalso