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1865 Bridge Photo
3

1865 Bridge Photo

1865 Bridge Photo

(OP)
Just a cool photo of a view down the Chain Bridge over the Potomac at Washington circa 1865.

RE: 1865 Bridge Photo

Cool photo!  Looks like it is being guarded by Union troops.

DaveAtkins

RE: 1865 Bridge Photo

Looking at those Yankees, I wonder how they won the war.  Guess by that time, our boys looked even worse.

RE: 1865 Bridge Photo

Awesome pics!

RE: 1865 Bridge Photo

Looks like the designer couldn't decide on a truss bridge or an arch bridge, so he used both.  I wonder how long a timber bridge like that lasted.  Looks like pine from Virginia, not exactly a durable timber.  The rods would have been cast iron, so would have outlasted the wood.

RE: 1865 Bridge Photo

hokie66 - it's actually called a Burr Bridge after Theodore Burr; a combination arch & truss.

If you're ever in the Allentown PA vicinity, go to Covered Bridge State Park. There are two well preserved Burr Bridges from the 1850's - and still open to traffic.

RE: 1865 Bridge Photo

Thanks Bridgebuster, that's a new one for my vocabulary.  Will look him up.  What materials were used in the Allentown bridges?

RE: 1865 Bridge Photo

We just completed a bridge much like the one in the photo. Ours was a 128' single span. All timber. HS20 loading. The only steel in it was the bolts and plates at the connections.
Those were some fun shop drawings to check.

RE: 1865 Bridge Photo

(OP)
DWHA, can you post a picture of it here?

RE: 1865 Bridge Photo

Anybody else besides me astonished at the sharpness of this picture? You can pick out grain directions on some of the beams. Most pictures I've seen from that era are blurry (and yes, I know what causes that!); but this one is very sharp.

Aren't a bunch of the surviving covered bridges around the US made with the Burr design? Many aren't open to traffic, but many still are (for instance, western Indiana). Remarkable design-use the natural strength of the arch, combined with the practicality of a standard truss design. Does the bridge collapse without the arch?

RE: 1865 Bridge Photo

(OP)
DWHA - sweet.

Thanks.

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