Overview
http://www.columbiamagazine.com/photoarchive.php?photo_id=64...
Photo taken by Lawrence Hamilton
BH Photo #348881
http://historicbridges.org/info/intro/index.htm
This will explain the differences. It is difficult to see clearly but the photo, I believe, shows this to be a Pratt. Also, I can not be sure but I do not believe the bridge in the Sat. view is the same the bridge in the photo
Royce
I am somewhat confused by this bridge being described as a Warren Through Truss, and it may very well be; however, this bridge has verticals.
My understanding about the various bridge designs is that a Warren has no vertical members.
Were this bridge not already described as a Warren, I would label it as a Pratt Through Truss, as it has all the design attributes of a Pratt.
Could someone please enlighten me on this; and, if it is indeed a Warren, please point out what makes it a Warren.
Thank you.
at least it's a truss, not a UCEB.
I meant to get back on this one. Yeah Nathan your right about there being no v-lacing and such. The thing that got me is the bridge being a modern one lane through truss. But the trusses being made of solid beams makes it not look exactly like the old bridge. I like to see a historic bridge in its original location open for what it was built for. But this cant always happen. The historic truss bridge should be moved and not destroyed. If thats the case and a county or whoever wants a modern through truss, this Bach Steel should be put to work to build a modern through truss with the v-lacing and other historic details.
I agree with Nathan here, the bracing is not present, and I also notice a lack of rivets.
Clarence,
That's only true if a company is not set up to do them and most of the industry isn't. With the right contractor and the right spec. a cost effective approach to a much better result is achievable.
Regards,
Art S.
Can't please everyone I guess would be the short answer. Rivets and bolts are not really modern or cost effective building materials.
You can't have your cake and eat it too.
Am I looking at the same photo/bridge? The new bridge looks nothing like the old bridge! The most glaring difference is the lack of v-lacing, so instead of intricate geometry and an open-air appearance, you get solid beams.
Next time get Bach Steel www.bachsteel.com and their engineers to rivet together a nice looking modern bridge that pays true homage to the historic bridge and fabrication methods. Or even better, select an available historic bridge for relocation and reuse. A 1930s era truss bridge for example would be able to offer much increased roadway width and load capacity, much like the modern truss seen here.
Now, I would normally bash a modern covered or metal truss being constructed to replace a historic bridge being demolished. Well, since the old bridge is being saved, I'm alright with this modern truss bridge. It looks so much like the old bridge and the portals are more neat than plain. As long as a historic bridge is not demolished, I wish more modern metal truss bridges were constructed rather than UCEBs. Truss bridges have more character.
Thank you for the info.
I just uploaded five new photos that show the side view of the completed bridge.
I could not do better that day, as there was a lot of traffic due to a festival on the same road and no way to get out of the road to get a better angle.
As to the 1907 bridge being replaced, my wife and I walked out on the old bridge in September 2014 and the whole thing shook with every step; no way would I have ventured onto it with a vehicle.
That being said, in the 1980s and 90s, I crossed it frequently with a loaded gooseneck cattle trailer; even then, had I have gotten out and took a closer look, I probably would have vetoed such a foolish move and went the long way around.