Looking outheast
Bridge crosses Fischer Creek where it empties into Lake Michigan
Photo taken by Robert Thompson in April 2013
BH Photo #252124
Well, Nathan and Clark, I learn something new every day! I had assumed it was a county highway department re-decking a bridge the "cheap and smart" way. I hadn't realized this technique had a name!
Not the first jack arch I've seen here. Should there be a category for them?
The deck on this bridge is actually a rare type of deck called a jack arch deck. The corrugated metal and concrete is likely part of the original deck. They were used most often in the first couple decades of the 20th Century. The corrugated metal base between steel stringers with concrete on top is the standard design for jack-arch bridge decks. However, one thing I have recently pieced together is that the metal/concrete jack arch deck may have origins further back, where brick arches were constructed between parallel steel stringers. I think this design was used in buildings. I have not found a bridge example, but here is a storm drain that uses it.
J.R. - I found it quite a few years ago, but didn't have a chance to document it until last weekend.
Great find, Robert! Did you find this while looking for something else, or did you suspect this bridge was out there?
OK, Luke, you win. I meant "Abandoned by thingies with wheels". ;)
RKT
I see we have a "steel deck grate" category, so a jack-arch deck category is appropriate. I created one here: http://bridgehunter.com/category/tag/jack-arch-deck/
I listed a few bridges, mostly ones I am familiar with but will rely on others to populate the category. A good overview of this deck type is here: http://www.nh.gov/dot/org/projectdevelopment/environment/doc...