View from frozen river
Foursquare user Paul L. January 2013
View this photo at irs2.4sqi.net
BH Photo #316853
My report and photos following field visit, in general, confirm the discussion had here on Bridgehunter. http://historicbridges.org/bridges/browser/?bridgebrowser=il...
As a bridge historian, I consider this a pony truss because that is what it was originally designed as.
Bridge existed in 1942
This question about whether this bridge is a pony truss or a through truss persuaded me to go on a field visit with my camera. It raised more questions than it answered about this bridge's history.
This bridge is much more massive than is required for a pedestrian bridge. That means it was clearly relocated to here from some previous use. It does seem likely that it had been a road-over-railroad bridge, built in about the 1890's. There's lots of double-intersection Warren truss road over railroad bridges built in that era. But where did this one come from?
And then there's the question of whether it's a pony truss or a through truss. It almost certainly was a pony truss in its original location and use. It may have had outriggers, like many bridges of this type and vintage; connection points that could have been for outriggers still remain. But when it was narrowed for its new purpose the outriggers were dispensed with, and replaced structurally with overhead supports. There was still more than enough clearance for pedestrian traffic. The overhead supports are sturdy enough to be structural; the bridge is already too narrow for a vehicle, and has stairs at either end, so they would not have been added to keep vehicles off it. So, does that make it a trough truss in its new configuration?
It's a fascinating, definitely old and possibly historic, little bridge buried in a tangled web of 1-way streets in a quiet residential neighborhood.
Pretty much every feature of this bridge points to it being a former railroad bridge, from the connections to the diagonals, to the size. Nathan, would you agree?
Most of the chicago & north western trusses which serve as road crossings came from a bunch of 1880s/1890s pony trusses. Is it possible in your opinions that this is actually an original railroad truss, relocated here?
Likely relocated here and narrowed. Similar design to bridges found on HWY over RR as here: http://www.historicbridges.org/bridges/browser/?bridgebrowse...
Paint color on this particular bridge suggests the bridge is owned and maintained by City of Chicago.
questions about this bridge: Obviously this bridge is a real historic pony truss....it just looks too narrow for the street that it uses to bridge. Im wondering, first of all, is this bridge used to be the actual street bridge and then it was retrofitted and narrowed for pedestrian use?
Also, the design: Am I right in calling this a double intersection warren pony truss? Anyway, please comment.