Distinguish Jacksonville: The Bridges of Downtown

[YellowBluffRoad]

That's a nice shot of the Old Acosta; the layout had changed by the time I moved here as a kid but I do remember that old "666 Colds" building at the northeastern foot of the bridge. I always grinned to see that emblazoned in bright neon in a Bible Belt town. I was surprised to find the company is still in business and headquartered in Jacksonville. Here's a better shot of that building as I remember it, from their web site:

http://www.monticellodrug.com/mdc-our-history.html

[LPBrennan]

The original railroad bridge mentioned above was built by Flagler for the Jacksonville, St. Augustine & Indian River Railway, which became the Florida East Coast in 1895. The first Acosta Bridge was built so high because it had to clear the open span of the railroad bridge below it. (I'm guessing it was built beside it because of the government, since a bridge represented a potential hazard to navigation and beside the existing bridge would preserve the existing channel with minimum impedance.) The bridge was opened and closed by one of two small steam engines housed on either side of the center of the span. There were two boilers and engines so one could be out of service for maintenance. There's a picture of the bridge in the Publix on Riverside Avenue from the Jacksonville Historical Society, although the caption says the bridge was opened and closed with a manual crank mechanism. While small drawbridges were hand-cranked (the Seaboard bridge over the Trout River was), it would have been impossible to operate such a big bridge that way considering the number of times it was opened and closed every day. If you look at the picture closely, you will see the boiler houses and the twin smoke stacks above them.
The increase of traffic in the 1920s caused the FEC to double-track its main line as far as Miami (the Key West extension not needing it) and replace the bottle-neck bridge with the current structure, which is a Strauss Heel-Trunion. The trusses are Pratt, which is what the old Acosta was, too. The 1920s was about the end of that style's popularity. A Pratt truss looks like this: /|/|/|/|\|\|\|\
The Main Street-St. Elmo Acosta is a Warren truss:  /|\|/|\|/|\|/|\
The diagonal members of the truss give it the strength. In a Pratt truss the vertical members are an integral part of the triangle. Many smaller Warren trusses have no vertical members: /\/\/\/\

[stjr]

^LP, thanks for the enlightenment.  I posted this picture at another thread (see http://www.metrojacksonville.com/forum/index.php/topic,4671.0.html  ) and identified it as the 1925 bridge which is what the label called it.  Mtrain disagreed, noting a single track in the picture.  On review, it appears that is because the second track was under construction.  What is your take?

[Ocklawaha]

While small drawbridges were hand-cranked (the Seaboard bridge over the Trout River was), it would have been impossible to operate such a big bridge that way considering the number of times it was opened and closed every day.

STJR, the 1890 bridge was double tracked in 1925, 6 years after the Jacksonville Terminal (Prime Osbourne) was completed. Your photo find is certainly during the construction, as is mine.

Nice contribution LP, I like the /// description of some of the bridge types. As of a recent JTA study, the Trout River bridge is STILL a hand cranked span which I suppose is almost never used by river traffic. The study for Commuter Rail listed it as a choke point as well as an expense to modernize and automate it.


OCKLAWAHA

[LPBrennan]

stjr: Your picture does show the double-track bridge being installed in 1925. There is one track shown, but you can see the girders to the left which supported the second track. There's an aerial view of the new bridge in Wayne Wood's book on Jacksonville's Historic Architecture. If you look closely at the picture, you can see the swing span of the old bridge mounted on a barge near the south end of the bridge, in the area where Baptist Hospital and the old Prudential buildings are now.

OCK: I saw the Trout River bridge being opened one day about twenty years ago. I happened to be on the old Main Street bridge there when the bridge tender came out of his shack with a long bar, which he inserted in the center of the bridge. He then walked around in circles, opening the bridge for a boat. The bridge is no longer manned, I believe, as CSX has posted signs on it indicating a number to be called 24 hours in advance of the bridge's needing to be opened. Apparently the Army Corps of Engineers allowed this as the Trout River is not really a commercially navigable waterway. (Just a guess on my part.) Large recreational boats on it are rare, I suppose.