Windsor Harbor Bridge

Not much of a bridge geek but this article may help to clarify things, it has some blow apart diagrams and cross sections that look interesting...

http://www.historycooperative.org/journals/sia/31.1/jackson.html

Hoping to visit this bridge in person and see for myself what these keystone columns are all about :-)

Some of the design differences in the exact shape of the Keystone columns have to do with the size of the column. Different designs for different sizes. That explains some of the differences between members on WIBC bowstrings as well as Keystone column bridges like Mead Avenue in PA. Two designs:

http://www.historicbridges.org/iowa/freeport/little_dscf5430.jpg

http://www.historicbridges.org/pennsylvania/beattymills/armstrong098.JPG

However, as for this particular bridge it is indeed an unusual variation and I really don't know a lot about it. The little brackets you mention are both functional and decorative and are designed to look like little hands grabbing the parts of the column.

Anthony, I think that you are right. I have spent some time puzzling over this bridge as well. I have interpreted the columns to be Keystone Columns that have not been fully sutured. The components of the column seem to be held together by some type of bracket.

Anthony,

Are you referring to WIBC's "Plate and Channel" bowstrings? Like this one: http://www.historicbridges.org/michigan/bennettpark/index.php You would think these would be more common, but I have only seen a small number.

I have to admit, I am pretty unfamiliar with the Keystone columns. After looking at this bridge, which was built by the Keystone Bridge Company I see the flat sections of the column like the ones on the WIBC bowstrings. Would be interesting to know what made them choose one over the other with each job.

I had read somewhere (wish I could remember where!) that the Wrought Iron Bridge Company supposedly did have another type of "non-tubular" bowstring. Probably the same thing you are speaking of Nathan.