Irondequoit Bay Seasonal Outlet Bridge

This is a 24-foot-wide, 2-span swing bridge with a 132 1/2-foot main span and a back span of 53 feet. The structure is a galvanized pony truss with all bolted connections and has a 5-foot cantilevered walkway along each side. An open grate steel decking was used to reduce the weight of the bridge.

Hot dip galvanizing was specified because a cost comparison between it and the traditional 3-coat paint system proved that galvanizing was not only competitive in initial cost, but also that galvanizing was superior in long-term costs.

Irondequoit Bay in Up-State New York had a problem to deal with. Summer vacation homes in the Harbor were starting to become full-time housing for those who wanted to live there. In the summer they would ferry across the bay for transportation to work, grocery, etc... in the winter the area on the other side of the Bay was cut off. The idea of building a Bridge they never considered because it would cut off the waterways for barges to come in the US and popular sailing events that brought the tourist during the summer. The Army Corp of Engineers with the help of the Erdman, Anthony Engineering group designed a "rotating" bridge that can swing almost like a large gate. The bridge allowed people to live in these homes in prime areas of the Bay year round, and the swing/rotating bridge could allow the water events to go on, complete with the "Tall Ships" and no obstruction for the Barges to come in from the Seaway. In 1997 there was no idea of Galvanizing such a structures and was thought to be too big. The Army Corp said "no-way" so the Galvanizer contacted Erdman, Anthony. A forward thinking firm who asked, why not? The Galvanizer had a part in the design of the structure, as to be able to fit in local kettles at the time. Some sections were sent to the parent Company in Columbus. In 1998 the Bridge was constructed. Timing was critical; as it had to be constructed in the winter months so as not to interfere with the Spring/Summer water traffic, but being careful not to get into the terrible winter months known in that area. (Another reason Galvanizing was selected). This Bridge we visited this past summer and took measurement readings. We had available to us some of the original readings recorded in 1998. This Bridge is doing exceptionally over water, in one of the most aggressive winter areas of the Country.

Coating Thickness

Desc	Read. 1	Read. 2	Read. 3	Read. 4	Read. 5	Avg.
top of structure north side middle	7.8	7.7	7.9	7.8	7.6	7.76
Underside floor beam south end of the first beam on the east entry	8.2	8.8	9.0	8.5	8.6	8.5
South end first horizontal on west end of bridge entry	9.8	9.7	8.2	8.3	9.2	9.0