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Port of Oswego Floating Precast Concrete Docks

April 13, 2011

Floating Precast Concrete Dock 1

In his eerie 1970's ballad of the Edmund Fitzgerald, Gordon Lightfoot wrote about the fury of the Great Lakes. Oswego, NY is no stranger to the weather systems that sweep across the great expanse of Lake Ontario. Located on the eastern most end of the Lake, it bears the brunt of the storms that are pushed across by the prevailing winds unabated for 193 miles.

Such was the challenge when in 2009 the Port of Oswego Authority decided to build 630 ft. of dockage extending out into Lake Ontario. The structure would have to serve, not only as a boat dock, but also as a breakwater to help protect the inner harbor. In their search for a solution they turned to a company which specializes in waterfront solutions. Marinetek is an Inter-national company based in Helsinki, Finland. It currently operates in 40 countries around the world and is the largest marina builder in Europe. Their expertise seemed to be what was needed to provide a functional, durable and attractive product that was also cost effective.

Floating Precast Concrete Dock 2

The solution was a precast concrete floating dock system. Marinetek had been building these for years in Finland where they experience many of the same weather conditions as seen in Oswego, NY. The dock would consist of 10 precast pieces. Eight pieces would be 65 1/2 ft. long, 11 ft. 9 in. wide and 4 ft. 3 in. tall weighing in at 103,588 lbs. each. The remaining two pieces would be 521/2 ft. long, 11 ft. 9 in. wide and 4 ft. 3 in. tall weighing 81,548 lbs. each. These pieces would all bolt together to form one continuous L-shaped dock. They would be anchored to concrete blocks strategically placed on the lake bottom providing excellent stability to the structure.

Floating Precast Concrete Dock 3

Marinetek had the expertise but did not have a manufacturing facility in close enough proximity to the project. Their search for a local pre- caster with experience and the equipment necessary to handle the heavy weights led them to Jefferson Concrete Corporation of Watertown, NY. In April of 2010, Marinetek shipped a mold from West Palm Beach, Florida to Watertown, NY and also provided training for the Jefferson Concrete Production Team led by Jim Motes. Doug Dickerson would also play a vital role as QC Manager for Jefferson concrete, developing an acceptable mix design and doing the final finish on each piece. Marinetek insisted that every dock they put their name on needed to look the same no matter where it was built. Achieving a consistent finish was one of the most formidable problems the crew had to deal with. These dock sections were being built outdoors and the weather ranged from a wet 40 degree day to a dry and windy 80 degree day and everything in-between.

Accuracy was very important and tolerances were tight. In order for these pieces to float level, everything had to be exactly where it was supposed to be. If the large Styrofoam voids, which were shipped from Florida, were off 1/4 inch, the piece would list to one side. The exposed Styrofoam had to be coated to keep marine organisms from burrowing into it. Every piece of metal that went into the mold had to be galvanized.

The handling requirements of the dock pieces were also very demanding.

Floating Precast Concrete Dock 4

The cables used to lift the pieces couldn't deviate more than 3 degrees from vertical. There were also only 2 acceptable blocking areas that could be used for storage or shipping. With so few places to support these large pieces, shipping and storing them without damage became a real concern. Marinetek brought in experts - JPW Erectors out of Syracuse. They modified one of their trailers to conform to the support requirements of these docks. Loading and shipping went flawlessly and all pieces were delivered in excellent condition.

The success or failure of the project would be determined when the 10 dock pieces were set in the water. They would have to float level and have a minimum 21 inches floating out of the water. A resounding success - every piece was level and floated 22 inches out of the water. One who takes a stroll on these docks would not believe they are floating. They are stable platforms, very neat and attractive, expandable and low maintenance.

Floating Precast Concrete Dock 5