EXPERIENCE WITH A FLOATING TIRE BREAKWATER 

 AT LAKE CHARLEVOIX, MICHIGAN 



Clifford D. Biddick 



BACKGROUND : 



Irish Boat Shop, Inc. operates two boat yards ^ one in Harbor Springs and 

 one in Charlevoix, Michigan, serving primarily pleasure boats to 75 feet* in 

 length. These marinas maintain and perform all types of boat repair and pro- 

 vide storage and dockage to all customers. In 1977, it was decided to expand 

 the 120-slip capacity at Charlevoix, Water depths varied to 26 feet, making 

 bottom resting breakwaters an expensive proposition. Therefore, we began to 

 investigate the Floating Tire Breakwater concept as an alternative to conven- 

 tional wave protection structures. 



Following a field trip to the known Floating Tire Breakwaters on the east 

 coast of the U.S.A., we set about to design and build a complete harbor en- 

 closure, utilizing the available Floating Tire Breakwater information. We 

 selected the Goodyear design of 18 tire modules as developed by Richard Candle 

 (Goodyear Tire and Rubber Co.) and Neil Ross (University of Rhode Island). 

 With this as a start we designed an enclosed harbor for 62 boats adjacent to 

 our existing 120-slip facility. This structure extended 450 feet out into the 

 lake and was 330 feet wide. Our exposure was to the southeast with an 18-mile 

 fetch down a relatively narrow (3+ mile) width. The sea approaching us at 

 worst was about 3 feet from trough to crest, with a 2- to 2.5-second period. 



BREAKWATER DESIGN ; 



The marina has the land forming the west side, a floating car tire break-- 

 water on the southside, with a laid down "F" forming the north and east sides 

 and middle leg. Refer to Figure 1. The "F" was a steel-framed, wood-covered 

 12-foot-wide dock, supported on fully foamed car tires arranged in a Goodyear 

 pattern (2 modules wide) . Outside the top of the "F" was a 3-module row of 

 partially foamed truck tires which formed the major wave reduction breakwater. 

 Refer to Figure 2. The project utilizes 7,500 car tires and 3,500 truck tires. 

 Together they are supported with 10,000 cubic feet of urethane foam. 



CONSTRUCTION : 



The entire project was planned to be, and ultimately was, assembled on 

 12 to 24 inches (thick) ice during the winter of 1978-1979. We utilized a ten 

 man crew and a great deal of equipment including a hydraulic crane, fork lift, 

 front end loader, pickup trucks, welders, generators, pumps to thicken the ice, 

 and many trucks and trailers. The temperature ranged down to 26 below zero 

 (Fahrenheit) and despite the cold, morale of the crew was high. The goal was 

 to have the dock and breakwater intact when the ice melted. Work on the ice 

 began in early January and was finished by late March, 1979. 



After assembly was complete, we cut holes in the ice and had a diver bury 

 120 Danforth style anchors and attach them via 1/2 inch 1x7 galvanized cable to 

 the tire modules. With the dock tentatively anchored, we waited anxiously for it 

 to melt through the ice. As it did so, it tipped drastically, but leveled out 

 after all the ice melted. 



* A table of factors for converting non-SI to SI (metric) units of measurement 

 is presented on page 4. 



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