7. Estimated Scrap-Tire Floating Breakwater Cost . 



The total cost of a scrap-tire floating breakwater will depend to a large 

 degree on the labor cost of accumulating and assembling the tires onsite, and 

 on the types of binding and flotation materials used. With an estimated 

 existing stockpile of more than 2 billion scrap tires in the United States, 

 large quantities are available free-of-charge at most metropolitan regions. 

 However, labor involved with transporting the tires to the project location 

 can become significant. Giles and Sorensen (1978) estimated that flotation 

 and tieline typically account for one-third of the breakwater cost, with 

 labor and the anchoring system accounting for the remaining cost. Candle and 

 Fischer (1976) estimated the cost of a 26-foot-wide breakwater to be about $27 

 per linear foot, and of a 105-foot-wide breakwater to be about $98 per linear 

 foot (based on the Goodyear concept). The City of Ounkird, New York, con- 

 structed a 28-foot-wide section in 1976 at a cost of $17 per linear foot (Fig. 

 99); at about the same time, the Dock and Coal Marina at Plattsburg, New York, 

 was constructed with scrap-tire units 28 feet wide at a cost of about $28 per 

 linear foot (DeYoung, 1978). For the Goodyear concept in 1976, the estimated 

 cost of a scrap-tire floating breakwater was about $1 per square foot of 

 breakwater area. 



Because the Wave-Maze is considerably more dense than the Goodyear con- 

 cept, Noble (1976) estimated a one-tier assembly to cost about $4 per square 

 foot of surface area. A royalty for the use of this patent adds about 10 

 percent to the construction cost. Historically, the Goodyear Tire and Rubber 

 Company scrap-tire floating breakwater concept has been used primarily on the 

 Great Lakes and the Atlantic coastal areas, while the Wave-Maze has been con- 

 structed on Pacific waters suitable for its installation. An example of the 

 Wave-Maze in operation is the siting in San Francisco Bay where two sections 

 of the structure protect the expanded Pier 39 marinas and berthing complex 

 (Fig. 100). A fixed-timber breakwater approximately 1,190 feet long was 

 erected on the we^t side of the pier, and the two sections of a scrap-tire 

 floating breakwater with a combined length of 1,815 feet, are permanently 

 anchored with a combination concrete-block and steel anchoring system. 



Since the Wave-Guard concept of scrap-tire floating breakwater has been 

 laboratory tested only, a direct comparison of prototype cost with other con- 

 cepts is not possible. However, to obtain an indication of variations in the 

 construction costs of the three dominant concepts, Harms (1979a) performed 

 calculations based on "equal wave protection," since the wave attenuation 

 performance of the three types of breakwaters are quite different, even for 

 the same beam width. The cost of each structure was evaluated only after 

 having been "sized" to provide the same degree of wave protection. The 

 cost of the mooring system was not included because it is inherently site- 

 dependent, and probably does not vary greatly in cost from one type of 

 breakwater to another. Harms (1979a) determined that the Wave-Guard con- 

 struction costs are slightly less than the Goodyear Tire and Rubber Company 

 concept, but at the same time it is significantly smaller for the same degree 

 of protection. Although the Wave-Maze scrap-tire floating breakwater concept 

 was found to be far more costly than either the Goodyear concept or the Wave- 

 Guard, it perhaps has a longer useful life and greater extreme event survival 

 capability. 



147 



