The pipe-tire floating breakwater first conceived by V, Harms is a more 

 recent development. This design utilizes rigid steel tubes judiciously 

 interleaved into the tire arrays such that only flexible rubber connections 

 exist between the tire mazes and the steel tubes. 



Engineering tests to obtain wave transmission and mooring force data have 

 been conducted on both the Goodyear^ all -tire modular and the V. Harms^ 

 pipe-tire designs. These tests were conducted in the large wave flume at the 

 former Army Corps of Engineers Coastal Engineering Research Center (CERC) at Ft. 

 Belvoir, Virginia. The first series of tests, conducted in 1977, on the 

 Goodyear modular configuration were a joint effort between CERC and Lake Erie 

 Institute for Marine Science (LEIMS). The LEIMS organization provided the 

 prototype scale breakwater section, the anchoring system and the mooring force 

 measuring equipment, while CERC conducted the tests in their large wave flume 

 using CERC wave measuring instrumentation. Pierce and Lewis^ of the LEIMS 

 organization reported on the general aspects of the test programs, and Giles and 

 Sorenson^ of CERC reported the detailed engineering data. 



In 1979, V. Harms'* tested a prototype scale pipe-tire configuration dubbed 

 PT-1, which features a heavier design with improved front-to-back structural 

 rigidity. It utilizes a truck tire design with a denser packing of tires than 

 the forerunner Goodyear modular units. 



Goodyear type assemblies four modules deep (beam length approx. 28 ft.) and 

 six modules deep (beam length approx. 42 ft.) were tested in 1977. The beam 

 width or depth of the pipe-tire assembly tested in 1979 was 40 ft. The observed 

 differences in the wave attenuation characteristics between the Goodyear type 

 assemblies and the pipe-tire assembly were rather dramatic. The larger draft, 

 the more dense packing of tires, and the increased front-to-back rigidity 

 attributed to the interwoven steel tubes are all factors contributing to the 

 improved attenuation characteristics of the PT-1 design. By contrast, the 

 Goodyear design is much more flexible to upward and downward modal type bending. 

 In addition, considerable lengthwise stretching and compacting occurs with the 

 Goodyear design due principally to tire motion and stretching in the module 

 coupling areas. These structural characteristics tend to permit more 

 accommodation of the wave motion than does a more rigid configuration. 

 Recognizing the need to obtain floating tire breakwater (FTB) performance data 

 in a typical field situation, New York Sea Grant Institute funded the LEIMS 

 organization in 1980 to construct and field test a pipe-tire floating 

 breakwater. A site was selected near the south shore of Presque Isle Bay and a 

 120-ft. length by 40-ft. beam width pipe-tire floating breakwater assembly was 

 installed approximately 360 ft. off-shore (9-ft. water depth) during the summer 

 of 1982. The site was instrumented to obtain wave transmission data during the 

 time the bay is free of ice. 



Fabricated in sections, the breakwater utilized three different design 

 configurations. The first (PT-1) is the original Harms design. The second 

 (PGYM-1) utilizes truck tire mazes fabricated in a Goodyear modular design 

 fastened at each end to the tire-cladded tubes. The fabrication details, 

 installation, and certain field procedures have been reported by Pierce^. This 

 paper summarizes some of the previously reported results while treating in more 

 detail certain aspects of the construction procedures. Observations ranging 

 over an extended period and some field measurement results are also included. 



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