Along inner row of anchors: -15 feet MLLW 



Along breakwater: -30 feet 



Along outer row of anchors: -45 to -55 feet 



A wave monitoring program was in operation during the winter season of 

 1973-74. However, maximum windspeeds recorded were only about 30 knots, which 

 is not representative of the usual winter season when, according to local res- 

 idents, waves 4 feet and higher occur. Boat wake is not a problem. 



The harbor is without power or other amenities. There is no harbormaster 

 nor designated official on the site. The operation is best described as "Alas- 

 kan informal." Long-time local residents are a good source of information on 

 the harbor . 



c. Breakwater Description. 



(1) Design. This structure was the first of the Alaska-catamaran or 

 ladder type, consisting of 3- by 5- by 15-foot reinforced, lightweight con- 

 crete pontoons with solid polystyrene foam core. Units of 15 feet were post- 

 tensioned with 1-1/2-inch galvanized bars to form the ladder module, 5 feet 

 deep, 21 feet wide, and 60 feet long, with a draft of about 3.5 feet. Five 

 modules were coupled with chain links and compression bumpers to form a shal- 

 low V-shaped breakwater 308 feet long, as shown in Figure 11. The V-joint was 

 a weak link in the system, and was removed in 1977. The alinement was then 

 straightened (see Fig. 12, a) with module connectors of a modified design shown 

 in Figure 13, and an additional 60-foot section of breakwater added to help 

 close off a wave window from the southeast. 



Anchor chains of 1-3/8-inch stud links at each of the five 60-foot modules 

 are attached on the harborside to 26-ton concrete anchors and to two 26-ton 

 anchors on the seaward side. A shallow soil layer over rock ruled out the use 

 of stake piles at the site. 



(2) Installation . The breakwater was installed in the fall of 1972 

 at a cost of $425 per foot. It had been designed for field assembly where 

 facilities and equipment size were limited. The pontoons and other components 

 were barged to the site. 



Assembly problems were caused primarily by nonsquare faces on surfaces 

 that were to be matched. Some spalling of concrete occurred during the devel- 

 opment of the specified posttensioned forces and was attributed to improper 

 location of reinforcing steel during fabrication. Dimensions for the connec- 

 ting modules must be accurate to avoid assembly delays. Those responsible for 

 the breakwater design, construction, and operation are as follows: 



Designer-Owner-Operator: State of Alaska 



Division of Ports and Harbors 

 Division of Harbor Design and 



Construction 

 Juneau 



Design Engineer: D.S. Miller 



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