Table 1. Galvanic Compatibility of Fasteners in Seawater 



Base Metal 



Aluminum* 



Carbon Steel 



Silicon Bronz 



Nickel 



Nickel-Chromium 

 Alloys 



Type 304 



SS 



Nickel-Copper 

 Alloy 400 



Type 316 



SS 



Aluminum 



Neutral 



C 



Unsatisfactory t 



ct 



C 



c 



Ct 



c 



Steel and 

 Cast Iron 



NC 



Neutral 



C 



c 



C 



c 



c 



c 



Austenitic 

 Nickel Cast 

 Iron 



NC 



NC 



C 



c 



c 



c 



c 



c 



Copper 



NC 



NC 



C 



c 



c 



c 



c 



c 



70/30 



Copper-Nickel 



Alloy 



NC 



NC 



NC 



c 



c 



c 



c 



c 



Nickel 



NC 



NC 



NC 



Neutral 



c$ 



ct 



c 



c 



Type 304 



NC 



NC 



NC 



NC 



May Vary § 



Neutral $ 



c 



c 



Nickel-Copper 

 Alloy 400 



NC 



NC 



NC 



NC 



May Vary § 



May Vary § 



Neutral 



May Vary § 



Type 316 



NC 



NC 



NC 



NC 



May Vary § 



May Vary § May Vary § 



Neutral § 



* Anodizing would change ratings as fastener. 



t Fasteners are compatible and protected but may lead to enlargement of bolthole in aluminum plate. 



% Cathodic protection afforded fastener by the base metal may not be enough to prevent crevice corrosion 



of fastener particularly under head of bolt fasteners. 

 § May suffer crevice corrosion under head of bolt fasteners. 

 NOTE: C = compatible. Protected. NC = Not Compatible, Preferentially Corroded. 



The concrete section may either be of unreinforced gravity construction, or a reinforced 

 section. Where construction in the dry is possible, the reinforced concrete L-wall is usually 

 the most economical for exposed faces not exceeding 15 feet in height (Fig. 51). For greater 

 exposures, counterforted walls or cellular construction may be more economical. Design 

 details for monolithic wall sections are too complex for inclusion in a manual of this scope. 

 The design effort falls into two general categories: analysis of the external forces and 

 structural design of the section to resist these forces. A treatise on external forces is 

 available in Bowles (1968), and Navy Bureau of Yards and Docks (current DM-7). Bowles 

 (1968) presents enough design data and examples of internal design to cover most sections 

 used in marinas. 



Where the wall site cannot be conveniently unwatered, concrete sheet piling is usually 

 the simplest alternative, but tiebacks are usually required. The most difficult part of 

 concrete sheet-pile construction is the achievement of sand tightness in the joints. Joints are 

 usually of the tongue-and-groove type that are not provided with interlocks for horizontal 

 tensile strength. A common method of achieving the necessary joint tightness is the casting 



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