Widths of headwalks and finger piers vary from one region to another, although cities, 

 counties and other local agencies have begun to set minimum limits. The average headwalk 

 width is about 8 feet, with a range of about 5 to 16 feet. The wider headwalks usually have 

 some width for bearing-pile risers, locker boxes, firefighting equipment, and utihty lines 

 (Fig. 66). The narrower piers often have all obstructions moved to knees at the junctions of 

 finger piers. Extra-wide headwalks are usually in fixed-pier installations because of the 

 higher cost of floating construction. Long, fixed headwalks can also serve as roadways for 

 service vehicles. 



Boarding fingers for single-boat slips are usually about 3 feet wide, normally the 

 minimum allowed for floating construction because of the instability of narrower floats. For 

 this reason, floating fingers longer than 35 feet are usually 4 feet wide. In double-boat slip 

 construction, a finger width of 4 feet is common for all slip lengths. A compromise system 

 of alternating full width and narrow fingers (about 12 inches) is used in some areas. An 

 interesting use of short cantilevered fingers supported only by headwalk piles, and used for 

 boarding (not mooring ties), is shown in Figure 67. A reverse variation of the cantilevered 

 finger is the above-deck-level finger, with its outboard end supported on a pile and the 

 inboard end resting on the headwalk (Fig. 68). A hanging ladder system used for boarding 

 from high level fixed fingers is shown in Figure 69. 



e. Fixed-Pier Structures. Structural design criteria for fixed-timber headwalks and 

 fingers are presented in Chaney (1961). All timber used for construction should be treated 

 to avoid damage by dry rot and living organisms. Both Chaney and the American Society of 

 Civil Engineers (1969) present data on timber treatment. The American Wood Preserver's 

 Association (1971), Standard C-1, describes the treatment processes, materials used, and 

 results of preservative treatment for wood products by various preservatives applied by the 

 pressure process. AWPA Standard C-18 extends the coverage of Standard C-1 to include the 

 specific requirements for pressure-treated piles and timbers used in marine construction. 

 These standards are updated periodically to include the latest techniques and materials; 

 hence, only the current editions should be used. Because of possible failure due to 

 undetected weakness in the wood, all deck planking should be of nominal 2-inch thickness 

 and not less than 6 inches in width. Galvanized nails and hardware should be used. Deck 

 nailing should penetrate the supporting timbers at least 3 inches so the nails will not pull up 

 under repeated flexure caused by passing traffic. Creosoted piles that project above deck 

 level should be protected with battens (Fig. 70) or some protective sheathing. 



Metal framework berthing structures are generally too costly to fabricate commercially 

 available basic components, but several systems have been developed that use factory -built 

 components for easy field installation. Most are of tubular and pressed-steel construction 

 with either stamped metal or timber plank decks. Bottom conditions in the berthing basin 

 must be checked to determine if the anticipated loading will cause settlement or if the 

 depths in the basin are too great for the system. Most prefabricated systems are for small 

 individual docks along a lakefront or riverbank and are not normally suitable for large 

 installations. 



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