Type II Ventura Marina, California. .. .Figure 6-51 



Type III Fire Island Inlet, Nei^r York. . .Figure 6-52 



Type III Oceanside Harbor, California. .Figure 6-53 



Type IV Ponce de Leon, Florida Figure 6-54 



Type IV East Pass, Florida Figure 6-55 



6.53 LAND-BASED VEHICLES 



A bypassing operation at Shark River Inlet, New Jersey {Angas, I960) 

 used land-based vehicles. The project consisted of removing 250,000 cubic 

 yards of sand from an area 225 feet south of the south jetty and placing 

 this material along 2,500 feet of beach on the north side of the inlet. 

 (See Figures 6-56 and 6-57.) On the south side of the inlet a trestle 

 was built in the borrow area to a point beyond the low water line allow- 

 ing trucks access from the highway to a crane with a 2 1/2-yard bucket. 

 (See Figure 6-57.) Three shorter trestles were built north of the inlet 

 from which the sand was diraiped on the beach allowing wave action to 

 distribute it to downdrift beaches. 



6.6 GROINS 



6.61 TYPES 



As described in Section 5.6, groins are classified principally as to 

 permeability, height and length. Groins built of common construction 

 materials can be made permeable or impermeable, and high or low in profile. 

 The materials used are stone, concrete, timber, and steel. Asphalt and 

 sand-filled nylon bags have also been used to a limited extent. Various 

 structural types of groins built with different construction materials are 

 illustrated in Figures 6-58 through 6-63. 



6.611 Timber Groins . A common type of timber groin is an impermeable 

 structure composed of sheet piles supported by wales and round piles. 

 Some permeable timber groins have been built, by leaving spaces between 

 the sheeting. A typical timber groin is shown in Figure 6-58. The round 

 timber piles forming the primary structural support should be at least 12 

 inches in diameter at the butt. Stringers or wales, bolted to the piling, 

 should be at least 8 by 10 inches, preferably cut and drilled before being 

 pressure treated with creosote. The sheet piles are usually either of the 

 Wakefield, tongue and groove, or ship-lap type, supported in a vertical 

 position between the wales and secured to the wales with nails. All 

 timbers and piles used for marine construction should be given the maximum 

 recommended pressure treatment of creosote or creosote and coal-tar 

 solution. 



6.612 Steel Groins . A typical design for a timber-steel sheet-pile groin 

 is shown in Figure 6-59. Steel sheet-pile groins have been constructed 

 with straight web, arch web, or Z piles. Some have been made permeable 

 by cutting openings in the piles. The interlock type of joint of steel 

 sheet-piles provides a sandtight connection. The selection of the type 



6-76 



