c. Design Criteria . Material and workmanship standards have been 

 assumed as first class to provide the best durability at such an 

 exposed offshore location. Assumed standards include that: (a) concrete 

 was to have a compressive strength of 3,500 pounds per square inch; (b) 

 rock products were as dense and durable as available; (c) holes cast in 

 perforated walls were to have rounded edges at faces formed by using 

 either a precast concrete liner or reusable steel forms; (d) a 0.125-inch 

 steel sheet liner was required in oil storage compartments to protect 

 against leakage through concrete cracks (with the low operating head 

 expected, but further study may indicate that plastic liners are adequate 

 and more economical) ; (e) a 2-foot layer of quarry-run rock over the sand 

 in filled compartments was used to protect against splash and minor wave 

 action within cells; (f) grout for preplaced aggregate contained a mini- 

 mum of cement since it is primarily for mass and stiffness rather than 

 for strength or durability. 



A paved roadway was assumed along the low level deck along the inner 

 side of the breakwater for servicing various mechanical and electrical 

 installations on the oil storage breakwater. The paved roadway was not 

 deemed necessary for the nonstorage type. Mechanical and electrical 

 installations, including aids to navigation, fenders, mooring hardware, 

 and berth dredging, have not been included in the cost estimate. 



d. Cost of Materials and Labor . For all labor performed in areas 

 north of Cape Cod, labor costs would be about 15 percent less than the 

 basic estimate, reflecting lower wage rates and better efficiency. Labor 

 costs in the Delaware Bay area would be about 10 percent lower, and about 

 15 percent lower in the Chesapeake Bay area. The basic estimate can be 

 adjusted accordingly to reflect the lower wage scales in these areas. 



Towing costs per mile per unit remain the same throughout these 

 areas. 



Material cost variations at different sites would nearly balance out. 

 This is because the various rock products make up the largest material 

 requirements, and in cheaper labor areas rock sources are usually distant 

 from the point of use, and vice versa. Hence, lower quarrying costs are 

 offset by higher delivery costs. 



e. Construction Methods . The plan for an initial precasting basin 

 requires an open excavation to about -30 foot elevation along the edge 

 of Long Island Sound at Port Jefferson. The excavated spoil would be 

 used to build up berms around the pit for working areas and to build a 

 closure dike across the side fronting on the Sound. 



The planned size is 1,100 feet by 800 feet of working area at the 

 bottom of the sloping sides to accommodate six of the largest units, with 

 adequate roadways and working space around each unit. A concrete slab 

 is to be provided for each unit as a working surface over which a parting 

 compound or fabric is placed so the units float free when the basin is 



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