they can become a hazard to navigation, a danger to recreationalists, and 

 very unsightly from an esthetic point of view. 



(2) Salvaged Barges . Barges may be of wood, steel or concrete. 

 They are usually smaller than ships, more rectangular in dimension, and 

 easier to place into position. They are usually flat bottomed and have a 

 tendency to slide out of position under the force of storm waves. If 

 positioned on sand, they are also subject to severe scouring action and may 

 tilt or slide out of position. Like ships, they are usually many years old 

 and seriously deteriorated before being salvaged. Wooden barges are the 

 least desirable. They lack the deadweight of steel or concrete and once 

 they start to disintegrate, the process is more rapid. Also, if filled 

 with sand or gravel for stability they may even attain partial buoyancy as 

 the waves remove this material. 



Concrete barges are unsightly and dangerous due to the mass of rein- 

 forcing bars exposed as they deteriorate and break up. Steel barges, like 

 ships, have relatively thin hull plates and through corrosion or wave 

 forces deteriorate very rapidly, especially in seawater. 



(3) Breakwaters and Jetties . Neither salvaged ships or barges are 

 recommended for breakwater or jetty construction. Wave action is generally 

 too severe and, in the case of breakwaters, the waves strike broadside, 



the most unstable position. Even for temporary or emergency protection, 

 salvaged ships and barges are not recommended due to the difficulty of 

 removal . 



(4) Groins . There has been some limited success with the use of 

 several barges in tandem. They must be securely fastened to each other and 

 well seated on the bottom. Even so, because of deterioration, provisions 

 must be made to either remove them or cover them with rock at a later date. 



(5) Revetment . Salvaged ships or barges are not recommended for 

 revetment. They are rigid structures and in an area of breaking waves will 

 generate so much scouring action that more erosion may result than without 

 these structues. 



c. Salvaged Railroad Cars, Automobile Bodies, Refrigerators, and Others . 

 These are used mostly for bank or shore protection in nonrecreational 

 areas. They are all unsightly and, while made of metal, generally do not - 

 have much weight compared to total dimensions and are easily moved by waves 

 or currents. Because of their rigidity and numerous flat surfaces they can 

 cause accelerated scouring and may even accelerate the erosion process. 

 Like other metals they are normally corroded before salvage and, if in 

 seawater, the corrosion process is accelerated. Railroad cars and automobile 

 bodies, in particular, will disintegrate within a few years. Their use is 

 not recommended except in a nonrecreational area and only then as an emergency 

 temporary measure, to be removed as soon as a long-term protective system 

 can be implemented. 



6. Rubber Tires . 



a. General . About 2 million rubber tires, too worn for further use on 

 trucks and automobiles, and not capable of being recapped or retreaded, are 



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