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piles. These piles were 10 to 30 feet long, 12 inches outside diameter and the metal 

 was 1 inch thick. They were all filled with concrete after driving. The longer piles 

 were dri\'en into the mud and the shorter piles were set on concrete bases. Between 

 that time and 1906 a total of about 1250 cast iron or wrought iron piles were placed 

 in government structures, and practically all of them are still in service. Some of the 

 piles have been broken off by the shock of vessels or other causes, at the point where 

 the braces are fastened. These were repaired by placing an iron collar around them at 

 the break. When placed, the cost of the piles was about SI. 50 per lineal foot. No 

 information is available as to their present cost, but it would probably be around 

 $3.00 per lineal foot. In the Service Records (Chapter IX) the available information 

 concerning the character, location and service given by these piles is presented. It will 

 be noted that some of them have been in service for 55 years, which is a remarkable 

 record. 



The chief advantage possessed by these piles seems to be their great durability. 

 Below water they are reported to be practically as good as new. Above low water 

 they have rusted to some extent, in spite of attempts to protect them with paint, but 

 the>- are still serviceable. The iron bracing has rusted more rapidly and on some of 

 the docks has been renewed several times. Among their disadvantages are: (1) high 

 cost; (2) the need for driving them with extreme care in order that the fittings and 

 bolt holes for the bracing may come right; (3) their tendency to break at bracing points; 

 (4) the relatively short lengths which can be used. 



