129 



r.uNrn<: rii.i-: protkctiox 



This is a pre-cast reinforced concrete c\linfier or slee\e, applied to the wooden 

 pile o\er pre\iously attached reinforcement, in the initial fabrication; or fabricated 

 separately and applied subscciuently to the pile, in place. This is done by shooting 

 cement grout on to the reinforcement fabric with a cement gim. This process has been 

 used in the San Francisco Bay region since 1912, when a number of gunite coated 

 piles were driven in a marine railway in the bay. Since then it has been used here 

 chiefly by the .Shell Company of California. The service life is not yet complete, but 

 they seem to ha\e gi\en excellent satisfaction thus far. The cost of the protection is 

 relati^■ely high. An installation of 1450 of these piles was also made in 1022 at the Port 

 of Tacoma, Washington. 



Fig. 49. (junite concrete piling and plant, Los .\ngeles. 



REINFORCED CONCRETE SUPPORTS 

 Reinforced Concrete Piles 



Reinforced concrete piles have been used both on the Oakland and .San Francisco 

 waterfronts since 1911. Along the latter, more than 11,000 have been used in the 

 construction of five piers as well as numerous wharves, ferry slips and building founda- 

 tions. The first, used in 1911, were for supports for aprons of passenger ferry slips. 

 In 1912 a section of bulkhead wharf adjacent to Pier 17 was constructed with them. 

 Pier 35 constructed in 1914-15 was the first to be built exclusively with reinforced 

 concrete piles. 



Of the numerous installations made during the last se\-eral years no serious defects 

 have been noted in the portion of the piling below high water level. In the older 

 structures, however, cracks due to the rusting of embedded steel have appeared be- 



