13 



During the years 1888 to 1890 untreated wooden piling began to 

 be replaced by creosoted piling. This statement does not consider as 

 creosoted piling that treated in San Francisco as early as 1869, by the 

 Robins process of subjecting the wood, in a closed tank, to vapors of 

 creosote. The possibilities of the early creosoted piling at its best were 

 demonstrated by the Oakland Long Wharf piling, reported on at the 

 1920 convention of this Association, some of which lasted up to 29 

 years. But that few then realized how the service of potentially ex- 

 cellent creosoted piles could be cut in half, or even more nearly anni- 

 hilated, by puncturing the creosoted zone with dogs, pikes, axes, and 

 bolt holes is not hard to understand when it is still impossible to pre- 

 vent the piles from being thus abused. The percentage of creosoted 

 piling failures shown by the Harbor Commission report to be due to 

 dogging, it is believed will astonish even many who thought they 

 knew. So a great deal of creosoted piling failed prematurely, and was 

 blamed accordingly, in the decade of the nineties. During that de- 

 cade, also (or, like creosote, at the last end of the eighties), appeared 

 the first crop of the superficial bituminous coating methods. 



The second big wave of anxiety about piling protection appeared in 

 the years from 1898 to 1900, although the introduction of concrete cas- 

 ings placed in steel cylinders had preceded this period by a couple of 

 years. During this time the first form of the Holmes' concrete encas- 

 ing cylinder with a wooden form was produced. This first form, as it 

 was not made clear in last year's report, was the large cylinder enclos- 

 ing a cluster of wooden piles. Unfortunately, this less perfect form of 

 the Holmes' pile was for a number of years believed by many engin- 

 eers of this region to be the one final answer to the problem. 



In the decade beginning in 1908 attention continued to be focussed 

 strongly on the possibilities of concrete. The more efficient single-pile 

 form of the Holmes' cylinder appeared in that year, as did also .the 

 Black's Patent method, which was the forerunner of several forms now 

 used for pouring a concrete jacket around a wooden pile in place, sec- 

 tion by section, without contact with the water till after it is poured; 

 in the same year also appeared the Koetitz precast concrete cylinder 

 protection for wooden piles, which is shown by the service record to 

 have been so remarkably effective; and at about the same time was 

 introduced the concrete cylinder constructed in place inside a caisson, 

 and the modern precast reinforced concrete pile. In addition to the 

 concrete activity, this decade witnessed renewed and greatly extended 

 use of creosote, as well as a new crop of the superficial coating, or paint 

 and batten, methods. 



The period since 1918, which has witnessed the disastrous appear- 

 ance of Teredo activity in San Francisco Bay, has brought renewed 

 development of protective and construction processes, which include 

 representatives of practically every class of process brought forward in 

 previous years. It seems often as if little has been learned, or taken 



