Creosote Treatment of Douglas Fir Ties Your Sub-Committee recommends that this subject be given further consideration and report made on this treatment next year. The development of the creosote treatment for Douglas Fir ties goes hand in hand with the development of the perforating process and while ties perforated as above described fit in well with the zinc chloride treatment, yet it is our opinion that Douglas Fir offers greater resistance to the penetration of creosote than it does to the zinc chloride solution, and for this reason it is quite probable that a closer spacing of the perforations will be desirable for creosote treatment, and when such spacing of perforations is once decided upon the details of the creosote treatment can be arranged accordingly. PACIFIC COAST MARINE PILING W. H. KIRKBRIDE, Chairman; A. GIBSON, J. F. PINSON, Sub-Committee Introduction: The following report is the first to be submitted by the above SubCommittee, and has been arranged as an introduction to the work coming within its scope dealing with the preservation and development of marine substructures. The extensive timber lands of this Coast offer an almost unlimited supply of material for such structures, but the destructive work of marine boring pests has reached such proportions that effective preservation must be secured, or the value of this timber be greatly reduced for such purposes. It is generally believed that the Pacific Coast has suffered the severest marine borer attack of any part of the United States seaboard, and it is evident therefore that the greatest effort to resist them must be made in this locality. The existence of these pests on this Coast has been known since the beginning of marine construction, and their action has been under the observation of individual investigators for about 30 years. But heretofore no thoroughly organized, scientific effort has been made to study their separate characteristics and boring proclivities, with the idea of both resisting and exterminating them, if possible. This must not be construed as depreciating the splendid work of these past investigators, who, among innumerable protective agencies, evolved the creosoting process, which remains today the most effective timber pile preservative. The Sub-Committee simply desires to make it clear that for some time to come its work must be confined for the most part to investigation and to the correlation of existing data, and that definite recommendations in regard to preservatives or construction materials cannot be made until after the results have been carefully analyzed. Pacific Coast Marine Borers: HISTORICAL The presence of marine borers in several Pacific Coast harbors has been known for half a century. But, on the other hand, certain other harbors have been free of them until recently. The increase in their destructive activity has taken place simultaneously with the increase of shipping at each harbor, indicating that to a certain degree they have been brought in by the ships from their original breeding places and have then established themselves in the new locations. The agencies of this transplanting process may have been the hulls of wooden ships, salt water tanks of all ships, log booms, and driftwood. As an evidence of the possibility of such transportation, the engineers of a California sugar refinery discovered that teredo were destroying a redwood salt water tank located on the ninth floor of the refinery. The larvae had been pumped in through the salt water pipes and, having fastened themselves to the side walls, soon began to bore into the wood. It is natural, therefore, that with proper conditions for their propagation, such as seems to exist on the Pacific Coast, the larger ports of Puget Sound and San Francisco Bay were the first to become seriously infested, and were the first places where protective efforts were made. By 1880 untreated piling had proven itself impractical in certain localities, and creosoting and numerous forms of surface covering were adopted. At the same time new pile material, other than wood, began to be introduced with varying success. Creosote was selected in the majority of cases, because of its comparative cheapness, and because it had already demonstrated its superiority over the majority of other preservatives. In this class were innumerable ones which had been tried and discarded in Europe and elsewhere. The absence of creosoting plants, which involved a considerable investment and had previously been considered unnecessary, led to much imperfect treatment, the majority of preservatives being applied on the surface by hand. It was soon demonstrated that this method only caused a thin outer shell to become impregnated, and that the slightest flaw in this armor opened the way for a complete invasion by the marine borers. The next step was the establishment of creosoting plants by private firms, wherein the treatment could be carried out more thoroughly by placing the piles in sealed retorts and injecting the oil. These privately owned plants now handle all the Pacific Coast business (with the exception of that of one railroad, which operates its own plants) and are located for the most part in the northwest territory around Seattle. In 1889 the Southern Pacific Company completed a temporary creosoting plant at San Pedro, where piles were to be treated for a projected wharf in the vicinity. All material used was Douglas Fir, and had been thoroughly air-seasoned by being laid out along the beach for about a year. It was then treated by the "Bethel" process, in which the average injection of oil was 14.17 lbs. per cubic foot. Some of the piles were shipped by rail to Oakland, where they were driven in 1890 in the Old Long Wharf. The balance were used in the Santa Monica Wharf, which was completed about 1891. Both of these structures have been removed within the last few years, the former in 1919 and the latter in 1915; but a majority of the original piles were found to be perfectly sound and having been redriven elsewhere are still in service after having successfully withstood the attack of marine borers for 30 years. These are not the only cases where creosoting of piles has achieved marked results. The Southern Pacific Company built a permanent creosoting plant at Oakland, which began to operate about 1891. Piles from this plant were driven in various docks on the east side of San Francisco Bay, including docks of Old Long Wharf, and three other structures, the last of which was completed in 1904. The majority of these piles are still in service, after having been in service from 17 to 30 years. |