« PreviousContinue »
Northern Pacific Railway Company
Test piles placed March 29 and 30, 1920, between bents 47 and HR and 48 and 49, south side of Pier No. 1, Seattle, Wash. Identification marks on copper plates near top of piles on east side.
Under water inspection
H. F. Brown, by diver, Oct. 8, 1920.
Asst. Engineer Piles E. F. G..... From S. P. Ry., had been in service in Long Wharf, Oakland, Cal., Dock A,
from 1890-1919, 29 years. Removed April 10, 1919. Pile D.
From same company, had been in service in same wharf, Dock E, 1901-1919, 18 years.
Removed April, 1919. Piles A, C. From same company, freshly treated August, 1919, but not previously used.
Boiling process, 14 lbs. per cu. ft. Pile B
From same company, not treated, but peeled and driven in same condition as
received. Pile H
Freshly treated, Pacific Creosoting Company, March, 1919, boiling under
vacuum. 14 lbs. creosote per cu. ft. Pile I.
Freshly treated, Coleman Creosoting Company, March, 1919, steaming process.
16 lbs. creosote per cu. ft. Pile J
From Coleman Company, peeled but not treated, driven same condition. Pile K
From Coleman Co. with bark on, driven same condition.
Object of test to find out if possible how water in Puget Sound at Seattle compares with San Francisco Bay, Oakland, Cal., with reference to activity of marine borers, also if preservative used in long-lived Oakland piling had a more retarding effect on the borers than that generally used at Puget Sound points.
In addition to the above, whole piles, sections from Long Wharf Piles Nos. 1, 3 and 27, Dock A, creosoted in 1890, were sent to the Louisville & Nashville Railroad at Pensacola, Fla., and were there installed by the Forest Products Laboratory in connection with other treated timber samples for the purpose of testing marine borer action.
During the past summer your Committee examined the transplanted piles at several of these points and received reports from the others. To date the untreated piles only show any signs of attack. Both the freshly
creosoted and the old piles are still apparently sound. The next few years should show results one way or the other.
In view of the long resistance of these piles careful studies were made as to the composition of the creosote contained in these piles at the time they were pulled. In the following table the analyses made from a number of these piles are given, divided into the sections taken from the air, water and mud portion of each pile. In addition attention is called to the analysis of an oil sample secured from a hole in the mud section of one of these piles which ran out in liquid form at the time of examination. This oil probably collected in a pocket, and in view of the fact that this section of the pile was protected by the mud the chances for changes during the period of service were very small. In other words, this oil may be regarded as fairly approximating the oil originally used in the treatment of these piles. Further investigations are now in progress with reference to the significance of the findings resulting from the analyses of the extracted oils, upon which it is hoped to give a full report next year.
% Oil in treated part
55 65 25.90
315-355 Tar Acids by volume.
1.9 38.8 17.7
9.4 16.5 15.0
07 48.4 18.3
6.9 13.0 12.2
0 0.7 5.4 23.3 22.5 26.0 21.3
CREOSOTE OIL WHICH RIN FROM CAVITY IN Pile No. 1
Two feet below Mud Line
20.46 315° C..
19.576 Sp. Gr. 38/15.5 of 235-315.
1.045 Sp. Gr. 38/15.5 of 315-355.
1.122 Acids by volume.....
.2.8% In view of the importance of obtaining further data as to the relation between impregnated piles and marine borers, investigations are now in progress, conducted by the San Francisco Bay Marine Piling Committee. A large number of test specimens are being exposed at a central point in San Francisco Bay, consisting of both treated and untreated pieces. Through the courtesy and with the coöperation of the San Francisco Bay Marine Piling Committee your Committee has inaugurated a series of similar exposures, consisting of round pieces of southern pine and Douglas fir impregnated with various special oils prepared for the use of the Committee through the courtesy of the Barrett Company.
In addition to these oils similar poles have been treated, among others with the following processes: Aczol process, Antimony Trichloride (on account of the high toxic character of this sale to lower organisms), a highly toxic wood tar preparation, etc. Full details as to these tests will not be available before the printing of this report, but it is anticipatel that preliminary results with reference thereto will be available for next year's report.
Recent Literature: For those interested the following references are given pertaining to recent literature on this subject :
1. Report on Creosoted Piling Removed from Long Wharf, Oakland, Cal. (Proccedings of American Wood Preservers' Association, 1920,
2. Report on San Francisco Bay Marine Piling Survey. (Proceedings of American Wood Preservers' Association, 1921, pp. 189-339.) Report of the outbreak of marine borers in San Francisco Bay, containing discussion of types of borers found on the Pacific Coast, biological conditions, salinities and temperatures of waters, nature of attacks, protective measures and service records. Illustrated.
3. First report of Committee of the British Institution of Civil Engineers appointed to investigate the Deterioration of Structures of Timber, Metal and Creosote exposed to the action of sea water. (London, 1920, pp. 1-301.) A very complete report dealing with timbers used in various parts of the world for use in marine construction, description of marine borers, protective measures, and detailed reports from engineer, in
British possessions of their experience with marine protection. The report is illustrated with many plates and drawings.
4. Impragnering af Haventommer. A. Collstrop and Edv. Bülow. (Ingenioren, No. 11, 1919, Copenhagen, Denmark.) Inpregnation of Harbor Timbers, report by A. Collstrop and Edv. Bülow. (The Engineer, No. 11, 1919.) A general paper on piling protection with references to recent European and American investigations. The following recommendations are of special interest at this time :
1. “For pilings round timbers should be used exclusively, and other timbers should be of good sound wood without excessive specifications as to heartwood."
2. "Pilings and other timbers exposed to shipworms and marine borers are impregnated with tar oil (full cell treatment 180 kg. or more per cu, meter-11.2 lb. per cu. ft.). Other timbers are treated with tar oil according to Reuping method with absorption of 63 kg. (ultimately 80-90) per cu. meter. If timbers be green at time of impregnation treatment should be made subsequent to previous drying.
3. “In treatment coal tar oil is to be used with specific gravity of 1.04-1.1, preferably 1.075. It must distill as follows:
Up to 150 deg. C., not over 3 per cent
Up to 235 deg. C., not over 25 per cent Proportion of tar acids about 6 to 10 per cent. Light tar oils are absolutely useless.
4. "All timbers are trimmed before treatment and heartwood must not be exposed
5. “In structures impregnated timbers are to be used throughout ; besides, care must be taken in repairs not to place green timbers along with impregnated timbers.”
6. Om Palmaskens och Palkräftans Skadegörelse vid Skandinaviens Kuster. (Teknisk Tidskrift, June 25 and July 9, 1921, 15 figures.)
7. Holzzerstörende Krebse-F. Moll. (Naturwiss. Zeitschrift für Forst- u. Landwirtschaft, 13:178-207, 1915.) A complete description of species of Limnoria, Sphaeroma and Chelura, their structure, life history. distribution, habits and methods to be used to protect timber structures. Has a list of 140 titles of books and articles dating from 1723 to 1915.
8. Undersogelser vedrorende Paeleors og Paelekrebs Angreb ved Skandinaviens Kyster og Anvendte Forebyggelsesmidler. Report dealing with the attacks of Teredo and Limnoria on the coasts of Scandinavia together with description of protective measures used. A digest of information gathered by the section on roads, water and railroads of the Danish Engineering Society in co-operation with the Norwegian and Swedish Engineering Societies. (The report is printed in Ingenioren Nr. 41, 1921.)
This is an important report prepared by the Danish Engineering Society in co-operation with the Swedish and Norwegian Engineering Societies. The report summarizes information obtained as the result of an extensive questionnaire. It includes description of the life history of the Teredo and the Limnoria the influence of temperature and salinity, character of bottom, purity of water, currents, resistance to attack of piles driven at different times of the year, resistance of various kinds of wood, nature of attack, changes in violence of attack, seasonal variations, depth of water in relation to virulence of attack, etc., etc. There is also extensive discussion as to protective measures and it is of particular interest to note the reference to successful protection obtained where iron nails were driven into piles. One of the most interesting parts of the report consists of two maps on which the distribution of Teredo and Limnoria attack is given in great detail, with particular reference to extent or virulence of attack.
The Danish Committee established six grades, as follows:
(1) Where the marine borers have been traced in one or more places but where it cannot be said that the attacks are of much practical import.
(2) Where borers have been found here and there, but where attacks have done actual harm in only a few places.
(3) Where the borers are numerous enough to destroy a pile 25 centimeter (9 inches) in diameter in the course of a period of ten to twenty years so that the same must be replaced.
(4) Where such destruction occurs in the course of five to ten years,
(5) Where such destruction occurs in the course of two to five years.
(6) Where such destruction occurs in the course of one year.
The indications on the maps clearly show where Teredo or Limnoria is responsible.
Destruction of the sixth grade is particularly marked in the waters of Norway and Sweden at the entrance of the North Sea.
FUTURE Work: Realizing the international character of marine borer activities, the National Research Council was appealed to for the purpose of formulating a broad program to coördinate the various investigative activities now being conducted and to stimulate additional research work A preliminary committee has been appointed which has drawn up such an outline. It is hoped that those interested will contribute and coöperate with the Research Council to the end that this plan may represent the broadest possible viewpoint.
Your Committee strongly recommends that the A.R.E.A. continue to actively participate in the prosecution of the research work so necessary for a proper understanding of the habits of marine borers and methods for their control.
RECOMMENDATIONS: The result of examination of service records of piling on all coasts during the past few years leads your Committee to recommend that good creosoting will offer the best protection so far found. By good creosoting the Committee means a treatment conforming to the recommended practices of the A.R.E.A. both as to oil and treatment. We do not believe that there is sufficient knowledge as yet to warrant the use of special oils and that the A.R.E.A. No. I creosote oil should still be regarded as the standard for piling protection.