12 



SUMMARY OF WORK ACCOMPLISHED 



Subsequently the Committee has completed a biological study of the marine 

 borers represented in this Bay, which has materially contributed toward bridging the 

 gap previously existing in knowledge of the shipworms between the larval and adult 

 stages, and is believed to be the most complete study of these organisms and of their 

 physical environment as here surrounding them, thus far made. The Committee has 

 compiled service records covering not less than 90 per cent of the approximately 

 250,000 piles in San Francisco Bay and tributary waters and whose completeness has 

 added much to the assurance with which the life of various piles or piling protections 

 can be estimated. Specifications for creosote and creosoting practice have been 

 presented by the Committee, whose observance it believes will contribute to the 

 production of the most satisfactory treated material for use in marine structures. 

 Through the Sub-Committee on Chemical Research a number of problems have been 

 solved, or their solution materially contributed to, such for example as that respecting 

 the supposed selective filtering action of wood upon creosote injected into it, and the 

 character and probable significance of the progressive decrease in lighter fractions 

 and increase in those of higher boiling point which takes place in the composition of 

 injected creosote during subsequent exposure. The work of this Sub-Committee has 

 also demonstrated the effectiveness, or otherwise, of certain chemical methods of 

 piling protection employing means other than the ones customary in the injection of 

 the preservatives into the wood or their application to its surface. Such, for example, 

 is the so-called electrolytic chlorine process. Through mutual cooperation of the 

 Sub-Committees on Protections, Biology and Chemical Research the extensive ex- 

 posure tests of the Committee have yielded a material amount of knowledge respecting 

 the comparative value of a large number of proprietary preservatives and processes 

 of piling protection, in respect to which the user of piling products has hitherto had 

 available little or no authentic information. The Committee has also been able to 

 make valuable suggestions for improved construction practice in the erection and 

 maintenance of creosoted wharves and other marine structures, which are being in- 

 creasingly observed in the San Francisco Bay region, due largely to the Committee's 

 educational efforts. This observance has already reduced greatly the needless damage 

 inflicted upon such structures in that area and bids fair to increase the life of those 

 structures measurably towards the maximum of nearly double the past average, 

 whose possible attainment has been demonstrated by such installations as the now 

 famous Southern Pacific "Long Wharf." In respect to concrete construction, which 

 has a definite and probably an increasing place in marine structures, standards have 

 been worked out by the Committee which are believed to meet the specific and ex- 

 acting requirements of this field — which seems elsewhere to have received inadequate 

 attention, being dismissed in the monumental "Joint Committee Report" on reinforced 

 concrete, for example, with a single page of discussion. 



