450 THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1953 



southern pine poles — like those in the cited lines — made them unac- 

 ceptable either as replacements for chestnut or for new construction 

 in large sections of the northern and central telephone plant areas, and 

 for basic reasons of economy, new specifications for creosoted southern 

 pine poles were being issued. In preparing these specifications the Lab- 

 oratories reduced the retention requirements to 8 pounds of creosote per 

 cubic foot and provided for treatment by an empty cell process with a 

 view to providing a clean pole, and set definite quality limits on penetra- 

 tion to insure an economic service life. These moves were made after 

 careful experiment, and after analysis of 8-pound treatment results. The 

 experience in the pole test lines had an indirect effect rather than a 

 determining effect on the proposed new penetration requirements. 



The Laboratories by 1932 had been operating the Gulf port test plot 

 for 7 years and the Chester test plot for 3 years. Research and develop- 

 ment programs on laboratory and test plot evaluation procedures ' 

 ^^^ were well under way. The aim of this broad program was to determine 

 the necessary requirements for preservatives, for retention, for treatment 

 and for penetration before the poles were placed in line; which is quite 

 different from the philosophy of depending on service tests or records to 

 reveal at some later date what was done wrong in the first place. 



The reader should not get the idea that service tests can be dispensed 

 with entirely. Material in service in the telephone plant is always under 

 observation, casual or intensive, and the development of any obvious 

 faults is corrected by the application of results of more and perhaps 

 better laboratory experiments. In very many cases the faults are dis- 

 covered in the laboratory or test plot before they are found in the field. 

 However, one can never brush aside the insistent and determining effect 

 of long and satisfactory field experience with treated wood. 



For example, when the behavior of creosoted poles in line is good the 

 service tests take on what seems to be the outstanding characteristic of 

 their present function, namely that of a comforting confirmation of 

 previous conclusions. The results of some of the Laboratories' analyses of 

 the relation between penetration and decay in creosoted poles were pub- 

 lished in July, 1936, in this Journal^^ and again in 1939.^ These results 

 confirmed the previous actions involved in specifying an empty cell treat- 

 ment and a retention of 8 pounds of creosote per cubic foot. The poles 

 were clean, they were being accepted generally for line construction, and 

 the incidence of infection and probable early failure seemed to be about 

 in line with anticipation. 



Emphasis in the last two papers cited was on penetration, which is 

 easily determined, relatively speaking, and not on retention. The relation 



