The time for each session represents the total "in— water" time for two 

 divers. Using multiple regression analysis, the proportion of the total 

 time that can be assigned to each independent variable can be estimated. 

 Any unaccounted time will be reflected in the analysis as a constant number. 

 This number may be interpreted as the sura of time assigned to other "events' 

 that occurred during the inspection. Tables 7a and 7b tabulate the results 

 of the regression analysis. 



Table 7a. Multiple Regression Analysis (Output) — Mean Values 



Variable 



Mean 

 Value 



No. of bents 

 No. of piles by Level I 

 No. of piles by Level II 

 Diving time, min 



18.67 

 165.17 



80.00 

 132.00 



Table 7a gives the mean values for the activities performed during 

 the diving sessions. Included are the number of bents inspected, piles 

 inspected via Level I, piles inspected via Level II, and the average 

 "in-water" time for each diving session. 



Table 7b. Multiple Regression Analysis (Output) — 

 Time to Perform Each Activity 



Variable 



Minutes 



Seconds 



Transit time for bents 

 Level I inspection 

 Level II inspection 

 Overhead time 



1.08 

 0.30 

 0.67 

 8.08 



65 



18 



40 



485 



Note: Multiple Correlation Coefficient of 0.95. This 

 indicates that there is a strong correlation 

 among the variables. 



Table 7b estimates the time required to perform each particular 

 activity. The time to move from bent to bent was 1.08 minutes. Since 

 the selection of pilings was via a random process, the divers traversed 

 various bent increments and were not necessarily moving to adjacent bents 

 The average inspection time for a Level I inspection, including both 

 Level I and modified Level I, was 0.3 minute. The average inspection 

 time for a Level II inspection was 0.67 minute or about 2-1/4 times a 

 Level I inspection. Other activities account for 8.08 minutes for each 

 diving session. 



35 



