PART IV 



SAFE CONSTRUCTION PERIOD 



On-site construction operations can be carried out 

 safely at the five proposed locations only during 



THE PERIOD BETWEEN Ma Y | AND AUGUST |0 OF ANY YEAR. 



The Woods Hole Oce anograph i c Institute has reported 



THAT strong EASTERLY AND NORTHEASTERLY STORM OCCUR 

 AND CAN BE ANTICIPATED DURING THE WINTER AND SPRING 

 MONTHS UP TO ABOUT THE END OF APRIL AND THAT AUGUST 

 10 IS THE EARLIEST DATE RECORDED FOR THE PASSAGE OF 

 HURRICANES OFF THE NeW ENGLAND COAST. DURiNG THE 

 PERIOD FROM Ma Y I TO AUGUST jO, NOT MORE THAN FOUR 

 OR FIVE DAYS OF DEAD CALM WEATHER NORMALLY OCCUR. 

 At all OTHER TIMES THE WAVES VARY FROM A MINIMUM OF 

 APPROXIMATELY k FEET TO A MAXIMUM OF APPROXIMATELY 

 15 FEET. A STUDY OF THE WEATHER RECORDS BETWEEN 



May I AND AUGUST 10, including 1200 observations of 



WIND VELOCITY, SHOW THAT IN ONLY |0 CASES OUT OF 

 1200 WAS THE WIND VELOCITY GREATER THAN 28 MILES 

 PER HOUR AND IN ONLY ONE CASE WAS THE WIND VELOCITY 

 GREATER THAN ^0 MILES PER HOUR. A WIND VELOCITY OF 

 28 MILES PER HOUR COULD PRODUCE WAVES THE HIGHEST 

 OF WHICH WOULD BE APPROXIMATELY I5 FEET. ThE ONE 



case of a wind velocity of over ko miles per hour 

 could have produced a few waves as high as 2^ feet. 

 Thus, over the period of about 15 years study, there were 



10 OCCASIONS when MAXIMUM HEIGHTS OF WAVES COULD HAVE 

 BEEN ABOUT 15 FEET AND ONE CASE WHERE MAXIMUM HEIGHT 

 OF WAVE COULD HAVE BEEN 2^ FEET. UNDER THESE CONDI- 

 TIONS IT IS NOT FEASIBLE TO USE ANY SCHEME WHICH 

 REQUIRES ON-SITE CONSTRUCTION PROCEDURES FROM FLOAT- 

 ING EQUIPMENT. Such equipment can NOT OPERATE SAFELY 

 AND SUCCESSFULLY IN WAVES OVER k FEET IN HEIGHT. 

 For DESIGN OF CONSTRUCTION PROCEDURES NOT USING 

 FLOATING EQUIPMENT, WAVE HEIGHTS OF I5 FEET AND WIND 

 VELOCITY OF '^0 MILES PER HOUR SEEM TO BE SAFE FOR ALL 

 EXCEPT EXTREME AND UNUSUAL CONDITIONS. 



WAVE HEIGHT AND CONDITION AND DESIGN STRESSES 



The POSSIBILITIES of protection OF THE STRUCTURES 

 AGAINST MAXIMUM WAVE FORCES BY CHOICE OF LOCATION 

 HAS BEEN REVIEWED WITH THE WoODS HOLE OC E AN OGR A P H I C 



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