(4) Winds. 150 miles per hour (hurricane season in late summer and fall). 



(5) Storm Surge and Astronomical Tide. 9 feet total. 



(6) Littoral Transport. None; offshore location. 



(7) Water Depth at Structure. 37 feet at MLW. 



(8) Foundation Conditions. Piles driven through soft silty clay bottom into medium 

 dense sand layer with shell fragments. 



e. Basic Structural Features (Figs. 51 through 54). 



(1) Dimensions of Basic Structures. 



Oil storage platform, 50 by 100 feet 

 Separator platform, 98 by 136 feet 

 Pump and compressor platform, 72 by 141 feet 

 Living quarters platform, 44 by 87 feet 



(2) Unusual Structural Features. All structures except living quarters platform 

 constructed with Raymond concrete cylinder-pile template (rather than usual steel template 

 structure) with 36-inch-diameter concrete cylinder piles driven through template supporting 

 concrete platform decks. Living quarters platform is a jack-up rig with barge-type deck 

 structure supported on 72-inch-diameter steel caissons. 



All concrete design selected for savings in corrosion protection and maintenance costs. 

 /. Design Data (Figs. 52 and 53). 



(1) Design Conditions. 



Depth at structure, 37 feet at MLW 



Astronomical tide, 2 feet 



Storm surge, 7 feet 



Maximum depth, 46 feet 



Design wave height, 32 feet 



Wind load, 150-mile per hour hurricane winds 



(2) Model Study. None made. 



(3) Instrumentation. None. 

 g. Structural Performance. 



(1) Performance. Structure's performance has been very good, particularly since the 

 full design conditions have occurred during two hurricanes. Although personnel are 

 evacuated during such storms, winds are recorded and, from evidence of damage, it is 

 possible to estimate the height reached by the seas during storms. Winds of about 1 50 miles 

 per hour have been recorded and damage to walkways has indicated that waves have reached 

 a height of 40 feet above MLW. Sand has been deposited in the living quarters a few feet 

 above that. With personnel still on the platform, waves cresting at 15 feet above MLW have 

 been observed. Normal seas crest at approximately 5 feet above MLW. 



It should be noted that, while the owner's design practice to establish the physical 

 environment has not changed, his method for computing wave forces has changed so that 

 the design is below his present standards. 



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