The anchorage of a covered floating system is usually required to be much stronger than 

 that of an open system. In sheltered sites an ordinary guide-pile system may be adequate if 

 the number of piles required is not prohibitive. It is more common to use some other 

 anchorage system. Dolphins that develop their strength on the A-frame principle rather than 

 through the combined cantilever bending strength of their component pile members are 

 often in this situation (Fig. 89). Considerable internal strength can be built into the 



Figure 89. A-frame dolphins guide a floating pier at Shilshole Bay Marina, Washington. 



structural framework of the cover so that points of lateral support may be widely separated. 

 A single dolphin may develop 10 to 20 times the strength of one guide pile, and few may be 

 needed. If the water is deep enough, submerged structural ties across finger ends well below 

 the keel depth of the berthed craft are sometimes used to strengthen a covered floating 

 system (Fig. 90). 



Since a large amount of flotation is required for covered sUps and high windloading must 

 be resisted by the anchorage system, a separate berthing system and cover may be desirable. 

 At sites where tlie bottom is not too deep and the water level does not fluctuate more than 

 a few feet, the cover may be a pole-supported shed. Long poles driven into the bottom 

 support the roof and sides of the sheltering structure. The floating slips are then placed 

 within the covered area and the supporting piles of the shed are spaced so that they can be 



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