Thus, equation (4-22) reduces to 



Tp ^ ]^^ ^m C4-24a) 



or, to obtain similar refraction patterns, model-to-prototype, in 

 distorted-scale models. 



■w; 



(4-24b) 



3. Model Design. 



a. Field Data Required . The following information and field data 

 are needed for hydraulic model studies of harbor wave action problems: 



(1) Statistical data describing the wave environment. 



(2) Tide data referred to a standard datum. 



(3) Accurate depth contours within the harbor area and 

 outside the harbor to a sufficient depth seaward to allow the 

 construction of refraction diagrams or orthogonals from deep 

 water to the harbor area for the different deepwater directions 

 of wave approach. The depth contours should be referred to the 

 same datum as that used for the tide data. 



(4) Topographic and hydrographic maps of the harbor and 

 adjacent land area showing locations of all pertinent harbor 

 and shoreline structures. The maps should be referred to the 

 same horizontal control and vertical datum as those used to 

 show depth contours. 



(5) Construction details of existing and proposed break- 

 waters, jetties, wave absorbers, seawalls, piers, and docks. 



(6) Details of existing and proposed plans for the dredging 

 of turning basins and navigation channels. 



(7) The resonant wave periods for both surge and sway (fore- 

 and-aft motion of the vessel parallel to the dock line and side- 

 ways motion perpendicular to the dock line, respectively) of all 

 types and classes of large vessels expected to moor in the har- 

 bor. The resonant wave periods should be obtained for the type 

 of mooring-line assembly used for each type and class of vessel. 

 For small craft it is usually unnecessary to obtain resonant 

 wave periods for motions other than those of surge fore and aft. 



(8) The maximum allowable wave height for each type and 

 class of vessel as a function of wave period. 



212 



