Analyses of Multiple-Float-Supported Platforms in Waves 



from the model centerline directly abeam of the row of floats in which 

 measurements were being made, and d) at a location 4-ft aft of the 

 last row of floats and about 1-ft abeam of the model centerline. Again, 

 wave tests were done at wavemaker settings for which wave measure- 

 ments with the model present were available. 



Results 

 Motion Tests 



Articulated model motions tests were carried out with regular 

 waves in the 75-ft wide Tank No. 2 to compare with results previously 

 obtained in the 12-ft wide Tank No. 3. Presumably if any effects of 

 tank wall interference were present for the first series of tests, they 

 will not be present in the tests in the wide tank. 



Results in the form of heave amplitude divided by wave ampli- 

 tude, Z/f (in/ in) for Row 18 are given in Figure 4 7 as a function of 

 model-scale frequency. The repeat test results of Tank 2 are given 

 with different plotting symbols to distinguish them from the previous 

 Tank 3 results. The differences between the results are not great and 

 similar agreement exists for measurements for Rows 1,9,2 7 and 35. 

 The results have been cross-faired by means of "carpet-plotting" and 

 the smoothed curves are presented in the composite Figure 48 which 

 shows the substantial tail-wagging. 



Force Tests 

 Large Model 



Force measurements results, in the form of oscillatory heave 

 force amplitude divided by wave amplitude, Z/f (lb/ in), for Row 17, 

 are given same as for the articulated motions model. 



One row of lfoats is not connected to the strongbacks but is 

 coupled ot a force balance system for measuring vertical and horizontal 

 wave forces. This row may be located in any desired position, while 

 the "fixed" rows are also relocatable so that the forces acting on any 

 one of the 35 rows of floats can be measured. 



Wave elevation measurements were made at several locations 

 during these tests : a) at a location 10-ft forward of the row of floats 

 nearest the wavemaker and about 1-ft abeam of the model centerline 

 (this first row was situated 35 feet from the wavemaker) ; b) at a lo- 

 cation 2 7-in from the model centerline directly abeam of the row of 

 floats on which measurements were being made ; and c) at a location 

 4-ft aft of the last row of floats and about 1-ft abeam of the model 



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