k * H'q/Lq 

 H /L 



Replacing L in the denominator by 5„12t2 

 k ■ ^oj^oj x 5»12 



(2) 



By a combination of Plates I and II (H«0o No„ 234) and the use of Equation 

 (2) a curve to show the relationship between H b /fa and oc can be constructed 

 (Diagram B of Figure 2)„ Breaker height H D then can be obtained from another 

 diagram which shows values of H, /h o plotted against H D with curves of con- 

 stant H (Diagram C s Figure 2), 



The procedure in computing data for plotting Diagram B is as follows; 



Assume a value of H /L ■ 0,0780 



Then Ho/T 2 - 0„078 x 5.12 = 0,40 



For various assumed values of d^/l. computations are made in tabular form, 

 (Table I). 



TABLE I 



PLOTTING DATA FOR DIAGRAM B 





H o 



K 



= 0,078 (H /T2 



= 0o40) 





Assumed 



H V H b 



From Plate I (H 

 No„ 234) 



(2) (3) 



„o„ 



k 

 H'o - 



(4) 



Ho 



^0 



H b 



Ho 

 Col, 3 

 times 

 Colo 4 



(5) 



-deg. dego 



Value 

 of 



d b^o 

 (1) 



From Plate II 

 H0O0 Noo 234 with 

 Cols. (1) and (4) as 

 Arguments 



(6) (7) 



0o06 

 0„07 



0„0445 1»03 

 0o052 1,02 





0,570 

 0.666 





0.59 

 0.68 



74»3 34oO 

 680 5 34c7 



Computations as shown in Table I are made with other values of H_/L , 

 Cross plots then permit a diagram to be constructed with Hh/H Q plotted 

 against <x for various constant values of H /L or H /t2 (see Diagram 

 B s Figure 2)„ In order to eliminate a slide-rule computation of H q /t2 from 

 the forecast values of H and T 3 Diagram A has been prepared. 



26 



