500 

 400 

 300 

 200 

 100 



s pV)H 



OR 



VAAtf- 



3*0** 



4- 



T-GROIN ^MODELED 



45 50 56 



b. 



500 

 400 

 300 

 200 

 100 



ANGLED JETTY 



ACTUAL 



DIFFRACTING GROIN WITH SPUR 



MODELED 



100 



DISTANCE ALONGSHORE/GRID CELL NUMBER 



d. 



Figure 34. Examples of complex groin and jetty configurations 



333. Several features in the examples in Figure 34 deserve attention: 



a. At locations where structures are attached, IX , Y , and D- 

 type variables must be identical. If not, GENESIS will not 

 recognize the structures as being connected. 



b. The top of the "T" forming a T-groin (such as in example c) 

 must be represented by two structures, each attaching to the 

 diffracting groin. Otherwise, the configuration would be 

 illegal (overlap of diffracting structures) as shown in Figure 

 31. 



c. The connection between two detached breakwaters must be at the 

 exact same point in all specifications (as in example c). 



d. All groins attaching to detached breakwaters must be repre- 

 sented as diffracting. 



144 



