(equation derived from preliminary geometry of cross section on page 8-48) 



(5) Volume of First Underlayer . The volume per 100 m of structure 

 (in thousands of m ) is shown in the tabulation below. 



Valid for tribars and tetrapods because Vi depends only on 

 (r, is dependent on the armor unit size, but not the type). 

 See Figure 8-26 for a graphic comparison of costs. 



e and r 



1 



8-63 



