Table 7-10. Types of armor units . 



S. Army Engineer Waterways Elxperiment Station (WES); not all units were tested in two- 



Modlfled from Hudson, 1974. 



Not available. 



Units have been tested, some extensively, at the U. 

 layer armor layers. 



Cubes and rectangular blocks are known to have been used in masonry- type breakwaters since early Roman times and in rubble-mound breakwaters 

 during the last few centuries. The cube was tested at WES as a construction block for breakwaters as early as 1943. 



Solid tetrahedrons are known to have been used in hydraulic works for many years. This unit was tested at WES in 1959. 



7-216 



