Safety Of Monolayer Breakwaters

The authors present their concern for the use of (interlocking) monolayer armour units with high porosity, also referred to as bulky monolayer units. It is based upon their long experience in the study and design of all types of breakwaters and revetments including vast experience in hydraulic model tests of such structures. The paper thus relies on this experience including the involvement in the study of damaged breakwaters and a study of what appears on the subject in the public domain. The paper finally presents the authors’ own conclusion and proposal on new guidelines for the use of such units; with the aim of arriving at safer design in the future, thus avoiding or significantly reducing the too high number of damaged breakwaters that the costal engineering profession has witnessed. It also presents ideas for safer design of large, exposed breakwaters in deeper water, where such monolayer units should be avoided.