Geosynthetic concrete mattress systems are regularly used underwater to provide reliable in situ concrete protection. As vessel sizes and propulsion types advance, bed scour velocities in berths are increasing. Concrete mattress provides high scour resistance due to its interlocked slab nature, with experience of protection against jet flows presently up to 12.5 m/s.

Design methods will be presented for the following actions in berths: Propeller, Jet (by reference), Side Thruster, Current and Wave.

Concrete mattress has been used for berth scour protection for some 50 years providing a good understanding of performance. The technology and relative merits of the system will be outlined along with case history examples of usage in Africa: Cotonou, Benin; Abidjan, Ivory Coast; Tanzania.

This paper may be of interest to Port Authorities, Design Engineers, Contractors and Operators.