Revetments and units for use in constructing revetments

摘要

Revetments are constructed using a plurality of revetment units which are arranged on river bed or the like. Each revetment unit comprises a stem and a disc-like head. The stem is stepped so that it has a relatively short larger diameter part and a relatively long smaller diameter part. The heads of units in each upper course lie behind the heads of the units in the course below and rest on the larger diameter parts. The heads and stems are preferably circular in cross-section but can be multi-facetted.