The dolos armour unit has been used all over the world and, although most projects have been successful, there have also been some major failures. When moved around, armour units in general and the rather slender dolosse in particular are prone to structural damage and when dolosse break through the shank, one is left with very unstable pieces of rubble. It is shown in this paper that a safe and economic dolos structure can be obtained if the correct design process is followed. The "optimum" design is based on a reasonable degree of dolos movement which must be established in detailed and representative model tests. To ensure that the dolosse can withstand these movements, prototype dolos behaviour must be monitored, and such monitoring must be supplemented by representative structural tests, analytical studies and special prototype measurements. To increase the structural strength of dolosse, the waist to height ratio can be increased and some (simple) form of reinforcing can be included.