The dolos breakwater block

The dolos breakwater armour unit was developed by the late Eric M Merrifield when he was harbour engineer at East London. The need arose when, in 1963. approximately 60 per cent of the 37 t rectangular concrete blocks used to protect the seaward side of the East London breakwater had disappeared and major repair works were called for. It was obvious that repairing the breakwater with similar blocks would be ineffective unless they were made significantly heavier. This would have caused serious construction problems in that the available crane could not handle such blocks.