EM Merrifield

Engineer EM Merrifield's breakwater dolosse.

© Public domain

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EM Merrifield and draughtsman Aubrey Kruger revolutionised global breakwaters with the simple yet efficient dolos invention. The story of the dolos began in 1963 when the Eastern Cape coast of South Africa was battered by a terrible storm. The East London harbour - where engineer EM Merrifield worked - suffered substantial damage.

The breakwater system used in the country at the time comprised massive cement blocks. A South African-born engineer, EM Merrifield was curious as to the true effectiveness of this system. He theorised that a permeable structure that absorbed the power of the sea, breaking up the waves, could offer better resistance than a solid structure trying to defy one of nature's greatest forces.

EM Merrifield and Kruger came up with an anchor-like design that resembled a T with a perpendicular foot running front to back that was able to interlock with other such structures. In this way, the concrete structures formed an absorbent sea wall.

Merrifield sent the design to the Council for Scientific and Industrial Research (CSIR), where it was rigorously tested and found to be most successful in its purpose.

He was at a loss for a name, however. The design resembled an animal's knucklebone, often used in traditional African divination and the old South African children's game called dolosse. The story goes that after Kruger's father, Joe, commented that Merrifield was playing with his own dolosse of sorts, he adopted this name for the breakwater invention.

Merrifield first took the dolos abroad, where it was used at Denmark's Hirtshalls Harbour, after which countries around the world adopted the dolosse design for their breakwaters. Interestingly, Merrifield never patented the design, saying that he wanted the dolos to be his contribution to civil engineering.

Merrifield was awarded a Shell Design Award in Japan for the dolos and an Associated Scientific & Technology Societies' Gold Medal for his contribution to the scientific field. He passed away in 1982.