Home Innovation Inventor of global ‘dolos’ sea buffer system dies in East London, South...

Inventor of global ‘dolos’ sea buffer system dies in East London, South Africa

The man who designed the ingenious interlocking sea buffer system used all over the world called ‘dolosse’, died in his home town of East London in South Africa last week.

“Aubrey Kruger (pictured), the former East London harbour draughtsman designed the ‘dolos’ sea buffer system 53 years ago. The keen fisherman and diver died two days before his 82nd birthday last Tuesday (19 July, 2016)

Reporter Barbara Hollands of the Eastern Cape regional newspaper Daily Dispatch writes that although harbour engineer Eric Merrifield was initially credited for their invention of ‘dolos’ it emerged during the 1990s that it was in fact Kruger who came up with the ingenious interlocking concrete design. The system is used all over the world to dissipate waves at breakwaters.

Hollands quotes Kruger’s son, Lance Kruger, who said the family had been delighted when Kruger’s hand in the ‘dolos’ design had been commemorated by the South African Mint in the company’s South African Inventions theme just a couple of weeks before his father passed away.

Two sterling silver coins – a R2 Crown and a 2½ cent ‘tickey’ – imprinted with geometric ‘dolos’ shapes were posted to the family. “The family was emotional when they arrived from the Mint recently. We were all in the room when we gave him the coins and he got to touch them. He held them tight. We knew he was deteriorating and it was exciting to give this to him before he left us,” said (Lance) Kruger. 

According to Wikipedia concrete ‘dolosse’ (pronounced “dohl-awe-sah”) have a complex geometric shape and can weigh up to 20 tons. “They were developed in East London in 1963.” Apart from use in oceans ‘dolosse’ are also used in rivers in the Pacific Northwest of the United States of America to control erosion, prevent channel migration and to create and restore salmon habitat.

Kruger said his father used to tell the story of how he came up with the very first mock-up of the ‘dolos’ after Merrifield instructed him to design a concrete structure that would protect the East London harbour breakwater from battering waves. “He drove home to Cambridge on his Vespa and asked my mother for the broom. He sawed it into three pieces and made the shape of [what was to be] the ‘dolos’.

His father had then made a small prototype of the structure, which Lance said was named by his grandfather, Joseph Kruger, who worked at the harbour’s dry-dock. “He came into Merrifield and dad’s office and said: ‘Ek sien julle speel met dolosse.’ [I see you are playing with dolosse]. Dolosse were joint bones children used to play with. And that’s how they were named.”