Harbour walls and breakwaters all over the world make use of dolosse to create that barrier between the ocean and land.  A dolos (plural dolosse) is a concrete block in a complex geometric shape weighing up to 30 tons.  The new Coega Harbour in Port Elizabeth made use of 28 000 dolosse in the construction of its breakwater.  The dolos is named after the knucklebone of a sheep.

Dolosse were developed in East London in 1963 by one-time East London Harbour Engineer Eric Mowbray Merrifield who won various awards for the invention.  In the late 1990s Aubrey Kruger made a claim that he worked with Merrifield and was the one who came up with the design but never received any recognition.

The picture above was taken at the Port Elizabeth Harbour wall with Kings Beach in the background.

Leave a Reply

This Post Has 4 Comments

  1. bumblebee

    Sad that the ubiquitous dolos is associated with bitterness about who invented it. Also sad that the inventor (whoever he was) didn't patent his invention. He'd have made millions.

  2. Jo

    I agree with bumblebee above; such a pity Merrifield and/or Kruger didn't patent this amazing design. We had them at the St Lucia Estuary mouth in Zululand too. Often fished off the dolosse! Have a great weekend. Jo

  3. Edward Knipe

    It has without a doubt been proven that the late Aubrey Kruger was in fact the person who came up with the idea of the dolos. There was no bitterness from Kruger; mere disappointment that he had not patented the prototype. Witnesses to the conversation between Merrifield and Kruger (documented) about the prototype stated that Merrifield encouraged Kruger not to patent his dolos prototype. Much has been written about this matter and finally the real inventor has been rightly honoured – pity though that it had to take so long.

  4. Ben Pieters

    As employee of the state and as part of his functions he was asked to solve the problem. Could not patent it unless it was agreed to beforehand.