Civil Engineering May 2022 | Vol 30 No 4

20 May 2022 Civil Engineering Magnificent as these great docks are, it is the humble slipway that is the most technically complex and satisfying to work with. Dry docking, slipways in par- ticular, have seen little technical develop- ment compared to other fields. It is still suffused with the lore of the shipwrights. I’ve never been much into angling, but at times I have had the privilege of oper- ating the winch and winding in the great mass of the vessel – the biggest fish you could image! What I remember more than anything else was working with our shipwright, the late James Kasner – a bull of a man, salt of the earth, confidant of archbishops. It was from him I learned the practical reality of engineering, of “bush mechanics”. When he was working up the coast, he always seemed to have his site office in the teeth of the gale and the spray from the sea. Lunch was a shovel braai and a steaming hot, chipped enamel mug of strong rooibos tea and condensed milk, all the while standing out in the wind and the spray – all in the best tradition of the old-time navvies. CULTIVATING A BLUE MIND The waters of the Cape are the domain of the titan, Adamastor, Poseidon’s gillie. He guards them jealously and flings his great storms against these shores. He was the nemesis of sailors rounding the Cape who once called it the Cape of Storms. This is a coast that is the most inhospitable in the world – a matter first noticed by the father of economics, Adam Smith, in 1776 when he wrote in his Wealth of Nations , “There are in Africa none of those great inlets, such as the Baltic and Adriatic seas in Europe, the Mediterranean and the Euxine seas in both Europe and Asia...”. In Southern Africa the coast is a scarce resource. I have since confirmed Smith’s assessment with an accurate calculation, at a nominal 50 m step size, of the fractal index of the South African coast at 1.048 – probably the lowest in the world for that amount of coast. In the semi-desert lands of South Africa there is probably more impounded fresh water in the interior than protected sea water on the coast. As Smith anticipated, this character- istic of the African shores has probably been the dominant factor in the socio- economics of Africa and no amount of politics is going to solve the problem. Only engineering intervention is going to be able to do that and engineers, particu- larly marine engineers, need to be acutely aware of the skills needed of them; not just straight technical expertise but also a sensitivity to the seashore – a blue mind. The sea is a harsh mistress and does not lightly tolerate sloppy work. This is most noticeable in corrosion, which has all sorts of fascinating characteristics. There is accelerated low water corrosion of steel and accelerated high water cor- rosion of reinforced concrete. In the tidal zone slipway rails exhibit corrugation corrosion on the railhead and differential aeration corrosion at fishplate joints, and the cables supporting shiplifts have a peculiar form of corrosion all their own. I had the great privilege to be the last person to learn corrosion science from Commander Wilfred Copenhagen OBE. He was a chemist by training, a pioneer in marine corrosion, one of the founders of the South African Navy, and set up a training school for the navy during the war. His name is still revered in Simonstown. My father went through his officer training under “Copie”, as he was affectionately called, and just went “grrmmff” when I mentioned his name. My wife adored the old man and he Modern 200 ton slipway James Kasner (left) with Jon Savage (right), our diver/ pilot, on Ichaboe Island with the original annexation notice Late Bronze Age style shipsled