On September 14, 1964, a freighter had capsized at the docks in Kuwait harbor. Since the city of Kuwait pumped its drinking water from the harbour, the health hazard made it nescessary to raise the ship rapidly. Danish inventor Karl Krøyer was called in to raise the ship, which he did on December 31, 1964, by using tiny plastic balls[?] made of expandable polystyrene foam. He used 27 billion balls which weighed 65 tons. The scientific magazines "Popular Science", April 1965 (page 118-119); "Die BASF" vol. 15 no. 3, 1965 (page 148-156); and "Chemistry", September 1966, descibed his method together with some pictures from the Donald Duck story. Later on, Krøyer used the same method to raise the ship Martin S of Svendborg which stood at the bottom of a harbour in Greenland (Sukkertoppen).
There are some rumours about where Barks got the idea: In 1938, the American millionaire Howard Hughes used ping pong balls in his plane to prevent it from sinking in case he had to make a forced landing on the water.
Note: "Die BASF" is / was the company magazine of German chemistry company BASF, their article on Krøyer is reprinted in fanzine "Der Hamburger Donaldist" no. 39, 1983 (page 23-25).
Question: Another date for the Kuwait ship raising given in my sources is "Dec. 29/30th," while Michael Barrier mentions that the ship sank in December 1964. What is the right date?