Breakwater Blocks. Workmen loading a 40-ton concrete block on to a railway "grid-iron" at the Public Works Department's yards adjacent to Cringela Quarry at Port Kembla. The blocks are constructed at the rate of three a day-and are used for the extension of the eastern break-water at Port Kembla. Already 1700 of the blocks, which consist of one part cement, one part sand and 2? parts blue-metal, have been used on the breakwater. September 11, 1947.