In relation with a previous article on hoppernozzle engineering, I publish here a Powerpoint presentation on observations onboard "Gerardus Mercator", 2002, on the use and layout of hoppernozzles, in a -succesful- attempt to reduce restload.
Some idea's are obsolete, but the presentation gives a good impression what goes on in the hopper during discharge; "a symphony of water and sand".
Furthermore, "Gerardus" was equipped with doors, to allow the sand-water mixture into the selfemptying channels.
Hopperdredgers nowadays are mostly designed with a system of suction bends and valves, with other problems and opportunities.
Marc Van de Velde