On the bridge a Radio Direction Finder (RDF) is connected to an antenna on the wheelhouse top. The RDF was compulsory until the end of the nineties of the former century. It was introduced before Decca, Loran-C and GPS came into use. With the RDF one could find the position of the ship by hearing and combining several beacons. The RDF was not necessary anymore when the Global Maritime Distress and Safety System (GMDSS) was introduced (courtesy of the PI4HAL transmitting society on board the ss Rotterdam). During the eighties the original circular antenna on the ss Rotterdam was replaced by a square one as shown on the following picture (Picture Koos Sanderse).
This summer Hilckmann Maritiem in Nijmegen offered a circular antenna, probably used on the ss Nieuw Amsterdam (scrapped in 1974). With funding of WestCord Hotels the antenna was bought and transported to Rotterdam. Thanks to Mammoet the antenna (100 kilo) was hoisted to the wheelhouse top (Picture Paul Kitsz).
Our volunteers mounted the antenna on its place (Picture Koos Sanderse)
Our volunteer Jan Tjassens Keiser made the following picture at the end of the day.