After the simulation study it was decided to perform a reference measurement corresponding to the actual regulations in the port of Delfzijl. The present regulations stipulate a minimum UKC with respect to the water-mud interface of 10%. For this purpose an outbound general cargo vessel was selected. The survey was performed at April 30th, 2013 on the between the berth in the Zeehavenkanaal and the river Ems. During the measurements a survey vessel performed a single beam survey at 33 kHz and 210 kHz.
The motions of the vessel and the application of rudder and propeller were compared to the local bottom conditions in the port.
Although the CSL-Rhine did sail at a minimum under keel clearance of 14% with respect to the top of the mud layer, the trial did reveal significant impact from the mud layer on the ship speed and the manoeuvring behaviour of the vessel.