MARIN uses thrusters in many projects. For a typical model scale, around 1:50 to 1:60, relatively small thrusters are required. Thrusters for these models are available ranging from 50 mm to 80 mm nozzle diameters. In the past these thrusters were always modelled with a horizontal shaft.
By tilting the nozzle, the closest possible match was achieved between the client specifications and the modelled thruster for the basin tests.
Due to the ever-evolving process in improving the models, new thrusters were built witha 7-degree tilted thruster shaft.
Special gears were made for a reliable and durable thruster model and with these new thrusters it is still possible to mount nozzles with a slightly different angle. See figures for examples.
The newly built thrusters give clients the ability to choose a more accurate representation of the thrusters used during model testing.
Robert Heerkink is project manager at the Ships department of MARIN, the Maritime Research Institute Netherlands. MARIN offers simulation, model testing, full-scale measurements and training programs, to the shipbuilding and offshore industry and governments.
(As published in the September edition of Maritime Reporter & Engineering News - www.marinelink.com)
