Keel-Rudder Interaction: A look into the wake of a sailing yacht

In the early 00 of this century, Keuning et al. (2007) looked into the hydrodynamic forces on the rudder and the influence of the hull and keel on these forces. Among others, they have assessed the lift and drag forces on the rudder. One of the outcomes of this study was an asymmetric lift curve; for negative rudder angles the rudder seems to...

Research on lift-carry-over in hull-keel-centre board configurations, to improve the performance prediction of sailing yachts at Dykstra Naval Architects

Dykstra Naval Architects are regularly designing large classic sailing yachts or motor-sailors, of which the draft is an important design restriction.The sailing performance is increased by adding lift-generating appendages,without increasing the draft. An example is a retractable centre board, havinga big influence on the sailing properties....

Quantification of Thruster Forces for Escorting Tugs

DAMEN tugs can be found in nearly any port or terminal around the world. Operating in ports and terminals requires the tugs to be highly efficient in ship handling in order to quickly escort larger vessels. To predict the escort capabilities of a tug, DAMEN has developed the computer program DAMEN TUGSIM. Since the tool is becoming a decisive...

Rudder loads of moored FPSO's in waves and current: A study by experimental means

The rudders of moored FPSO’s are fixed in the center to avoid unwanted rudder motions. This is often done by mechanical locking of the rudder machine. Due to waves and current, the loads on the rudder are higher than expected, causing failure of the locking system. An empirical study is executed to predict the combined wave and current loads on...

The horizontal added mass of a suction bucket jacket (SBJ)

The new rapidly growing wind energy market has been moving to offshore waters the last few years. New techniques and growing experiences make it possible to move to challenging offshore domains and towards harsher conditions and deeper waters. From the oil & gas industry a lot of expertise is already available on support structures. The...

Combining a spar type floating offshore wind turbine with a current turbine

With the shift towards a more sustainable energy society, the increase in the electricity produced by renewable energy sources is steadily rising. However the cost of renewable energy sources still remains high compared to the traditional fossil fuel based energy sources. With the total worldwide energy demand also rising, combining renewable...

3D motion compensation for an offshore crane: Assessing the feasibility for wind turbine maintenance

When working offshore on a floating vessel, the vessel will be subjected to wave induced motions and with a moving crane tip, a suspended load can start to swing. When the motions of the load become too large, the operation is interrupted. Alternatives such as jack-ups, function as a fixed platform to which the crane is attached, therefore...