Bank Effects

The asymmetrical flow around a vessel, such as induced through the proximity of banks, leads to pressure variations between the starboard and port sides. Consequently, the vessel will be attracted to the nearest bank, while the bow is pushed towards the centre of the fairway. The effect is, of course, largely dependent on the distance between the vessel and the bank, but also on the vessel's speed and under keel clearance. Safe control of the vessel will become impossible with too strong bank effects. A reliable estimate for these bank effects is of importance in order to be aware of the limit conditions for safe traffic.

A website was built for the research carried out in 2006. The research contributes toward determining the limits of safe shipping traffic to the Flemish ports.

In March 2010 new oblique towing tests with five different ship models were initiated. The tested ship types are:

• Inland vessel
• Estuary vessel
• KVLCC (Moeri II)
• 12000 TEU container carrier
• Mathematical Wigley Hull

Four different bank geometries are installed in our towing tank. These surface piercing banks have a slope of 1/4, 1/3, 1/1 and a vertical quay wall. The models are systematically towed at different speeds, lateral distances, propeller rates and water depths. At different discrete positions the wave pattern is registered.

These model tests will be used to create a mathematical model for these different (from the 2006 tests) ship types. A second ambitious aim is to integrate the vessel's geometry into the mathematical model.