The bank effect (channel effect, bank suction, bank cushion, stern suction, ship-bank interaction) is the tendency of the

stern The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Ori ...

of a

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguishe ...

to swing toward the near bank when operating in a river or constricted

waterway A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary ...

Paywall A paywall is a method of restricting access to content, with a purchase or a paid subscription, especially news. Beginning in the mid-2010s, newspapers started implementing paywalls on their websites as a way to increase revenue after years of ...

Phenomenon

The asymmetric flow around a ship induced by the vicinity of banks causes pressure differences (

Bernoulli's principle In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy. The principle is named after the Swiss mathematic ...

) between port and starboard sides. As a result, a lateral force will act on the ship, mostly directed towards the closest bank, as well as a

yawing moment Adverse yaw is the natural and undesirable tendency for an aircraft to yaw in the opposite direction of a roll. It is caused by the difference in lift and drag of each wing. The effect can be greatly minimized with ailerons deliberately designed to ...

pushing her bow towards the centre of the waterway. The

squat effect The squat effect is the hydrodynamic phenomenon by which a vessel moving through shallow water creates an area of reduced pressure that causes the ship to increase its draft and thereby be closer to the seabed than would otherwise be expected. ...

increases due to the decreased blockage. This phenomenon depends on many parameters, such as bank shape, water depth, ship-bank distance, ship properties, ship speed and propeller action. A reliable estimation of bank effects is important for determining the limiting conditions in which a ship can safely navigate a waterway.

Examples

It was cited as a possible cause of the

2021 Suez Canal obstruction In March 2021, the Suez Canal was blocked for six days after the grounding of , a container ship. The vessel was buffeted by strong winds on the morning of 23 March, and ended up wedged across the waterway with its bow and stern stuck in th ...

by the cargo ship ''

Ever Given ''Ever Given'' () is one of the largest container ships in the world. The ship is owned by Shoei Kisen Kaisha (a ship-owning and leasing subsidiary of the large Japanese shipbuilding company Imabari Shipbuilding), and is time chartered and op ...

''.

References

External links

Model tests demonstrating the bank effect
for ''International Conference on Ship Manoeuvring in Shallow and Confined Water'' (MASHCON) at ''

Ghent University Ghent University ( nl, Universiteit Gent, abbreviated as UGent) is a public research university located in Ghent, Belgium. Established before the state of Belgium itself, the university was founded by the Dutch King William I in 1817, whe ...

'' January 2010
Bank Effects
at ''Knowledge Centre, Manoeuvring in Shallow and Confined Water''

''MASHCON'' 1
: Bank Effects

: Ship to Ship Interaction

: Lock effects

: Ship Bottom Interaction

: waves, wind and current

: Port Manoeuvres (May 2022) Nautical terminology Marine propulsion {{water-transport-stub

Phenomenon

Examples

See also

References

External links