How to solve the problem of ship swaying at sea

Seakeeping refers to the ability of a ship to overcome waves and other movements. In order to improve the seakeeping of ships, so as to reduce the shaking amplitude and change the shaking period, which is the key purpose to realize the comfort of ships, anti-rolling equipment is usually installed on ships:

1. catamaran design

Catamaran design

Many high-speed cruise ships you see are catamarans. Generally speaking, it is to connect two hulls, generally equipped with double propellers and double rudders, with good handling performance. The design of catamaran greatly improves the floating center and reduces the center of gravity. The distance between the center of buoyancy and the center of gravity determines the stability of the ship, so the stability of this kind of ship is greatly improved, and the swing is smaller than that of a single ship, which increases the riding comfort of the crew and reduces the probability of seasickness. At the same time, there is no need to install "stabilizer" equipment, which also reduces the purchase cost.

2. Install bilge keel

Bilge keel

Stern keel is the most widely used and simplest anti-rolling device. It is installed at the stern of the ship along the captain's direction, which disturbs the flow field around the hull during rolling and makes the ship generate additional damping, thus increasing the rolling damping and achieving the purpose of reducing rolling. It is effective in all sea conditions, especially when the ship periodically rolls and waves periodically act. The only drawback is that the stern keel will slightly increase the resistance of the ship. Because of simple structure, low construction cost and little influence on speed, almost all seagoing ships are equipped with bilge keel, which has become a part of seagoing ship hull. So in general, the so-called anti-rolling device refers to anti-rolling measures and equipment other than bilge keel.

3. Install the fin stabilizer

fin stabilizer

Fin stabilizer is one of the most popular anti-rolling devices in the world. In the process of ship rolling, the angle of fin stabilizer relative to the water flow is automatically adjusted by the control mechanism, so that the left and right fin stabilizers produce the maximum torque opposite to the rolling direction, and the rolling effect is achieved. This anti-rolling device has a good effect, especially suitable for high-speed passenger ships. It is an active anti-rolling device with good anti-rolling effect and wide application. Fin stabilizer first appeared in 1889, and was patented by JohnI.Thomeyeroft. In 1923, Nobutaro Beam Element of Japan designed the first set of fin stabilizer, and achieved good anti-rolling effect through loading test. 1935, the fin stabilizer designed by British Brown Brothers Company was successfully applied to a 2200-ton channel ferry, and it has been widely used since then.