Japanese Partner Up on Anti-Roll Tank Research for Large Containerships

ClassNK has signed a joint R&D agreement with Nihon Shipyard and IMC to ensure the safety and performance evaluation of anti-roll tanks (ART) installed on large containerships.

Under the R&D agreement, Nihon Shipyard, IMC, and ClassNK will work together to expand the application of ART to large containerships.

Utilizing the obtained data and knowledge, each party will collaborate to ensure the safer application of ART on an actual ship and performance evaluation.

AS part of the partnership, Nihon Shipayard will design of optimal installation plan of ART on large containerships, IMC will conduct demonstration of ART's reduction effect on ship’s roll, while ClassNK establish the appropriate evaluation methods for ART.

An ART is a device designed to suppress the ship's roll by moving liquid, such as water, within the tank.

Consideration for ART installation on large containerships is advancing due to the expectation of improving container loading efficiency by reducing roll motion and preventing parametric roll, which is regarded as one of the causes of container collapse accidents.

The parametric role is a type of resonance phenomenon where ship’s roll amplifies, that occurs when the natural roll period is twice the wave encounter period.

ClassNK has added standards to ensure safe and efficient operation of containerships in its ‘Guidelines on Preventive Measures against Parametric Rolling (Edition 1.0)’ to grant a notation to the ship equipped with ART.

Together with the National Maritime Research Institute, Japan, ClassNK performed tank tests on a containership model equipped with ART that can switch between activated and deactivated states to verify the reduction effect of ART against parametric and synchronous roll, and data for evaluation was obtained.

The tests, conducted in 2023, confirmed their anti-rolling effect against parametric and synchronous roll, and collected data.