Purpose

It can be of great advantage to consider the sea keeping characteristics of a vessel during the design stage. Severe vessels motions and wave loads are typically associated with specific sea conditions and will vary from ship to ship. It is important to ensure that the design of the vessel has been optimised to minimise the motions and wave loads, or at the very least that is fit for purpose, to work in certain locations and specific environmental conditions.

Benefits

DNV has long experience and in depth competence within sea keeping and concept evaluation for the following ship types:

• Tankers

• Bulk Carriers

• Container ships

• High Speed Light Craft

• LNG Carriers

• Offshore vessels

Optimising the design will not only enable the ship to carry out longer operations in harsh environment or choose more challenging trading routes, but it will increase the safety and minimise the risk of the operations. For instance, for vessels where people work on the main deck optimising the vessel motions to minimise the amount of water on deck will increase the safety and operability. Waterlines and hull shapes may also be optimised such that the slamming loads and are reduced.

Features

Features which are coped with the area of seakeeping include:

• General ship motions at different locations of the ship

• Green seas on deck

• Parametric roll

• Side by side offloading

Typical deliverables in a seakeeping report may include long and short term statistics of expected extremes or distributions, probabilities, linear transfer functions and animations.