With a volume of 40,000 tonnes of clear water, our Ocean Basin is one of the largest testing tanks in the world. It is used by commercial and defence customers for manoeuvring and seakeeping tests in calm water and waves.
With a length of 121m, a breadth of 61m and depth of 5.5m the Ocean Basin spans a surface area greater than the pitch at Wembley Stadium. The size of our basin allows the testing of large or high speed models that other facilities can’t achieve.
The basin contains 122 recently installed individually actuated wave making paddles which are capable of recreating any sea state in the world at model scale. In the basin free-manoeuvring models acre controlled remotely using the either underwater or wireless technology. Two-way real time communication or on-board data logging is possible, allowing feedback and logging of parameters such as pitch and roll, rudder angle, and shaft speed. Model motions can be accurately captured and recorded by the Qualisys Motion Capture System during testing to provide high quality information regarding vessel performance. State-of-the-art infra-red motion capture technology uses 19 cameras to track and log the position of up to 5 models simultaneously with an impressive relative accuracy of 3mm and spatial accuracy of 0.3mm at a rate of 100Hz.
We produce the key indicators for seakeeping performance including Response Amplitude Operators, Motion Induced Interruptions and Motion Sickness Incidence. Our wavemakers can produce regular, irregular long or short crested irregular seas up to 0.75m in height (with significant heights up to 0.4m) and our large basin size allows us to test the response of the vessel to waves from any angle. This wavemaking capability also allows investigation of floating, moored and offshore vessels and structures. In addition the wave-maker system can damp reflected waves after trials runs offering efficiencies and time-savings in running trials, by reducing waiting times between trials runs.
Our autopilot control systems not only control the speed and heading of the vessel, but can also control stabilising fins, hence we are able to report on the likely effectiveness of these devices in damping the roll motion of the vessel.
For manoeuvring performance our tests report against the requirements of IMO manoeuvring criteria (MSC 137(76)), or against role-specific manoeuvring requirements.