Maritime Dynamics Laboratory
The Maritime Dynamics Laboratory (MDL) is a versatile facility for the research and development of seakeeping and manoeuvring behaviour of ships and other structures.
The MDL can also be used for assessing manoeuvring properties in waves. Model tests in oblique wave conditions play an important part when developing new hull forms for surface vessels. The angle of roll, degree of deck wetness, and course-keeping qualities of a vessel in bow, beam, and stern quartering seas are parameters that are difficult to predict accurately from theoretical calculations alone. Model tests in oblique seas, combined with simulations, have proved to be valuable tools in the study of ship projects.
The computer controlled, multi-motion carriage, spanning the whole basin, offers unique possibilities for conducting captive or free sailing manoeuvring tests. In captive manoeuvring tests, the facility can be used to perform both large-amplitude PMM tests and rotating arm tests, without having to change the set-up between the tests.
For free sailing tests, the width of the basin allows most manoeuvres to be performed with fairly large models, thus reducing the influence of scale effects. The MDL is also a very useful tool when determining whether a new or existing project fulfils the IMO regulations concerning turning ability and yaw checking. Course keeping abilities can also be studied.
Technical data
| Basin | Dimensions Water depth Deep-water pit |
88 × 39 × 3.5 m 0 - 3.2 m 5 × 9 m, depth 8 m |
| Waves | Wave length Wave height Frequencies |
0.2 < lambda < inf. m 0 < H < 0.4 m 0 < f < 3 Hz |
| Wind | Speed approx. | 0 - 10 m/sec |
| Current | Towing up to 3.5 m/sec Pump system up to 1.0 m/sec |
|
| Carriage | Motion x’0 y’0 psi’0 |
Speed ± 3.50 m/sec ± 3.00 m/sec ± 30 °/sec |
Research project: Predicting ship performance in waves
SSPA is now conducting a research project to increase the accuracy and efficiency of detecting added resistance in waves experimentally and numerically. More accurate and efficient numerical and experimental procedures will make it possible to cost-effectively predict overall ship performance in a seaway early during the design process and to avoid costly pitfalls.
Manoeuvring and seakeeping simulations, and the importance of high-quality data
Simulations are an efficient tool for gaining valuable insights for decision-making. To perform high-quality ship simulations, high-quality input data is required. Without good input data, the output from the simulations will not be a reliable source of support for decision-making. Thanks to SSPA’s test facilities, and the development and use of CFD, we have access to extremely good data which supports the simulation models in the SEAMAN Simulation toolbox.
SSPA ramps up yacht testing
Lately, SSPA has tested models for a number of major yacht projects. Yacht testing requires attention to details not only in terms of the methods and model accuracy, but also, and possibly most importantly, in terms of how to handle the demands and criteria set by the client.
Safer and higher-performing LNG bunker vessels
The days when HFO was the supreme fuel are over and environmental concerns, demands for sustainability and stricter legislation have led to a variety of fuels to choose from: methanol, low sulphur heavy fuel oil (LSHFO), liquefied natural gas (LNG) and a variety of mixes of MGO (marine gas oil) and MDO (marine diesel oil).