SSPA Sweden

Introduction to SSPA Sweden's test facilities

New technology needs to be tested, new ideas demonstrated and validated and SSPA offers the arena, tools and methods to do it. Our experts have a broad range of knowledge and profound expertise and we use our resources such as databases, analysis and calculation capabilities, laboratories, collaborative platforms and skills to create value. SSPA has the capability to perform most kinds of model testing in its facilities: the towing tank, the large cavitation tunnel, the seakeeping and manoeuvring basin and combine with computer tests.

All test facilities at SSPA are designed for performing tests with large models, which have many advantages, given that scale effects are reduced and more reliable measurements can be performed. The test procedures used are in accordance, as applicable, with the ITTC Recommended Procedures. As a complement, methods for performing field (outdoor) model testing with fully equipped models have been developed at SSPA and can be used if needed.

Towing tank

The towing tank has many applications, primarily concerning hull and propeller form optimisation for all kinds of ships or energy saving devices with respect to resistance and propulsion. The tank dimensions and the high carriage speed facilitate the use of large, self-propelled displacement models and testing of high-speed vessels. The flap type wave generators provide regular as well as irregular waves for the determination of seakeeping characteristics and ride comfort. By combining the results with simulations, behavior in oblique seas can be estimated.

A database containing over 8,000 ship hull forms provides the basis for result analysis and guidance for hull form optimisation of merchant ships, as well as high-speed and planning crafts. In-house research activities ensure enhanced knowledge and the continuous development of methods within the field of ship hydrodynamics.

Technical data

Basin dimensions; length 260 metres, breadth 10 metres, depth 5 metres. More technical data, for example speed, wave length and wave height will be found at http://www.sspa.se/our-facilities-and-tools/towing-tank

Cavitation tunnel

SSPA has over 50 years of experience in cavitation testing. The cavitation tunnel consist of three interchangeable measuring sections allowing high speed testing of propellers up to 23 m/s as well as large ship models of up to 10 meters in section number three. When performing cavitation studies for ships, the complete ship models can be installed in SSPAs cavitation tunnel, which provides a very good representation of the wake field.

Since the cavitation tunnel is a very cost-effective facility, there are many possibilities for solving any problems that might occur. In addition to cavitation studies and erosion prediction, the tunnel is used to measure pressure pulses and radiated noise. Tests can be performed for all kinds of vessels, including merchant ships and fast naval ships, as well as submarines and other underwater vehicles. In addition to study the ship propeller also energy saving devices, rudders, fins and PODs can be included in the scope. The cavitation tunnel is also very valuable in various types of flow studies. Well-correlated traditional methods are combined with high-speed video, PIV etc. Both in-house and external tools and programs are available to analyse the results. The cavitation tunnel can also be used for studying and developing the latest green technologies such as ships equipped with an air cavity, air lubrication of ship hulls and tidal water turbines.

Technical data

Tunnel sections; 1 - 2.5 metres, 2 - 9.6 metres, 3 - 8.0 metres. More technical data, for example sections diameters, max speed, m/sec and more, will be found at http://www.sspa.se/our-facilities-and-tools/cavitation-tunnel

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 and the facility 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; length 88 metres, breadth 39 metres, depth 3,5 metres. More technical data, for example; water depth, deep-water pit, wave length, wave height and more will be found at http://www.sspa.se/our-facilities-and-tools/maritime-dynamics-laboratory

Model manufacturing

We have facilities for designing, building and outfitting of models for all kinds of model tests. Our procedures for manufacturing and tests follows SSPA Quality System and ITTC Quality Manual. This includes milling machines for hulls and propellers, paint box, a team of measurement engineers and a workshop for the assembly of hulls, propellers, rudders and other appendages as well as propulsion motors and measurement systems. The superb flexibility of SSPA’s milling system for large objects makes it one of the best systems for manufacturing ship models, moulds, and patterns. Propellers and models are laser measured on a regularly basis to ensure high accuracy, in accordance with ITTC tolerances. Read more at http://www.sspa.se/our-facilities-and-tools/model-manufacturing

SEAMAN Simulations

Simulations is an efficient tool for maritime infrastructure development projects. The output will directly support clients in their decisions of alternative layouts of ports, fairways and terminals. SSPA has decades of experience and records supporting clients worldwide.

For each simulation assignment, SSPA communicates with the customer to ensure that the simulation has the right level of detail, with regard to both accuracy and cost efficiency. To reach the proper level there are a number of areas that SSPA will tailor to the customer's needs: Ship Dynamics, Modelling, Instrumentation, Visualisation and Analysis. Read more at http://www.sspa.se/tools-and-methods/simulations

Pictures (left to right):

- The 7th Hydro Testing Forum meeting were held at SSPA, April 2016;

- The towing tank has many applications, primarily concerning hull and propeller form optimisation for all kinds of ships or energy saving devices with respect to resistance/ propulsion;

- A database containing over 8,000 ship hull forms provides the basis for result analysis and guidance for hull form optimisation;

- For each simulation assignment, SSPA communicates with the customer to ensure that the simulation has the right level of detail, with regard to both accuracy and cost efficiency;

- SSPA has decades of experience and records supporting clients worldwide;

- The cavitation tunnel consist of three interchangeable measuring sections allowing high speed testing of propellers up to 23 m/s as well as large ship models of up to 10 meters in section number three;

- Well-correlated traditional methods are combined with high-speed video, PIV etc. Both in-house and external tools and programs are available to analyse the results;

- The computer controlled, multi-motion carriage, spanning the whole basin, offers unique possibilities for conducting captive or free sailing maneuvering tests;

- The superb flexibility of SSPA’s milling system for large objects makes it one of the best systems for manufacturing ship models, moulds, and patterns;

- Propellers and models are laser measured on a regularly basis to ensure high accuracy, in accordance with ITTC tolerances.