In the North Sea there is a tiny archipelago named Heligoland. Its two islands are home to just 1,400 people. However, for the German shipping industry, the region is of great interest. This is because only here do the ecological conditions in the sea – the salinity as well as the flora and fauna – almost exactly match those of the world’s oceans. Heligoland therefore serves as a natural laboratory where SKF can test the durability of ship components under realistic conditions.
Field research under the microscope
SKF technicians observe the material tests that their company carries out in collaboration with Fraunhofer IFAM, a research institute from Bremen, Germany, specializing in materials. All types of materials and components are tested, including GRP casings and bushes.
As ship components are exposed to harsh conditions, coatings are applied to them to protect them from wear and corrosion. But new types of coating also need to be tested. The specialists check the resilience of the coating and ensure it provides the necessary protection. There are even anti-fouling coatings, specifically designed to prevent the buildup of plants and algae on vessels.
Technicians use what is known as an exposure test, whereby the samples are examined in contact with seawater. The testing area can be used to test ship components under different conditions for varying lengths of time – not in a laboratory but in a natural environment.
Depending on the future purpose of the component, of which there are many possibilities, there are various questions that need answering. For example: will the component in question exclusively be exposed to sea spray, only submerged under high tides, or permanently under water? This ultimately depends where in the ship the components will be used later. For example, the permanently submerged zone is particularly useful for testing shaft seals because these are constantly under water in real use. The testing area can be used to test ship components under different conditions for varying lengths of time – not in a laboratory but in a natural environment.
Months of exposure
Corrosion and vegetation are of particular interest to researchers – and both of these do not appear overnight. Most samples are therefore tested for between six and twelve months, but it can sometimes take much longer. Only once the sample material has passed the endurance test can it be released onto the market.
Such rigorous testing is not required by the law. But SKF likes to ensure that its products, such as the sterntube seal, meet the highest standards. These seals may be tested for as long as a year before being brought back to land to be examined. After such rigorous testing, the product will no longer look brand new on the outside – but the chances are high it will have passed the test with flying colors.