A full scale test rig for assessment of abrasive wear of shackle chains

During industrial fishing are link chains used to drag the trawls and churning of the seabed. The latter application wears off the steel chain in less than 6 months. However, there has been no tribological research concerning full scale testing of shackle chains in presence of seawater and sand. We therefore designed a new test rig at Ghent University, Soete Laboratory. The test rig generates wear in a single shackle contact and uses full scale specimens with the correct geometry. This paper describes the design of the test rig, emphasizing two innovative features compared to ordinary wear test rigs. First one is the possibility to apply two types of relative motion between neighbouring shackles: planar and circular motion. The second novel feature is the supply of harsh environmental conditions like seawater, sand or a mixture of both. The presented results reveal the wear mechanism as abrasive wear. The wear rate is measured by weight reduction and chain elongation. Higher wear rates are found in case of circular relative motion and in case of environmental harsh conditions. The test rig can be used for the validation of new wear models or the comparison of materials.