Effect of hardness in shackle chain wear under harsh environmentally conditions

Industrial fishing (e.g. bottom trawling) uses shackle chains as a sea soil rake to increase the catch. Serving in such extreme conditions (seawater, sand) results in limited lifetimes less than 6 months. To increase the lifetime, hardened ‘wear resistant’ chains could be a possible alternative but quantitative data on their lifetime is unclear. In this study we quantified the wear rate and wear mechanism of two commercially available chain materials. The wear experiments performed on a custom designed full scale test rig show a significant difference between both materials. The hardened chains wear out ~1.5× less comparing with the ‘normal’ chains. The current investigation allows fishermen to make an economical trade-off between both types of chains.