The possibility of reducing offshore structural response under strong external excitations such as wind storm, sea ice and
earthquake via control systems is attracting the interest of a large number of researchers. Up to now, lots of dampers
have been installed on different offshore platforms. As one new kind of effective semi-active device, magnetorheological
fluid (MRF) damper has been used in the field of mechanical equipment, automobile and civil buildings, however, the
practical application for vibration control of offshore platform has not seen before. In this paper, 8 MRF dampers with
maximum damping force of 100kN for vibration control of one offshore platform with total weight of 650t have been
manufactured and tested. The general situation of MRF damper system and the offshore platform include manufacturing
issues, powering, range of variability of the mechanical parameters and response time are introduced.