Numerical simulations are carried out to examine the interaction of a managed ice cover with a drillship. Station keeping is maintained using a mooring system and Thruster-Assisted Mooring. The ice model is based on solving the momentum and constitutive equations, which determine the stresses and deformations of the ice cover. The drillship is modeled as rigid body of three degrees-of-freedom: surge, sway and yaw. A Base Case examines a managed ice cover consisting of floes with sizes ranging from 20 m to 50 m, and a uniform ice thickness of 1 m. The ice cover moves at 0.3 m/s along the surge direction. The drillship has a length of 130 m, beam of 42 m and a mass of 100,000 Mt. The resulting ice force shows peak values reaching 1.7 MN. Analysis of the ice force-time records gives probability distributions of the peak forces, the time required for the force to reach the peak (rise time to peak force), and the rate of force increase. The work includes a parametric study, which examines the effects of the size of the drillship, ice thickness variations, the existence of large ridge fragments in the ice cover, the presence of brash ice, patterns of icebreaking tracks, and thruster assistance to the mooring system.

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