This report estimates a possible maximum collision velocity between a supply vessel , drifting out of control and a fixed platform. Many simplifying assumptions are made in this initial study.

The maximum collision velocity is found be 3.3m/s in the presence of collinear 0.5 m/s current, 18m/s wind and 3m significant wave height. No attempt is ma& to assign a probability of occurrence to this collision velocity.

This work was commissioned by the Department of Energy, Petroleum Engineering Division.