The plume resulting from a subsea well blowout alters the
environmental loading on a floating platform which is
directly above the well. Horizontal ocean currents deflect
the plume and may create a more severe loading on the
structure. During the early stages of a blowout the
"starting plume" induces forces of a different magnitude on
the structure. A preliminary experimental study,
investigating the transient loads induced by starting plumes
and the effects of currents on blowout plumes, was
conducted. The results of the experiments showed that the
forces involve significant fluctuations which are quite
different from the average values. The normal forces induced
by starting plumes were slightly greater. Horizontal
currents caused an increase in the moment acting on the
structure. This is of considerable importance as moments,
when coupled with the situation of flooded decks and
compartments, may cause the structure to sink.