The drift of sea ice ridges and hits on an offshore structure with dimensions 200 m by 200 m
have been studied for the Dolginskoye oil field in the Pechora Sea. The calculations were
made with the computer program ICEBERG. The mean drift speed of the ice ridges was
found to be 0·21 m/s with a maximum speed of 0·89 m/s. The expected number of hits per
year was calculated to be 737. It was assumed that a total number of 133000 sea ice ridges
would be produced in (or have entered) the Pechora Sea per year. Under the same
assumption, the expected number of ridges entering a safety zone around a platform of
1852 m by 1852 m was found to be 5649. However, due to uncertainties concerning the
population of ridges, their shapes, sizes, drag coefficients and tidal action, the results should
be used with care and only considered as indicative. The ridge drift pattern was
predominantly to the northeast in the winter months. A structure located at Dolginskoye will
most probably be exposed to sea ice ridges that are formed in the area around Khodovarihka.