This study concentrates on simple concepts for the mathematical modelling of the probability of an iceberg hitting a fixed offshore structure in regions like the Northern Barents Sea. It illustrates the sensitivity of the estimate to various physical assumptions. The study indicates that iceberg collision risks for fixed offshore structures are significant. The paper gives concepts for the description and estimation of iceberg production and the spatial distribution of iceberg trajectories.
There is virtually no experience with the use of fixed platforms in Arctic waters at depths allowing large icebergs to float freely without grounding. For large icebergs this may require water depths of 100 m or more. High estimates of iceberg collision likelihoods will determine the layout and costs of such platforms. That may well be the case in the Northern Barents Sea region. This paper discusses how to estimate the probability of an iceberg collision with a fixed platform in this region. The perspectives for collision risk assessment are different for government agencies, oil or insurance companies. A trivial example is that an agency usually not explicitly includes in its analyses the most unfavourable, low-probability events that may lead to bankruptcy - the game-over-event. A mandatory disaster insurance coverage will, however, impose a wider perspective. Low estimates of risks may have, for example, the favourable consequence that the insurance premiums will be low. Therefore collision risk estimates should be as objective, standardised and general as possible. Objective and standardised general approaches may also promote efficient reporting for operator"s management. The purpose of this paper is to clarify certain key concepts and show that it is possible to make reasonably accurate and consistent estimates of iceberg collision risks. The paper gives some simplified and illustrative case studies.