Lessons learned from Offloading Oil from Potentially Polluting Ship Wrecks from World War II in Norwegian Waters.

Abstract

ABSTRACT Norway has more than 2100 ship wrecks within its territorial waters. They have been classified according to their pollution potential, both from cargo and bunker oils. Most concern has been paid to World War II wrecks with large amounts of bunker oil or oil tankers. 30 high risk wrecks have been monitored since 1993, with concern about corrosion and oil leakage. New knowledge on corrosion status and toxicity of different oil types has radically changed the priority list for which ships will be handled first. The Norwegian Coastal Administration, has conducted oil recovery from eight of these ships (30 – 150 meters depth). The amount of oil had been estimated on all ships based mainly on ships' papers, eyewitnesses to the incident and known damage to ships (hits by bombs, torpedoes, etc). We have tested different oils for their environmental effects to marine organisms. We have also tested for operational purposes in case we have to handle large amounts of oil after a sudden collapse of one or more tanks. The very high toxicity effects on marine environments from some German oils (coal based) compared to British oils (mineral oils) is important new information that will alter the priority list for oil recovery from World War II ships. The methods for hot tapping have also been developed and refined during the different operations. This brings the time and cost of each operation down significantly. The use of highly experienced personnel and standardized equipment from the off-shore oil industry contributes to the same.