OHMSETT TESTS OF A ROPE-MOP SKIMMER IN ICE-INFESTED WATERS1

Abstract

ABSTRACT The increase in petroleum development activities in the arctic region has raised concerns over potential oil spills during the broken ice season. Currently, exploratory drilling for oil and gas is restricted during this season due to the lack of proven oil spill cleanup methods for broken ice fields. Test programs have been conducted at the U.S. Environmental Protection Agency's Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) to determine the feasibility of cold weather testing and to evaluate various oil spill cleanup methods considered for use in the arctic. This paper describes a test program to determine the practicality of using a catamaran-mounted rope-mop skimmer for spill cleanup in broken ice fields. An Oil Map Pollution Control, Ltd., prototype arctic skimmer was tested in the test tank under controlled conditions during January 30 to February 7, 1984. Freshwater ice cubes of 250 to 280 millimeters (mm) were used in the tests to approximate a broken ice field. During tests, a predetermined ice condition was established across the encounter width of the rope mops and oil was distributed over the ice. The oil and ice were channeled into the skimmer by two booms, which were joined to the skimmer at the bow. Nine tests were conducted at a tow speed of 1 knot using Circo 4X light oil. During the tests, ice concentrations were varied from 0 to 75 percent of the surface area, and oil slick thickness varied from 3 to 8 mm. The test results demonstrated the spill cleanup capability of the skimmer in ice-infested waters having up to 50 percent ice coverage. At higher ice concentrations, the skimmer was ineffective due to ice jamming at the skimmer inlet.