The Coast Guard has long recognized the need for a systems approach to open ocean pollution response. At the time of the IXTOC I blowout and the Burmah Agate spill, a series of at sea handling. tests of pollution response equipment had been completed and more were scheduled. This paper describes the Coast Guard's integrated system approach, operational test results, and actual performance 9uring the IXTOC I blowout and Burmah Agate responses. The performance of the Coast Guard skimming barrier at these pollution incidents is highlighted along with an analysis of lessons learned and future work needed.
In the early 1970's Marine Environmental Protection became established as a new Coast Guard mission. During this period a significant research and development program was undertaken to develop pollution response equipment for high sea states inherent in open water. However, the sophisticated new equipment had never been used in the severe spill situation for which it was designed. Following the Argo Merchant incident, the President re-emphasized concern for achieving large spill response capability, and Congress provided additional funds for more equipment to be sited around the country.
Although Coast Guard R&D's goal was to achieve a state-of-the-art open water (high sea state) capability, it was not known if this capability was sufficient or whether higher technology equipment was required.
To find out, the Coast Guard's Office of Marine Environment and Systems tasked the Office of Research and Development in 1979 with conducting an instrumented test to assess the performance of the Coast Guard's skimming barrier and disc drum skimmer in rough seas. The test was to differ from all others: oil would be deliberately spilled, since data from an at sea spill would be vastly superior to tank testing data. The difficulties involved in conducting any at sea test were recognized. Previous testing at the EPA'sCHMSETT tank was good but insufficient. Those tests were limited by bottom effects, sidewall effects, insufficient maximum wave height, and small spill volume.
Before proceeding further, a discussion of the Coast Guard equipment is required.
The skimming barrier (figure 1), manufactured by Offshore Devices Inc., consists of a 62l-ft long, 48-in, vertical, coated fabric curtain with 102 rigidizing struts. The six center struts incorporate skimming weirs and sump tanks. Its container is an l8-ft long, 9-ft wide, 5-ft high aluminum box which is used to store, transport, and rapidly deploy the barrier.
