Comparison Between Full-Scale and Model Experiments of Oil Fences

This study examines the performance of an air expansion oil fence system as deployed in two different configurations. Geometric and tension characteristics of the oil fence are investigated for (1) the system attached to two vessels and (2) the system attached to one vessel with spreading devices. Since full-scale testing can be time consuming and expensive, another component of the study was to examine how well models would perform. A scaling technique was developed and a set of experiments were conducted with a 1/20-th scale model of the oil fence in a towing tank facility. Performance results from the model tests were compared with those conducted at sea. The tension (N) in the full-scale results were rep-resented by R = av~b, where v is the current velocity in m/s and the values for a and b used for comparison purposes. Both sets of full-scale and model tests were conducted with an oil fence opening of 120 m and 160 m. In the full-scale experiment with spreading devices attached to the forward ends of the oil fence, the horizontal distance of the spreading devices has a tendency to linearly increase as the current velocity increases when the warp length is as short as 50 m, but to linearly decrease as the current velocity increases when the warp length is extended to 100 m and 150 m. The spreading distance at uniform current velocitys in the model test increases as the warp length is extended. While there is no significant difference of spreading distance between the cases of 100 m and 150 m, the spreading distance becomes shorter when the warp length is 50 m.