Two ice booms in the international section of the St. Lawrence Seaway, near Ogdensburg, New York, were instrumented for measuring ice forces in the winter of 1972-73. These ice booms are among several installed annually by the United States and Canada primarily to prevent ice jams from forming and severely restricting water flows. As presently used, they act as barriers to the navigation of ships. Measurements were initiated at a shore anchor site. The system used for these measurements consisted of a commercial tension cell, located in a new line spliced to the anchor rope, which provided electrical signals to a strip chart recorder that operated continuously. A second system consisted primarily of two special tension cells, an armored signal cable, a direct conversion electric generator, and a recorder. This system was used to measure two concurrent forces at a midstream location where high loads were expected. (Modified author abstract).

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