Multi-purpose permanent booms: Design approach and past experience

Safety booms are designed for a range of resistance capacities to withstand environmental forces. Some are permanent installations, while others are deployed only during the summer months. During the past two decades, many owners considered permanent booms as a preferred option. The added cost was justified because of the increased safety provided at dam intakes and spillways. As the booms would be in place permanently, the public would be protected immediately when the ice had gone, especially during the spring freshet, which is the most dangerous time to be near dams because of the higher than average flows. Experience has proven that permanent booms last at least 25 years, and are in fact less expensive in overall terms, as a result of the additional labour costs associated with the annual removal and deployment of seasonal booms. This paper discusses a number of past projects where permanent booms were installed 25 years ago and are still providing excellent performance today.