We use Fiber Reinforced Polymer (FRP) composite materials to manufacture crush blocks. These blocks serve as safety equipment at locks and dams. There's very little room between vessels and lock walls so these 12”x12”x14” crush blocks are kept nearby. If someone were to fall into the water, the crush blocks are thrown in, preventing the person from being crushed by a vessel. In the past, aluminum was often used - it resists corrosion better than wood or steel. However, aluminum must be welded carefully to maintain a watertight cube.
Composite Advantage molded FRP crush blocks will never corrode. Fiber reinforced foam core means that the block handles the crushing loads and is naturally buoyant.