 Each leaf of the bridge floats on a steel barrel in hydraulic oil, situated in center piers at each side of the river.As the bridge intersects the river at an oblique angle, both leaves rotate only 45 degrees (one-eighth turn) to clear the shipping channel instead of the 90-degree turn of most swing spans.It is claimed to be the only bridge of its type in the world and it has received several awards for its innovation, including the Outstanding Engineering Achievement Award of the American Society of Civil Engineers in 1992.