Flying

The Old River Control Auxiliary Structure is a rank of seven towers, each buff with a white crown. They are vertical on the upstream side, and they slope toward the Atchafalaya. Therefore, they resemble flying buttresses facing the Mississippi. The towers are separated by six arciform gates, convex to the Mississippi, and hinged in trunnion blocks secured with steel to carom the force of the river into the core of the structure. Lifted by cables, these tainter gates, as they are called, are about as light and graceful as anything could be that has a composite weight of twenty-six hundred tons. Each of them is sixty-two feet wide. They are the strongest the Corps has ever designed and built. A work of engineering such as a Maillart bridge or a bridge by Christian Menn can outdo some other works of art, because it is not only a gift to the imagination but also structural in the matrix of the world. The auxiliary structure at Old River contains too many working components to be classed with such a bridge, but in grandeur and in profile it would not shame a pharaoh.

—John McPhee, “Atchafalaya” (1989)