Tracy Alloway

The US Navy operates a 50,000 acre forest in Indiana whose entire job is keeping one wooden ship from 1797 afloat. The ship is USS Constitution, still a commissioned warship with an active-duty crew. Cannonballs bounced off her in 1812 because the hull sandwiches a wall of live oak ribs between two layers of white oak planking, nearly 2 feet of solid wood so dense it barely floats. British 18-pounders hit it and dropped into the sea. A sailor yelled "her sides are made of iron" and the nickname stuck. Here's the problem with owning a 229-year-old wooden ship: you can't buy the parts. Hull planks run up to 40 feet long and 7 inches thick, cut from single white oak trunks. A white oak takes over a century to grow that big. No lumberyard on earth stocks it. So the Navy grows its own. Constitution Grove at Naval Support Activity Crane holds trees over 100 years old, reserved exclusively for this ship. Foresters there are managing oaks today that will become hull planking in the 2100s. The maintenance plan literally runs on tree time. Every 20 years or so she enters dry dock and shipwrights swap out rotted timber. After two centuries of this, estimates put original 1797 wood at maybe 10 to 15 percent of the ship. The Navy keeps replacing her plank by plank because Congress mandated her preservation and because she's the only active US warship that has sunk an enemy vessel. Every other asset in the Navy has a decommission date. This one has a tree farm.