Tree Rings Under the Trade Center

I first mentioned dendrochronology—the new science of matching up the thicknesses of tree rings to identify the age and source of a piece of wood—back in 2007. It’s usually applied to buildings, and especially to determining whether they’re as old as tradition says.

This week there was a remarkable example of “dendro” in action, applied to a remarkable bit of wood: a small ship’s hull found in 2010 during the excavation for the new World Trade Center in Manhattan.

As Live Science reported, a paper in Tree-Ring Research says a dendrochronology team led by Dario Martin-Benito was able to identify the ship’s wood as white oak. They further matched up the ring pattern in one timber to white oak timbers found in Independence Hall, suggesting that the wood had been hewn in eastern Pennsylvania in 1773.

In addition to the rings, the timbers showed holes bored by worms from the Caribbean, indicating the ship spent considerable time in those waters. The research team estimates that this ship was in use for two or three decades, meaning that it sailed through the Revolutionary War and into the early American republic before coming to rest on what was then the Manhattan shore.

Above is one of the photos from the Live Science report showing a cross-section of the keel with a common modern profile portrait of George Washington for scale. I suspect the holes at the top are from the worms. Here’s the abstract for the paper, “Dendrochronological Dating of the World Trade Center Ship, Lower Manhattan, New York City.”