World Trade Center Wreck

This paper is  linked here .

Many dendrochronological studies of timbers from excavated ships are commissioned to determine the dates the trees were felled and the region of the original tree-stands. Contrary to the popular misconception, such tree-ring analysis can reveal far more when applied to nautical archaeology, the study of history through people and physical artifacts in areas relating to the sea. The application of dendrochronology to nautical archaeology coupled with supplementary analyses of artifacts, produces results that can be profoundly telling of the societies that constructed the seafaring vessels. 

As seen throughout history, wood has served as an unparalleled resource for the success and advancement of civilizations, especially sea-faring empires. Thereby, the study of nautical vessels is incomplete without considering the political, economic, and social conditions influencing the construction of ships as well as timber, the paramount resource consumed throughout production.

The application of dendrochronology in nautical archaeology can lead to advancements in understanding how construction practices evolved as well as when and where technological innovation took place; specifically furthering our understanding of forest management and construction practices as well as expanding the means to either support or disprove archaeological hypotheses.

Ability to Evaluate Archaeological Hypotheses.

Often, when dendrochronology is employed, researchers will try to ascertain when and where the timbers are from. In practice, there are various marine areas where specific ships are presumed to have sunk. While the study of ships from these regions follows the same methodology, their findings are often used to support or dispute a specific interpretation of evidence. For example, in July of 2010, a section of a ship’s hull was discovered during excavation at the WTC, World Trade Center site. Through the comparison of the WTC ship chronology and Philadelphia master chronology, dendroprovenancing indicated that the timbers used to construct the vessel were from the same area, an area that was also in close proximity to the shipyard where construction presumably took place.

These results support a hypothesis made by Norman Brouwer, a historian specializing in the maritime history of New York City. Due to the peculiar and unique design of the vessel, Brouwer inferred it was built at a small rural shipyard rather than a large shipyard. The large shipyards would have been producing many of several types of vessels; thereby making them more common, unlike the idiosyncratic design of the WTC ship. Tree-ring analysis indicating that the timbers were most likely from the same area supports Brouwer’s hypothesis as well as the subsequent implications of it. One such implication is that a small shipyard, as described, would have a limited spatial range to acquire timber from as opposed to a well funded large-scale shipyard that would have had the expansive resources to procure timber from a broader geographic region (Martin-Benito 65, 74 &75). The ability to extrapolate information about industry resources and operations through dendroprovenancing ship timbers offers useful new insights to the study of human cultures.

The data for these maps is published in Dario Martin-Benito's "Dendrochronological Dating of the World Trade Center Ship, Lower Manhattan, New York City"

 Linked Here. 

Abstract: "On July 2010, archaeologists monitoring excavation at the World Trade Center site (WTC) in Lower Manhattan found the remains of a portion of a ship's hull. Because the date of construction and origin of the timbers were unknown, samples from different parts of the ship were taken for dendrochronological dating and provenancing. After developing a 280-year long floating chronology from 19 samples of the white oak group (Quercus section Leucobalanus), we used 21 oak chronologies from the eastern United States to evaluate absolute dating and provenance. Our results showed the highest agreement between the WTC ship chronology and two chronologies from Philadelphia (r = 0.36; t = 6.4; p < 0.001; n = 280) and eastern Pennsylvania (r = 0.35; t = 6.3; p < 0.001; n = 280). The last ring dates of the seven best-preserved samples suggest trees for the ship were felled in 1773 CE or soon after. Our analyses suggest that all the oak timbers used to build the ship most likely originated from the same location within the Philadelphia region, which supports the hypothesis independently drawn from idiosyncratic aspects of the vessel's construction, that the ship was the product of a small shipyard. Few late-18th Century ships have been found and there is little historical documentation of how vessels of this period were constructed. Therefore, the ship's construction date of 1773 is important in confirming that the hull encountered at the World Trade Center represents a rare and valuable piece of American shipbuilding history."