Remains of mystery ship under Twin Towers site dated to 1773

Almost exactly four years ago, construction work at the new World Trade Centre site came to a halt after the remains of an ancient ship were discovered just where the Twin Towers once stood.

The remains of the ship's bottom, salvaged from beneath where the Twin Towers stood

The ship was uncovered 22 feet below street level in a space that had since been converted into an underground car park. Work was halted for weeks after the unlikely discovery as the ship was being removed.

According to a new report, the mysterious ship was probably built in the 18th century in a shipyard near Philadelphia, most probably in 1773.

The findings, published this month in the Tree Ring Journal, come following analysis of the wood samples from the ship at Columbia University.

According to archaeologists who examined tree rings from the wood of the ship's hull, the wood had come from a forest of White Oak trees near Philadelphia. They say the wood would have been cut around 1773.

The pieces matched historic samples of wood from Philadelphia as also samples of wood taken from Independence Hall, Philadelphia, which was opened in 1753, where the Declaration of Independence and the US Constitution were both signed.

According to archaeologists, the vessel was from the 1700s based on its shape and the type of wood used in its construction.

According to a story in Mashable, the ship was probably a Hudson River Sloop, a Dutch ship designed to navigate shallow, rocky water.

According to scientists, the ship ended up at the World Trade Center site after it was docked in Manhattan. In the late 1700s the ship came to be ultimately buried under trash and other landfill.

Scientists say the ship disappeared from view around 1818 and did not reappear until 11 September 2001 after the terrorists struck New York's Twin Towers.

A Hudson River Sloop, designed by New York's first European settlers