ECU Bermuda field school digs into shipwreck

Don’t let the name fool you! Bermuda’s Iron Knee Shipwreck is not about sailors with peg legs, or even about seafaring legends and the like, but it’s a mystery ship nonetheless and one that East Carolina University’s fall semester maritime field school has found intriguing.

The field school team, led by Gordon Watts, a professor in the Maritime History graduate program, has been working with the Bermuda Maritime Museum staff since September in trying to unravel the identity of an old ship that sank on one of the northwest island reefs. The timbers of the old vessel rest in a pocket of sand between the coral heads that destroyed the ship in the late 18th or early 19th century. Watts and an earlier field school team located the site in1997. Excavation by another ECU team in 1999 exposed and examined sections of the bow and stern. This year, the team took their search to the middle section of the vessel that had been the ship’s cargo hold.

With ballast stones covering much of the hull, the team members had to remove the stones to map and measure the ship’s timbers. They constructed an aluminum grid over the excavation area so that they could plot each element of the hull structure, specific features and fasteners. The data were recorded on graph paper and digitized using computers and special software.

“We hoped that the architectural and construction features of the wreck would help in developing a more comprehensive understanding of the evolution of ship design and construction in the 18th century,” said Watts. But what the team found were only the pieces of an intricate puzzle.

Most shipwreck sites are littered with broken glass and ceramics that help in determining when the ship sank and where the vessel came from. There were no such fragments on this wreck. The only cultural material found were the remains of hundreds of cut nails that had spilled in among the ballast stones. The nails indicated the wreck occurred late in the 18th century or early in the 19th century, but they didn’t help pin down a date or country of origin.

Another surprise was that the ship’s construction made use of “L” shaped, cast iron knee braces that served as supporting beams under the upper and lower decks of the vessel. “Iron knees” were a popular replacement for wood in the 19th century, but shipbuilders used wrought iron — not cast iron — for these braces.

“To date, research has not identified one reference to the production or use of cast iron knees in shipbuilding,” said Watts.

He said cast iron is common in the construction of buildings, but shipbuilders may have considered them too brittle for use in an early ocean-going vessel that must be able to give and flex when the seas are high and rolling. None of the cast iron knees found at the site were stressed or broken. Watts suggested that the Iron Knee Shipwreck was most likely a British vessel, built in the last quarter of the 18th century. He said the ship’s construction methods along with the cut nails found among the ballast stones serve as clues to the ship’s origin and date.

He said that while it is generally assumed that iron knees did not appear in ships before the 19th century, the French were known to have experimented with these components in the 18th century. The British had developed a sophisticated iron industry during the 1700s and were likely experimenting with iron knees too.

Other questions ask whether the ship was built for carrying cargo or for waging war? No weapons and no cargo, except for the nails, were found among the ship’s remains.