In 2009, an area off the coast of North Carolina nicknamed the Graveyard of the Atlantic was pummeled by a series of fierce, back-to-back winter storms. After weeks of churning waters smashing against the coast, a twelve-ton shipwreck was pushed up onto the beach after spending nearly 400 years at the bottom of the ocean floor. The ship’s 12-inch by 12-inch beams were made of European white pine oak, and held together not by iron spikes, but by large, individually tooled wooden pegs. It was thought to have been the remains of a slow-moving mercantile ship dating back to the 1600s and is one of the oldest wrecks ever discovered off of the North Carolina coast.
For historians and local researchers the shipwreck was a remarkable find, but excitement soon turned to worry, as the surf relentlessly pounded the recently exposed remains and threatened to completely destroy it and wash back out to sea. After several days of damage, the decision was finally made to pull the wreck up onto the beach despite the fact that without the centuries of preservation offered by the frigid Atlantic waters it would end up drying out and wither from exposure to the sun and salty air. Six years later the wreck, eventually moved to the Graveyard of the Atlantic Museum in Hatteras, is barely recognizable as the timbers have shrunken, decayed and lost their shape. An irreplaceable piece of history is being lost forever, a victim of the elements, and there really isn’t much anyone can do about it.
Determined to not lose more history like this, the education programs coordinator for the University of North Carolina Coastal Studies Institute in Wanchese John McCord has turned to 3D printing and 3D photogrammetry to take virtual snapshots that can last forever. In September McCord dove down to the wreck of a submarine that sank off the Outer Banks of North Carolina back in 1942, and took over 700 pictures from every conceivable angle. Back in his lab he simply loaded all of those pictures into a software package that uses an algorithm to convert all of the separate images into a 3D printable model of the submarine. Seven years ago it took a crew of five a full four days and hundreds of hours to produce a drawing of the same wreck that was much less accurate than the one that McCord created in a single dive.
The process of using multiple images to accurately measure objects or landscapes that are too large to accurately measure quickly is called photogrammetry, and the software capable of converting those measurements into a 3D model is relatively new. Originally created for large construction projects or to track the movements of wildlife, several researchers are beginning to adapt the software for historical finds like shipwrecks that are often in danger of being lost or destroyed by forces outside of their control. Especially in places like the Graveyard of the Atlantic, where local weather and environmental conditions have caused thousands of ships to sink, and also have made them notoriously difficult to locate. When storms do push wrecks up onto shore researchers and locals do their best to document and preserve them, but they are often battling the same forces that pushed them up onto shore.
“One minute they are there and the next minute they are washed out to sea. Part of what we’re looking to do is get to the shipwreck very fast, soon after they are uncovered, or discovered, with minimal equipment and capture the most accurate data in a short time. The next project is whatever wreck is next exposed,” explained Nathan Richards, head of the Maritime Studies Program at the Institute, told the Virginian Pilot.
McCord and Richards’ latest project is using 3D photogrammetry to capture what is known locally as the O’Keefe wreck, after Charles O’Keefe, the man who discovered the wreck on the beach in the 1990s. The shipwreck located on the Corolla beach area regularly appears and disappears throughout the year, and is believed to be the remains of the Metropolis, a Civil War-era steamer that sank back in 1878. McCord captured areal data of the wreck using a drone fitted with a powerful camera, while Richards took close-up images on the beach, including under the exposed areas that the drone cameras wouldn’t be able to see. The process took McCord and Richards a little over twenty minutes to capture the hundreds of images that they needed. Once the images were loaded into the software, they had a highly accurate, full-color 3D model of the shipwreck in a little over an hour.
Not only does this process make research of shipwrecks cheaper, faster and easier, but it provided them with data far more accurate than they would traditionally be able to capture. According to McCord, 3D models like these could create a virtual atlas of shipwrecks that anyone could access online and study independently. He also suggests that in the future interactive images of underwater shipwrecks typically inaccessible to average people will be regularly used by visitors to museums and historical centers all over the world.
While 3D photogrammetry doesn’t replace the need for researchers like McCord and Richards to visit sites locally to study the material characteristics and workmanship of the ship’s remains, it does allow them to create a more accurate record of their findings. Especially in the face of environmental forces that could take their finds away from them, possibly even forever.
We’ve seen similar techniques used to great effect in the Great Lakes, as well, illustrating further the broad range of use for photogrammetry and other high-tech methods for preservation. Discuss this story in the 3D Printed Shipwreck forum thread on 3DPB.com.