A hunch about the Hunley

Posted: May 7, 2014 - 5:21pm | Y-12 Report | Volume 10, Issue 2 | 2014

Interior view of the H. L. Hunley, the first submarine to sink an enemy ship in combat. Use of photo courtesy of the Friends of the Hunley

A few years ago best-selling author Patricia Cornwell sought the aid of several East Tennessee researchers, including Y‑12 engineer Steve Dekanich, in solving a puzzle. She hoped the team would discover what caused the demise of the H. L. Hunley, a Civil War submarine that mysteriously sank off the South Carolina coast.

Here are the facts of the case: One February night in 1864, the eight-member crew of the H. L. Hunley used a hand crank to propel the Confederate submarine into Charleston Harbor. Their mission was to torpedo the Union warship USS Housatonic. The crew successfully blasted and sunk the enemy vessel, but shortly after, the Hunley itself sank.

In 1995 the Hunley was discovered on the ocean floor. Five years later, archaeologists raised the vessel and transported it to the Warren Lasch Conservation Center in Charleston for excavation.

What actually caused the Hunley to sink? Hypotheses and clues abound, but 150 years later, what happened remains a naval mystery.

Cornwell, having worked with East Tennessee researchers on previous projects, returned to the region to fund a team of scientists to investigate. “Y‑12 was chosen because of our extensive expertise and work with metals,” said Dekanich. “We also had the tools to do the analyses, such as the large-chamber scanning electron microscope.” At the time, the microscope was one of the largest chamber scanning electron microscopes in the world — big enough to accommodate an entire V6 engine block and with a resolution about 10,000 times smaller than the thickness of a human hair.

As part of his examination, Dekanich explored inside the sub. “To physically touch and experience something from the past was exciting but eerie,” he said. “The paint on the bench where the crew sat looked almost as fresh as the day it was painted, and it was easy to imagine them sitting at their stations.”

As Dekanich delved, he started to develop an intriguing hypothesis. He also realized the many ways Y‑12 could apply its expertise in testing it.

Because the crewmen’s skeletal remains were found seated at their stations, Dekanich hypothesized that the sub sank after the men were knocked unconscious from the shock waves of the torpedo blast. He proposed conducting a hardness test on the vessel’s leading edge, the metal closest to the blast, and trailing edge and using the data to determine the force of the explosion.

“A comprehensive investigation of this type would require knowledge of failure analysis, materials behavior, scanning and optical microscopy, chemical analysis, X-ray applications and dynamic loading, which are the forces that move or change when acting on a structure,” Dekanich said. “These are all capabilities Y‑12 excels in.”

Although Dekanich didn’t have the opportunity to test his hypothesis (his proposal wasn’t selected for further funding), Cornwell did write Y‑12’s capabilities and personalities into a couple of her novels. “She was so impressed with our skills and the large-chamber scanning electron microscope that she included Y‑12 and the microscope in Book of the Dead and Scarpetta,” Dekanich said. “And her Dr. Franz character is a combination of a former Y‑12 researcher and me.”

Cornwell’s crime-solving forensic pathologist Kay Scarpetta may be accustomed to cracking cases, but one mystery yet to be fully solved is the fate of the H. L. Hunley. For more information on the sub’s history, recovery and conservation, visit the Friends of the Hunley website.