The crew of the Civil War submarine HL Hunley likely died from airblast injuries, according to a study published August 23, 2017 in the open-access journal PLOS ONE by Rachel Lance from Duke University, USA and colleagues.
The Confederate submarine HL Hunley sank the Union ship Housatonic on February 17, 1864 by setting off a black powder torpedo against its hull. Following its attack on the Union ship, however, the Hunley also ended up sinking. When the submarine was raised from the ocean floor in 2000, the skeletons of its 8 crewmembers were found seated at their respective stations, with no physical injuries or indications that they were attempting to escape. 150 years later, it's still not clear how the crew of the HL Hunley died.
To recreate and measure the black powder explosion that occurred in 1864, Rachel Lance and colleagues constructed a scale model of the HL Hunley, named the CSS Tiny, and exposed it to underwater blasts. An internal pressure gauge at the center of the Tiny measured the pressure inside the cabin generated by each blast. The experiment was scaled so that the force of the blast transmitted in the same way as the pressure transmission into the HL Hunley. This data was used in combination with archival experimental data to calculate the risk to the cabin crew from its own torpedo.
While the actual blast transmission of the HL Hunley is likely underestimated in this scaled model, the strength of the blast was estimated to be sufficient enough to cause pulmonary and brain trauma to the cabin crew. Therefore, the authors suggest that the blast wave transmitted from the Hunley's hull to its cabin likely killed its crew.
"The disappearance of the Hunley has long stood as one of the great mysteries of American history," says Lance. "Finding the cause of death of the crew has finally allowed us to declare the mystery solved."
In your coverage please use this URL to provide access to the freely available article in PLOS ONE: http://journals.plos.org/plosone/article?id=10.1371/journal. pone.0182244
Citation: Lance RM, Stalcup L, Wojtylak B, Bass CR (2017) Air blast injuries killed the crew of the submarine H.L. Hunley. PLoS ONE 12(8): e0182244. https://doi.org/10.1371/journal.pone.0182244
Funding: We would like to gratefully acknowledge funding and support from the Josiah Charles Trent Memorial Foundation Endowment Fund at Duke University for directly funding this research. We would also like to acknowledge funding from the DoD SMART Scholarship Program for the research and education of Rachel M. Lance. We also gratefully acknowledge funding provided by the US Army MURI program (U Penn prime--W911NF-10-1-0526) partially supporting Cameron Bass. In addition, we would like to thank the Hagley Library's Center for the History of Business, Technology and Society for funding via an Exploratory Research Grant that enabled the historical black powder research.
Competing Interests: The authors have declared that no competing interests exist.