Underwater Blast Injuries, and the Sinking Of the Submarine HL Hunley by Rachel Marie Lance Department of Biomedical Engineering Duke University Date: Approved: ___________________________ Cameron R. Bass, Supervisor ___________________________ John Camperman ___________________________ Laurens Howle ___________________________ Barry S. Myers ___________________________ Roger Nightingale Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biomedical Engineering in the Graduate School of Duke University 2016 i v ABSTRACT Underwater Blast Injuries, and the Sinking Of the Submarine HL Hunley by Rachel Marie Lance Department of Biomedical Engineering Duke University Date: Approved: ___________________________ Cameron R. Bass, Supervisor ___________________________ John Camperman ___________________________ Laurens Howle ___________________________ Barry S. Myers ___________________________ Roger Nightingale An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biomedical Engineering in the Graduate School of Duke University 2016 i v Copyright by Rachel M. Lance 2016 Abstract Underwater blasts travel further and injury more easily than blasts in air. However, because of a relative lack of data and study dedicated to the subject, the tolerances of personnel in the water to blast exposures have historically been poorly quantified. This dissertation presents an analysis of underwater blast exposures that have resulted in injuries and fatalities. Previously known standards for risk were evaluated and determined to be insufficient. Historical medical reports of exposed divers in the water were then evaluated and reconstructed to form the first known curves to prescribe a quantitative risk of injury or fatality. The mystery of the submarine HL Hunley is an historical underwater blast exposure that has puzzled generations of enthusiasts. The tools for evaluating blast transmission through the water were applied to this puzzle, and it was concluded that sufficient blast transmitted through the hull of the submarine itself to cause fatal or at least injurious levels of air blast trauma to the crew inside. iv Dedication This dissertation is partially dedicated to my parents, Ron and Denise Lance. Thank you to my dad for giving me his love of history, and to my mom for giving me her love of math, even though I was not always the most willing recipient. I would also like to dedicate this dissertation to my fiancé, Nicholas Azan. The incredible support, unwavering encouragement, experimental assistance, and bottomless ice cream he has provided have on many days been all that separated me from failure. The words “thank you” can’t even begin to describe my gratitude. Finally, this dissertation is also dedicated to my grandfather, Earl Lance, one of the original Navy frogmen and underwater explosives experts. I think of him often and wish we could’ve set some charges together. v Contents Abstract ........................................................................................... 4 List of Tables ................................................................................ 11 Acknowledgements .................................................................... 18 1. Introduction .............................................................................. 1 1.1 Statement of the Problem and Hypotheses .............................................................. 1 1.2 Relevance ...................................................................................................................... 3 1.3 Dissertation Organization .......................................................................................... 5 2. Background .............................................................................. 6 2.1 Physics of Air Blast ...................................................................................................... 6 2.2 Physics of Underwater Blasts ..................................................................................... 8 2.2.1 Scaling of Blasts in Water ..................................................................................... 12 2.2.2 Structural Scaling and Transmission into Structures ....................................... 16 2.2.3 DYSMAS Modeling Software .............................................................................. 20 2.2.3.1 GEMINI Structure and Function ................................................................ 21 2.2.3.2 Software Validation ...................................................................................... 22 2.3 TNT Relative Equivalency ........................................................................................ 23 2.4 Blast Injuries ............................................................................................................... 24 2.4.1 Injuries from Air Blast .......................................................................................... 26 2.4.2 Injuries from Underwater Blast ........................................................................... 27 2.4.3 Guidelines for Assessing Injury Risk in Air ...................................................... 28 vi 2.5 Respiratory Physiology During Exercise ............................................................... 30 2.6 Confederate Submarine HL Hunley ....................................................................... 32 2.6.1 The Attack on the USS Housatonic ..................................................................... 32 2.6.2 Features of the Submarine and Archaeological Discoveries ........................... 37 2.6.3 Previous Theories to Explain the Sinking .......................................................... 40 2.6.3.1 Suffocation ..................................................................................................... 41 2.6.3.2 “Lucky Shot” Theory ................................................................................... 42 2.7 Miscellaneous Background ...................................................................................... 44 2.7.1 Ballistic Scaling Methods and Historical Tests ................................................. 44 2.7.2 Bathymetry of Charleston Harbor ...................................................................... 45 2.7.3 Tidal Patterns and Currents ................................................................................. 46 2.7.4 Black Powder ......................................................................................................... 47 3. Underwater Blast Injury: A Review of Standards ............ 50 3.1 Introduction ................................................................................................................ 50 3.2 Methods ...................................................................................................................... 51 3.2.1 Homogenization of Guideline Types ................................................................. 51 3.2.2 Guidelines Based on Peak Pressure .................................................................... 53 3.2.3 Guidelines Based on Charge Weight and Range .............................................. 58 3.2.4 Guidelines Based on Impulse .............................................................................. 62 3.3 Results ......................................................................................................................... 66 3.4 Discussion ................................................................................................................... 69 4. Human Injury Criteria for Underwater Blast Injuries ..... 73 vii 4.1 Introduction ................................................................................................................ 73 4.2 Methods ...................................................................................................................... 74 4.2.1 Injury Ratings......................................................................................................... 74 4.2.2 Blast Assessment ................................................................................................... 80 4.2.3 Protection ................................................................................................................ 84 4.2.4 Survival Analysis .................................................................................................. 85 4.2.5 Range Predictions .................................................................................................. 87 4.3 Results ......................................................................................................................... 88 4.3.1 Sensitivity Analysis ............................................................................................... 88 4.3.2 Protection ................................................................................................................ 88 4.3.3 Survival Analysis .................................................................................................. 90 4.3.4 Range Predictions .................................................................................................. 94 4.4 Discussion ................................................................................................................... 96 5. Suffocation Risks for the Crew of the HL Hunley ......... 103 5.1 Introduction .............................................................................................................