HIGH SPEED CRAFT - PERFORMANCE & PROTECTION - Dr Trevor Dobbins

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1 HIGH SPEED CRAFT - PERFORMANCE & PROTECTION - Dr Trevor Dobbins STResearch Ltd, UK - STResearch LLC, USA

2 TOPICS The high speed marine environment Shock & vibration Shock mitigation Crash safety Design

3 STResearch High Speed Craft Human Factors Research Design Test & Evaluation Examples Other related work: Yacht racing Motor racing Aviation EU and US

4 High Speed Craft provide one of the worst operating environments due to exposure to high levels of Shock &Vibration Ensign, et al (2000), A survey of self-reported injuries among special boat operators; Naval Health Research Centre, Tech Report Carvalhais, (2004) Incidence and severity of injury to surf boat operators. Conference Proceedings 75th SAVIAC Conference, Virginia Beach, VA. October Smith, G. CASE STUDY; Vertebral wedge fracture after speedboat splash down. J Royal Navy Medical Service. 2007; 93(2):75-7.

5 In Europe, legislation limits exposure to Whole Body Vibration (WBV). This is driving improvements in HSC design, by focusing on the Human Factors (HF) issues, which will result in: Reduced levels of Motion-Induced-Fatigue (MIF) Reduced risk of acute and chronic musculoskeletal injury Improved operational effectiveness & readiness.

6 SHOCK EXPOSURE IN HIGH SPEED CRAFT

7 SHOCK EXPOSURE IN HIGH SPEED CRAFT 50 ~ 50kts, sea state

8 SHOCK EXPOSURE IN HIGH SPEED CRAFT 28 military ~ kts, sea state 1-2

9 SHOCK EXPOSURE IN HIGH SPEED CRAFT 28 military ~ kts, Sea State 4-5

10 INJURIES ON HIGH SPEED CRAFT EXAMPLE OF AN ACUTE BACK INJURY Wedge fracture of the T12 vertebrae Smith, G. CASE STUDY; Vertebral wedge fracture after speedboat splash down. J Royal Navy Medical Service. 2007; 93(2):75-7.

11 CRASH SAFETY Race boats & pleasure/commercial boats

12 HIGH SPEED CRAFT DO CRASH!

13 HIGH SPEED CRAFT DO CRASH!

14 HIGH SPEED CRAFT DO CRASH!

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17 Sea Snake High-speed pleasure boat (7.7m) ran aground at night whilst traveling at ~40 knots The steering wheel had been pushed into the instrument panel, which was cracked and indented (Section 1.5 and Figure 6a) by being hit by the unrestrained coxswain.

18 The post-mortem examination (Section 1.8) concluded: There were multiple injuries to Mr Thomson s chest, which resulted in severe internal bleeding..the injuries were consistent with a heavy impact against a hard surface, such as a cockpit or wheel. Mr Brechin died from severe injuries to his chest..the injuries were consistent with a hard impact against a hard surface such as a cockpit or wheel. There were sharp force injuries to his left hand. Mrs Flemming died from severe injuries to her chest. She also suffered severe injuries to her neck. The description of the accident (Section 2.4.1) includes;..tragically, everyone who had been sitting or standing at the front of the cockpit lost their lives, and the others who were behind them and survived cannot remember the events leading up to and after the accident.

19 INJURIES IN NORMAL HSC OPERATION Harsh RS & WBV + Pitch, Roll & Yaw Anecdotal reports of musculoskeletal injuries: cuts and bruises damaged ligaments & tendons broken bones MAIB Investigations New MCA & RYA Guidelines

20 SAFETY IN OTHER TRANSPORT SECTORS Automotive Safety design standards NCAP Testing Aviation Rail

21 RESEARCH PROJECT MODEL Human Vehicle Environment Temporal Domain Pre-impact Situational awareness Posture Speed Motion (6 Degrees-of- Freedom) Visibility Sea state Impact Restraint systems Cockpit structure/equipment interaction with body Structural response, Crash impulse received at the cockpit Impact site, beach, harbour wall, etc Post-impact Secondary impact 6 Degrees of Freedom motion following the impact Position of HSC, e.g. upside down, on land, on water

22 SHOCK MITIGATION COUNTING IMPACTS

23 SHOCK MITIGATION OPERATIONAL: Slow down Reduction in exposure time Enhanced crew robustness TECHNICAL: Hull design Suspended decks Suspension seats

24 SHOCK MITIGATION TESTING MOTION INDUCED FATIGUE: post-transit performance

25 IMPACT COUNT: Deck vs. Fixed Seat

26 IMPACT COUNT: Deck vs. Suspension Seat

27 IMPACT COUNT: Deck vs. Fixed vs. Susp. Seat PERFORMANCE REDUCTION 26% 0%

28 DON T STAND UP! 1:1 relationship

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30 CONSOLE LAYOUT

31 ISSUES WITH LINES OF SIGHT

32 MAINTAINANCE IS IMPORTANT

33 FREE DOWNLOAD EBDIG European Boat Design Innovation Group Future Symposium Safety & Engineering UIM & FIA Institute

34 ? QUESTIONS? Dr Trevor Dobbins