The High Speed Navy

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McCauley, Pierce & Matsangas (2007) - The High Speed Navy: Vessel Motion Influences on Human Performance

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The High Speed Navy

  1. 1. The High Speed Navy: Vessel Motion Influences on Human Performance Michael E. McCauley, PhD Eric C. Pierce, MA and Panagiotis Matsangas, MS Naval Postgraduate School and NSWC-Panama City
  2. 2. Ongoing Series of Analyses of High Speed Operations and Human Performance <ul><li>Prior Analyses </li></ul><ul><ul><li>HSV-2 SWIFT </li></ul></ul><ul><ul><li>FSF-1 Sea Fighter </li></ul></ul><ul><li>Present Analysis </li></ul><ul><ul><li>Benchijigua Express (General Dynamics Team hull for LCS) </li></ul></ul><ul><li>Future, Planned Analyses </li></ul><ul><ul><li>LCS-1 Freedom (Lockheed Martin team) </li></ul></ul><ul><ul><li>LCS-2 </li></ul></ul>
  3. 3. Objectives <ul><li>In support of the LCS program, determine the influence of high speed vessel motion on human performance, safety, and health </li></ul><ul><ul><li>Vessel motion measurement </li></ul></ul><ul><ul><li>Motion Sickness Incidence (MSI) </li></ul></ul><ul><ul><li>Motion Induced Interruptions (MII) (biomechanics => posture, locomotion & tasks) </li></ul></ul><ul><ul><li>Identify problematic tasks & activities </li></ul></ul><ul><ul><li>Contribute to operational envelopes </li></ul></ul>
  4. 4. Benchijigua Express I. <ul><li>Length 127 m </li></ul><ul><li>Width 30.4 m </li></ul><ul><li>Hull Trimaran (stabilized monohull) </li></ul><ul><li>Draft 4 m </li></ul><ul><li>Speed 40+ knots </li></ul><ul><li>Engines Four 20V 8000 MTU engines provide an output of 32,800 kW </li></ul><ul><li>Propulsion Water jets & bow thrusters </li></ul><ul><li>Capacity 1300 passengers and 340 autos </li></ul><ul><li>Design Austal </li></ul><ul><li>Application Ferry service in the Canary Islands </li></ul><ul><li>Operator Fred.Olsen, S.A. </li></ul>
  5. 5. Benchijigua Express
  6. 6. LCS Competing Team Concepts General Dynamics Trimaran Lockheed Martin Semi-planing Monohull
  7. 7. Passenger Deck <ul><li>Passenger locations were requested on the questionnaire surveys, indexed by seat color (see brackets in figure) </li></ul>Bow
  8. 8. Instrumentation by NSWC-Panama City <ul><li>6 DoF motion sensors installed at four locations on the passenger deck and two locations on the auto deck (mission bay) </li></ul><ul><li>GPS control box, video cameras, & video recorder </li></ul>
  9. 9. Seaway Data: Two Systems <ul><li>Miros WAVEX system (radar) </li></ul><ul><li>TSK Wave Height Meter system (microwave) </li></ul><ul><ul><li>Output captured and stored in NSWCPC control box </li></ul></ul>
  10. 10. Questionnaire Items <ul><li>Recent experience at sea </li></ul><ul><li>MII Frequency & description </li></ul><ul><li>MSAQ </li></ul><ul><li>Seating location (by graphic) </li></ul><ul><li>Open question– comments on ship motion & comfort </li></ul>
  11. 11. Manual Dexterity Functional Range of Motion (FROM) <ul><li>Peg placement task </li></ul><ul><li>Manual speed (total time) and accuracy </li></ul><ul><li>Two contestants compete for prizes </li></ul>
  12. 12. Procedures: Ferry Schedule <ul><li>The Benchijigua Express began each day in La Palma a sailed a 2-hr transit to Tenerife </li></ul><ul><li>Multiple ½ hr transits during the day to La Gomera </li></ul><ul><li>Return each evening, 2-hr transit to La Palma </li></ul><ul><li>Data were collected on the two 2-hr transits each day for 10 days </li></ul><ul><li>Supplemental data collected by Fred.Olsen crew on the following 30 days </li></ul>
  13. 13. Procedures per Transit <ul><li>Vessel motion sensors initialized </li></ul><ul><li>Participants recruited for the FROM “game” </li></ul><ul><li>One-hour after launch, questionnaires distributed by the Fred.Olsen study coordinator to all passengers who agreed to participate </li></ul><ul><li>Bridge log data obtained </li></ul><ul><li>Questionnaires collected prior to arrival </li></ul>
  14. 14. Data Set <ul><li>86 two-hour transits </li></ul><ul><li>1,994 questionnaires </li></ul>THANK YOU to the Fred.Olsen, S.A. personnel for their strong support in data collection “ Morning”: between 07:00 and 10:00 (aprox.) “ Evening”: between 20:00 and 22:00 (aprox.)
  15. 15. Motion Sickness: MSAQ <ul><li>The MSAQ has 4 scales & total </li></ul><ul><ul><li>G= gastrointestinal </li></ul></ul><ul><ul><li>C= central </li></ul></ul><ul><ul><li>P= peripheral </li></ul></ul><ul><ul><li>S= sopite </li></ul></ul><ul><ul><li>Total </li></ul></ul>
  16. 16. MSAQ Results
  17. 17. MSAQ Results <ul><li>Passengers with recent experience at sea (>9 times in the prior month) were </li></ul><ul><ul><li>Less likely to respond to the questionnaire (5% as opposed to 50%) </li></ul></ul><ul><ul><li>Less likely to report motion sickness symptoms, either gastrointestinal, sopite, or total MSAQ score </li></ul></ul>
  18. 18. MSAQ: Morning versus Evening Transits <ul><li>All four subscales were significantly higher during evening transits. </li></ul><ul><li>Sopite significantly evident in both transits (morning-evening) </li></ul>
  19. 19. MSAQ by Relative Heading of Seas Motion sickness greatest with head and following seas; least with beam seas
  20. 20. MIIs Defined <ul><li>MIIs are interruptions in your balance, movement, or task performance, caused by ship’s motion. If standing, an MII could be slipping, sliding, losing your balance, not being able to walk, or having to grab hold of something to continue conducting your task. If seated, an MII could be holding your chair so as not to slide, holding onto objects to keep them from falling off a table, or unusual difficulty in using your computer keyboard or mouse. In general, whenever the ship’s motion makes you stop what you have been doing, even for a short amount of time, it is an MII. </li></ul>
  21. 21. MII Frequency by Relative Heading of Seas MIIs per hour were least with beam seas, even though the RMS vertical acceleration was high with beam seas
  22. 22. MII Results & Discussion <ul><li>One type of MII is when an individual has to hold onto something to maintain their balance. </li></ul><ul><li>39% of the participants reported that this type of MII occurred at some time during their transit </li></ul><ul><li>This percentage was significantly higher during evening (43%) compared to morning (33%) data collection periods </li></ul><ul><li> The reason for this finding is unclear, but several factors may have contributed -- increased fatigue, higher proportion of alcohol consumption, and reduced external environment light conditions (lack of visual input – horizon) </li></ul>
  23. 23. Observed MIIs and the “Tipping Equation” <ul><li>Analysis of the video data resulted in a frequency count of MIIs </li></ul><ul><li>The accelerometer data were used to compute the “Graham Tipping Equations” (Graham, 1990) </li></ul><ul><li>Results of this analysis showed that the tipping equations over-predicted MIIs by a factor of 47 </li></ul>
  24. 24. The FROM Dexterity Task and Wave Height Surprisingly, increased wave height did not influence FROM performance in either the standing or stooping positions. Participants were able to perform the task successfully, compensating for ship motion and MIIs
  25. 25. Summary and Conclusions I. <ul><li>Motion sickness symptoms were reported by 60-90% of the participants, depending on wave height and heading </li></ul><ul><li>The reason that MSI was higher during evening transits cannot be determined from the data </li></ul><ul><li>Sopite syndrome is evident in all conditions </li></ul><ul><li>These data on motion sickness are likely to be consistent with military passengers, but not adapted crew </li></ul>
  26. 26. Summary & Conclusions II. <ul><li>Head seas resulted in more motion sickness whereas beam seas resulted in more MIIs </li></ul><ul><li>The motion effects of the Benchijigua Express were relatively benign; given that it was operating at speeds in excess of 32 knots and that the participants were unadapted passengers rather than crew </li></ul><ul><li>The motion of this vessel did not interfere with manual dexterity performance </li></ul>

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