Performance of diving equipment

1
Performance of diving equipment

• A Brief summary of the report
• Nick Bailey HSL

2
Objectives

• Examine equipment implicated in accidents
• Establish guidelines to preserve evidence
• Provide reports to OSD on equipment

3
History to the report

• Initially started in 1999
• To last for 3 diving seasons
• Incidents from various sources
• HSE
• Police
• Local Authority

4
Equipment Purchased

• ANSTI Life Support Test Facility
• ANSTI Computerised Surface Test Facility
• 300 Bar Compressor
• Trimix Panel
• Gas Analysis Test Equipment

5
Test Methods

• Visual Inspection
• Gas Test
• EN 250 performance
• Dive computer interrogation

6
Visual Inspection

• Equipment Condition
• Configuration of the Equipment
• Valve Settings
• Gauge Readings

7
Gas Tests

• Comparing gas quality to EN 12021
• Oxygen 21 1
• Carbon Dioxidelt500 ppm
• Carbon Monoxidelt15 ppm
• Lubricants lt0.5mg m-3
• No Odour or Taste
• Water Content lt25mg m-3
• Other Contaminants None Present

8
Gas Tests

• Measured moisture content of air in cylinders up
  to 200 bar

EN 12021 limit
9
EN 250 Performance tests

• Work of Breathing lt3.0J l-1
• Peak Respiratory Pressure 25 millibar
• Inhalation Work of Breathing lt0.3 J l-1

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Dive Computers

• Manufacturer Supplied Interfaces
• Allowing Profiles to be Studied

11
Dive Computers

• Information was Correlated to Witness statements
• Allowed recreation of events with the ANSTI
  breathing Machine
• Some personal programming errors were found that
  may have been a contributing factor

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Incidents

• 54 Incidents
• 46 were fatalities
• 10 were non fatal
• 9 Out of water, Divers equipment or gas supply
  involved

13
Incidents

• Lone diver, or separated from buddy 14
• Failed to surface 10
• Observed in difficulty, and blacked out
• beneath water 8
• Rapid uncontrolled ascent 7 (2 with
  inversion)

14
Incidents

• Suspected bad fill of air 5
• Free flow from second stage 4
• Trainee diver panic / inexperience 6
• Unable to establish buoyancy at the surface 5

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Incidents

• Sets of diving equipment received 45
• (sets include one or more of the following)
• Open circuit air 35
• Open circuit Nitrox 15
• Open circuit Trimix 4
• Rebreathers 7

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Incidents

• Depth range

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Clear Up

• 46 of Regulators tested did not meet EN250
• 20 of incidents below 50 metres
• Moisture content of air not being met in high
  number of cases

18
Clear Up

• All cases are now complete
• Final coroners court attendance on 18th November
  2005
• Accidental death verdict

19
Where the report can be read

• The report is available to be read on the HSE
• Website. hse.gov.uk/research/rrhtm/rr424.htm