Testing Magnets Installed on EPIRB Brackets

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Testing Magnets Installed on EPIRB Brackets

• Prepared by Robert G. Garrott
• CGD Five CFVS Coordinator
• July 3, 2007

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Background Information 1

• In 2006, CGD Seven CFVS Coordinator Larry
  Yarborough and SEC Charleston Lead Examiner Greg
  Johnson lead a detailed analysis of EPIRB false
  alerts. They found air and surface sorties
  triggered by false alerts cost the Coast Guard
  millions in fuel, personnel and maintenance
  expenses each year, and that there were two main
  causes for these false alerts.

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Background Information 2

• Modern 406 MHz EPIRBs are designed to
  automatically activate if removed from their
  mounting bracket and in contact with water. To
  reduce false alerts, a magnet mounted in the
  bracket opens a magnetic reed switch in the EPIRB
  circuitry. The two most common problems causing
  false alerts are mounting the EPIRB in the
  bracket incorrectly, and for the magnet to be
  missing or out of position.

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Background Information 3

• Because they can be placed in the bracket
  backwards (with the line spool facing out), ACR
  Satellite EPIRBs are more susceptible to
  incorrect mounting than other EPIRBs.
• Careful attention to Owners Manuals and mounting
  diagrams can prevent false alerts due to
  incorrect mounting in the bracket.

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Testing for the Magnets

• It takes just a few seconds to verify the magnet
  is properly installed in the bracket. The test
  device an inexpensive magnetic compass. The
  bracket magnet will cause the compass needle to
  swing and point at the bracket instead of
  pointing at the magnetic north pole. The
  following slides show this occurring for several
  of the most frequently encountered marine EPIRBs.

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Category 1 ACR Satellite2 406 MHz
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Category 1 ACR Satellite2 406 MHz
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Category 2 ACR Satellite2 406 MHz
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Category 2 ACR Satellite2 406 MHz
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Category 1 McMurdo 406 GPS
Note The magnet is positioned under the EPIRB
and is not visible until the EPIRB is removed.
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Category 1 McMurdo 406 GPS
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Category 1 Pains Wessex 406 MHz
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Category 1 Pains Wessex 406 MHz
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Category 2 Pains Wessex 406 MHz
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Category 2 Pains Wessex 406 MHz
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Corrective Action

• Although magnets arent mentioned in the
  regulations, EPIRB design standards require this
  type of protective feature.
• If the bracket is damaged or the magnet is
  missing, the defective bracket is not in
  compliance with 46 CFR 25.26 and must be serviced
  by an approved EPIRB servicing facility.

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Examiner Action

• Advise the vessel operator that the bracket is
  defective. Possible negative outcomes
• Early replacement of discharged battery per 46
  CFR 25.26-50(c)(1).
• Government claims for reimbursing the cost of
  search and rescue sorties.
• Issue a worklist item for timely servicing of the
  defective bracket and follow up.
• Worst case Request Sector use COTP Order to
  enforce compliance with 46 CFR 25.26-50(c)(1).

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Boarding Officer Action

• Advise the vessel operator that the bracket is
  defective. Possible negative outcomes
• Early replacement of discharged battery per 46
  CFR 25.26-50(c)(1).
• Government claims for reimbursing the cost of
  search and rescue sorties.
• Issue a 4100 citation for non-compliant EPIRB and
  follow up with Sector Lead Examiner.
• Worst case Request Sector use COTP Order to
  enforce compliance with 46 CFR 25.26-50(c)(1).