Electrical Hazards for Fire and Rescue Departments Part III: Fires Near High Tension Power Lines

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Electrical Hazards for Fire and Rescue
DepartmentsPart III Fires Near High Tension
Power Lines
Captain I Gary C. Dize Health and Safety
Division Fairfax County, Virginia
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Electrical Hazards
Fires Near High Tension Towers

• High tension lines are typically located in
  right-of-ways.
• They can be along railroad track beds,
  un-buildable tracks of land, or commercial
  property yards.
• They can pose a number of problems, such as
  access, uneven terrain, lack of water supply, and
  poor visibility due to lighting conditions.

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Fires Near High Tension Towers
Electrical Hazards

• OSHA requires greater than 10 feet of clearance
  from lines that are over 50,000 volts. For
  example, the minimum clearance for a 500,000-volt
  line is 18 feet. There are no visible markers to
  identify a power lines voltage, so call the
  local electric utility for clearance information
  if you are unsure.
• Transmission lines mounted on steel towers
  normally are 110,000 500,000 volts.

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Fires Near High Tension Towers
Electrical Hazards

• Transmission lines have sensitive breakers, but
  WILL NOT prevent death or injury from contact.
• Transmission lines require greater safe working
  distances than the normal due to higher voltage
  (example 500,000 volts 18 feet).

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Fires Near High Tension Towers
Electrical Hazards

• Transmission lines 500,000 volts and under will
  sometimes have an electric field near them. The
  field may cause a static shock to firefighters
  and large equipment located in the field.
• Fires such as brush, trees, buildings, and auto
  fires have the potential to weaken the lines and
  insulators, causing failure of the towers.

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Fires Near High Tension Towers
Electrical Hazards

• No matter how routine the fire may appear, a plan
  of action is needed and all crew members need to
  be advised.
• The plan should include what is burning, the
  terrain, life hazards and whether we should we
  let it burn or put it out.
• Solids streams should never be used it provides
  a conductive path for electricity.

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Case Study Part III Close Call involving High
Tension Lines(Please see PDF Handout)
Electrical Hazards
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Discussion

• Vehicle positioning on all incidents is critical
  to the safe operation and crew safety. Sometimes
  vehicle positioning cannot be placed completely
  out of the way of danger however, it is
  paramount that the crew is aware of the hazards
  once the vehicle has been positioned.
• All FRD personnel are reminded to increase safety
  awareness and to provide a risk analysis when
  responding to any fire. The decision-making
  process must start prior to the arrival and a
  plan to mitigate the incident should be
  discussed. This includes the level of PPE for the
  identified hazard.

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Discussion

• All FRD personnel need to maintain situational
  awareness on all incidents no matter the nature.
  Also, all members of a crew need to have the same
  incident action plan and follow the plan to
  mitigate the situation. Other tools that should
  have been used would be the Crew Resource
  Management model and the Firefighter Life Safety
  Initiatives, which empowers all personnel to
  identify any and all hazards and alerts other
  crew members to the hazard.
• All FRD personnel are to be reminded that, per
  the power company, when any equipment comes in
  contact with an overhead power line, personnel
  are to stay put and keep others away from the
  equipment in question until the power company
  personnel gives the all clear. If imminent
  danger forces you off of the equipment, jump
  clear, keeping both feet together without
  touching the equipment and ground at the same
  time.