Confined Space Safety  

As a wind technician, you are ready to encounter dangerous heights, extreme weather conditions and long hours, but confined space hazards as well? Yes, that's right. Wind turbine towers are large enough for entry in order to perform work, they have limited access for entry and egress and are not intended for long term occupancy by technicians. Those characteristics describe what OSHA defines as a confined space. Additionally, many hazards exist in the tower, nacelle, hub and blades. Oxygen deficient atmospheres, temperature extremes, mechanical hazards, engulfment hazards, just to name a few. If these areas contain or have the potential to contain a hazardous atmosphere, contain material with the potential of engulfing a worker who enters the space, contains recognized safety or health hazards, or has an internal configuration that may cause the occupant to be trapped or asphyxiated by accumulated gasses due to wall construction, OSHA requires these areas to be designated as "permit require  d" confined spaces.

Gemini provides service to clients for jobs such as commissioning, construction and corrective maintenance. Many may make the assumption that confined space entry only poses a threat after initial construction of a tower, but that is not the case. It is important to be aware that hazards exist during maintenance, inspection and repair work. Never enter a permit-required space without the proper training and permits for that space. Each site is different and may have their own confined space policy. Verify you understand the policy for the site, as well as Gemini's Confined Space Policy. It is located on our SharePoint easily accessible to our technicians from their smart phone or laptop. Gemini Safety Policy (GSP)-110 covers topics from Roles and Responsibilities to Common Hazards and Emergency Rescue Procedures. After reviewing the applicable documentation, prior to entering the space, the atmosphere must be sampled. Oxygen content, combustibility/flammability and toxicity are analyzed.

• Check for Oxygen content:
  • At least 19.5% and less than 23.5%.
  • Check for Combustibles:
    • Less than 10% of the LEL (Lower Explosive Limit).
    • Check for Toxic Gases:
      • Most commonly carbon monoxide (PEL <35 ppm)
      • Hydrogen Sulfide (H2S) less than 10ppm (parts per million)
      • Others Substances must be less than PEL (Permissible Exposure Limit).         

Once results are deemed satisfactory, the supervisor, attendant and entrant must know their duties and responsibilities from start to finish.

Supervisor:

• Oversees all confined space activities and conducts a pre-entry briefing
• Ensure that personnel evacuated when necessary during an emergency
• Makers certain that permits are complete and removed when work is finished and verifies all necessary equipment is returned to its proper location.

Attendant:

• Attend pre-entry brief and know and recognize the hazards of the space
• Control and secure access to the space as well as maintain communication with the entrants
• Must remain at the site while entrants are inside, and know how many occupants at all times
• Must summon emergency services, but not enter the space for rescue, only assist in rescue efforts outside of the space.

Entrant:

• Must attend pre-entry brief and know the hazards of the space
• Must use appropriate equipment properly and exit the space if the alarm is activated, communication is lost, unknown hazards are encountered or entrant is ordered out

In the event an emergency occurs, self-rescue by the entrant is the most effective means of escaping a recognized confined space hazard. If a self-rescue is not possible due to the entrant being unconscious or incapacitated, non-entry rescue should be initiated. If these methods fail, an outside rescue must be performed by nearby emergency services.

The dangers of confined spaces cannot be emphasized enough. OSHA.gov states that over 90 deaths each year involved confined spaces and over 40% of those involve attempted rescuers. Please know the characteristics of a confined space, when a permit is required and what actions you should take prior to entering one. For more information, if you are currently part of the Gemini Team, please visit Gemini SharePoint and checkout the Safety Policies and Procedures section. Otherwise, please visit https://www.osha.gov/dep/greenjobs/windenergy and http://www.nfpa.org for more information on confined space hazards.