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Fisk Descenders

Fisk Descenders are components of a rope descent systems commonly used in work positioning and rescue operations. For descent applications,  the Fisk Descender is used as part of a complete descent and personnel riding system. A descent application configuration typically includes a full body harness, boatswain’s chair or workseat, independent personal fall protection system, and the Fisk Descender with working line.  For rescue applications, the Fisk Descender is used as part of a complete rescue system which would typically include a full body harness or rescue sling, anchorage connector (i.e. carabiner) and the Fisk Descender with working line.



Design Considerations

 Wind Energy Fall Protection Design Considerations

Wind energy is a multi-faceted fall protection requirement.  Maintenance personnel need to safely climb between 100 to 300 feet from the ground level to reach the wind turbine’s mechanical drives in the power generation area.  This climb can be extremely physically demanding as temperatures in the wind turbine’s support chamber can reach 200 degrees in summer months.  Once the maintenance staff reaches the top of the ladder system, a shell protecting the drive system retracts, creating a confined yet open air work space requiring OSHA compliant fall protection. Although most wind turbines feature resting platforms that are spaced at 50 foot increments, scaling a 100-300 foot ladder system remains difficult and potentially dangerous.  To make climbing from ground level to the generation bay easier and safer, we recommend the use vertical lifelines in conjunction with climb-assist products that remove 45-55% of a climber’s body weight.  Generation bay work areas are protected with horizontal lifeline cable systems or single point anchors to ensure 100% tie-off.  Diversified Fall Protection can also help install systems and train personnel for rescue situations in the event of a fall.  Despite the relative youth of this emerging market, Diversified Fall Protection has years of experience installing OSHA compliant fall protection systems for the wind energy market including:
  • Horizontal Lifelines
  • Rescue and Descent
  • Single Point Anchors
  • Vertical Lifelines and Ladder Systems

OSHA Regulations

Rescue and Descent

  • Personal Fall Arrest Systems: System performance criteria. In addition to the general requirements in paragraph (c) of this section, the employer must ensure that personal fall arrest systems: 1910.140(d)(1)(i)
    • Limit the maximum arresting force on the employee to 1,800 pounds (8 kN); 1910.140(d)(1)(ii)
    • Bring the employee to a complete stop and limit the maximum deceleration distance the employee travels to 3.5 feet (1.1 m); 1910.140(d)(1)(iii)
    • Have sufficient strength to withstand twice the potential impact energy of the employee free falling a distance of 6 feet (1.8 m), or the free fall distance permitted by the system; and... 1910.140(d)(1)(iv)
    • Sustain the employee within the system/strap configuration without making contact with the employee's neck and chin area. 1910.140(d)(1)(v)

  If the personal fall arrest system meets the criteria and protocols in appendix D of this subpart, and is being used by an employee having a combined body and tool weight of less than 310 pounds (140 kg), the system is considered to be in compliance with the provisions of paragraphs (d)(1)(i) through (iii) of this section. If the system is used by an employee having a combined body and tool weight of 310 pounds (140kg) or more and the employer has appropriately modified the criteria and protocols in appendix D, then the system will be deemed to be in compliance with the requirements of paragraphs (d)(1)(i) through (iii). 1910.140(d)(2)   The employer must ensure that:

    • On any horizontal lifeline that may become a vertical lifeline, the device used to connect to the horizontal lifeline is capable of locking in both directions on the lifeline. 1910.140(d)(2)(ii)
    • Personal fall arrest systems are rigged in such a manner that the employee cannot free fall more than 6 feet (1.8 m) or contact a lower level. A free fall may be more than 6 feet (1.8 m) provided the employer can demonstrate the manufacturer designed the system to allow a free fall of more than 6 feet and tested the system to ensure a maximum arresting force of 1,800 pounds (8 kN) is not exceeded. 1910.140(d)(3)
    • Body belts. Body belts are prohibited as part of a personal fall arrest system.

Talk to a fall protection specialist

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