Rigging (9)

  1. A Good Rigger's Skill Set
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  9. What is a Rigger?

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  1. House Movers Depend on Heavy Load Moving Equipment
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  1. Becoming an API Qualified Rigger
  2. Helicopter Rigging & Lifts
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  4. Understanding Rigging Design Factors

Safety (10)

  1. Critical Lift
  2. Estimating the Capacity of Chains & Hooks
  3. Evaluating Your Load's Weight
  4. Lifting People Safely
  5. Non-Critical Lift
  6. Rigging in the Aftermath of a Natural Disaster
  7. The Dangers of Shock Forces
  8. The Problem of Moving a Load with 4 Skates
  9. Who Sets the Standards for Safety?
  10. Why Does a Rigger Need Insurance?

How it Works(13)

  1. Center of Gravity
  2. Chain Slings
  3. Gravity & Rigging
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  5. How It Works: Mobile Cranes
  6. How It Works: Stationary Cranes
  7. Lift Planning
  8. Nylon for Slings
  9. Rotational Resistant Wire Rope
  10. Spreader Bars
  11. Synthetic Rope
  12. Understanding Hydraulic Cylinders Part 1 - Single & Double Acting
  13. Which Sling is Right for the Job?

Critical Lift

While there appears to be no precise, all encompassing definition of a critical lift, some common items consistently appear in the numerous published lists of reasons for a lift to be considered critical. Lists researched for this article were universally presented in a fashion that indicated that any single occurring item in the list would cause the lift to be considered critical.

OSHA Defined Critical Lift
According to OSHA (29 CFR 1926.751) a critical lift means a lift that: (1) exceeds 75 percent of the rated capacity of the crane or derrick, or (2) requires the use of more than one crane or derrick.

Federal laws are published in a collection of codified documents known as the Code of Federal Regulations, CFR for short. The details we as riggers are interested in are in the Labor section, Title 29, Part 1926 – Safety and Health Regulations for Construction.

No Brain-er Approach
Before presenting the list of commonly appearing reasons for critical lift classification, let's think about the very nature of word “critical” to arrive at a no brain-er approach that should be used in the field. Given safety implications and the risk involved in any lift, some people would argue that every lift to some degree should be considered critical. Aside from this viewpoint however, critical means, if lost, crisis would ensue; critical means urgently needed.

Critical Lift Criteria
So, after reviewing various industry and governmental agency lists, here is the commonly appearing reasons why a lift should be considered a critical lift:

  • More than one crane, in combination, required
  • Loads exceeding 75% of the rated capacity of any one crane
  • Personnel lifting
  • Loads that will require suspension directly above rigging personnel
  • Lifts that result in loads leaving direct view of the crane operator
  • Loads that are extremely valuable, irreplaceable, or unrepairable
  • Loads that could potentially become damaging to other equipment or utilities
  • Loads that are potentially unstable in flight

Other Interesting Reasons
Among other reasons for considering a lift to be critical were these that were developed by industrial interests to satisfy unique requirements:

  • Lifting of loads whose replacement (purchasing lead) time exceeded 10 days
  • Lifting of loads whose loss would result in plant production shutdown exceeding 10 days
  • Lifting of loads whose loss would result in loss of plant production greater than $100,000