Greetings Brothers and Sisters,
Hopefully everyone weathered this past winter and is ready to get into the spring season.
I would like to take this opportunity to talk about “critical lifts.” A critical lift is generally one that by the nature of the work, the load, or the site, poses a greater degree of risk than usual. It is a term we’ve all heard but it still may be surrounded by some confusion. Even OSHA and ASME describe critical lifts differently.
According to OSHA Subpart R Steel Erection 1926.751, a critical lift means a lift that:
- Exceeds 75% of the rated capacity of a crane or derrick; or
- Requires the use of one or more cranes or derricks.
ASME goes into it a little deeper than OSHA does. According to ASME B30.5, the determination of what qualifies as a critical lift is up to the company, site supervision, project management, or a qualified person. The circumstances that would deem a lift critical are too numerous and sometimes too specific for them to come up with a definitive list. But they do give us some examples and guidelines to follow.
- The total lift exceeds a predetermined threshold, which may vary with company policy and may depend on crane capacity, available rigging, and employee experience.
- The lift exceeds a predetermined percentage of the crane’s capacity. (75% per OSHA, sometimes 50% near certain railroads) this may be adjusted depending on jobsite conditions.
- Hoisting of personnel, which is covered in more detail in ASME B30.23, and OSHA 1926.1431.
- Lifts involving more than one crane.
- If the load is unique and if damaged would be irreplaceable or not repairable.
- Demolition work where the item to be lifted is being removed from a structure and the structural integrity or the actual weight are in question.
- If working near powerlines, above active work areas, occupied buildings, roadways or transportation systems.
- Lifting with limited clearances or in confined areas.
- Lifting at extreme height makes control of the load difficult.
- Lifts utilizing a specially engineered load rigging system.
There may be other criteria that an employer applies due to their own policies.
ASME states that a critical lift plan shall be prepared on all critical lifts before the lift begins. The plan must address the special conditions of the lift including but not limited to:
- The gross load.
- Set up factors including but not limited to, ground conditions & support materials, boom swing area, crawler or outrigger loading, electrical hazards.
- Identification of the crane/cranes to be used; capacity, radius, configuration, and the percent of lifting capacity utilized.
All rigging considerations such as size, capacity, and weight of rigging to be used, sling angles & hitches to be used, arrangement of rigging, load center of gravity, pick points, and pick up and placement locations of the load.
The plan shall be approved by site management, rigging supervision, operator and qualified personnel who came up with the plan. The approvals shall be signed
and dated.
Finally, there needs to be a pre-lift meeting with all participating personnel to review and discuss the details of the plan. All concerns must be resolved before beginning the lift.
While it is important to follow these guidelines for all critical lifts, every lift we make should be planned. As the operator we need to be able to correctly interpret and apply all the information contained in the operator manual and load chart. Many crane manufacturers handle things differently, even from one model to another. We absolutely must read the manuals and load charts that belong to the crane.
I hope you all have a safe and
prosperous season.
Fraternally,
Peter Gardiner
Co-Safety Officer