Mobile cranes are an essential part of any business in the heavy-lifting industries, but when a crane operator attempt to lift a load more than the weight capacity of the crane the results can be disastrous.
There’s no room for error when it comes to critical crane lifts, and load calculations are absolutely essential. Crane incidents, more often than not, are the fault of those operating them and this has serious safety consequences for your business.
With proper training, planning and preparations, however, the dangers associated with a critical lift can be almost eliminated.
What is a critical lift?
A crane lift is considered critical when damage from the lift could cause a significant delay in operations, comprise the safety and operations of a facility either now or in the future, cause significant levels of hazardous substances such as radioactive materials to be released or cause serious injury or illness.
BC Crane Safety describes a critical lift as:
- a lift by a mobile crane or boom truck that exceeds 90% of its rated capacity while it is lifting the load at a load radius of more than 50% of its maximum permitted load radius, taking into account its position and configuration during the lift;
- a tandem lift if the load on any one crane, hoist or other piece of powered lifting equipment exceeds 75% of the rated capacity of that crane, hoist or other piece of powered lifting equipment;
- a tandem lift involving the simultaneous use of more than two cranes, hoists or other pieces of powered lifting equipment;
- a lift of a person in a work platform suspended from or attached to a crane or hoist;
- a lift in which the centre of gravity of the load changes during the lift;
- a lift in which the length of one or more sling legs changes during a lift;
- a lift by a crane, boom truck or hoist, supported on a floating base, that exceeds 90% of rated capacity for the lifting system;
- a lift of a load over or between energized high voltage electrical conductors, or;
- a lift of a submerged load.
Who decides if it’s a critical lift?
Crane operators are responsible for deciding whether a lift is critical, meaning their training is absolutely essential for the safety of your employees. Each critical lift should follow a specific protocol and plan of action that mitigates any potential risks.
Any lifts that are close to the limit should not be underestimated. These lifts are classified as an incident and should be evaluated as such, not ignored. Safety is imperative when it comes to critical lifts.
Safety aspects of a critical lift
Safety is highly important during any lift, but even more so in critical lifts where increased safety hazards are involved. Following strict safety guidelines and regulations will mitigate these risks as much as possible.
It’s essential all crane operators have had adequate training on the protocols of critical lifts, and all pieces of equipment should undergo routine inspections on a regular basis – including both mechanical and stability tests.
Each crane is load-tested by the manufacturer prior to shipment by a company, and these intentional overloading tests are designed to make sure the crane meets required standards and regulations.
Each time the crane is modified, or every time a crane is mounted onto a truck, stability tests and load testing should be performed. In fact, in some countries, stability tests are required by law each time the configuration of the crane is changed.
Meanwhile, a thorough mechanical examination will find any structural failures that may be the result of cracks or fatigues. These defects are often not found during a load test. This should include a visual inspection of the weld, as well as non-destructive tests such as magnetic particle inspection.
Sparta Engineering is experienced in crane stability tests and will certify all jobs done. Contact us today for more information.