Page 16 - Crane and Rigging

Corrosion deteriorates wire rope. Pitting may indicate it, but it is sometimes hard to detect. Therefore, if
a wire rope sling shows any sign of significant deterioration, that sling must be removed until a person
who is qualified to determine the extent of the damage can examine it.

By following the above guidelines to proper sling use and maintenance, and by the avoidance of
kinking, it is possible to greatly extend a wire rope sling's useful service life.

Fiber Ropes and Synthetic Webs
Fiber ropes and synthetic webs are generally discarded rather than serviced or repaired. Operators
must always follow manufacturer's recommendations.

Chapter 5 – Rigging the Load

Rigging the load involves three major components. These are determining the weight to be lifted;
selecting the proper rigging gear; and using sound practices to secure the load. Rigging must also be
assigned to a competent person. Only the employer may designate a “competent person.” An
important part of the competent person’s qualifications is the authority to stop an operation and to take
corrective action as necessary.

DETERMINING LOAD WEIGHT

Check the crane’s lifting capacity. It should be stenciled on both sides of the hoist.

Determine the weight of the load by checking the following:
• The manufacturer’s plate attached to the load
• Shipping papers that came with the load
• Any work order
• Design drawings.

Calculate the weight of the load by using a chart for the material to be lifted.

Use a dynamometer, preferably one that can be connected to the hoist.

As a last resort, estimate the weight of the object.
Compare the load to a similar load with a known weight that you lifted in the past.
Get a second estimate from a co-worker.
Do not exceed 50% of the lifting capacity of the crane when lifting an estimated load.
Ask your supervisor about the safety regulations applicable to your work area.

SELECTING PROPER RIGGING GEAR
Select sound rigging gear that is within the safe working load of the fiber
or wire rope being used. Most wire rope slings have the safe working
load (SWL) inscribed on the end fitting.
If the SWL is not inscribed on the end fittings, call the manufacturer or
refer to a standards chart for weight load test.

Fiber slings may have a different label.
Vertical, choker and basket weight limits are usually sewn on the inside
of the strap.
If your fiber sling has no SWL label, get a stronger sling that has the
limits inscribed on it.

Overhead Crane and Rigging 16 Rev 3 November 2021