RE: Structural Connection Points for Attaching Chain Hoists (load drifting)
In power plants, refineries, aboard ships, in paper mill and other industrial settings, equipment must be installed or removed to accommodate the facility’s operation. Often riggers must be creative when rigging loads in tight quarters where there are no existing overhead cranes.
If the proposal is to use existing structural beams or columns for chain hoist connections prior to a load drifting activity a number of things should take place.
- Ensure that the facility engineering team has approved the rigging point based on the anticipated loading. Obtain the maximum allowable working load limit in writing.
- Identify the proper connector for the beam; welded pad eye, bolted swivel hoist ring, beam clamp, etc. Get a qualified engineer to approve the connector, and in the case of weldments get the details of the required material type, size, shape, thickness and shackle pin hole size and its location. If the desired connector is a pad eye also get a listing of the engineer’s minimum “removal criteria” based on wear, deformation and weld condition.
- Have a qualified welder, install the pad eye and inspect the welding using the recommended non-destructive examination method (dye penetrant, magnetic particle, etc.). A documented load test may be required.
- Mark the pad eye for its maximum rated capacity and angular limitations as provided by the engineer. The pad eye can be serial numbered (RFID identifier) so that it can be referenced on a site plan for original data, limitations and the name of the approving engineer. Maximum capacity and angular markings should be stenciled near the pad eye for future “quick reference” by all rigging personnel.
- Inspect all rigging pad eyes before and after use to ensure their integrity.
Chain hoist information can be obtained by reviewing ASME B30.16. This document can be obtained at www.iti.com/bookstore or through www.asme.org.
Happy trails to my crane and rigging friends.
Mike Parnell
PresidentITI – Field Services
Source: http://iti.com/simscrane
