Hitches & Capacities

Choosing the right rigging configuration is crucial for effective load management. A key consideration is the wire rope sling capacity, which can significantly differ based on the hitch arrangement used.

In the upcoming diagrams, you will find 10 unique rigging sling types, each demonstrating various sling hitches. For this task, we will assume all slings are 1” (wire rope) E/E mechanical splices with a D/d ratio (load diameter/sling diameter) of 30/1. Your goal is to evaluate the slings (A-J) based on their wire sling capacity, ranking them from highest to lowest, and estimate their respective rated capacities.

For detailed sling capacity information, refer to Panel 1 of the ITI Bookstore's Journeyman Rigger's Reference Card and the AISI chart provided below.

Hitch & Capacities
WORKSHOP SOLUTIONS

Understanding the wire rope sling capacity is crucial, as the type of hitch utilized significantly affects the sling's rated capacity. For instance, a 1” wire rope sling can achieve a lifting capacity of up to 34,000 lbs, but this can drop to as low as 6,272 lbs depending on the rigging method used. Once the appropriate rigging system is chosen, it becomes the rigger's responsibility to ensure that the sling retains its necessary rated capacity to safely lift the intended load portion.

Wishing you successful rigging,

Mike Parnell.

P.S. Our training programs, including Intermediate Rigging Training and Master Rigger Training, cover hitches and capacities in greater detail.

This article is sourced from The Professional Rigger newsletter, 1990.