Rigging Hardware - Shackles, Hooks, Links & Clamps
Proper use and inspection of shackles, hooks, master links, eye hooks, plate clamps, and connecting hardware per ASME B30.26.
- Describe proper shackle orientation and explain why side loading is prohibited
- Identify hook inspection criteria including throat opening and latch condition
- Explain the function of master links and eye hooks in multi-sling assemblies
- List ASME B30.26 requirements for rigging hardware inspection and use
Lección 1
Shackles - Types, Orientation & Side Loading
Shackle Fundamentals
Shackles are one of the most common pieces of rigging hardware. They connect slings to the load, slings to each other, and slings to the crane hook. Two main types are used in rigging:
- Anchor shackles (bow type) - wider body, accommodates multiple slings or side loading better
- Chain shackles (D-type) - narrower, for in-line loading only
Anchor (Bow) Shackle
Wider body shape
Allows slight angular loading
Preferred for multi-sling connections
Chain (D) Shackle
Narrower D-shape body
In-line loading only
Higher capacity at same size
Proper Shackle Orientation
The exam heavily tests shackle orientation. The critical rule is: bowl over the hook, pin on the load side, with one sling per shackle unless the shackle is specifically rated for multiple slings.
When using a shackle with a two-leg bridle:
- The bow (body) sits in the hook
- The pin faces toward the load
- Only one sling eye per shackle unless rated otherwise
- Never allow the pin to bear the primary load - the bow is designed for that
Side Loading
Side loading a shackle means applying force at an angle to the shackle's intended load plane. This dramatically reduces capacity and can cause failure. Chain (D-type) shackles must never be side loaded. Anchor (bow) shackles tolerate slight angular loading but lose capacity.
Exam Alert
When asked about proper shackle orientation with a two-leg bridle: bowl over hook, pins on load side, one sling per shackle unless rated for more.
Shackles must be oriented with the bowl over the hook and the pin on the load side. Never side load a shackle, and never place more than one sling on a shackle pin unless the shackle is specifically rated for it.