Crane operations are the lifeblood of an offshore deck. From loading food containers to moving drill pipes, lifting happens 24/7. However, a dropped object is one of the most lethal incidents that can occur on a rig.
Safety doesn’t start with the crane operator; it starts with the rigging hardware. “Below the hook” equipment—slings, shackles, and pad eyes—must be rigorously inspected. Here is what to look for to ensure compliance with standards like LOLER (Lifting Operations and Lifting Equipment Regulations).
1. Wire Rope Slings: Counting the Broken Wires Wire rope slings are tough, but they are not indestructible.
-
Kinks and Bird-Caging: If the wire rope is deformed or “bird-caged” (where the strands open up), the structural integrity is compromised. It must be destroyed immediately.
-
Corrosion: Surface rust is common offshore, but “pitting” is dangerous. If you cannot wipe the rust off, or if it has eaten into the metal wires, the sling is unsafe.
-
Broken Wires: A certain number of broken wires are allowed depending on the standard, but as a rule of thumb: if you see clusters of broken wires in one strand, condemn the sling.
2. Shackles: The Pin is Key The shackle is the connecting link, and the pin is its weakest point.
-
Distortion: If the shackle body is bent or twisted, it has likely been overloaded. Never try to hammer it back into shape—replace it.
-
The Thread: The pin should screw in smoothly by hand. If it requires a wrench to force it, the threads are damaged.
-
Markings: Every lifting shackle must have a visible “WLL” (Working Load Limit) stamped on it. If the stamp is worn off by rust or friction, the shackle cannot be used, as you cannot verify its capacity.
3. Webbing Slings (Soft Slings) Synthetic slings are great for protecting delicate loads, but they are fragile.
-
Cuts and Chafe: Look for cuts on the edges or surface of the sling. Even a small cut can reduce the sling’s strength by 50%.
-
Chemical Burns: If the sling has been exposed to acid or caustic soda, the fibers may become brittle. Discoloration or “flaking” fibers are signs of chemical damage.
Conclusion Lifting safety is binary: equipment is either safe, or it is not. There is no gray area. Regular visual inspections by the deck crew, combined with 6-monthly thorough examinations by certified inspectors, ensure that every lift is a safe lift.
