Rigging discipline at the strip

The hazard

Stripping is the point in the day when a very heavy object is hanging over people. A precast panel that lets go unevenly, a sling that fails, an insert that pulls out, or a person standing in the wrong place turns into a fatality rather than an injury. There is no minor version of this event.

There is a second thing happening at the strip that a crew that only rigs finished product does not always think about. The load on the rigging while a panel is still stuck to the bed is more than the panel’s own weight, because form adhesion and suction are pulling back. That extra load is not on the piece ticket, and it is why a pick that is fine on a stored panel can overload rigging at the bed.

Before the hook comes over

Inspect the slings. Every shift, before use, by the person who is going to use them. You are looking for cut or broken fibers, crushed or worn synthetic webbing, missing or unreadable tags, broken wires, kinks, corrosion, heat or chemical damage, and hooks that are bent, cracked, or have a damaged latch. A sling with an unreadable tag has no rated capacity you can prove, which means it has none.

A damaged sling comes out of service and gets destroyed, not hung back on the rack for the next person to find. Cut it.

Read the piece drawing. Pick points, insert type, and panel weight are engineered for that panel. Two panels that look the same from ten feet can have different pick points, and using the wrong ones is how an insert pulls.

Know the sling angle. As the angle between the sling leg and the horizontal gets shallower, the tension in each leg goes up, and the capacity of the arrangement comes down. Spreading the legs wide to make a pick reach is the version of this that gets people hurt. The rated capacity chart for the sling in your hand is what answers it, not a guess.

During the lift

Stay out from under the load and out of its swing path. No hand goes on a panel that is moving.

If the panel needs steadying, that is what a tag line is for. A hand on a panel that suddenly releases is a crushed hand.

One person signals. Everyone else stays out of it. If the signal person cannot see the load and the operator both, get someone who can.

When it does not come loose

A panel that will not break loose is telling you something. Stop, set the load back down, and find out why before pulling harder. It might be a bulkhead still bolted, a blockout that was not stripped, an embed catching, or a liner that is holding by suction and needs a wedge worked in at a corner.

Pulling harder to see what happens is how the crane finds out the answer for you, and the answer arrives all at once.

After the pick

Panels go where they are supposed to go, on dunnage, stable, blocked, and not leaning against anything that is holding them up by luck. A panel that has been set down badly is still a hazard hours later, to a crew that was not here when it was placed.