Signaling and Cone of Influence

Rigging Pt. 3 Signaling and Cone of Influence

Schaus-Vorhies provides a wide variety of services through our numerous companies. We offer expert professional work in areas as different as metal cleaning and industrial fabrication. Something we provide that is in demand in virtually every industry is rigging.

The ability to safely and precisely lift and move loads of various kinds is often tight, and limited spaces are a necessity. If a crane operator makes a false move, or a spotter isn’t paying attention, the result can be damage to expensive equipment or even the loss of life. Because of this, Schaus-Vorhies takes the skills necessary to do this very seriously. Our riggers are trained extensively to ensure that they can perform even difficult rigging tasks safely. In this series, we’ve been taking a look at some of those necessary skills.

The skills we’ve looked at in the two previous installments of this series are:

  • Calculating the load – You need to know how much you are lifting to lift it safely.
  • Sling configuration – To make sure that your load is stable, you need to know how to pick the right slings for the job and how to arrange them in the best way possible.
  • Drifting a load – Knowing how to transfer a load from one lifting device to another is vital. It isn’t often we’re called upon to pick up a load and put it down again.
  • Inspection criteria – You need to know that your equipment is in good condition. We looked at inspection criteria for the most common equipment riggers use, such as slings, shackles, and chain falls.

In this final installment on rigging, we are going to take a look at two other skills, knowing the cone of influence and signaling. These two skills aren’t directly rigging skills and often are not even part of a rigging qualification. However, they are still necessary skills for people involved in rigging activities, as they are directly related to moving the load safely and keeping others safe while doing so. Let’s start with signaling.

  • Hand Signals – When moving a load with a hoist or a crane, it is often that the operator cannot see exactly what he is doing. The load may be two or three levels up or down from where he is. Or there may be various obstructions blocking the view of the laydown area. Rather than letting him guess his way to landing the load, a signal person will provide direction. Ideally, the signal person will be in the operator’s line of sight, allowing for clear and swift communication. Naturally, the signals are almost always hand signals rather than voice communication. With voice communication, there are too many words that sound similar, leading to confusion on the part of the operator. Also, the operator, at least, will be almost always be working in a loud environment. That crane engine is noisy, after all. Even with a remotely controlled overhead hoist, there will be noise as this kind of equipment is almost always being operated in an active industrial environment.

There are also blind lifts, in which case the operator cannot see the landing zone at all, nor can he see the signal person. In this case, the two will communicate via radio. Clear and precise communication in such a situation is critical. More than just direction has to be provided. The signal person has to provide direction on how much distance remains to the landing zone, and when to slow down.

We won’t go into the various signals here. They can be found in the Rigging Handbook, along with a wealth of other relevant information. The important thing to understand is that whether you use voice or hand signals, is that both parties agree upon the signals before the lift starts and that the signal person communicates them clearly.


  • Cone of Influence – Also known as the cone of exposure, this term refers to the area in which a load might fall. Too often, people assume that the only danger zone is directly under the load. However, if the load is tall, high off the ground, or outside in windy conditions (not too windy, there are regulations governing when a crane can be operated based on wind speed), the cone of influence can be much larger than the load’s footprint. Because of this, it is important to keep personnel out of this cone as the load could potentially drop anywhere within it.

This concludes our look at Signaling and Cone of Influence.  We have taken a brief look at some of the skills and concepts that riggers at Schaus-Vorhies need to have a firm understanding of before we allow them to perform any rigging task for the company. Ensuring that our riggers are well-trained gives our clients the confidence that when they call a Schaus-Vorhies company to handle their load, it will get delivered where it needs to go safe and error-free.