Most riggers and other trades use a standard set of hand signals to communicate with crane operators on the jobsite. Hand signals, which riggers and operators have used for decades, cut across cultural boundaries, enhance safety and are easy to learn.

Michael Goodman Students take written tests.

But Jeff York, president of Signal-Rite LLC, San Leandro, Calif., thinks they are not enough. A veteran crane operator of 23 years, York is trumpeting the need for a standard set of verbal crane signals. He says verbal signals are more applicable to today's super-large-scale construction sites, which often leave the crane operator working "in the blind". His system, which has been published in rigging books and adopted by many large contractors on the West Coast, allows operators to maintain safety over a two-way radio, and significantly reduces spotting mistakes.