Nothing is scarier for a crane operator than driving in the dark, with a heavy hook and load out of view, and taking instructions over the radio. It is an all too common situation for operators, who complain that few riggers and signalers know how to give them proper directions. As radios replace hand signals as the standard mode of communication among those who work near cranes, inconsistent signals can lead to accidents. They are costly and tragic, and this year has seen plenty of them. Vocal communication is a problem in construction that national standards are only beginning to address.

Michael Goodman/ENR
Signaling students give York instructions while he operates with blacked-out windows.

Radio signals are at the heart of broader efforts to improve crane safety, and operators on the forefront of the debate. Working in the blind "is one of the most dangerous things we do with a crane," says Duffy L. Best, a retired operator in Redding, Calif. Guiding an invisible load that hangs hundreds of feet from the cab requires concentration and, most important, signals from spotters that are loud and clear. When a load moves into the blind, "it's like your brain clicks into a different mode," Best says. And "if you've got an idiot on the radio, it's a nightmare," he adds.

When confusion ensues, operators often will put their rigs "on the dog," or shut them down, until they are satisfied that the riggers and signalers are properly trained. Workers often label operators as "prima donnas" for such displays of power, but the intention is for everyone to go home safe.

Others are not so careful, and for those who are lucky enough to live, crane accidents can follow surviving operators around like an albatross. This year, an estimated 300 crane accidents will plague the industry worldwide, according to Doyle Peeks, who maintains in Port Charlotte, Fla. And he says the number goes up every year. Government statistics are less shocking, but still significant. The Occupational Safety and Health Administration says up to 82 workers are killed each year in the U.S. due to crane accidents, with hundreds more injured. A study released in September by the National Institute for Occupational Safety and Health points to 719 fatal crane accidents between 1992 and 2002. Construction accounted for about half of these deaths, with cranes killing about 36 construction workers, on average, every year. Other studies show that a crane accident occurs every 10,000 hours of use in the U.S. Insurers estimate that 80% are caused by operator errors.

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  • It is no wonder that operators have a lot to think about. Efforts at developing radio standards are one step in helping riggers and other personnel share the load. National standards boards have plans to define responsibility around cranes more clearly by the end of the decade, as does OSHA. "Right now, there is no definition as to who is responsible for what," says Peter Juhren, national service manager for Liebherr dealer Morrow Equipment Co., Salem, Ore.

    One of his company's tower cranes came crashing down rather dramatically last month in Bellevue, Wash., killing a Microsoft emloyee while he was relaxing in his living room. The operator survived.

    Site responsibilities seem to be at the core of the accident, which apparently was a structural failure of the 210-ft-tall crane. Chuck Lemon, who is investigating the accident for the state's Labor Dept., says that while there is no early indication that operator error was the problem, it has not yet been ruled out. "We want to know who did the daily inspection," he says. Whether or not the operator put the jib in "weather vane" mode each night also is a question, since high winds had swept through Bellevue prior to the accident. Not allowing the jib to spin freely could have torqued the tower's frame and damaged it, says Lemon.

    Michael Goodman/ENR
    York ran cranes on new Bay Bridge.

    Meet the Coach

    Whatever the cause, the Bellevue accident and rarity of a collapsing tower crane is a potent safety reminder. Before Best slipped and fell on the job several years ago, tearing a ligament in his left leg and ending a 28-year career as an operating engineer, he had several close calls that stemmed from signal failure. So did Jeff York, a crane operator in Hayward, Calif., a friend with 23 years of experience. Most recently, York manned a crane on the San Francisco-Oakland Bay Bridge for Omaha-based Kiewit.

    York's attention to safety is guiding him as he moves from operator to trainer. He quit his job last year to train riggers in a standard set of voice signals that he developed on the Oakland job. He uses short, one or two-word phrases, like "up easy" (slow hoist speed), "up" (medium speed) and "up up" (high speed). He chooses to use the word "high" in place of "stop" because it sounds too much like "up" over a two-way radio. He has handed out thousands of cards displaying his signals, and his system this year was featured in the latest edition of Bob's Rigging & Crane Handbook, a popular field guide.

    Don Pellow, a Kansas City, Mo.-based consulting engineer who publishes the book, says today's equipment is well designed. But he claims the rigging environment is more dangerous than ever, with heavier lifts, newer workers and an increasingly diverse fleet of machinery, such as tower cranes, entering the U.S. "It is so important to have the proper terminology," he says.

    Michael Goodman/ENR
    Students also take written tests.

    York says he was "sick and tired" of "incompetent" personnel and gained a reputation among area riggers as a stickler for safety. At the Oakland site, he would regularly take riggers and signalers up to the cab of his tower crane to give them his perspective of the jobsite. Then, he would coach them on his system. Those who were less interested in learning were shut out of crane time. Knowing operators leads to safer signals, experts say. York "is turning heads here in the Bay area," says Rick Raef, a San Francisco-based safety consultant for Willis Group. "Jeff has come up with a unique idea," Pellow adds.

    York has trained hundreds of workers on the West Coast. General contractors' safety personnel working in the Bay Area are using his trademarked "Signal-Rite" program to teach workers how to radio cranes. Subcontractors also "are really into it," says Rod Verrips, a senior safety manager for San Mateo, Calif.-based Webcor Builders. Standard signaling enables foremen to "get everyone on the same page" and it has greatly improved crane production, he says.

    Politically Incorrect?

    In his crusade to make crane operations safer, York also has ruffled some feathers. Despite an upcoming federal regulation and state efforts to require crane operator certification, York argues that riggers and signalers also need to be trained and certified and he wants them to use his system. An operator is "only as good as [the] signalman," he says.

    Members of standards boards argue that York's interest is financial. He now is president of Signal-Rite LLC, based in San Leandro, Calif. Others think that his system is provincial. "Jeff wants the industry to accept a specific voice signal for every task," says Larry DeMark, training director for operating engineers' Local 825 in Springfield, N.J. "It's a little restrictive. I'd rather see some standardized training and testing requirements for signal people." DeMark, a veteran operator, is a member of the American Society of Mechanical Engineers' B30.5 subcommittee on mobile cranes, which is accredited by the American National Standards Institute. Opponents also believe that York's system breaks safety protocol by not requiring constant radio "chatter."

    Additionally, "you can never write and mandate words," says Ron Kohner, another B30.5 member. Committee members, however, recognize the need for standard radio signals. "If you have somebody who is poor at hand signaling, you have less risk than somebody who is poor at radio signaling," Kohner says. Still, "it is very difficult to write a standard that is one-size-fits-all," says Juhren, chairman of ASME's B30.3 subcommittee on tower cranes. "We don't push somebody's product," adds DeMark.

    Independent of York's efforts to woo the B30.5 subcommittee, the group recently included criteria for voice signals in its 2004 revision, after having only hand signals in the standard for more than 35 years. Juhren says that B30.3 also plans to adopt it when its revision comes due for publication in 2008.

    As standard voice signals slowly work their way into the rigging lexicon, signalers will need to describe every load's movement, speed and direction, and be trained on basic crane operations. But it seems that few, except York, can agree on what people actually should say. DeMark warns, though, that signals are not a magic bullet: "There's still unqualified people running cranes, unqualified people supervising, and the more cranes that you have out there, the more problems that occur."

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    Tudor Hampton/ENR
    Cranes display hand signals but fall silent on radio talk.

    Still, voice signals "are probably one the weaker areas" of crane work, adds Dave Ritchie, risk controller for St. Paul Travelers in Bastrop, Texas, and B30.5 member. He, along with DeMark, is a proponent of new verbal requirements.

    York also criticizes certification test writers for not including questions on voice signals. Examiners say questions appear as signals become standard. "He is preaching to the choir," says Graham Brent, executive director of Fairfax, Va.-based National Commission for the Certification of Crane Operators (CCO).

    And more tests are on the way. CCO is considering certification programs for riggers and signalers. In January, operators also will be able to take a competing certification program jointly developed by the National Center for Construction Education and Research, Gainesville, Fla., and North American Crane Bureau. Officials say it likely will include questions on signaling as discussed in ASME B30.5-2004. NCCER Vice President Steve Greene thinks "hundreds of thousands" of U.S. operators are uncertified.

    Voice signals are on their way to becoming a federal requirement, too. A change to the Occupational Safety and Health Administration's crane and derrick standard, based on ASME B30.5-1968, is due for proposed rulemaking next year. It is expected to require riggers to have voice signal training that complies with ASME B30.5-2004. Adopting the latest standard "would get our crane regulations up to date," says Ritchie. The need is out there. "Confusion causes accidents," adds York.

    Reader Comment:
    Dec. 12, 2006

    There is a good precedent in standard voice terminology. All pilots are taught standard phrases to use when talking to air traffic control (ATC), and the connection to safety is obvious. Roger, Wilco, do not make the current list.

    William L. Gamble
    Professor Emeritus of Civil and Environmental Engineering
    University of Illinois at Urbana-Champaign