A very small percentage of tower cranes are involved in deadly U.S. accidents—only about 5%, studies show. Yet all it took this year was one big failure in New York City to turn them into a towering symbol of the hazards that hundreds of thousands of workers face daily on the jobsite.
Tudor Van Hampton/ENR
OSHA inspectors have stepped up spot checks in the wake of crane accidents.
A disturbing trend of bystander deaths, inconsistent work practices and a fast-flowing Internet news stream is feeding public awareness, political pressure and intense scrutiny of hoisting operations nationwide. More accidents have followed a March 15 tower crane collapse in Midtown Manhattan, the deadliest in the country, with six workers and one bystander killed. It was a wake-up call to the industry and the public, exposing problems of unsafe rigging, questionable training, loose oversight and corruption.
That was not the end of it. A crash in Miami and several others involving mobile cranes have added fuel to the fire. A high-profile failure on May 30 in New York’s Upper East Side, killing two, raised more concerns over how machines are designed, maintained and inspected.
|Two Decades of Deadly Crane Accidents||
November 28, 1989 San Francisco Tower crane snaps from its mast during a climbing maneuver -
August 18, 1994 Seattle
July 14, 1999 Milwaukee Crawlercrane erecting ballpark truss collapses under high wind -
Globalization may be part of the problem. Sources close to the investigation say the collapse of the vintage Kodiak crane that fell on E. 91st St. in May is being blamed on a faulty weld made in China. They say a foreign turntable part was substituted because replacement parts were not available for the early-model machine, which was manufactured in the 1980s and has since been discontinued. Whether or not the parts were inspected and certified properly before the crane was put back in service is being studied. Other accidents, such as a 2,500-ton mobile crane that collapsed in Houston, killing four workers, have shed light on the questionable training of workers and supervisors, and whether or not regulators have the right tools to police lifts. The momentum for comprehensive crane safety has reached a tipping point.
Garbage In, Garbage Out
For many, these accidents are hitting all too close to home. “When the general public thinks ‘it could happen to me,’ it has a big impact,” explains Alan Barnhart, president of Memphis-Tenn.-based hoisting contractor Barnhart Crane & Rigging Co. The crashes are hitting home on another level, he adds. “We spend millions of dollars a year on safety and training, we push the programs, and you are still seeing a lot of premier crane companies right now having some very big accidents. I pray for these guys,” he says.
No one is immune. Barnhart regularly lifts bulky objects like pressure vessels that weight hundreds of tons, year after year, with zero incidents. Yet it experienced its first fatality on July 24 in Oklahoma City on a seemingly innocuous project where a 90-ton Grove truck crane tipped over while it was lifting a mere 700-pound church steeple. The boom crashed, killing an elderly man and injuring his wife as they watched the pick from their car.
May 21, 2000 London
Aug. 21, 2003
U.K. Health & Safety Executive
Studies show that crane accidents are usually the result of some kind of human error, or multiple, cascading errors. One problem could be an over-reliance on technology. Prior to lifting the steeple, Barnhart’s crane operator misread the amount of counterweight on the crane and punched in the wrong number into the crane’s load monitor. The crane “thought” it was heavier and could handle the load and radius. Otherwise, it might have locked out the controls and prevented the lift. But the operator, who was certified, “was quite new on the crane,” Barnhart explains, and the crash exposed a training lapse. “It obviously was a tragedy for us,” he says.
Barnhart declines to name the operator, saying that the company is weighing corrective action: “The basic question is whether this is something that was an isolated incident...or was this a revealer of a trait of this person?” No lawsuits have been filed because “we are basically going to take responsibility for what we did,” Barnhart says.
Reading the Data
Crane accidents by themselves are seemingly random, but studying them as a group reveals systemic problems. A University of Tennessee study of accidents from 1997 through 2003, funded by the Occupational Safety and Health Administration and published in the September 2006 issue of the Journal of Construction Engineering and Management, found that workers being struck by loads or cranes was the prime reason for crane fatalities, followed by electrocutions from booms touching power lines. It also revealed that buildings, roads and bridges take up the majority of crane accidents, far more of which involve mobile cranes (88.4%) than tower cranes (4.1%).
February 16, 2004
April 13, 2004
Though many safety programs over the past decade have focused largely on the training of crane operators, a disparity between the low deaths of crane operators and the high deaths of other workers, such as riggers and signalers, is placing more pressure on employers to step up training people working under the hook.
Tudor Van Hampton/ENR
Young (left) and Fink (right) pushed Philadelphia rule.
Recent statistics have borne this out. A National Institute of Occupational Safety and Health-funded study of accidents published this year by the Center for Construction Research and Training, a research arm of the AFL-CIO, found that more construction laborers were killed in crane accidents from 1992 through 2006 (30%) than crane operators (23%). The University of Tennessee study also found that a large percentage of workers who died in crane accidents were varied trades working under or near cranes. “More attention needs to be given across the construction industry to the training of such workers,” it concludes.
Crane accidents happen nearly every day, but their exposure on the evening news has skyrocketed since March 15. If the Oklahoma incident normally would have been a forgotten story, it now is suddenly a headline in hundreds of media outlets across the country. It is difficult to say whether accidents are increasing or just reported more frequently. Federal accident statistics stop at 2006, and not all injuries are reported or categorized correctly. But available data show crane-worker accidents declined slightly during the 10-year period from 1997 to 2006, killing an average of 82 workers a year, according to the Bureau of Labor Statistics. Meanwhile, demand for mobile and tower cranes has doubled or tripled in that time, says market analyst Stuart Anderson, president of Hagerstown, Md.-based Chortsey Barr Associates. Some believe that suggests safety around cranes has increased. Still, globally, reports of accidents and fatalities have kept climbing, according to Internet clearinghouse.
A New Model for Crane Safety?
|Operators must be certified|
|Riggers must be certified|
|Signalers must be certified|
|General contractor must purchase $15-million umbrella policy and name city as certificate holder and additional insured|
|Plan review for tower crane building struts, foundations, etc.|
|Cranes must be inspected at least twice a year by a certified, independent inspector|
|Crane owners must disclose equipment age, status of original-equipment manufacturer and availability of OEM parts|
|SOURCE: CITY OF PHILADELPHIA. APPLIES TO TOWER CRANES ONLY. CERTIFICATION APPROVED FOR NCCA AND ANSI-ACCREDITED TEST ADMINISTRATORS. RIGGER AND SIGNALER CERTIFICATION EFFECTIVE JANUARY 2010. INSPECTOR CERTIFICATION EFFECTIVE JULY 2010.|
Public officials across the U.S. are looking at how to minimize risk through new regulation, especially in the face of an updated federal rule that was written in 2004 but has yet to be implemented. This summer, a revision to the decades-old OSHA standard moved to the White House Office and Management and Budget for review, but it still is not expected to go into effect until 2013 or later. Some experts argue it is already out of date.
Cities and states are taking matters into their own hands. New York City since March 15 and May 30 has deemed nylon slings unsuitable for crane climbing, increased...