Human Error Caused Superstorm Sandy Crane Failure, Expert Says
"He had no idea what he was doing," Jim D. Wiethorn, chairman and principal of Haag Engineering, tells ENR. Wiethorn discusses the collapse in the new book, "Crane Accidents: A Study of Causes & Trends To Create a Safer Work Environment," published last month. The book is the result of seven years of compiling more than 500 investigations of crane accidents that Haag's crane group, based in Sugar Land, Texas, has conducted since 1983.
Until now, few have pointed to a cause for the 2012 accident. Officials with the building's construction manager, Lend Lease, told ENR the crane operator put the unit in weather-vane mode, as standards and best practices dictate; city officials concurred. Further, the engineer that designed the crane's tie-ins characterized the incident as an "act of God."
Wiethorn does not dispute the contractor's claim but says one or more workers later grabbed two fall-protection lanyards attached to the climbing frame, on the machine's tower structure, and hooked the loose ends around the crane's slewing-gear bolts on the rotating upper structure in an effort to secure the straps prior to the storm.
As wind speeds increased, "the lanyards on both sides of the turntable prevented rotation," says the author. The boom had nowhere to go, so it flipped backward. Wiethorn, who visited the wreckage one day after the storm, took close-up photos but did not provide them to ENR.
Officials at Lend Lease would not confirm Wiethorn's theory. "As with many natural disasters, the aftermath of the damage caused by Superstorm Sandy will be forever the subject of speculation," it says in a statement. "Lend Lease stands by its prior statements related to the crane incident and declines to comment further given the pending insurance claims."
Messages left with the building developer, Extell, and the crane operator, Pinnacle Industries, were not returned. A spokesman for the city buildings department declined to comment, as well, saying the agency has not finalized its report on the failure. The building opened in late May, about six months behind schedule.
Whether the crane was covered under the project's insurance policy is the subject of a lawsuit in New York State Supreme Court. Last October, Lend Lease and Extell sued Zurich and others that underwrote the job. According to court filings, the 74-floor luxury condominium, called One57, was valued at $700 million, for which Zurich had insured $350 million, or half the job. Ace, XL, Travelers, Surplus Lines and Axis Surplus are also defendants named in the suit.
After the storm, Extell and Lend Lease submitted nearly $11 million in claims. Zurich refused to pay, arguing that the crane was not covered. Lend Lease says the rig was included in an $89-million concrete contract, which Pinnacle was to perform using the rented crane. In Zurich's filings, it argues that contractor equipment is not covered unless endorsed as part of the builder's risk policy.
Scaffolding was insured because it was endorsed as part of a $15-million hoist and sidewalk-bridge contract. "The same cannot be said for the crane," says Miles Wemken, a Zurich underwriter, in an affidavit filed on April 29.
When asked about the new collapse theory, a spokeswoman for Zurich told ENR in an emailed statement that the company "did not insure the crane involved in the case study and does not speculate on causes of accidents."
The new book, available from Haag for $249, is full of data. The study shows that "other field personnel," or workers not involved in a lift, are killed more often than any other workers, including those doing the lift. Injuries for non-lift workers are also high, second only to riggers (see chart). Wiethorn says crews can reduce danger by taping off the lifting zone and restricting it to authorized personnel.
Another finding is that booms collapse more frequently on large cranes than on small ones. You would think that heavier lifts are planned more carefully, but Wiethorn says that "those lifts are getting more complicated, and now the little things catch you." Ground preparation is critical to maintain proper lift radius, a boom deflects as it grows longer, and distance magnifies problems, he explains. Project controls, such as a restriction on lift radius, can prevent accidents, he adds.
Ray A. King, an associate engineer at Haag who gathered data for the book, says he hopes it will inform future industry standards. "To make those standards more applicable, it really helps to understand why an accident happens in the first place," he says. "That's ultimately the main objective."
Wiethorn is regarded by many as a go-to accident expert, but his theories often draw criticism. In the 2012 criminal trial of crane owner James Lomma in New York City, he testified that a fatal collapse in May 2008 resulted from operator error, not a faulty weld, as prosecutors contended. Lomma was acquitted but still faces a civil trial this fall. In both cases, Wiethorn was hired as an expert witness.
"I anticipate that his credibility will be seriously challenged at the upcoming civil trial," says Bernadette Panzella, an attorney representing one of the victims. Another attorney involved in a separate matter told ENR that Wiethorn "is not pro-worker. He is pro-business."
Wiethorn says his conclusions are based on engineering principles and an analysis of the facts. "When I tell a client they don't have a case, it drops," he says. "We're done."
CRANE ACCIDENT TRENDS: FATALITIES AND INJURIES | ||
TRADE | FATALS | INJURIES |
---|---|---|
Rigger | 28 | 91 |
Operator | 28 | 29 |
Oiler | 1 | 1 |
Ironworker | 23 | 50 |
Management | 10 | 5 |
Signal person | 0 | 9 |
Other field personnel | 51 | 82 |
Pedestrian, bystander | 6 | 14 |
TOTAL | 147 | 281 |
Source: HAAG ENGINEERING CO. |