By Neal Tepel
Investigative Report Finds Improper Rigging Operations as Cause of Collapse
Following an extensive investigation by the New York City Buildings Department, it was concluded that improper rigging operations caused an 11,000-pound steel collar to fall March 15, 2008 while it was being connected to the building under construction. When the collar fell, it struck and severely damaged the crane’s lower connections to the building, which resulted in the collapse of the entire tower crane structure. The collapse killed six construction workers and one civilian, demolished a four-story brownstone on East 50th Street, and damaged more than a dozen buildings in the East Side neighborhood.
Based on this comprehensive review, the investigation concluded the collapse was caused by a number of critical errors, including: Four synthetic slings ere used instead of the required eight chain blocks specified by the anufacturer to support the 11,279-pound steel collar; One of the slings used to support the collar had prior physical damage; Slings were not attached at he collar points specified by the manufacturer; Slings were attached to the mast in a way that compromised their capacity; and Padding for the slings at the mast’s sharp edges was not provided.
DOB Inspectors and Engineers worked with Department of Investigation (DOI) and the Manhattan District Attorney’s Office on the investigation into the collapse, and in January, Manhattan District Attorney Robert Morgenthau announced the indictment of the tower crane rigger and his company on multiple charges of manslaughter, criminally negligent homicide, assault, and reckless endangerment. DOB continues to work with the District Attorney and DOI to prosecute the case.
A copy of the 298-page report, titled “51st Street Crane Investigation Report,” is available at this link.