Investigators are focusing on failed steel as a possible cause for the deadly I-280 truss crane collapse last month, and have sent several pieces to a laboratory for analysis, The Blade has learned.
Jule Jones, head of the Toledo office of the U.S. Occupational Safety and Health Administration, said yesterday that investigators sent “fairly large pieces” of fractured steel to Lehigh University in eastern Pennsylvania earlier this week.
The Lehigh laboratory specializes in testing the integrity of steel structures.
“Obviously there was a failure and we need to determine through testing and interviewing and investigative techniques what failed first,” Ms. Jones said. She emphasized investigators have not ruled out other causes.
“At this point,” she said, “we just need to get input from the expert metallurgists.”
Four men were killed and four others were injured after one of two 1.8-million-pound truss cranes collapsed about 2:20 p.m. Feb. 16 during the construction of the southern approach to the new I-280 Maumee River crossing.
Lehigh s Engineering Research Center for Advanced Technology for Large Structural Systems has done extensive work on the strength and failure of construction materials. The center has investigated many notable structural failures, including the collapse of the World Trade Center because of the terrorist attacks.
Studying the fractures under a microscope and subjecting portions of the samples to standard steel stress tests, the lab will try to determine if the steel failed - and therefore, caused the accident - or if it may have fractured when it collapsed as a result of some other cause, according to engineers at Lehigh s ATLSS.
Like OSHA, the Ohio Department of Transportation has been careful to emphasize it has not ruled out any potential cause, including weather, human error, and equipment failure.
“Our goal is to have a thorough and accurate investigation,” ODOT spokesman Joe Rutherford said. “And testing various components of the truss and whatever the results may be are part of that investigation.”
Mr. Rutherford said several different parts of the truss were sent for testing, including portions of the overbridge, the portion of the truss that supports the concrete roadway segments as they are lifted into position.
Investigators have posed a number of questions about the steel, and several witnesses have reported hearing “the sound of a large piece of steel fracturing,” said Chuck LaFaso, the local business agent for the International Union of Operating Engineers.
That sound is familiar to construction workers, and differs distinctly from the sound of failing concrete, he said.
Mr. LaFaso, who has sat in on several interviews with members of his union who were at the job site when the bridge collapsed, said investigators were looking at both the truss and the temporary steel legs upon which it stands when it is being moved from one concrete pier to the next.
The operating engineers run the truss, working with ironworkers to move the truss and place the roadway segments in position.
Workers from both unions take an active role inspecting the truss on a regular basis, he said.
At the time of the collapse, workers were extending the “underbridge” portion of the truss, which is used to move or “launch” the entire truss. The truss temporary legs were on the middle pier and were supporting most of the weight, because the forward legs of the underbridge had not yet been set on the next pier, Mr. LaFaso said.
ODOT officials said the piers appeared to have been damaged only as a result of the truss collapse.
After the accident, the second truss crane was placed in a more secure position; it is unclear if it will be used again.
Paolo de Nicola, an Italian company, manufactured the two truss cranes, that were then assembled here in Toledo. The massive trusses, which stand 40 feet high, extend about 315 feet.
Company representatives flew to Toledo in the days after the accident. Among the nearly dozen representatives was a metallurgist, ODOT officials said at the time.
The company could not be reached for comment yesterday, and has not responded to phone and e-mail messages from The Blade.
Although it s a high profile project in his district, state Rep. Peter Ujvagi (D., Toledo) said it s important to give investigators time to do their job.
“No matter what it points to, it has to be solved,” he said.
Robin Erb can be reached at email@example.com or 419-724-6133.
Mike Wilkinson can be reached at firstname.lastname@example.org or 419-724-6104.