The Award-Winning Bridge That Failed
By William Allan Jr.
from special issue "Pittsburgh Bridges Falling Down," The Pittsburgh Press Roto
Sunday, June 5, 1977
Copyright acknowledged. This article is reproduced here for historical and educational purposes.
view page - More info on Neville Island Bridge over Ohio River back channel
This year's mystery question: What caused the crack in the Interstate 79 bridge?
No one seems too sure, but the federal government has suspicions.
An "about-face" directive issued by the Federal Highway Administration prohibits the welding process used on certain portions of the bridge from being used again in similar circumstances.
The ban, which applies to welding on main support beams, pertains to any highway administration project anywhere.
Ralph L. Romberger, the administration's Pennsylvania division bridge engineer, recently revealed -- for the first time publicly -- that the order was handed down on a national basis from headquarters in Washington, D.C. It came through a short time after the embarrassing I-79 crack was discovered, forcing officials to close the majestic-looking span for two months only five months after it was opened to traffic.
Subsequently, the crack had to be repaired, all other electro-slag welds on the bridge were reinspected, and nine were reinforced. Then officials became worried about similar welds on the new Brady Street Bridge (Birmingham Bridge), and a series of hairline cracks were found.
Electro-slag welding -- to which the federal government had given its blessing -- was used extensively on the I-79 bridge. The now-famous crack occurred right beside an electro-slag weld in a support beam, leading many authorities to theorize immediately that intense heat generated in the welding process may have weakened the surrounding steel.
The process is relatively new to bridge building. Proponents say it is more economical and faster than traditional methods. Oversimplified, electro-slag welding involves joining heavy pieces of steel with a single pass of welding equipment. Conventional methods use multiple passes.
The hurried highway administration ban on electro-slag welding reads, in part, as follows:
"Based on preliminary results of recent research and the actual observations in the field, the use of electro-slag weldments on main structural tension members (like in the I-79 beam which cracked) will not be permitted on federal aid projects."
"This restriction will continue until such time as the quality of this weld can be insured by possible modification in the welding process and/or improvement in the inspection and quality control procedures which appear necessary at this time."
The directive is written in typical, confusing jargon, but what it means, basically, is that electro-slag welding is out in most situations until the feds decide it is a reliable process.
Romberger thinks the highway administration notice was a result of the I-79 crack.
A towboat captain spotted the 10-foot-long crack in the girder last Jan. 28 (1976) and notified authorities. The damaged area was in a bridge section which spanned the "back channel" of the Ohio River, connecting Neville Island with the south shore at Groveton.
The back channel portion of the bridge was closed immediately to all traffic. The "main span" of the new bridge, connecting Neville Island with the north shore of the Ohio at Glenfield, remained open to local traffic for several more days. But it was determined that the entire bridge had to be inspected for further damage, and it was shut down altogether --and an enraged motoring public demanded an explanation.
The effect the I-79 bridge closing had on traffic in the area was catastrophic. People who live and work on both sides of the Ohio depend heavily on the I-79 bridge. Then the nearby 67-year-old Sewickley Bridge was closed. Aged and crumbling, that span was finally barricaded by the Pennsylvania Department of Transportation (PennDot).
With both bridges kayoed, traveler had to go all the way downriver to Ambridge to use a two-lane bridge or travel over pothole-infested streets to the McKees Rocks Bridge.
Either route was extremely inconvenient, circuitous and time-consuming Traffic became a nightmare. There were horror stories of commuters getting to work or returning to their homes three hours later than normal.
With traffic hopelessly snarled and local residents headhunting to find out who goofed on the heralded and long-awaited I-79 span,ironic memories of the bridge's opening drifted into mind.
The $50-million Interstate 79 span was unveiled amid much hoopla Sept. 3, 1976 -- closing the last gap in Western Pennsylvania's only modern 180-mile north-south highway. At the time, Allegheny County Commissioner Jim Flaherty made a classic statement:
"It's a great pleasure to stand on a bridge and not have to worry about it falling."
Even more ironic was an announcement which arrived in the mail Jan. 29, the day after the infamous crack was discovered. The Pittsburgh Section, American Society of Civil Engineers, revealed PennDot had been presented its "Annual Award for the Outstanding Engineering Project of the Year." The award was presented for (you guessed it) -- the Interstate 79 bridge design.
Engineers and inspectors soon swarmed over the bridge as PennDot launched a two-stage investigation. Dr. John Fisher, a professor of civil engineering at Lehigh University and a widely known bridge expert, was appointed to determine the actual, technical cause of the crack. And the late William H. Sherlock, PennDot secretary who has since died in a plane crash, formed a "blue ribbon" committee of three additional university engineering professors to review the entire bridge-building process and monitor the repairs.
The "blue ribbon" committee is chaired by Dr. Max L. Williams Jr., dean of the University of Pittsburgh School of Engineering. Also on the team are Dr. Raymond E. Untrauer, head of the engineering department at Penn State University, and Dr. Steven J. Fenves, a professor of civil engineering at Carnegie-Mellon university.
Both Fisher and Williams said it would be months before their studies are completed and reports issued.
Neither was eager to say his investigation would actually "point the finger"at a particular person or persons. It is generally assumed, however, that one or both of the investigations will uncover who goofed, if anyone.
Fisher said he and his staff at Lehigh "will provide the technical facts . . . as far as pointing the finger, that will be someone else's responsibility."
Williams said it would be "highly unlikely" that his team would name persons responsible for the crack, but the specialist added he "wouldn't exclude the possibility."
Robert W. Cunliffe, chief counsel for PennDot, said litigation in the matter, if there is any, probably won't take place until the investigations are compete and any culpability in the matter is determined. Cunliffe maintained, however, that PennDot is prepared to go to court if necessary to protect the interests of the taxpayers.
Exploring who or what could be at fault for the crack in the Interstate 79 bridge is an undertaking as challenging as trying to determine which came first -- the chicken or the egg. Many different contractors, inspectors and government agencies were involved. Although the electro-slag welding process is highly suspect, it by no means has been pinpointed as the actual cause of the crack.
For the purpose of starting somewhere, however, electro-slag was used on the cracked beam at the option of the general contractor, according to Bernard Kotalik, PennDot's chief bridge engineer. The general contractor was Bristol Steel and Iron Works Inc., of Bristol, Va.
Some people still want to know why PennDot awarded the contract to a Virginia firm when some of the biggest steel manufacturers and most reputable bridge-building companies are located right here in Pittsburgh. The answer is simple: The I-79 bridge project was thrown open to public bidding, a required by law, and Bristol submitted the low bid.
As general contractor, Bristol was required to repair the crack once it was discovered.
"In any agreement between the department (PennDot) and a contractor, if work is found to be defective, the contractor is required to correct it," Kotalik said.
This does not necessarily mean that Bristol will have to swallow the final repair bill. Although the steel firm initially made and paid for the repairs, it might get off the hook if investigators can pin the blame on someone else.
Actual repair of the crack was completed in two months, and the powder-blue color, six-lane bridge was reopened -- without any fanfare this time -- on March 31.
John A. Hawkins, vice president of sales and engineering for Bristol, confirm that the electro-slag process was chosen at the option of his firm. He explained that the contract with PennDot stipulated Bristol could pick any one of several welding processes.
"We had several (welding) options. We chose that (electro-slag)," Hawkins said.
Defending the process, Hawkins said it was a "known fact in the industry" that electro-slag is faster and more economical than other types of welding on projects like the I-79 bridge.
"At this point, we see no reason why we should not use electro-slag again," Hawkins said.
Anthony J. Gaeta, PennDot's engineer in District 11 (Allegheny and Beaver counties), said that although he was "not familiar with the electro-slag process" because that was not his particular specialty, he knew it was "an accepted procedure" used "in a lot of places."
Romberger called electro-slag "generally a good process -- it saves the taxpayers' money. You can do it faster; therefore, it's cheaper."
"To the best of my knowledge, I know of no failures due to this welding process which have occurred on a federal aid project."
Hawkins declined to reveal the cost of the crack repairs, noting the matter of final billing is still up in the air. He explained hydraulic jacks were used to force the cracked beam back to its original position, then heavy plates were bolted over the damaged area to create what amounts to a splice.
Various experts have agreed the repair method restored the bridge to its original strength.
Bristol made no repairs or reinforcements on the bridge other than on the beam that cracked, Hawkins said.
Additional reinforcements to the bridge were made by Pittsburgh-Des Moines Steel Co. Bristol, as general contractor, sublet to Pittsburgh-Des Moines the "fabrication" of the "arch span." In bridge jargon, "fabricate" means to take pieces of steel from a mill and form them into structural shapes (such a I-beams) as specified in the bridge design. "Arch span," in this case, is the actual arc rising above the I-79 bridge deck over the Ohio's main channel.
L. E. Anderson Jr., manager of Pittsburgh-Des Moines' eastern division, explained the firm made a total of nine electro-slag welds in the steel it fabricated. All nine of these welds were reinforced by fastening steel plates over them with high-strength bolts.
The sequence of events that led to the Pittsburgh-Des Moines' reinforcement of its electro-slag welds went as follows: The bridge cracked, and Bristol made repairs. Meanwhile, Pittsburgh Testing Lab, an independent agency working for PennDot, inspected the nine welds made on the arch span. As a result, Pittsburgh-Des Moines was required to make the reinforcements as a precautionary measure, because the bridge should last at least another 50 years.
Asked whether Pittsburgh Testing actually found any of the Pittsburgh-Des Moines welds to be defective, Kotalik cited the possible upcoming litigation and begged off the subject, saying, "I am not in a position to make a statement about those (welds)."
Like Bristol, Pittsburgh-Des Moines footed the bill for additional work but is awaiting the outcome of the investigation to find out who will stand final responsibility.
Pittsburgh-Des Moines fabricated the steel for the arch span at its plant on Neville Island (only a short distance from the bridge site). Anderson claimed no problems occurred during fabrication. Like Bristol, the electro-slag process was used at the option of Pittsburgh-Des Moines.
The electro-slag weld where the crack occurred was made by Bristol during fabrication at its plant in Bessemer, Ala., Hawkins said. He added the company encountered noting unusual during fabrication.
The fabrication process was monitored in various manners. In addition to Bristol's own quality control inspectors, PennDot employed an independent inspection agency to check the fabrication work in the Bristol shop, Hawkins said. Kotalik identified Pittsburgh Testing Laboratory as the agency that handled these inspections.
According to Hawkins, the electro-slag welds on the Bristol-fabricated steel "were X-rayed in the shop before they were shipped. Copies of those X-rays were supplied to PennDot and their inspection agency. We had to get approval of the X-rays before the steel could be shipped."
Kotalik said Pittsburgh Testing Lab also monitored the fabrication at Pittsburgh-Des Moines' shop. Anderson said that these inspections were in addition to Pittsburgh-Des Moines' own quality control procedures (like Bristol).
Steel for the bridge itself was erected by American Bridge Co., a highly respected division of U. S. Steel Corp. Gaeta said many different PennDot construction inspectors periodically checked the work.
Gaeta said he feels -- and hopes -- the bridge's cracking problems are over. When asked about the chances for more cracks, he replied:
"I wouldn't think so because we've X-rayed and checked every weld on the bridge. We don't anticipate any more problems."
One other firm which was deeply involved in the I-79 bridge project should be mentioned -- Richardson, Gordon and Associates, which was responsible for design.
Norman G. Marks, a partner in the firm, said he was directed by PennDot not to discuss the "reason for failure."
Romberger, the highway administration bridge engineer who disclosed the government's ban on electro-slag welding, said construction of the I-79 bridge "was conducted like a normal federal aid project." He explained federal engineers normally visit interstate projects regularly to discuss various problems that may be encountered and offer advice. "It's a brief visit -- he doesn't inspect," Romberger explained.
Romberger confirmed an area engineer from the administration did conduct routine visits to the bridge during construction. This engineer was Thomas Abraham, who works out of Harrisburg. Romberger called him a "very competent, registered professional engineer" and said he has no reason to believe Abraham did anything less than his duty.
Romberger confirmed a more detailed inspection could have been carried out by the administration -- a process review, where an engineer inspects one particular phase of a project in depth. To the best of his knowledge, Romberger said, no process review had been conducted on electro-slag welding in Pennsylvania. He added "we had no reason" to conduct a process review on electro-slag welding here. Ironically, Romberger went on to say, now that the electro-slag welding method has been partially banned by the highway administration, there is no opportunity to conduct a process review on the system.
Too Few People
Romberger also explained that the administration does not conduct a process review on every bridge. "There are too many bridges and not enough people," he declared. "That's like asking a policeman 'Do you catch all speeders?' "
Romberger said the feds aren't conducting their own investigation of the I-79 crack because the bridge "is a state project" which the federal government helped finance (it picked up 90 percent of the tab). "The problem is between the contractor and the owner," he said. "In this case, it's the state."
So many questions remain unanswered.
What happened and who was responsible? Should the electro-slag welding process ever be resumed on bridges? Have PennDot and the highway administration, both funded by tax money, adequately represented taxpayer interests? And all those tests on the other electro-slag welds on the I-79 bridge -- what did they show? What did they cost? And who's going to pay?
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Original Document: Allan, William, Jr. "Pittsburgh Bridges Falling Down: The Award-Winning Bridge That Failed" The Pittsburgh Press Roto. Sunday, June 5, 1977