Tag Archives: Inspection

Inspection showed Mercier Bridge corrosion trouble in 2006

Five years before Quebec closed part of the Mercier Bridge due to dangerously deteriorating steel plates on the span’s provincial side, an inspection found plates on the federal side were corroding and had to be replaced.

The report said repairing the plates – steel connectors that hold together the bridge’s girders and beams – should be a top priority.

“These gusset plates play a major role in the integrity of the bridge structure,” the report stated. “Therefore, the progress of corrosion at these plates must be monitored, and, if necessary, a capacity assessment should be done to evaluate more accurately the behavior of the material affected by the corrosion.”

The inspections were commissioned by Jacques Cartier and Champlain Bridges Inc., which owns the federal side of the Mercier.

Ottawa reinforced about 50 gussets in 2008, replacing two and repairing the rest. Meanwhile, Quebec, long criticized for neglecting transportation infrastructure, decided not to do work on its gussets.

The Mercier’s federal half was built in the late 1950s, while the provincial part that was closed for gusset repairs went up in the early 1930s.

The 2006 report, by an engineering firm, paints a troubling picture of the Mercier at the time.

For example, it warns the bridge’s side curbs and median were so deteriorated that cars that accidentally plowed into them could be launched into oncoming traffic or off the bridge.

Follow-up federal inspections in 2007, 2008 and 2009 also disclosed in response to the access-to-info request, found that repairs helped improve the overall condition of the bridge’s federal half.

The disclosure that federal officials were advised about gusset deterioration as early as 2006 is another indication Transport Quebec may have missed crucial corrosion on the provincial side.

If the deterioration had been caught earlier, traffic disruptions that affected tens of thousands of commuters during the Mercier closing could have been avoided.

To fix its gusset plates, Transport Quebec closed two of the Mercier’s four lanes on June 14. One of the closed lanes reopened Sept. 6. But, to allow for ongoing gusset work, the bridge still goes down to two lanes overnight and on weekends. All four lanes are to be permanently reopened by December.

This summer, Quebec initially refused to make public the inspection of its side of the Mercier, finally relenting in September under pressure from the public, engineers, politicians and the media.

In September, Transport Minister Pierre Moreau said provincial plates deteriorated “at a faster rate than what was expected” and the damage could not have been caught earlier.

Independent engineers question this version of events, noting corrosion does not speed up.

The 2006 inspection report recommended 37 repairs, nine of which were classified as “A” priority jobs, meaning they were “necessary to maintain the integrity of the system’s structure and of its auxiliary components.”

The first item on the list of top-priority repairs: gusset plates, which, the report said, should be reinforced by 2010.

The report recommended close to $32 million in federal repairs.

The $74-million federal expenditure is part of a $174-million Mercier overhaul that Ottawa and Quebec began in 2008 and that is to be completed by 2014. Quebec has not said how much it has spent on the project so far.

The 2006 federal inspection was the last general inspection of the bridge.

SOURCE: http://www.montrealgazette.com/Inspection+showed+Mercier+Bridge+trouble+2006/5693667/story.html#ixzz1dnwJT1yO


Millennium Pipeline clears safety check

Millennium Pipeline has been given the go-ahead to return to full service, company officials said, after a natural gas leak led to a government investigation that uncovered missing weld inspection records. While the records weren’t located, new weld inspections were conducted to verify the integrity of four “suspect” welds that raised the ire of federal officials for inadequate paperwork.

“Our integrity confirmations revealed that no additional anomalies were found, no weld defects of any kind were found. Our digs didn’t reveal anything out of the ordinary or unusual to be of concern.”

State and federal officials launched an investigation into the pipeline after a weld, located near the Broome-Tioga county border, sprung a leak on Jan. 11. The leak released an estimated 1.3 million cubic of feet of natural gas — enough to heat an average home in the Northeast for 18 years — before repairs were completed five days later.

The results of that investigation were released in a U.S. Pipeline and Hazardous Materials Safety Administration document in July, which pointed to the three other welds in a 93-mile section of the Millennium system that were considered “suspect” because of missing inspection documents.

Between the leak and the recordkeeping deficiencies, the July PHMSA document expressed concerns about the integrity of the pipeline as a whole.

“Similar defects may also develop leaks and potentially lead to a rupture of the pipeline,” the federal document said.

Following the report, Millennium reduced pressure on the pipeline — which can reach a maximum of 1,200 pounds per square inch, but is normally lower — by 20 percent until the integrity of the welds could be verified.

On Sept. 21, Millennium and PHMSA reached a consent agreement, in which they agreed to conduct new testing to allay concerns about the welds by Dec. 31.

The consent agreement document identifies the “suspect” welds with approximate locations that would place all four in either western Tioga or eastern Broome counties.

Gibbon said the work was completed recently, and Millennium was given the green light to return to normal pressure in mid-October.

An estimated $500,000 to $600,000 in “pig testing” — a process in which camera equipment is shuttled through the pipeline to collect data from the inside — in addition to nine investigative digs provided information that was missing in the records.

The welds turned out to be OK, according to Gibbon.

“There were different places along the pipeline where they asked if we would please go through and get a visual to make sure that everything is okay, and it was” she said. “We submitted our findings back to PHMSA … and we’ve returned to normal pressures.”

‘Not a perfect system’
Richard Kuprewicz, a Bellingham, Wash.-based pipeline safety expert, said situations such as this are “not unusual.”

Pipeline operators are not required to conduct an X-ray inspection of every weld on a pipeline, even though it’s the best way to ensure the integrity of a weld.

On top of that, government agencies don’t typically look over the shoulder of pipeline operators during construction to make sure every single weld has an inspection record.

“Everyone thinks, especially during the construction, that there’s safety inspectors looking at this every step of the way,” he said. “They can’t be checking every weld or every record. There’s only a certain number of people.”

Case in point: Although the Millennium Pipeline gained government approval prior to going online in December 2008, PHMSA became aware of recordkeeping deficiencies only after the January leak.

“It’s not like it’s your car being built and there are quality controls,” Kuprewicz said. “It’s not a perfect system.”

Gibbon said Millennium takes “full responsibility” for the missing records, and has both revised its recordkeeping system and launched its own internal investigation.

“Even though we have modernized our system going forward, we’re going back and doing a very careful examination of where something could have slipped through the cracks,” she said.

PHMSA did not respond on Monday to questions about the agency’s records on inspection policies.

SOURCE: http://www.pressconnects.com/article/20111031/NEWS01/110310371/Millennium-Pipeline-clears-safety-check?odyssey=nav%7Chead

Footbridge closed as it’s ‘dangerous’ due to corrosion

THE INSPECTION in the United Kingdom which led to the closure of the footbridge to Whitby’s West Pier extension has revealed a long standing history of corrosion and decay.

Scarborough Borough Council’s report, compiled the day after the inspection a fortnight ago talks of “corrosion”, “failure” and “dangerous”.

The inspector examined the primary beams which are positioned at either side of the bridge and secondary beams which sit between them and support the wooden decking which pedestrians walk on.

Findings suggest the beams have not been painted or treated for some considerable time and given the exposure to airborne seasalt this has accelerated corrosion.

The report states: “The primary and secondary beams may once have been painted but there is now no evidence of a painted surface to any of the beams or associated fixings.

“This has resulted in significant corrosion leading to delamination which can be expected to result in a significant reduction in functionality.”

The primary beams which span 11.7 meters and 13 meters are undersized for the load it is carrying according to current British standards.

Furthermore supporting steel work appears to be 20% corroded and associated fixings are “exhibiting signs of extensive corrosion greater than 50% of their net cross section which could lead to failure of the beams.”

The balustrade posts and railings are painted but spot chips and cracks in the finishing coat were noted along with corrosion staining.

But the metalwork which fixed the posts and railings to the bridge are severely corroded.

The report says: “While the balustrade is overall in what can be considered in fair condition, the connection to the primary beam is near to failure and is considered dangerous.”

The report’s suggested future options have done nothing to stop rumors circulating town that the bridge is to be demolished and access to the extension being permanently cut off.

Three possible ways forward include: bridge removal and abandonment of access, replacement of the footbridge in its entirety or another more detailed inspection and refurbishment which would include removing the bridge to allow for the works.

But the report says this could be more costly than replacement.

Council member Joe Plant, who represents the West Cliff ward, said the first he heard of any issues with the extension and the footbridge was when he learned it had been closed along with everyone else and as far as he was concerned demolition or permanent closure “was not an option”.

He told the Gazette: “I have asked the question and in my view we should be looking at replacing the east and the west from the same funding pot.

“I have also asked for the maintenance regime. If this has not been done, why not? I know money is tight at the moment for a lot of things but at the end of the day if you maintain things it will save you money in the long run.”

Brian Bennett, SBC’s head of tourism and culture has said officers are looking at the possibility of re-opening the bridge to limited foot traffic pending a further inspection that requires scaffolding being put up.

This had to be postponed last week due to high winds but Mr Bennett added SBC had been in touch with English Heritage and a bridge manufacturer about a replacement.

If this goes ahead it is likely it will be manufactured off site, then delivered and installed.

SOURCE: http://www.whitbygazette.co.uk/news/local/footbridge_closed_as_it_s_dangerous_1_3790004

Mercier Bridge inspections reveal alarming decay

Quebec has released long-awaited inspection reports on Montreal’s Mercier Bridge that confirm rapidly accelerating decay in the aging structure forced its closure earlier this summer.

Corrosion noted in a 2011 inspection was so advanced that some bridge parts were perforated and deformed, the reports say.

In particular, the report said, 10 gusset plates that hold beams in an interlocking pattern are severely eroded.

Of 346 bridge parts inspected, 86 were given a “1” rating, meaning that they were deemed “incapable of perfoming required task.”

The 2011 report was dated June 11, and the Transport Ministry banned most traffic from the bridge three days later, citing the need for critical repairs to remedy safety-threatening corrosion and rust.

But Transport Minister Pierre Moreau was quick to point out that long-term repairs to remedy decay were underway when the span was shut down.

“The deterioration was going at a faster rate than what we expected,” but the bridge was in no danger of collapsing, Moreau said at a news conference Monday.

All emergency repairs have been completed, but other work is in progress.

The Mercier Bridge partially reopened Sept. 6, with remaining lanes scheduled to open in December if all repairs are completed.

The summer closure angered South Shore residents, officials and business owners who rely on the Mercier Bridge for daily commutes into the city.

The Transport Ministry has released inspection reports from 2007, 2008, 2009 and 2011 on its website.

The Mercier Bridge comprises two structures, one built in the 1930s and another inbound arm built in the 1960s.

SOURCE: http://www.cbc.ca/news/canada/montreal/story/2011/09/19/mercier-bridge-inspection-reports-released.html

Plymouth Avenue bridge closed until next year

There’s good news and bad news for traffic users of the Plymouth Avenue Bridge. The good news is that city officials appear to have found the money needed to repair the bridge. The bad news is that it will probably be a year or more before the bridge is open to motor vehicle traffic.

Minneapolis City Engineer and Public Works Director Steven Kotke said most of the money is coming from the State of Minnesota. “We were successful in obtaining two different pots of money. One was kind of an emergency fund that the state had, and then the governor actually put in the state bonding bill $4 million for the Plymouth Bridge, and that gave us a grand total of right around $6 million, which is about what we think we need to fix the bridge.”

He said, however, that the various parts of the repair work need to be done in a certain order and in very close succession, and there’s not enough time to do it all this year. So they won’t be able to start the work until next year.

“The work needs to be sequenced in a continuous manner, so that would not allow us to do the work this fall and then stop for the winter and the start again,” he said. “We intend to get the project all bid out and start first thing in the spring. We’re anticipating it will be about four months worth of work, so that would put us probably near the end of August of 2012 to have the bridge completed and opened back up.

“So the good news is we were able to give everybody the green light to keep moving forward. It would have been nice if we could have started right away, but given the manner of the work that needs to be done, it would prevent that from happening,” he said.

“So we are continuing to finish the final design, and then it has to go through a state review process to make sure everything is right.”

The bridge crosses the Mississippi River and connects Eighth Avenue NE and Plymouth Avenue N. Motorists can cross the river using the Broadway Bridge six blocks to the north.

City engineers closed the Plymouth Avenue Bridge Oct. 22 after finding corrosion in its support system during a routine annual inspection. It was built in the 1980s and was the first of its kind—called post-tension segmental box girder—in Minnesota. City officials brought a consulting firm that specializes in this bridge design, to inspect the bridge and recommend repairs.

They found serious corrosion in at least five of the post-tension tendons in the bridge’s center span. These tendons, Kotke said earlier, are similar to the cables that support suspension bridges, and are designed to keep the bridge’s concrete parts pushing inward when a load is placed on the bridge surface. The concrete, he said, is strongest when it’s in this “compression mode.”

An initial report, issued in late December, recommended four major repairs:

  • Reconfigure the bridge’s drainage system to direct water away from the bridge’s box girders
  • Replace five of the bridge’s corroded support tendons
  • Add more tendons to improve the bridge’s flexing capability
  • Seal the bridge’s wearing surface with a penetrant sealer, or replace the wearing surface.

The bridge is currently open to pedestrians and bicyclists; bicyclists are asked to walk their bikes while on the bridge.

SOURCE: http://www.tcdailyplanet.net/news/2011/08/14/plymouth-avennue-bridge-closed-until-next-year