Category Archives: Transportation

Cessna offers training on corrosion inspections

Cessna Aircraft Co. has developed a training program for service technicians to support a far-reaching effort to identify and correct corrosion, fatigue, and cracks in high-time aircraft.

The 40-hour training course in Wichita, Kan., is designed for mechanics, covering techniques for visual inspection, as well as ultrasound and other methods for visualizing airframe structures. The program is geared toward the massive fleet of 100-series aircraft built between 1946 and 1986. In December, Cessna announced pending updates to service manuals for 100- and 200-series aircraft. The FAA this month issued a direct-to-final-rule airworthiness directive (AD) requiring one-time inspection of the lower wing spar caps installed in Cessna 210, P210, and T210 models following reports of spar cap cracks in Australia and Canada.

Inspections there revealed five aircraft with cracks in Australia, and one in Canada, according to the Cessna Pilots Association.

Cessna spokesman Andy Woodward said procedures and repair requirements for any 200-series models found with spar cap problems is “an issue we’re still looking at.”

For the 100-series fleet, several times larger than the estimated 3,000 to 4,000 Cessna 210 models in the active U.S. fleet, the new inspection requirements vary by model and total time. According to Cessna, there are about 47,000 100-series aircraft registered in the U.S. that are subject to the inspections, out of roughly 84,000 made prior to 1986.

“Corrosion and fatigue are inevitable on any make and model of airframe with a high amount of hours. However, with early detection and proper maintenance, severity and effects can be minimized,” said Beth Gamble, Cessna’s principal airframe structure engineer. “The 100-series inspection requirements are very simple, and begin with a visual inspection that can be done quickly by a trained inspector during an annual inspection.”

Hammersmith tunnel ‘solution to crumbling flyover’

A west London council has said building a tunnel is the long-term solution to replace a “crumbling” flyover.

The Hammersmith Flyover has been under repair works since December and is scheduled to reopen fully on 30 May.

Hammersmith and Fulham Council said: “We must continue to push for an alternative solution, and that is a tunnel.”

Transport for London (TfL) said the flyover “would be able to survive for several further decades”.

A council spokesman said: “TfL must realise that we cannot simply accept patch-jobs to prolong the life of this monstrous outdated and crumbling structure.”

TfL Surface Transport spokesman Garrett Emmerson said: “Our engineers, contractors and traffic control operators continue to work flat out to deliver a permanent fix to the Hammersmith Flyover well ahead of the 2012 Games.

“The structure would be able to survive for several further decades.

“However the Mayor has also asked us to consider long term options for the area and that work will consider a range of possible solutions to the area’s future needs.”

The strengthening works, which began in January, have seen about 200m (650ft) of the central reservation along the flyover removed, a new structural slab and concrete barriers installed, as well as tailored anchorages for the new cables installed within the structure.

TfL has been carrying out two weeks of overnight closures to flyover since 15 May to carry out the final parts of this work.

It said it would return to the structure in 2013 for more strengthening work which will be carried out, where possible, with no weight or lane restrictions and minimal closures to the flyover.

SOURCE: http://www.bbc.co.uk/news/uk-england-london-18095448

Anthony Wayne Bridge (Ohio) to close in 2013 for 2 years

Toledo’s Anthony Wayne Bridge will be closed to all traffic for two years, likely to start sometime in 2013, as part of a three-year, $50 million overhaul of the 81-year-old structure by the Ohio Department of Transportation.

The fundamental main-span appearance of the bridge — which carries State Rts. 2, 51, and 65 over the Maumee River and is the last suspension bridge on Ohio’s state highway network — will not change. The first approach span on either side of the suspension spans will be completely replaced during the project with new two-span structures.

Deck replacement on all the other spans is planned, along with joint improvements, cable repairs, and corrosion removal on the bridge’s steel girders, said Theresa Pollick, a department spokesman in Bowling Green. A separate painting contract will be issued after all structural and deck work is done.

The shutdown will be required because of the complete replacement of the two approach spans, Ms. Pollick said.

The spans to be replaced, which have deck-truss designs, are “fracture critical,” meaning that if certain parts of their structures were to break, they lack the backups necessary to prevent a collapse.

“The closure duration is necessary for the amount of work we must do and for the safety of those who travel the bridge during construction,” said Todd Audet, the transportation department’s district deputy director.

As the last suspension bridge on the state system, he said, “it’s important to ODOT to preserve it.”

The Anthony Wayne Bridge — also known locally as the High Level Bridge — gained its distinctive status on Feb. 22 when the transportation agency dynamited the Fort Steuben Bridge over the Ohio River between Steubenville, Ohio, and Weirton, W.Va. No other suspension bridges still standing in Ohio, or across the Ohio River, are part of the state system, the agency said.

The Anthony Wayne bridge last underwent major repairs in 1997 and 1998, when its concrete deck was resurfaced, some steel suspender cables were replaced, its main suspension cables were wrapped with weatherproofing material, and other repairs were made.

SOURCE: http://www.wtol.com/story/17457960/aw-trail-bridge-to-close-in-2013-for-2-years

Corrosion Work on George Washington Bridge will take 10 years

Peter Zipf sounds more cardiologist than civil engineer when he talks about subjecting the George Washington Bridge to the equivalent of the classic battery of tests for heart disease and finding the first signs of plaque.

“It really is a little like giving somebody an EKG and checking their cholesterol levels,” said Zipf, the Port Authority’s chief engineer. “There are certain things you know you have to watch for, to catch them before they go too far.”

And chief among those certain things, as a bridge ages, is the corrosion that can sap the strength of its steel.

“Moisture is the big culprit,’” continued Zipf. “You have to constantly monitor the amount of corrosion and the rate of deterioration, and then determine when to intervene.”

The GWB’s test results have spurred the Port to intervene now and undertake the biggest rehabilitation in the 81-year history of the world’s busiest bridge. When the work is completed in 2022 – yes, 10 years from now – the Port will have spent $1.5 billion, a piffle in comparison to the $6-billion-to-$8-billion that it would cost to build the GWB today.

The centerpiece of this your-tolls-at-work program will be the first-ever replacement of the GWB’s suspender ropes, all 592 of them. The ropes, vertical bundles of woven steel wire that attach to the four main cables and support the deck, will be replaced a couple or three at a time to keep the 600,000-ton bridge on an even keel.

To assist, the Port, fittingly, has hired Ammann & Whitney, the consulting engineering firm founded by Othmar Ammann, the man who designed and built the GWB and five other suspension bridges in the city.

The Port will also rehabilitate the upper level’s deck (work already in progress), remove the lower level’s original, and failing, lead paint, rebuild the 177th and 178th Street ramps as well as the multiple ramps to the GWB bus station and repair the Center and Lemoine Avenue bridges.

“The bridge can withstand this extreme work because it’s very robust in terms of strength – remember it was built to handle rail,” explained Zipf. “So that extra strength becomes a safety factor that gives the bridge the tolerance for rehabilitation.”
(Careful readers will recall the Thruway Authority will spend more to build the new Tappan Zee Bridge strong enough to support rail – or serious rehabilitation in the next century, if rail is never added.)

Does any or all of this mean the bridge-and-tunnel crowd is doomed to construction delays at the GWB for 10 years?
“In all of our work, through design, staging of construction and so on, we strive to minimize the impact on traffic,” pledged Zipf. “We’ll only close a lane during off-hours or at night, so if you cross the bridge at rush hour, you aren’t going to be aware that anything’s going on.”

…For 10 years.

http://www.recordonline.com/apps/pbcs.dll/article?AID=/20120409/BIZ/120409746/-1/NEWS

Manx2 crash landing was caused by corrosion

Air accident investigators have confirmed that mechanical failure caused an aircraft to crash land at Ronaldsway.

The UK-based Air Accident Investigation Branch has issued a safety recommendation to the European Aviation Safety Agency following the accident.

Emergency services were called into action at just before 6pm on Thursday, March 8, when the Manx2 service from Leeds Bradford Airport got into difficulties after landing at Ronaldsway.

Twelve passengers were escorted shaken but unharmed from the aircraft which was operated by Lincolnshire-based Links Air, on behalf of Manx2. The two crew members also escaped unscathed.

Now a preliminary investigation by the AAIB has concluded that a corrosion crack in a metal component caused the right hand landing gear of the Jetstream to collapse, resulting in the plane skidding along the runway on its wingtip and coming to rest in the grass at the side.

The AAIB found that the accident was caused by stress corrosion cracking in a metal component at the top of the right main landing gear leg.

Its report describes how almost immediately after the aircraft touched down it leaned to the right and there was an unusual noise.

Investigators say that the corrosion was not detected by a visual inspection carried out 11 days before the incident nor during a test of the landing gear completed 10 months before – although the amount of corrosion in the crack and on the steel spigots suggest it was present then.

As these inspection requirements didn’t detect the crack, the AAIB has issued a safety recommendation to the European Aviation Safety Agency that it review the effectiveness of an airworthiness directive in identifying cracks in the yoke pintle housing on landing gears fitted to Jetstream 31 aircraft.

SOURCE: http://www.iomtoday.co.im/news/traffic-and-transport/manx2-crash-landing-was-caused-by-mechanical-failure-1-4384557

Lights out for the Blatnik Bridge?

The iconic lights that outline the Blatnik Bridge linking Duluth and Superior will go dark and come down later this year during maintenance on the bridge.

Whether they return when the work is complete in 2013 is up in the air.

Corroded, in the way and “failing at an alarming rate,” the more than 200 decorative lights and their wiring have to be removed as part of a $12 million, two-year maintenance project on the bridge that’s slated to start in May, said Beth Petrowske, public affairs coordinator for the Minnesota Department of Transportation in Duluth.

Putting the lights back up and replacing the wiring is estimated to cost $1.2 million. Minnesota generally splits costs with Wisconsin on Blatnik and Bong bridge projects, but the Blatnik’s decorative lights were a project initiated and paid for on the Minnesota side from the beginning back in the 1990s.

That’s the catch in replacing them.

MnDOT is “willing to cover and can commit to our 50 percent” of the replacement cost, or $600,000, said Duluth District Engineer Mike Tardy. But now, in a time of tight budgets and many other pending road projects, MnDOT says it wants Wisconsin — or some other source — to chip in for the other half.

“I understand that the decorative lights on the Blatnik are an important feature for the area,” Tardy said. “Our challenge is that the price tag to replace them is really substantial. The funding has to come from somewhere.”

To be clear, the lights in question do not include traffic lights and navigational beacons — only the bridge’s “aesthetic” lighting.

State Sen. Roger Reinert, DFL-Duluth, has gotten involved in the issue, reaching across the bridge to Superior Mayor Bruce Hagen and, in turn, officials from the Wisconsin Department of Transportation in an attempt to find a solution.

“I was incredulous, (thinking) ‘this can’t be possible,’” Reinert said of when he first heard the lights might be going away. “In terms of Duluth landmarks, I think of the Lift Bridge, Enger Tower and the Blatnik. … The idea of it being gone is just flat-out not OK by me.”

As for WisDOT chipping in money toward the lighting, Chris Ouellette, communications manager for WisDOT’s Northwest Region, said, “We haven’t said yes, but we haven’t said no.

“Our department is in the process of drafting policy for decorative lighting and how funding for that type of project might work,” she said. That discussion is taking place in Madison, she said, and there might be more details to report this week.

Wisconsin Rep. Nick Milroy, D-South Range, said he expects the lighting to be discussed during the annual Superior Days in Madison this week. But he said tight budgets may make it a tough sell.

“I think it’s going to be very difficult,” Milroy said. “It’s something that a lot of people think is an amenity” instead of a necessity.

“When there’s not a lot of money to go around you have to prioritize what’s important,”

Reinert said the goal is for the two states to split costs. But if that doesn’t happen, he said, he and Rep. Kerry Gauthier, DFL-Duluth, have drafted a bill to require MnDOT to find the money to reinstall the lights. Both legislators said that’s an option they don’t want to use.

“We’re hoping that MnDOT will partner with WisDOT to get the money to get those lights back up,” Gauthier said.

The lights

The decorative lights on the Blatnik originated with a letter from Duluth businessman Monnie Goldfine to then-state Sen. Sam Solon in 1991, said longtime MnDOT spokesman John Bray, now retired after three decades with the agency.

“A lit-up Blatnik Bridge would be a symbol of uniting Duluth with Superior and would serve as a sign that we welcome visitors,” Goldfine wrote in another 1991 letter on the topic to city and state officials.

The letter was written as planning was under way for a massive overhaul of the Blatnik Bridge in 1993-94, when the span was completely closed to traffic for months.

The lights were installed and — after a long delay caused by water leaks into the fixtures — they officially debuted on Nov. 21, 1996.

Since that time, they’ve become a familiar sight in the Twin Ports — and they’ve been subjected to a lot of abuse from Mother Nature and passing traffic.

“The lights are exposed to the harshest environmental conditions that there can be: rain, wind, snow, salt that can cause corrosion … vibrations from heavy trucks. It’s pretty intensive maintenance,” Tardy said.

Now the fixtures have to come down to allow for sandblasting and painting of gusset plates this summer. They’ll be saved for possible reuse; the corroded conduit and wiring won’t be.

The annual expense of operating the lights is about $15,000 to $20,000 — also paid for entirely by Minnesota at present, though Tardy said that’s of less concern than splitting the more-significant restoration cost. There’s a chance operating costs could be reduced with the use of LEDs or other, newer lighting technology if the lights are reinstalled.

Tardy said he’s hoping the return of the Blatnik lights is less an “if” and more a matter of “when.”

“I’m optimistic that we’re going to be able to make this work,” Tardy said.

SOURCE: http://www.duluthnewstribune.com/event/article/id/223396/

Corrosion threat on Ohio bridge deck discovered

Grout packed into bundles of steel cables that compress the Veterans’ Glass City Skyway’s concrete deck sections together may contain elevated levels of salts that would cause those cables to corrode prematurely, the grout’s manufacturer has warned the Ohio Department of Transportation.

The I-280 bridge over the Maumee River, which opened five years ago, is one of several dozen projects across the United States that used grout made at a Marion, Ohio, plant owned by Sika Corp. U.S. in which excessive chloride compounds, traced to cement the plant bought from an unnamed supplier, have been discovered.

Also potentially affected is the Perry Street bridge in Napoleon, which carries State Rt. 108 over the Maumee and was replaced in 2005, the U.S. 33 bridge over the Ohio River between Pomeroy, Ohio, and Mason, W.Va., and as many as eight other smaller bridges in Ohio. Mike Gramza, the planning and engineering administrator at the transportation department’s district office in Bowling Green, said about 30 projects were affected overall.

Mr. Gramza and a Sika spokesman both said last week they are not yet sure that the particular batches of grout used in the Toledo or Napoleon project contained the elevated chlorides. A company alert identified all grout produced in Marion during an unspecified time that ended in March, 2010, when production there stopped.

In the worst case, they said, chloride presence would not create an imminent — or even short-term — safety hazard on the $273 million bridge built between 2002 and 2007.

But there is the possibility, they said, that as the bridge ages, chloride in the grout could cause the cables — known formally as “post-tensioning tendons” — to corrode and fail sooner than they otherwise would.

Samples will be taken within a few months from the Skyway, Mr. Gramza said, for testing “to see if there is a problem or not.” “It’s not an immediate issue,” he said, “But it could impact the life of the structure.”

More than 3 million pounds of grout from five sources was used on the I-280 bridge to seal ducts through which the post-tensioning strands pass. Those cables, which are distinct from the stay cables that support the bridge deck vertically, compress the bridge’s precast concrete segments against each other and also maintain transverse tension to reinforce the structure.

Grout is a mixture of water, cement, and sand that hardens once mixed. Its purpose in post-tensioning tendons is to protect the steel cables from moisture, road salt, and anything else that would cause them to rust.

Mr. Gramza said the transportation department’s specifications for project materials included an 0.08 percent limit on chlorides in the grout, a normal industry standard. But the suspect grout from Marion, he said, had chloride concentrations as high as 0.5 percent.

Chlorides — the most common of which is sodium chloride, otherwise known as table salt — accelerate the corrosive action of water and oxygen on metals such as steel.

So as long as the grout keeps air or water from reaching the post-tensioning tendons, chlorides’ presence in the grout causes no damage.

But over time, it is likely that tiny cracks will develop in the grout. Any air or water that seeps into it through the post-tensioning tendons’ outer ductwork might eventually reach the cables themselves, delivering the grout’s chlorides — plus any salt already in the water from ice control on the bridge — to the cables and initiating the corrosive chemical reaction that creates rust.

Mr. Gramza said that although grout delivered to the project was tested for strength, it was not tested for chemical composition. The transportation department learned of the problem in “late October or early November,” when it was notified by Sika, he said.

Diana Pisciotta, the Sika Corp. spokesman, agreed that grout is not routinely tested for chloride concentration.

She would not elaborate on how the problem came to Sika’s attention, disclose the source of the cement used at the Marion plant, nor comment on any theories Sika may have about how that cement came to be high in chlorides. But she said the company had been forthright in notifying the grout’s users once it identified where material made in Marion had gone before production halted in 2010.

“We at Sika are not happy that this has happened. We have tried to be proactive in reaching out to people. This really is a situation where you want to be aware,” Ms. Pisciotta said. An advisory describing the matter on a Sika company Web site, dated Dec. 6, said the company had, “over the past several months,” been “working aggressively to address reports” of excessive chlorides in SikaGrout 300 PT product made in Marion.

“There is a concern that, depending on the level of elevated chlorides in the grout in installed locations, the risk of corrosion in the tendon strands could increase,” the advisory said. “While this issue could affect the long-term service life of certain infrastructure projects [roads, bridges, etc.] where the impacted grout was used, Sika is unaware of any damage to structures to date arising from this elevated chloride issue.”

In November, 2010, Sika began “an enhanced quality-control testing regime” that includes chloride analysis for SikaGrout 300 PT made at other plants.

With one exception, listed by the company, all of the Marion-produced grout had lot numbers ending with the letter “M” on bags of the material.

Mr. Gramza said detailed records were kept showing the sources of grout used on various areas of the I-280 bridge, so sampling will be limited to areas where Sika’s Marion-made grout was used. Samples will be tested at a transportation department laboratory, a Sika lab, and a third-party location, he said.

“If there is a problem, we will have to investigate it, and evaluate the potential impact on traffic,” he said. The transportation department will consider Sika liable for the cost of any corrective measures, Mr. Gramza said.

Asked Sika’s position on its liability exposure, Ms. Pisciotta responded: “Our intention is to collaborate with them [ODOT] as they review this issue. We will continue the conversation with them as to what the appropriate next steps are.”

The grout problem is at least the fourth significant materials problem with the Skyway.

In 2004, about 184 cubic yards of concrete was removed from the bridge’s central pylon after sample testing determined a particular batch was weaker than required. Later in the project, officials discovered cracks in the plastic coatings on the bridge’s stay cables and ordered them replaced at the supplier’s expense.

And in 2008, a year after the bridge opened to traffic, inspectors discovered that epoxy glue holding the stay cables’ stainless-steel sheaths together was not holding up and the sheaths were slipping. The sheaths were welded together to remedy that problem.

The bridge also has had sporadic problems with ice forming on its pylon and stays during winter storms, then falling off in sheets onto the roadway when the weather warms, but so far this winter, such ice has not been an issue.

SOURCE: http://www.toledoblade.com/local/2012/02/06/Corrosion-threat-on-Skyway-bridge-deck-discovered.html

Contaminated Fuel Found at Moscow’s Sheremetyevo Airport

Inspectors have uncovered risks in the aircraft refueling process at Moscow’s Sheremetyevo airport. The inspectors see a potential disaster in the quality of the fuel.

The Bermuda Department of Civil Aviation, where most Russian airliners are registered, has identified impurities that could lead to microbial corrosion in the fuel used at Moscow’s Sheremetyevo airport. Such a defect could trigger a spontaneous engine shutdown.

The inspectors believe that the cause of the corrosion is an old pipeline built in 1974. Aircraft fuel is distributed from a tank from that era. Since then, airport technicians have repeatedly inspected the fuel reservoir and performed the required scheduled maintenance but the inside of the pipe has accumulated a lot of dross over the decades, which affects the quality of the fuel. Therefore, the fuel that flows from the tank is usually dirtier than the fuel that flows in, said one expert.

Bermuda aviation authorities have sent a warning notification about the dangers of using this fuel to the Russian Federal Air Transport Agency (Rosaviatsiya), which is to resolve the situation. Rosaviatsiya officials found five cases of spontaneous engine shutdown in aircraft based at airports in the region over the past few years. The last such incident occurred on November 15. Bermuda officials believe that all these incidents are connected with flights from Sheremetyevo airport since no such incident has been recorded with aircraft from Vnukovo or Domodedovo airports.

At Sheremetyevo airport, journalists were advised to contact representatives of the fuel suppliers. TNK-BP insisted that it strictly observes fuel standards, fully complies with all applicable regulations, and has received no complaints from any airline on fuel quality.

Industry Challenges Texas Pipeline Ruling

Pipeline companies are asking the Texas Supreme Court to overturn a ruling they say jeopardizes new projects, escalating the battle over the costs of transporting oil and natural gas produced by the energy boom in South Texas.

The industry says its costs are soaring as landowners, bolstered by a recent appellate-court opinion, seek much higher payments for damage to their property values from pipelines and reject what they see as lowball offers from companies. Under Texas law, companies can build pipelines across private property over landowners’ objections, but must pay for use of the land and any damage to the value of the rest of the property.

The dispute in the South Texas case could have ramifications in other states where pipelines are proliferating along with new oil and gas fields, some legal experts say, as lawyers and appraisers build on arguments that have gained traction in court.

A year ago, an appellate court in San Antonio upheld a jury verdict against LaSalle Pipeline LP that awarded $600,000 to the Donnell family of McMullen County, Texas. The award was mostly for the loss of value to an 8,000-acre ranch after LaSalle built a natural-gas pipeline that stretched for four miles across the property.

LaSalle has appealed to the Texas Supreme Court, which has asked for briefs but not yet agreed to hear the case. Another pipeline company filed an amicus brief last month.

In the case, an appraiser hired by the family calculated the loss in value by studying sales of similar properties nearby, and found that those with pipelines sold for 20% less on average than those without pipelines.

A lawyer representing the family declined to comment on the case.

LaSalle didn’t dispute that it should pay for the rights to the 17 affected acres, but it said the pipeline didn’t diminish the value of the overall property at all. The Houston-based company argued that the landowner’s appraiser failed to consider factors besides a pipeline that could affect what people would pay for it, including location, shape and access to water.

LaSalle also maintained the landowner’s appraiser didn’t submit figures to the jury that would support his calculations.

Tom Zabel, a Houston lawyer representing LaSalle and other pipeline companies, said that costs to obtain rights of way have increased fivefold or sixfold in South Texas since the verdict in the Donnell trial.

In the Southwest alone, the Interstate Natural Gas Association of America estimates the region will need 50,100 miles of gathering pipelines, which take gas from wells to processing plants, between 2011 and 2020, 31% of the total nationally.

Energy Transfer Partners LP, a major pipeline operator that filed the amicus brief with the court in support of LaSalle, said that landowners, armed just with the appellate opinion, have argued in more than 20 condemnation hearings that pipelines would reduce their property values by at least 20%. Under state law, local panels hold hearings when pipeline companies sue landowners to obtain rights to build on their property.

Dallas-based Energy Transfer argued that if allowed to stand, the rationale affirmed in the appellate opinion would leave companies unable to “predict the costs associated with their projects and the viability of pipelines.”

Barry Diskin, a professor at Florida State University who has done work for pipeline companies, said he has never seen a study that found a systematic pattern in property values tied to pipelines. “I’ve not seen one, and I’ve looked,” he said.

But just the possibility of a major explosion is enough, in the real world, to depress property values near pipelines, said Marcus Schwartz, a lawyer in Halletsville, Texas, who represents landowners.

SOURCE: http://online.wsj.com/article/SB10001424052970203436904577153001395050804.html

Serious corrosion fears keep vital road in London closed

Transport for London has been forced to keep the vital A4 Hammersmith flyover closed for further inspections because of serious corrosion of steel supporting cables.

Problems with external concrete sprawling have been known about for several years, but engineers have called for extra time to assess the extent of damage within the 900m bridge structure.

The flyover was closed on 23 December due to concerns about a serious structural defect.

Since engineers and contractors have been working round the clock on a detailed investigation.

They hope to decide shortly on what remedial action needs to be taken and when the flyover can safely be reopened to traffic.

The damage to the aging 1960′s structure has been caused by water ingress, including salt water due to grit laid during the winter months, which has corroded and weakened supporting cables.

Engineers on-site continue to build a full picture of the condition of the complex and aging bridge structure, with much of the work taking place inside the structure.

TfL said that it was exploring all options to reopen the flyover to traffic as soon as possible, but must await the outcome of further work to test the extent of the problems found in the structure.

TfL is also actively working on the design of a solution to strengthen and extend the life of the flyover over the longer-term, by introducing additional cables into the structure.

Leon Daniels, TfL’s Managing Director of Surface Transport, said: “Our team continues to work night and day alongside the world’s leading structural engineers to fully understand the extent of the flyover’s structural problems.

“I have been inside the flyover and seen for myself the unique issues we face,” he explained.

“Safety must be our top priority and we have not taken the decision to close the flyover lightly.

“However, we are working flat-out to determine what measures we must put in place to safely reopen the flyover as soon as possible.”

SOURCE: http://www.constructionenquirer.com/2012/01/03/serious-corrosion-keeps-a4-flyover-closed