 It is the 3rd of August 2020 and Italian President Sergio Mattarella is inaugurating a new bridge in Genoa, Italy. This year has been a rollercoaster of ups and downs, but the event marks a moment of hope in the city's history, many looking at the bridge shed a tear. But these emotions aren't linked to the global pandemic, but to an event two years before. Mattarella isn't the first president to inaugurate a bridge on this site, but on a goes back to 1967 with the completion of this bridge's forerunner, the Ponti Morandi. The Morandi Bridge, so named after its designer Riccardo Morandi, met a tragic end in August 2018, which would raise questions about vital infrastructure throughout Italy and Europe as a whole. Today's video is about the story of this once engineering and architectural wonder, and it's quite literal downfall. Our story starts not in the baking hot sun of Genoa Italy, but that of western Venezuela. Engineer Riccardo Morandi had begun to pen a new bridge in 1957. This structure would become his signature of sorts. Morandi liked to design his bridges to look simple yet elegant. As such, his general Raphael Adantaya Bridge, a cable-stayed design, used as few as only two stays per span. Although striking in looks, this had a number of drawbacks, and that is of redundancy. Less stays equals more stress on the cables, and thus less redundancy, as the weight of the structure is spread over a smaller area. A failure of one of these stays can result in too much strain on the other, and thus makes a single point failure more likely. The bridge was completed in 1962. Well, so pleased with the bridge was Morandi, that he decided to do the old Control C, Control V trick, when he was asked to design a new structure back home in Italy. Morandi's concept was selected for the design for the new bridge, which was to span the Pulsevera Valley in Genoa. It would carry the new A-10 motorway through the city. The bridge's design would have a length of 1,182 meters, a height above the valley of 45 meters at road level, and free-towering reinforced concrete pylons reaching 90 meters in height. The maximum span was 210 meters. Like his previous bridge, this one would use cable stays, but unlike the general Raphael bridge, they would be 52 cables bundled together, encased in a post-tensioned concrete shell. At the time, the cable coating was boasted as maintenance-free and impervious to environmental elements that could rust away the vital stays, but it would also obscure the cables, making inspection for damage virtually impossible. Due to the extensive use of concrete, the bridge had minimal use of steel, something vital in post-war Italy, where resources, especially steel production, were limited, although a beautiful and clean-looking design, not a lot of thought was given to future traffic volumes, and thus its long-term durability. This feels very similar to the Silver Bridge. While spoiler alert, cars and trucks would gain weight over the years, and the concrete protections of the stays wouldn't actually stop corrosion. The deck was made almost entirely of reinforced concrete, further reducing its metal usage. Construction began in 1963. It was completed to great fanfare in 1969 and opened by President Giuseppe Sagarat. At the time of opening, the bridge met the specification set out by the government, and was thought to have an intended 50-year lifespan. As soon as the Ponti Morandi opened to traffic, the sleek and simple design proved to be a costly structure to maintain. You see, when the concrete was originally laid, the calculations for concrete creep were incorrect, and as such, shrinkage exceeded expectations, resulting in an uneven and undulating roadway. This would require a decade of remediation works, but this was not the only issue. You know the apparently safe on the environment cable stays? Well, they weren't so safe, as the concrete began to deteriorate. The issues with the bridge's concrete parts, which was most of it, were exacerbated by the salty sea air and pollution from industrial areas within the city. By 1979, the bridge had deteriorated to a point that even Morandi himself needed to investigate the structure. Meanwhile, the bridge in Venezuela was beginning to show signs of age, and with several of its cables corroding, replacement was essential. But because of the design, this proved to be difficult, as noted in an American Society of Civil Engineers article. As the original design consisted of two layers of suspension cables passing over each of the six main towers, replacing the cables without damaging the structure seemed nearly impossible, given time and cost constraints. But one difference between the two sister bridges was that Genoa's bridges stays were covered, and thus hiding the warning signs of corrosion. Back to Morandi's investigation into the bridge in 1979, he found cracks and issues with the concrete structure degrading. In his report of the same year, Morandi would say himself, to remove all traces of rust on the exposure of the reinforcements, fill the patches with epoxy resin and cover everything with anelastoma of very high chemical resistance. All during the 1980s, the cables on the bridge deteriorated, still hidden from view. In the early 90s, Pylon 11, the eastern most of the three main towers, was investigated, and it was found that roughly 30% of the steel tendons had experienced corrosion. So much so, that they are only to carry about half their design weight. To add more fuel to the fire, vehicles continued to increase in weight, and commercial trucks went from something like this in the 1960s to something like this in the 1990s. The affected areas were refurbished in a similar fashion to the Venezuelan bridge, as well as having reinforcing cables attached on the exterior. Pier 10 had the stays reinforced at the top, but this was the only remediation work on the troublesome steel cables. Autostrada per Italia took over management of the bridge in 1999, but no more work was undertaken on repairing the rusted out strands. As the new millennium came, and the bridge was becoming increasingly congested, a new replacement was put on the books. But this would take time, and more importantly money. And thus the years ticked on, and the warnings over the structure's reliability continued to mount. Government officials were told that the Miranda bridge needed maintenance. Autostrada commissioned a report into the condition of the bridge in October 2017 from Camelo Gentil and Antonello Rocolo of the Polytechnic University of Milan. Over four nights, Professor Gentil recorded the frequencies of the Miranda bridge. A smooth waveform would hint at a healthy structure, but when he tested the stays on Tower 9, he heard something worrying. The findings of the university team hinted towards the stays rusting inside their concrete enclosures. During 2018, the bridge was receiving more substantial central concrete dividers, adding considerable weight to the already weakened bridge. On the 3rd of May 2018, as the bridge was in its 51st year of existence, Autostrada announced the tender for structural upgrades of the viaduct, with a cost of around 20 million euro. But this would be too late. It is the late morning of the 14th of August 2018, and cars are making their way across the viaduct or pulse of error. The day has been marred with torrential rain. At around 11.36 am, a 210 meter long section of the bridge around Pylon 9 catastrophically and suddenly failed. Around 30 cars and three trucks were on the span that disappeared into the Pulse Severa Valley, and Turin, Genoa and Milan Genoa railways below. The failure point as seen by CCTV and witnesses was the southern stays. 43 people were lost that morning, with many more injured and at least 13 more missing. Because the bridge navigated over and around residential areas, all property nearby was evacuated for fears of the remaining spans collapsing. But remarkably, the remaining sections remained. One such story of pure luck was of a Demonte Transporti SRL truck, narrowly missing the plunge. The now iconic Volvo teetered on the edge and became a symbol of the disaster. Locals and emergency workers alike scrambled through the rubble to locate victims, as they called out from what used to be the bridge. But with such a catastrophic collapse, claiming many lives, authorities had to find out what was the cause of the Ponty Morandi collapse. The bridge's designer, Morandi, was the one person authorities would have liked to have talked to. But unfortunately, he had been dead for nearly 30 years. Instead, his design, notes and surveys of the bridge were combed through to build up a picture of the structure. In a case of perfect timing, Ricardo Morandi's design lasted almost exactly 51 years to the day, hinting he knew how to build the expected lifespan of 50 years. With design, which like many other striking simplistic designs looked beautiful in exchange for reduced redundancy and increased maintenance. Now the point of failure is not difficult to find out, as we have so much information and footage from both before, during and after the collapse. We also know that the bridge and many similar designs from Morandi had exhibited similar issues. The general Raphael Erdanita Bridge had in the late 1970s nearly collapsed due to corrosion after all. Pylon 9 was the only one of the three main towers which held up the strands to have not had any proper remediation work, and was the most concerning during the 2017 Polytechnic University of Milan report. Straight away, the newly elected government pointed the finger at Otto Strada. But the root cause was more than that. The bridge, right from his opening days, had drained resources just to keep it open. In the 467 page paper investigating the cause of the collapse, many theories were explored including excessive winds, which was put forward by Otto Strada. These were discounted, as most warning signs pointed towards the pesky concrete covered cable stays. It was discovered that Morandi himself concerned about this design choice had recommended regular checks on the cables. These checks were never undertaken. During the 90s when the bridge was still under state control, the concrete's water resistance had come into question. These concerns were passed on to the private operator Otto Strada, which was subsequently not investigated. Engineers had suggested annual maintenance and frequent inspections of the aging bridge. But according to the official investigation, inspection did not come until 2012, nearly 20 years after the bridge's last proper overhaul, which strengthened tower 11 and parts of tower 10. Funny enough, the two that didn't fail. Such was the perceived negligence of the private operator that it would turn into a criminal case against 59 employees of Otto Strada and its contractor Speer Engineering Company. We won't know the outcome of the trial yet, as at the time of working on this video, August 2022, it has only just begun. The city was in shock and the remains of the bridge acted as a grim headstone for those who were lost. But a tragedy would give way to pragmatism. There was the need of a crossing in the area, and as such, the decision to demolish the remains of the Ponty Morandi was made to make way for a new and hopefully safer crossing. The remains of the bridge was demolished in June 2019 and almost in record time of replacement was built, and that leads us back to the 3rd of August 2020, almost three years to the day, and the opening of the new Genoa St George Bridge. Costing €202 million, the bridge offers a new hope, but the issues concerning Italian and the wider European and UK communities infrastructure still exist. You see, much like many other subjects this channel covers, it always boils down to money and the risks of underinvestment. All videos on the channel are creative commons attribution share alike licensed. Plainly difficult videos are produced by me in a currently swelteringly hot corner of southern London UK. 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