EuroWire Sept 2015

Transatlantic cable

A concern about 3D-printing – or additive manufacturing, as it is also known – is whether the properties of 3D-printed materials are equal to those of conventional manufacture. Iain Todd of the Australian news service The Conversation reported that, generally speaking, 3D-printed components can be comparable to their traditionally produced equivalents. Beginning with the prototyping of objects through the various stages of development, the method has in fact been in use since the 1980s. Today, 3D-printed surgical devices – hip implants, for example – are not uncommon. And 3D-printed parts have been a feature of Formula One racing cars and military aircraft for years, performing very well. In reference to the canal bridge in Amsterdam, Mr Todd wrote (19 th June): “What we are seeing now is that the technology is becoming more mainstream – and that change is helping drive a huge explosion of creative thought about how, and where, we make things.” “From Day One I said, isn’t NHTSA just as guilty as General Motors is? It’s terri c they are nally owning up to their mistakes.” The stepfather of a victim of one of the 109 fatal accidents linked to a defective ignition switch in General Motors cars was referring to the National Highway Tra c Safety Administration. In June, after more than a year of castigating the automaker, the NHTSA, a unit of the US Department of Transportation (DOT), had acknowledged its own role in the gravest safety crisis in GM’s history. Two internal DOT reports identi ed a series of failings by the NHTSA that allowed millions of faulty GM cars to go unrepaired for more than a decade. The ignition switches could suddenly turn o , stalling the engine and disabling the airbags. As noted by New York Times reporters Bill Vlasic and Rebecca R Ruizjune, while the reports still xed blame for the crashes squarely on GM, the nation’s largest automaker, they also included an unusually blunt catalogue of mistakes made by its regulators. (“Safety Agency Admits Missing Clues to GM Ignition Defects,” 5 th June) The agency admitted having ignored signs of the defect, and failing to bring its full authority to bear on GM. In a conference call with reporters, transportation secretary Anthony Foxx said NHTSA is now revising its investigative procedures, stepping up e orts to obtain safety data from automakers, and creating an oversight team of outside experts to help put the changes into e ect. For his part, the NHTSA administrator, Mark R Rosekind, in the job only since December, had already adopted a more aggressive stance toward the auto industry, pushing in particular for quicker responses on continuing safety issues at Fiat Chrysler Automobiles and the Japanese airbag manufacturer Takata. Automotive In the wake of fatalities tied to General Motors cars, ‘a seminal shift’ in how US regulators will deal with automakers

the pressures of the Townsend but on a much smaller scale and using completely di erent mechanics. Mathematical calculations con rm that they essentially test the same types of strain. Mr Maroney’s materials advisors will be taking other measures, both mechanical and modelled, to tease out the cause of the failures. At the same time, the anchor rods are not the sole problem with the Bay Bridge. Rods under the main tower are threatened by water corrosion. There are misaligned deck sections. And inspections have turned up substandard welds in the tower and roads. But right now, Mr Stockton wrote, the main focus is on the 32 anchor rods in the eastern suspension pile “and what caused them to corrode where others did not.” Famous for its canals, Amsterdam is set to welcome a related attraction: the rst-ever 3D-printed steel bridge Another highly advanced bridge – the world’s rst to be constructed by means of 3D-printing methods – is attracting attention in the city of Amsterdam. In the rst large-scale test of the technology, a Dutch start-up plans to employ robotic printers to weld the structure even as it inches across a canal. This bridge has none of the problems currently experienced in San Francisco. But then, it was still in pre-production in advance of a September demonstration when the engineering company MX3D issued this statement: using robotic printers “that can ‘draw’ steel structures in 3D, we will print a pedestrian bridge over water in the centre of Amsterdam.” In a rst large-scale deployment of the technology, robotic-arm printers will “walk” across the canal, essentially printing their own support structure as they progress. The robotic arms will heat the steel to a searing 2,700º. Fahrenheit to weld the bridge – a sophisticated computer-generated design – drop-by-drop. “The underlying principle is very simple,” the bridge’s designer Joris Laarman told Agence France-Presse (16 th June). “We have connected an advanced welding machine to an industrial robot arm.” The technique could, the company said, become standard on construction sites, especially those involving dangerous tasks on high buildings. It also obviates the need for sca olding as the robot arms will support themselves with the very structure they print. It is obviously not a rapid- re method; nor can the permissions process be rushed. While Amsterdam City Council spokeswoman Charlene Verweij said the Dutch capital was supporting the project, in June there was still uncertainty about a speci c site for the bridge, which the designers hope will be completed by mid-2017. “I strongly believe in the future of digital manufacturing and local production,” said Mr Laarman, taking the long view. “This bridge can show how 3D-printing has nally entered the world of large-scale functional objects and sustainable materials.” (The Guardian, 16 th June) He added: “It’s a new form of craftsmanship.”

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September 2015