Tuesday was the 11th anniversary of the 9/11 attacks on the World Trade Center and Pentagon. The September "Fabricating Update" e-newsletter that went out that day described the safety elements that went into the design of the new One World Trade Center building. It also made special note of the welding aspect of the structure—how the welders are undoubtedly mindful of the serious nature of their work and are doing their best to ensure that the welds are sound, just as they do on bridges and other critical structures—every day.
As noted in a Wikipedia article about the building, along with the protection offered by the 185-foot (56 m) windowless concrete base—intended to protect it against truck bombs and other ground-level terror threats—a number of other safety features were included in its design to better prepare it for a major accident or terrorist attack: 3-foot (91 cm) thick reinforced concrete walls for all stairwells, elevator shafts, risers, and sprinkler systems; extra-wide, pressurized stairwells; a dedicated set of stairwells exclusively for the use of firefighters; and biological and chemical filters throughout its ventilation system.
The building is no longer 25 feet (8 m) away from West Street, as the Twin Towers were; at its closest point, West Street is 65 feet (20 m) away. The windows on the side of the building facing in this direction are equipped with specially tempered blast-resistant plastic, which looks nearly the same as the glass used in the other sides of the building. The 70 elevators and nine escalators for 1 World Trade Center will be provided by ThyssenKrupp, with steel counterweights supplied by Concord Steel.
The Port Authority has stated: "Its structure is designed around a strong, redundant steel moment frame consisting of beams and columns connected by a combination of welding and bolting. Paired with a concrete-core shear wall, the moment frame lends substantial rigidity and redundancy to the overall building structure while providing column-free interior spans for maximum flexibility."
How many of us have considered the welds as we’ve driven across bridges, boarded a ship or an airplane, taken a ride in our cars, peered out of a window on the top floor of a high-rise building, or turned on the gas heat in our homes? I imagine a show of hands would result in few if any. However, the welding that goes into each of these entities, from bridges to gas pipelines, is critical.
In 2011, a former shipyard welding inspector was sentenced to 37 months in prison for lying about the certification of weld inspections on Navy vessels. The inspector plead guilty to a charge that in 2007 he knowingly signed and put his employee ID number on the record of a pipe joint weld he knew he had not inspected. This pipe weld on the Missouri submarine had a half-inch crack on the bottom that could have sunk the sub.
In sentencing the inspector, the judge said, “ … you put the lives of potentially thousands of people, it seems to me, at risk. It almost leaves me speechless.”
Just last month, CBS News reported that Pacific Gas & Electric settlement documents showed more than $2 million went to a teenager burned in the San Bruno gas pipeline explosion. The 2010 blast that killed eight people and destroyed dozens of homes was blamed on an inferior pipeline weld.
Keep in mind that only inferior welds that cause harm make the news. For every bad weld, there are countless sound welds that enable us to go about our lives safely—to cross that bridge, fly to a city, and enjoy the view from a skyscraper.
TheFabricator.com provides metal fabrication professionals with market news, the industry's best articles, product news, and conference information from the Fabricators & Manufacturers Association, Intl.