It was early December in Seattle when the world’s biggest-diameter tunnel boring machine, called Bertha, came to a stop underneath Seattle. It was plowing through the city’s underground as part of the two-mile project to bring SR 99 underground and replace the Alaskan Way Viaduct. Overnight, it seemed as if the whole of Seattle and beyond was curious: was it buried treasure from the gold rush days? Or bootlegger artifacts?
According to a very confidential source, engineers currently working on the Waller Creek tunnel believe that Austin sits on top of some of the most optimal conditions for tunneling in the entire U.S. These number-crunching problem solvers claimed that a subway tunnel beneath the Texas State Capital’s downtown would cost 1/10th of the amount it would in most places in the country. However, the brainiacs also said that there are those in high places who do not want that knowledge spread around (read TxDOT) because the construction of more freeways is making certain people a great deal of money.
New York City’s Metropolitan Transportation Authority (MTA) has completed blasting through bedrock far below Grand Central Terminal for the East Side Access Tunnels that will connect the station with Sunnyside, Queens. As part of the announcement, one of the last production blasts from late March has debuted on YouTube. The video above reveals what has been transpiring beneath the streets of Manhattan during the tunneling process, and the sight is rather impressive. A camera caught the final blast that made way for a massive cavern. So far 2,424 production blasts have occurred below the commuter rail terminal station, which is celebrating its 100th birthday this year. For this explosion, sandhogs drilled more than 200 blast holes and loaded them with over 300 pounds of powder to guarantee a powerful explosion that could rival any action movie’s special effects.
Construction on the two-track Gateway project, a new tunnel between New Jersey and Manhattan, will commence this summer beneath Related Company’s Hudson Yards redevelopment site. Related Companies and Amtrak will build this 800-foot-long “box tunnel,” which will first serve as a shell for Amtrak’s rail connection linking the Hudson tunnel to Penn Station’s tracks, and, eventually, to the proposed Moynihan Station. The actual Amtrak Gateway Project is still years away, but construction on this first leg of the tunnel is happening now to coordinate with construction on Manhattan’s West Side. The project will be funded by the federal government including some funding from the Hurricane Sandy relief package meant to help mitigate flooding during future storms. It’s estimated to cost between $120 and $150 million.
Manhattan’s Second Avenue Subway continues construction on the island’s east side. A new construction update from the Metropolitan Transportation Authority details excavation work at what will one day be the line’s 86th Street station and the various pieces of heavy machinery that are used in the construction process. Take a look at the photos below and be sure to check out more spectacular tunneling photos from the Seven Line subway expansion and the East Side Access Tunnel for the Long Island Railroad.
The much-talked-about 7 line subway extension on Manhattan’s West Side isn’t the only mega-infrastructure project making progress in New York. Construction continues far below the streets of Manhattan’s East Side as crews tunnel through bedrock for the Second Avenue Subway line. This week, the MTA released a gallery of photos showing construction progress on stations between 63rd and 73rd streets. The photos show the enormous rock caverns that will one day be subway stations being prepped with liners, rebar, and concrete casing. According to Gothamist, construction progress varies by station, with the 72nd Street station 96 percent complete and the 86th Street station 42 percent done.
New York’s celebrated High Line may have turned an old rail trestle into a park, but the Northern Italian city of Trento has one-upped Manhattan, reclaiming two 1,000-foot-long tunnels in the Dolomite Mountains as an experimental history museum—and a fascinating example of the reuse of abandoned infrastructure. Read More