This video from Herrenknecht AG shows the operation of the enormous tunnel boring machine that will conduct the deep tunnelling for San Francisco's new subway lines. The machine obviates the necessity of tearing up city streets for subway construction, and somehow manages to be gentle enough to avoid shaking the buildings above it. There's a much older version of this monster on display at the fabulous London Transport Museum in Covent Garden that is truly awesome to behold.
A TBM consists of a rotating cutterhead within a cylindrical steel shell that is pushed forward along the axis of the tunnel while excavating the ground through the cutterhead. The steel shield supports the excavated ground as required until the final tunnel lining is built in the rear of the shield. The shield is propelled using hydraulic jacks that thrust against the erected tunnel lining system. The TBM is used in conjunction with a prefabricated ground support system, which consists of pre-cast concrete segments that are bolted and gasketed to form a watertight lining.
Pressure-face TBMs that are capable of exerting a balancing pressure against the tunnel face are used to control excavation rates and groundwater inflow, as well as to maintain stability of the tunnel face.
After completion of TBM excavation and installation of the lining, the temporary rail and conveyor system are removed, the invert is cleaned, and a flat invert for the permanent rail fixation and a raised walkway are constructed as reinforced, cast-in-place concrete. The invert contains embedded pipes and inlets for track drainage.
(Thanks, Fipi Lele!)
Last year’s Hello Barbie chatbot toy sent all your kid’s speech to cloud servers operated by Mattel and its tech partner, but only when your kid held down Barbie’s listen button — new chatbot toys like My Friend Cayla and the i-Que Intelligent Robot are in constant listening mode — as is your “OK Google” […]
Mr Robot is the most successful example of a small but fast-growing genre of “techno-realist” media, where the focus is on realistic portrayals of hackers, information security, surveillance and privacy, and it represents a huge reversal on the usual portrayal of hackers and computers as convenient plot elements whose details can be finessed to meet […]
dj BC writes, “My best Christmas mashups from the past decade are collected for this year’s Santastic (previously) holiday music sampler. You can also dig on the site for the full albums from past years, our ‘Menorah Mashups’ Chanukah collection, and my chill instrumental album of holiday classical remixes. It’s all free.”
The Boing Boing Store’s Gift Guide is full of ideas for pretty much anyone in your life like hipster ice cub trays, Xbox controllers, Halo Boards, and even diamond necklaces. As always, all products in the Boing Boing Store come at great discounts, too. Shop by price bucket starting at under $20. Under $20:Bloxx Jumbo Ice Trays […]
Unlike traditional lighters, the SaberLight features an electronic plasma beam that’s both rechargeable and butane-free. This sleek lighter is even approved by TSA, so you’ll never be stuck buying lighters you’ll just have to throw away partially used. For some people, like me, this is a pretty big game-changer. The SaberLight’s beam is actually both hotter and cleaner […]
Holiday shopping is in full swing, and the Striiv Touch is one of the best gift ideas I’ve landed on. Its simple design works for females and males, and its wide range of features makes it suitable for even the non-fitness enthusiasts in your life.Unlike traditional fitness trackers, the Striiv Touch also acts as a smartwatch. It […]