The Transbay Tube is the part of BART which runs under San Francisco Bay in California. The tube is 3.6 miles (5.8 km) long; including approaches from the nearest stations (one of which is underground), it totals 6 miles (9 km). It has a maximum depth of 135 feet (41 m) below the surface.
The tube was constructed on land, transported to the site then submerged and fastened to the bottom (mostly by packing the sides with sand and gravel). This immersed tube technique is in contrast to bored tunneling, where rock is removed to leave a passage.
Read more about Transbay Tube: Conception and Construction, Incidents, Future
Famous quotes containing the word tube:
“The last best hope of earth, two trillion dollars in debt, is spinning out of control, and all we can do is stare at a flickering cathode-ray tube as Ollie “answers” questions on TV while the press, resolutely irrelevant as ever, asks politicians if they have committed adultery. From V-J Day 1945 to this has been, my fellow countrymen, a perfect nightmare.”
—Gore Vidal (b. 1925)