Analysis of information sources in references of the Wikipedia article "Transbay Tube" in English language version.
{{cite report}}
: CS1 maint: multiple names: authors list (link)Donna "Lulu" Wilkinson, an experienced train operator, was barreling through the Transbay Tube at 80 miles per hour in the cab of a 10-car train when the quake hit.
"I didn't even feel it," she recalled. She was about halfway through to San Francisco when she got the order to stop and hold her position.
It was routine procedure (and remains so) to do a short hold after any earthquake, even smaller ones, and passengers were familiar with that routine. "They didn't panic," she said. "I got on the intercom and told them we were holding for a quake and would be moving shortly."
The design and strength of the tube, an engineering marvel sunk into mud on the bottom of the bay, had insulated the train and its passengers from feeling the earth's movements.
Howe & Peters, consulting engineers of San Francisco, have been working for nearly two years as Pacific Coast representatives of George W. Goethals, in getting together data on the construction of a subway for both vehicular and rail traffic, which would connect the foot of Market St. with Oakland Mole. Tentative plans on this project, made public some months ago, call for a shield-driven concrete tube, similar to the type General Goethals recommended for the New York-New Jersey tube under the Hudson River.
Provision would be made for two decks, the upper for use of motor vehicles and the lower for electric trains. [...] The gradient would be kept below 3 per cent so freight could be handled easily. The depth of water along the route the tube would follow does not exceed 65 ft. and soundings taken at various points indicate that its entire length would be in blue mud. Not only would mud facilitate driving by the shield method, it is pointed out, but it would constitute a cushion to safeguard the tube from possible disalignment due to earthquake shocks.
[...]If the results of such a survey confirm the rough estimates, it is suggested that the construction of the entire 3.5-mi. concrete tube would be between $40,000,000 and $50,000,000.
Any high bridge between Yerba Buena Island and San Francisco would naturally land on Telegragh Hill [sic]. It would not only involve very long and costly spans, even if piers were permitted in the channel, but would land the traffic in a section of the city already quite congested, and from which a proper distribution would be impracticable. Any tunnel on this location would have to be constructed at great depth in an unknown rock formation, as the water depth is too great for tunneling under air pressure, and the length would consequently be so great as to involve an extremely difficult problem in ventilation for vehicular traffic. We there fore consider this plan as impracticable. Any continuous tunnel across the bay, on any location, while practicable for purely electrically operated railroad traffic, would involve most serious ventilation problems for vehicular traffic, and enormous expense if constructed for all classes of traffic.
The impacts of the earthquake were much more than the loss of life and direct damage. The Bay Bridge is the principal transportation link between San Francisco and the East Bay. It was out of service for a [sic] over a month and caused substantial hardship as individuals and businesses accommodated themselves to its loss. [...] The most tragic impact of the earthquake was the life loss caused by the collapse of the Cypress Viaduct, while the most disruption was caused by the closure of the Bay Bridge for a month while it was repaired, leading to costly commute alternatives and probable economic losses. [...] On the other hand, the Board received reports of only very minor damage to the Golden Gate Bridge, which is founded on rock, and the BART Trans-bay Tube, which was specially engineered in the early 1960s to withstand earthquakes. [...] Two facts stand out: the importance of the Oakland–San Francisco link, and the volume of traffic borne by the San Francisco–Oakland Bay Bridge—approximately double that of the Golden Gate Bridge, and almost equal to the combined traffic carried by all four other bridges. For automobile traffic, the Golden Gate and Bay bridges are essentially nonredundant systems, with alternative routes via the other bridges being time consuming to a level that seriously impacts commercial and institutional productivity. [...] The critical role played by the BART Trans-bay Tube in cross-bay transportation is clear, as is the fact that the South Bay bridges (San Mateo and Dumbarton) accommodated most of the redistribution of vehicular traffic. [...] Engineering studies should be instigated of the Golden Gate and San Francisco–Oakland Bay Bridges, of the BART system, and of other important transportation structures throughout the State that are sufficiently detailed to reveal any possible weak links in their seimic resisting systems that could result in collapse or prolonged closure.
BART's success in maintaining continuous service directly after the 1989 Loma Prieta earthquake reconfirmed the system's importance as a transportation "lifeline." While the earthquake caused transient movements in the Tube there was no significant permanent movement and BART service was uninterrupted except for a short inspection period immediately following the quake. With the closure of the Bay Bridge and the Cypress Street Viaduct along the Nimitz Freeway, BART became the primary passenger transportation link between San Francisco and East Bay communities. Its average daily transport of 218,000 passengers before the earthquake increased to an average of 308,000 passengers per day during the first full business week following the earthquake.
Use of a precast concrete tube with metal shell for the underwater crossing between shore points is recommended.
Hitting speeds close to 80 mph only in the 3.6-mile tube under the bay, the trains average 36 mph for safety reasons, [BART spokesman Sy] Mouber said.
{{cite book}}
: |work=
ignored (help){{cite interview}}
: |author2=
has generic name (help)Believing Oakland Point to be the proper and only point of communication from this side of the Bay to San Francisco, we, Norton I, Dei gratia Emperor of the United States and Protector of Mexico, do hereby command the cities of Oakland and San Francisco to make an appropriation for paying the expense of a survey to determine the practicability of a tunnel under water; and if found practicable, that said tunnel be forthwith built for a railroad communication. Norton I. Given at Brooklyn the 12th day of May, 1872.
Whereas, we issued our decree, ordering the citizens of San Francisco and Oakland to appropriate funds for the survey of a suspension bridge from Oakland Point via Goat Island; also for a tunnel; and to ascertain which is the best project; and whereas, the said citizens have hitherto neglected to notice our said decree; and whereas, we are determined our authority shall be fully respected; now, therefore, we do hereby command the arrest, by the army, of both the Boards of City Fathers, if they persist in neglecting our decrees. Given under our royal hand and seal, at San Francisco, this 17th day of September, 1872. NORTON 1.