During my SF visit I got to drive across the new (sleek, shiny) bridge at night. The old one looms rather ominously out of the shadows next to it then.
The old one looks so strong and so 1930's. I heard a statistic many years ago - maybe in the 50 year anniversary celebration, that a large proportion of the total output of American steel production went into making the Bay Bridge - like half of all the steel produced in the country. (I can't remember the exact amount/proportion, but it was quite unbelievable to me when I heard it. The building and results of building the Bay Bridge probably helped end the Great Depression.
I made a trip in and out of the city the last day of the old structure and snapped a few documento shots which I posted back about 5 or 6 months ago. Then the bridge was closed for a long weekend while they disconnected the old one and connected up the new. There were traffic flow problems at first as they tried to get the laning figured out as about 12 lanes narrow down to 5 on the westbound (inbound) direction. There still seem to be some bugs in the traffic flow inbound compared to the older bridge, although "the maze" as they call it, over in Oakland, where three freeways converge onto the Bay Bridge, has always been problematic.
One would have thought another bridge, maybe down by the Oakland and San Francisco Airports would have been a better idea than this hugely expensive but impressive replacement bridge. The new bridge section took about 6 times as long to build, and probably was 100 times more costly than the entire original Bay Bridge.
The old cantilever was damaged in a big earthquake in 1989, and at that time, we the public found out that the footings for the old bridge eastern span - the cantilever section, had not been sunk down all the way to bedrock like the suspension towers. Instead giant pilings of lashed together redwood trees had been sunk into the bay mud and the bridge constructed on those. So, this span would eventually have needed to be replaced, the earthquake just made this event more urgent. We are told that the redwood has held up wonderfully and is as if newly cut.
Anyway, the ends were deconstructed first, then the upper deck was removed starting from the center of the large cantilever, and eventually, now, the two halves of the cantilever have been separated. I'll keep my eye out to see how things progress and from time to time do another picture post of the progress.
And they keep bragging about how complex and advanced the engineering is, but from common experience, we all know that complex systems are quicker to fail than simple solutions, sometimes spectacularly so. Even so, the freeway approaches will be under water in 50 years, so failure questions are probably moot.
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I made a trip in and out of the city the last day of the old structure and snapped a few documento shots which I posted back about 5 or 6 months ago. Then the bridge was closed for a long weekend while they disconnected the old one and connected up the new. There were traffic flow problems at first as they tried to get the laning figured out as about 12 lanes narrow down to 5 on the westbound (inbound) direction. There still seem to be some bugs in the traffic flow inbound compared to the older bridge, although "the maze" as they call it, over in Oakland, where three freeways converge onto the Bay Bridge, has always been problematic.
One would have thought another bridge, maybe down by the Oakland and San Francisco Airports would have been a better idea than this hugely expensive but impressive replacement bridge. The new bridge section took about 6 times as long to build, and probably was 100 times more costly than the entire original Bay Bridge.
The old cantilever was damaged in a big earthquake in 1989, and at that time, we the public found out that the footings for the old bridge eastern span - the cantilever section, had not been sunk down all the way to bedrock like the suspension towers. Instead giant pilings of lashed together redwood trees had been sunk into the bay mud and the bridge constructed on those. So, this span would eventually have needed to be replaced, the earthquake just made this event more urgent. We are told that the redwood has held up wonderfully and is as if newly cut.
Anyway, the ends were deconstructed first, then the upper deck was removed starting from the center of the large cantilever, and eventually, now, the two halves of the cantilever have been separated. I'll keep my eye out to see how things progress and from time to time do another picture post of the progress.
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And they keep bragging about how complex and advanced the engineering is, but from common experience, we all know that complex systems are quicker to fail than simple solutions, sometimes spectacularly so. Even so, the freeway approaches will be under water in 50 years, so failure questions are probably moot.