March 9, 2005
A rendering of the proposed
Image courtesy Donald MacDonald
California Governor Arnold Schwarzeneggers
campaign to change the design of part of the San Francisco-Oakland
Bay Bridge has sparked a controversy over one of the most
expensive and technically challenging bridge projects in United
The bridge was severely damaged in the 1989 Loma Prieta earthquake.
A plan to rebuild the eastern span, a cantilever bridge that
extends for almost two miles, calls for replacing it with
a viaduct, known as the skyway, that connects with a self
anchored suspension bridge, which has yet to be built.
Schwarzenegger and other legislators hope to prevent further
delays and cost overruns by extending the viaduct instead
of building the suspension bridge. The state could save $500
to $700 million by doing so, says Patrick Dorinson, Deputy
Secretary for Communications at the California Business, Transportation,
and Housing Agency.
The skyway is known technology, and we feel that it
could be done faster and cheaper, says Dorinson adding
that in contrast the suspension bridge has too many unknowns.
Further, the unencumbered views from skyway will be spectacular,
says Dorinson. The vistas of the Bay Area are going
to be beautiful.
But the architect for the Bay Bridge, Donald MacDonald, says,
the suspension bridge design would be much more pleasing aesthetically
than that of the skyway extension, which he says would have
the visual impact of a highway on stilts. The
self- anchored suspension design, he notes, would provide
Oakland with a signature bridge, which could play a role similar
to that of the Golden Gate Bridge in neighboring San Francisco,
says MacDonald, adding, you would go under the cable
system and it would be your gateway to the East Bayit
would frame the East Bay hills and give Oakland a bridge that
they can use as a symbol.
MacDonald also contends that the self-anchored suspension
bridges design is technologically the best suited for
the especially challenging marine environment and soil conditions
in the East Bay. Its main tower could be placed on a rock
ledge in the bay, whereas the viaduct would require imbedding
piers over 300 feet below the water line- the deepest ever
constructed in the San Francisco Bay.
MacDonald also contends the proposed changes will actually
delay the project further. The public does not realize
how extensive the changes are, he says, adding, It
is not just a matter of putting a viaduct into the same space.