Santiago Calatrava - Pushing the Limits: New Adventures in Engineering - page 97

Santiago Calatrava
The conception and design of most monumental structures involve a collaboration of architect and
engineer. However, except in the case of bridges, which are often considered to be pure engineer-
ing, it is usually the architect who gets credit for the creative idea. According to the conventional
wisdom—and most often in actuality—it is the architect who first sketches grand plans and facades
and the engineer who calculates what beams and columns are needed to make the artistic concept
work. Even for plans never realized, architectural drawings can take on lives of their own and be
the subjects of art shows, but the blueprints of engineers are seldom seen outside the design office
or construction site. Engineers curse architects who conceive buildings that require extraordinary
contortions of heavy concrete and steelwork to execute; architects look down on engineers whom
they accuse of lacking the structural creativity to solve unusual problems or the willingness to let
their imaginations soar.
As with all caricatures of groups of people and professions, this oversimplified view has both
elements of truth and many exceptions. Sydney Harbour provides an excellent juxtaposition of con-
trary examples. Jorn Utzon's original sketches for the Sydney Opera House so captivated the com-
petition judges that little consideration appears to have been given to constructability. It took the
innovative engineer Peter Rice, who would later have so much to do with the exposed structure of
the Centre Pompidou in Paris, six years to work out the practical matters of the shells in Sydney.
And still, within about fifteen years of its completion, the condition of the structure had deteriorated
to such an extent that it was evaluated to need repairs costing about as much as the structure itself.
In contrast to the opera house, the neighboring landmark Sydney Harbour Bridge, like most major
bridges, began not with an architect's sketch but with an engineer's concept of the structural form
that would be most appropriate for the site. In fact, a design was put forth as early as 1857, and
many others followed, but no scheme was agreed upon for more than fifty years. In 1911, John
Bradfield, principal design engineer of the New South Wales Public Works Department, began to
work on designs that would be buildable and functional as well as distinctive. His first plan was to
erect a nondescript and faddish cantilever, but this was finally changed when he visited America
and saw Gustav Lindenthal's design for the Hell Gate Bridge in New York City. The cantilever plan
was tabled, and Bradfield had the Sydney Harbour Bridge redesigned as an arch, which yielded a
scaled-up version of the Hell Gate with some improved structural details. The contribution of ar-
chitects was by and large limited to the stone pylons that frame the bridge proper, which opened in
1932.
Some of the most innovative and effective works of architecture and engineering have been true
collaborations, and two of the most striking examples stand in Chicago. Both the John Hancock
Center, completed in 1969, and the Sears Tower, finished in 1974, were made possible by the struc-
tural engineer Fazlur Khan and the architect Bruce Graham working together in the firm of Skid-
more, Owings & Merrill. For such tall buildings to use steel economically and yet stand steady
against the winds of Chicago, their structural bones and architectural skin had to evolve and work