ACCLAIM FOR
HENRY PETROSKI
“Petroski is an amiable and lucid writer.… [He] belongs with the poets.” —John Updike, The New Yorker
“A triumph.… Reading Engineers of Dreams is akin to sitting at the knee of a favorite uncle who spins golden yarns of far-off places and events.… There truly is something here for everyone.” —Morning Star-Telegram (Fort Worth, Texas)
“Henry Petroski is like a bright light sent from heaven.” —Durham Morning-Herald
“An engaging, entertaining history.” —News and Observer (Raleigh, North Carolina)
“Just as a good bridge weds sweeping visual grace with detailed mechanical calculations, Engineers of Dreams exhibits a rare mixture of eloquence and precision. That combination has made classics of Petroski’s previous books, and his latest deserves no less of a reception.” —Invention and Technology
“Engineers of Dreams makes [bridges] ever more marvelous.” —Rocky Mountain News
FIRST VINTAGE BOOKS EDITION, OCTOBER 1996
Copyright © 1995 by Henry Petroski
All rights reserved under International and Pan-American Copyright Conventions.
Published in the United States by Vintage Books, a division of Random House, Inc., New York, and simultaneously in Canada by Random House of Canada Limited, Toronto.
Originally published in hardcover by Alfred A. Knopf, Inc., New York, in 1995.
The Library of Congress has catalogued
the Knopf edition as follows:
Petroski, Henry.
Engineers of dreams: great bridge builders
and the spanning of America. / Henry Petroski. — 1st ed.
p. cm.
eISBN: 978-0-307-77313-5
1. Bridges—United States—History—19th century.
2. Bridges—United States—History—20th century.
3. Civil engineers—United States—Biography. I. Title.
TG23.P47 1995
624′.2′0973—DC20 94-48893
Random House Web address: http://www.randomhouse.com/
v3.1
to Catherine
CONTENTS
Cover
Title Page
Copyright
Dedication
Preface
I Imagine
II Eads
III Cooper
IV Lindenthal
V Ammann
VI Steinman
VII Realize
Notes
Bibliography
Illustrations
About the Author
Other Books by This Author
PREFACE
This book tells the stories of engineers who have dreamed and engineers who have toiled, of bridges of celebrity and bridges of burden, and it is about the nature of technology in a human context. Some renowned engineers and some famous bridges have tended to overshadow their contemporaries and neighbors, but the full range of stories reveals that the lesser-known engineers have been of no less importance in shaping our built environment. Indeed, the personalities of all kinds of engineers, with their faults and foibles coexisting with their dreams and designs, have played as much of a role as has their technical know-how in bringing familiar bridges to fruition.
As is to be expected, only some of the bridges of which any engineer dreams get realized, but that is not to say that even the wildest schemes have not influenced others, and hence our roadscapes. A full understanding of how and why a great bridge came to be what it is where it is requires appreciating the often decades-long struggles that engineers have experienced with themselves, their colleagues, and their communities. In telling the stories of some engineers and some bridges, this book must necessarily tell the stories of many bridges and many engineers engaged in the professional, economic, political, and personal conflicts that occur in the technical, social, and cultural activities in which we all participate. When we see in the stories of bridges the full human dimensions of engineers and engineering, we also see more clearly the inextricable interrelationships between technology and humanity. As no person is an island, so no thing is an island. Certainly no bridge is an island.
And no book is an island. Many bridges were provided by many people on the way to this book’s being realized, and I wish to acknowledge and thank at least some of them. Arthur Singer turned my rough sketch of an idea into a grant from the Alfred P. Sloan Foundation, which enabled me to travel to bridge sites, to gather illustrations, and to write. Ashbel Green, my editor at Knopf, has once again given me my head and his support. Anne T. Zaroff-Evans did a marvelous job of copy-editing, and Knopf’s Jennifer Bernstein and Melvin Rosenthal also made the process from manuscript to book a smooth one, at least from my point of view.
There was also, of course, much help long before there was a manuscript, and libraries and librarians were, as always, remarkably tolerant of my inquiries. The wonderful collection of the Aleksandar S. Vesić Engineering Library at Duke University continues to provide resources and convenience of immeasurable value. Eric Smith, its former librarian, who was forever patient with my endless requests, located and obtained for me important materials so diverse that no one institution could ever be expected to contain them all. Rich Hines and Dianne Himler have continued to get to me the many odd library materials that are so essential in the final stages of preparing a manuscript. The resources and facilities of Duke’s main library, the William R. Perkins Library, have once again been indispensable to me, as has the institution of Interlibrary Loan. I have also had much help from archives, historical societies, bridge authorities, and departments of transportation in locating information and photographs; the sources of these pictures are credited in the list of illustrations in the back of the book. Indeed, I am indebted to so many librarians, archivists, secretaries, assistants, and volunteers, at Duke and elsewhere, both known to me and anonymous, that I dare not begin to acknowledge them by name, lest I forget one.
I must, however, thank some other individuals by name. My brother, William Petroski, helped me early on to get a closer look at many New York bridges, and my sister, Marianne Petroski, gave me some helpful books. Stephen Petroski, my son and a student engineer, also helped me very early on by collecting essential material from newspaper indexes, and Ian Threlfall, a graduate student in civil and environmental engineering at Duke, later retrieved countless remarkably clear copies of articles from microfilm files. Margot Ammann Durrer kindly provided me with much material relating to her father, including letters and photographs. A host of engineers and friends of engineers have helped me with very useful material and leads, and I would like to thank especially Norman Ball, David Billington, Milton Brumer, Stephen Burges, Jameson Doig, Eugene Fasullo, Steven Fenves, Henry Fischer, Jay Fredrich, Myint Lwin, Louis Miller, W. S. Persons, Allan Ryan, Thomas Sullivan, and Neil Wotherspoon. I also wish to thank my daughter Karen Petroski for her insights into scholarship. Finally, I am as always indebted to Catherine Petroski, my wife, for being my first reader and most constructive critic, and for understanding, at times perhaps even better than I, my writing habits and needs.
H.P.
Durham, North Carolina
September 1994
IMAGINE
Imagine a world without bridges. Imagine London, Paris, and Rome without dry paths across the Thames, the Seine, and the Tiber. Imagine Manhattan as an island with no hard crossings of the Hudson and East rivers. Imagine San Francisco without road communication across the gate to the north and the bay to the east. Imagine Pittsburgh wedged bridgeless between the A
llegheny and the Monongahela rivers. Imagine Chicago without its massive lift- and drawbridges, or Amsterdam without its more modest canal crossings. Imagine Seattle without its long, low floating bridges, or St. Petersburg without its soaring cable-stayed structure arcing out over Tampa Bay.
Bridges and cities go together, in large part because so many of our greatest cities were founded where they are precisely because of the proximity of water. It is no mystery why so many settlements have grown up by rivers and bays, and it comes as no surprise that some of the oldest of them developed at important river crossings. Cambridge is one of the many English cities that date back to Roman times; a settlement was established there in A.D. 43. The location was that of a bridge over the navigable River Cam, on the road between Colchester and Lincoln. Oxford, another venerable English city, takes its name from its location as a crossing of the Thames. How many of our cities and towns have water words, like “port,” “bay,” and “haven,” as part of their names? How many of our states share the names of the rivers that bound or bisect them? Some towns, like Iron Bridge in England and Suspension Bridge at the Canadian border in New York, have even been named after the structures upon which they depended.
Water travel and commerce were highly developed long before there was the widespread erection of large bridges across navigable waters. Although today we transport so many products of manufacture and agriculture by railroad, truck, and airplane, we still “ship” the goods out and await new “shipments” of supplies. The priority of shipping and naval interests shaped the character of many of our port cities well into the twentieth century, until autobahns, autostradas, motorways, and interstate road networks focused attention elsewhere. But the water crossings of even the greatest roads still remain shaped by consideration for what happens in the water below.
Imagine Boston and Cambridge, Massachusetts, without bridges over the Charles and the early-morning rowers beneath them. Imagine Detroit without access to Windsor, its Canadian neighbor—by the oddity of local geography, to the south. Imagine Washington, D.C., without roads to Virginia across the Potomac and over its yachts. Imagine St. Louis—now with its arch, which is a bridge of sorts, bearing tourists to the sky—inaccessible across the Mississippi from Illinois. Imagine New Orleans, dry behind levees, but without a crossing of Lake Pontchartrain, or without the Huey P. Long Bridge across the lower Mississippi. Imagine Charleston without its serpentine Old Cooper River Bridge, known affectionately as Old Roller Coaster. Imagine Philadelphia isolated by the Delaware River because it had no Ben Franklin or Walt Whitman bridge. Imagine Portland, Oregon, with its beautiful hills but without its crossings of the Willamette River. Imagine Florence with its Uffizi and its Pitti Palace but without their connection across the Ponte Vecchio or Venice without its Ponte Rialto or its Bridge of Sighs, so called because the sounds of the prisoners who passed over it between the palace and prison could be heard on the canal below.
A view of Pittsburgh, circa 1969, showing many of its bridges (photo credit 1.1)
Bridges have become symbols and souls of cities, and each city’s bridges have been shaped by, and in turn shape, the character of that city. It is virtually impossible to go into a souvenir shop in San Francisco without being overwhelmed by images of the Golden Gate Bridge, on everything from T-shirts to spoons. The Sydney Harbour Bridge is as much a landmark of that city as is its famous harborside opera house. New York’s Brooklyn Bridge is legendary—as is London Bridge, even though its stones have been reassembled in Lake Havasu City, in western Arizona, and the now incongruous landmark stands as one of the strangest monuments to our sense of possession over purpose.
Imagine the Golden Gate spanned by anything but the Golden Gate Bridge. Is it possible? The bridge’s location, shape, proportions, scale, and color all seem so right for the site, and now it seems so for them. Is it possible even to imagine any other bridge between San Francisco and Marin County? Could, say, a copy of the Brooklyn Bridge, with taller towers and a longer span, have been cast across the gate? Or could a smaller version of the Golden Gate Bridge, color and all, have been erected between New York and New Jersey, where the George Washington Bridge now seems so naturally established? Yet this kind of questioning and imagining is precisely what engineers must do before any bridge exists. Some of the earliest proposals for bridges in New York and San Francisco looked nothing like what have since come to be such familiar features of those cities. Indeed, one nineteenth-century proposal for a crossing between New York and Brooklyn was a soaring arch, and an early idea for the Golden Gate Bridge was so ugly that it is a wonder any bridge there ever gained anyone’s support.
Bridges define the approaches to cities, and passing over or under some of the world’s great spans is an unforgettable experience. Many travelers from the north have their first view of San Francisco framed in the tunnel approach to the Golden Gate Bridge. To sail into New York Harbor today is to watch the Verrazano-Narrows Bridge grow to mythic proportions even before the Statue of Liberty comes into view. The first glimpse of the tallness of New York when driving south down the Palisades Parkway is of one of the monumental steel towers of the George Washington Bridge looming over the trees. Once within cities, the structures of great bridges often serve as landmarks and beacons for the disoriented tourist. If you are walking or driving about the canyons of New York, it is often possible to catch sight of the tops of the Brooklyn, Manhattan, Williamsburg, and other great suspension bridges whose necessarily tall towers once totally dominated the city’s skyline.
Imagine traveling into, out of, or around a modern port city without bridges. Having known the speed of road communication that bridges make possible, we would have little patience with the reintroduction of long-since-displaced ferryboats. Tunnels, generally having a much lower traffic capacity than bridges, would need to be much more numerous than above-ground spans, and would burrow underwater every which way. But travel into or out of a city by tunnel is a much less dramatic, relaxing, or satisfying experience for the average driver or automobile passenger. Tunnels have dark connotations, and for many people the prospect of water rushing in is much more dreadful than that of a bridge falling into the water. There are of course some exceptional tunnel approaches, such as that which spirals down from atop the New Jersey Palisades into the Lincoln Tunnel under the Hudson River to New York, giving one of the best imaginable views of Manhattan’s skyline. But generally, tunnel approaches cannot rival bridge approaches for the panoramas of great cities that they make accessible.
Bridges not only provide a balcony from which to appreciate the architecture of a place; they may also inspire its subsequent architecture. Though now long eclipsed in height, the towers of the Brooklyn Bridge, with their twin Gothic arches, seem still to dictate an architectural mood to lower Manhattan, and it is not hard to imagine the bridge’s two stone towers having had something to do with the design of the twin steel towers of the World Trade Center. The arched Eads Bridge, constructed contemporaneously with the Brooklyn, might similarly be said to have influenced Eero Saarinen’s brilliant concept of the Gateway Arch as a monument to the westward expansion of America across the Mississippi River through St. Louis. And the increasingly large lift and bascule bridges that began to cross the Chicago River around the turn of the century may have inspired that city’s drive to build higher and higher skyscrapers in steel.
Nor is it only cities that rely on bridges. Imagine farm roads without culverts over which cows can pass from barn to field and back. Imagine mountain roads without suspension bridges only one person wide, to carry hikers and campers high and dry across a gaping gorge. Imagine backwoods roads without the narrow bridges that provide milestones in directions back to the main road. Imagine rural roads without the covered bridges that concealed so many lovers’ trysts over rushing streams. Imagine Madison County without its bridges.
The Mississippi River at St. Louis, on July 4, 1982, with the Eads Bridge visible behind the Gateway Arch, and with the fireworks
recalling the opening of the bridge on July 4, 1874 (photo credit 1.2)
Though most of America’s more than half a million highway bridges are small and anonymous, they may not be any less important to the local traffic than the Golden Gate and Brooklyn bridges are to their hordes. The engineers of our greatest spans began by designing our smaller ones. The scale may be different, but the process is essentially the same, and so these bridges have proved to be the training grounds for dreams. Furthermore, every bridge, small or large, is also an aesthetic and environmental statement. Its lines are important beyond its span; every bridge must not only bear its burden, whether cows or coal trains, but must also be able to withstand the burden of proof that, in the final analysis, society is better served, tangibly and intangibly, by the bridge’s being there at all.
Imagine how a bridge can ruin a setting of natural beauty, whether the tranquillity of the countryside or the skyline of a city. Imagine what the wrong bridge across the Golden Gate might have done to that unique site. This is why place so often influences bridge design—for, contrary to the popular misconception, engineers are not insensitive to setting and aesthetics. The Rainbow arch bridge across the river gorge north of Niagara Falls was an appropriate form to mirror the rainbows ever present in the mist about the falls. Arch bridges can actually open up great spaces, as Navajo Bridge did over the Colorado gorge upriver from the Grand Canyon, providing to crossers views of Marble Canyon uninterrupted by any significant human artifact for as far as the eye can see. A second crossing, its steel structure again below the bridge deck, will also intrude only minimally on the natural beauty of the site. In Switzerland, the bridges of Robert Maillart and Christian Menn harmonize with the Alps in a different, yet totally compatible and successful way. In Tampa Bay, the replacement bridge for one that was rammed by a tanker is a soaring design whose pattern of towers and cables evokes the masts and sails of pleasure boats crisscrossing the bay. Though not a natural setting, the Tower of London so dominated the section of the Thames where a crossing was to be erected in the late nineteenth century that Tower Bridge was designed in consonance with the historic site, even at the risk of offending some structural purists with its stone-encased steel. Earlier in that century, Thomas Telford similarly respected the prior claim of Conwy Castle to the location of the river mouth in Wales for which he designed his suspension bridge with crenellated towers.
Engineers of Dreams: Great Bridge Builders and the Spanning of America Page 1