The Golden Gate Bridge Outdoor Exhibition: Public Works for Public Learning

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1 Proceedings of the 2011 American Society of Civil Engineers Architectural Engineering Institute Conference, March 31-April 2, 2011, Oakland, CA The Golden Gate Bridge Outdoor Exhibition: Public Works for Public Learning 1 Denis Mulligan and 2 Robert Reitherman 1 Denis Mulligan, General Manager, Golden Gate Bridge, Highway and Transportation District, P.O. Box 9000, Presidio Station, San Francisco, CA ; dmulligan@goldengate.org 2 Robert Reitherman, Executive Director, Consortium of Universities for Research in Earthquake Engineering (CUREE), 1301 S. 46 th Street, Building 420, Richmond, CA 94804; reitherman@curee.org ABSTRACT With $3 million in funding from the National Science Foundation, the Golden Gate Bridge, Highway and Transportation District (GGBHTD) is creating a permanent outdoor exhibition at the south end (San Francisco side) of the Golden Gate Bridge. The exhibition will be opened in The exhibition will include a variety of models, displays, and interactive exhibits to provide visitors ways to learn about the engineering, construction and maintenance, aesthetics, and history of the Bridge, which is one of the most famous monuments in the world and is visited by 10 million people a year. The centerpiece of the exhibition is a large (90-foot-long), stainless steel scale model of the Bridge, revealing its structural features in detail. Locations on the model are keyed to satellite exhibits that surround this large table of contents model. An international conference is being planned in partnership with the American Public Works Association, which will include a special tour of the exhibition and information on how to mount successful exhibits that explain architecture and engineering to the public. The conference will be held June 20, 21, and 22, 2012 in San Francisco. INFORMAL PUBLIC EDUCATION ABOUT ENGINEERING, ARCHITECTURE, AND CONSTRUCTION Informal education has been defined as education outside the classroom. A common way people learn about science, engineering, architecture, and construction outside the classroom is to visit museums and related centers where exhibits explain to them, or allow them to explore on their own, topics in these subject areas. It is also possible to provide this kind of learning opportunity outdoors. It is also possible to use the constructed or under-construction built environment as the primary exhibit. In effect, a building, bridge, utility infrastructure facility, or other kind of construction can be a free exhibit it is already paid for to provide its primary function, but it can be capitalized upon as an educational resource. There are three arguments for this approach: 1. There are major cost savings, as compared to designing and fabricating an entire set of exhibits the construction itself is the primary exhibit.

2 2. The public is interested in the built environment around it, is affected by it everyday, but doesn t have many opportunities to learn about it. 3. There is something intrinsically interesting about real things as compared to simulations. The project reported on here concerns the Golden Gate Bridge, but lessons learned in that project can be applied to ways to offer informal learning opportunities to the public concerning buildings and architectural engineering topics. THE GOLDEN GATE BRIDGE PERMANENT OUTDOOR EXHIBITION The currently underway Golden Gate Bridge Permanent Outdoor Exhibition at the San Francisco side of the Golden Gate (began with the recognition that the Bridge is a major sightseeing attraction, with approximately 10 million people per year visiting it. On a sunny weekend in the summer, about 6,000 bicyclists ride to and across the Bridge, for example, and tour buses are constantly coming and going. The premise of the project is that visitors will come to the Bridge as sightseers, and then we will surprise them with enjoyable opportunities to learn about how it was constructed, the engineering principles involved in how a long-span suspension bridge stands up and resists the forces of wind and earthquakes, the aesthetic design qualities of the Bridge, and how it has affected and been a major part of the history of the San Francisco Bay Region. Visitors will simultaneously be able to view the Bridge while they are seeing and interacting with exhibits related to various features of it. See Figure 1. Figure 1: The Golden Gate Bridge from the point of view of the Outdoor Exhibition area.

3 The centerpiece of the outdoor area s exhibits is a large, 90-ft-long precise scale model of the Bridge, which is the task of Prof. Maria Garlock at Princeton University, recent graduate and practicing engineer Sylvester Black, and students. The model functions as a three-dimensional structural diagram of the Bridge, for example revealing X-trussed struts that lie hidden beneath architectural cover plates in the towers. For durability in an environment where moist, salt-laden air is common, the model is being made of a special grade of stainless steel, Duplex See Figure 2. b. a. c. d. Figure 2: Outdoor exhibition area and the large-size (90-ft-long) scale model of the Bridge. a. general location looking south at the San Francisco end of the Bridge (view from south tower, photo by Jorge Lee, GGBHTD); b. the outdoor gallery in which most of the exhibits will be located, looking north (model by EHDD Architecture); (c) drawing of the large model of the Bridge, looking north, with eye-level views provided around it at elevated viewing areas, in addition to ground level views (drawing by EHDD Architecture); d. Professor Maria Garlock of Princeton University with one of the several prototypes of components of the model that have been test-fabricated.

4 This large model functions as a table of contents for the kiosk-scale, hands-on satellite exhibits clustered around it. For example, on the underside of the deck of the large model will be a callout number, matching the number on one of the satellite exhibits, which will explain how the torsional resistance of the deck was increased after a windstorm in 1953 by adding truss bracing to the underside of the deck in the horizontal plane. Instead of the original channel or inverted U cross section of the Bridge deck, it became a closed rectangular section, with greatly increased torsional resistance. Visitors can feel the difference in stiffness in two small scale models of sections of the deck as they try to twist them, one with the wind retrofit of lower lateral bracing, one without. Since this feature is on the bottom of the Bridge deck, it is not visible except by boat, but in the outdoor exhibition area, visitors can walk beneath the model and look up at this bracing. A number on the model will be keyed to the same number on the satellite model. At the same time, the actual Bridge is in view, providing visitors with a simultaneous experience of a close-up view and experience of the twisting of the deck, a view of the big model indicating where this is on the Bridge, and then the dramatic view of the Bridge itself. Figure 2. The role of the large-size scale model as a table of contents MASTER PLANNING A master planning effort was necessary not only because of the size of the centerpiece model and the space taken up by approximately 20 satellite exhibits (see Table 1), but also because of several characteristics of the site. The master planning was accomplished by EHDD Architecture of San Francisco (EHDD 2010). There are historic remnants from the pre-bridge US Army use of the site, and a complex array of circulation patterns bikes, pedestrians, buses, cars, and pedestrians. The Golden Gate Bridge is unusual among the world s largest bridges in providing bike and pedestrian access across it. The site planning has been closely coordinated with the National Park Service. The site is within the NPS Golden Gate National Recreation Area. Also involved in planning has been the Golden Gate National Parks Conservancy.

5 INDIVIDUAL EXHIBITS IN THE EXHIBITION A listing of the individual exhibits and their developers is shown in Table 1. Organization CUREE CUREE/GGBHTD CUREE/GGBHTD Exploratorium EyeThink Inc. Princeton University Sciencenter West Wind Laboratory Exhibits Sensation of wind pressure Force exerted on push-plate corresponds to pressure of a given wind speed Deck torsional stiffness, wind retrofit retrofit addition of bottom horizontal bracing of Bridge deck simulated by hands-on models of pre- and post-retrofit decks Suspender rope strength compared to weight of ferry vessel (exhibit on a GGBHTD ferry vessel; related exhibit on exhibition site) Geology underlying towers and anchorages Samples of types of rock found at those locations, mounted on the four columns supporting the large model of the Bridge Tower leg footprint at actual size Pattern imprinted in the outdoor gallery pavement, showing actual size of a tower leg (approximately the plan size of a house) History mural 80-ft-long illustrated montage of historic events in the life of the Golden Gate Bridge, not only engineering and construction but also the political and financial formation of the Bridge, its role in regional development, and its iconic role in popular culture Highlights, Facts & Figures Drawn from the popular GGBHTD book of same name Depiction of bridge deflection Displays how the Bridge moves daily under temperature, wind, and traffic load variations Dynamics of a suspension bridge the modal model Hands-on exhibit of the modes of vibration of the Bridge, the ways the Bridge shape can change if it undergoes an earthquake. Bridge Mechanics, Tug of War Visitor feels how hard it is to raise a weight suspended from a sagging chain as the slope of the chain flattens out LIFETILES animated mural of the construction of the Bridge As one walks past the glass tile mural, an animated sequence of the construction phases of the Bridge appears 87-ft-long scale (1:80) model of the Bridge, serving four purposes: (1) a table of contents for satellite exhibits; (2) a 3D structural diagram of the Golden Gate Bridge, differentiating structural from nonstructural components; (3) a big draw to beckon visitors to the Outdoor Exhibition area; (4) a beautiful sculpture in its own right Earthquakes, Seismic Design, Seismic Retrofits The site is near the San Andreas Fault and other active faults. Major seismic retrofit projects have been accomplished and others are still underway Rivets Millions of rivets hold thousands of pieces of steel together to make up the Bridge. What s a rivet? How were they installed? Color, Painting, and Corrosion-Protection of the Bridge Why is the Bridge orange? How often is it painted? Does it rust? Comparative aerodynamic torsional stability of scale model deck crosssections in the ambient wind of the site

6 The exhibits are the core of the project, but there are other activities underway. The Bridge District s website ( will provide more detailed information on topics than a visitor can absorb when at the exhibits. It will be useful prior to, after, or during (via smart phone) a visit, or even for those who never visit in person. Assisting in the development of content on the project for the website is Professor Thalia Anagnos of San Jose State University. The American Public Works Association is assisting in applying the results of the project elsewhere. APWA operates a large continuing education program for its 30,000 members, and a course on How to Mount Effective Public Exhibits will be developed for their continuing education program. JUNE 20-22, 2012 CONFERENCE: PUBLIC WORKS FOR PUBLIC UNDERSTANDING As part of the outreach effort of the project, we are holding an international conference shortly after the May, th Anniversary of the Golden Gate Bridge, on the theme of Public Works for Public Learning. There will be a variety of speakers explaining how their construction and facilities have been featured as a visitor-serving resource. The confirmed headliner keynote speaker is Dr. Wayne Clough, a civil engineer and the head of the Smithsonian Institution. An element of the project to be presented at the conference is a history of the research conducted on the Bridge, and on research conducted elsewhere that has affected the Bridge, from its early design phase to today. That is being carried out by Prof. Sarah Billington, Stanford University; Dr. David P. Billington, Jr., historian; and Prof. David P. Billington, Sr., Princeton University. EVALUATING AN EXHIBITION Our project employs two evaluation consulting firms. Inverness Research conducts front-end (characteristics of visitors before the exhibition is mounted) and formative Figure 3: An international conference on using the built environment as exhibits for public learning will take place in San Francisco June 20-22, evaluation (interviewing visitors as they try out prototypes of exhibits, advising the exhibit designers). Heil and Associates will conduct the summary evaluation and provide documentation on what was learned in this project so that others can benefit from our experience. APPLYING THIS EXAMPLE TO BUILDINGS AND CONSTRUCTION SITES While the present project is centered around a bridge, there are more numerous informal learning opportunities with buildings. A special opportunity exists when a building is under construction always an item of interest to passersby or those who live or work near the construction project.

7 Ideas on how to mount exhibits related to a building construction site are contained in Building Bridges Between Civil Engineers and Science Museums (Reitherman et al. 2008). See Figure 4. Figure 4. Possible construction site public exhibit. Exhibits can be temporary and small-scale and still be appreciated by the public. Using the built environment as the core of the exhibit allows for low-cost capitalizing on that resource, such as a building under construction. The public is interested in architecture, engineering, and construction, but rarely has an opportunity to learn about those topics. What may seem obvious to an architect or engineer is mysterious to the ordinary person. Some simple model or graphic exhibits could be displayed at the site to indicate the phases of the construction that will result in the finished product as shown in a rendering. A person walking by might wonder, why are they driving so many long concrete poles (piles) into the ground? Or, what are those pieces of steel being welded together to make the building stand-up, and how does it resist wind or earthquakes? What kind of panels are they lifting up by crane and attaching to the outside of the building? Why are the panels different on different sides of the building? Information in that Building Bridges book is also provided on issues such as safety and accessibility aspects of exhibit design and exhibit development resources. ACKNOWLEDGMENTS Funding for the project has been provided by the Division of Research on Learning in Formal and Informal Settings, National Science Foundation. Dr. Al DeSena is the NSF project officer

8 for this award. Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. Key GGBHTD staff involved in the project, besides Denis Mulligan, the Principal Investigator for the project, include Kary Witt, Bridge Manager; Mary Currie, Public Affairs Director; Kellee Hopper, Marketing Director; Jorge Lee, Civil Engineer. Key CUREE staff besides Co-Principal Investigator and Project Manager Bob Reitherman, who have central roles are Reed Helgens, Associate Executive Director, Darryl Wong, Graphics and Web Manager, and Aaron Neighbour, Exhibit Designer. A blue ribbon group of Advisors have helped guide the project: Jill Andrews, University of Michigan; Cathy Frankel, National Building Museum; Alan Friedman, The Museum Group; Chris Gallagher, San Francisco Bay Model Visitor Center, US Army Corps of Engineers; Roy Griffiths, North Carolina Museum of Life & Science; Howard Levitt, National Park Service; Lawrence Lux, Lux Advisors and American Public Works Association; Joyce Ma, the Exploratorium; Henry Petroski, Duke University; Stephen Ressler, US Military Academy Department of Civil and Mechanical Engineering; Carol Willis, the Skyscraper Museum. CITED REFERENCES EHDD Architecture (2010). Golden Gate south end master plan, Golden Gate Highway, Bridge and Transportation District, San Francisco, CA. Reitherman, Robert, Anagnos, Thalia, and Meluch, Wendy (2008). Building bridges between civil engineers and science museums, Consortium of Universities for Research in Earthquake Engineering, Richmond, CA, funded by the National Science Foundation, available as a free pdf at: