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Brooklyn Bridge: Epic of the Age

 J.M. Syken

Course Outline

In the post-Civil War era, science and technology were the new religion. Anything was possible including spanning the East River between the independent cities of Brooklyn and New York. The man chosen to undertake this heroic feat of engineering could be none other than John Augustus Roebling. A German immigrant to America, he was a brilliant linguist, artist, philosopher and engineer (a “Lesser Leonardo”). Where others had failed, John Roebling would succeed in perfecting the art and science of suspension bridge design with his intrinsic understanding of both the static and dynamic forces acting on a wire-cable suspension bridge.

This course will examine the background and events leading up to the design, construction and completion of the Brooklyn Bridge. It will examine the need for the bridge, main participants, politics, earlier New York City bridges and those designed/built previously by its principal designer (John A. Roebling). The main focus will be on the design engineering and construction aspects of the creation of what would be the longest suspension bridge in the world at the time of its completion in May, 1883.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will be able to

Intended Audience

This course is intended for architects, engineers, contractors and construction professionals.

Benefit to Attendees

The attendees will gain an intimate knowledge and insight into the creation of one of the greatest and enduring engineering wonders of the 19th century: Brooklyn Bridge.

Course Introduction

Once only a dream in the imagination of a visionary, Thomas Pope’s 1811 Flying Pendant Lever Arch Bridge over the East and/or Hudson Rivers would never be realized. By the mid-19th century, the dream of spanning wide bodies of water was no longer wishful thinking, it had become a reality over the Ohio, Allegheny, Delaware and Niagara Rivers with the suspension bridge designs of John A. Roebling. Suspension bridges could do the job, but their inherent flexibility and movement made them vulnerable to the dynamic forces of the wind and harmonic vibration caused by the loads passing over them. With 25% of suspension bridges failing in the 19th century, it was not an easy task to convince a skeptical public and press that suspension bridges were safe. A John Roebling suspension bridge never failed thus, he was the only choice when it came to spanning the East River with a wire-cable suspension bridge. Roebling’s triple approach utilizing flexible wire main cables (rather than much stiffer eye-bar chains), stiffening trusses and wire-rope cable stays/suspenders provided flexibility, redundancy and the necessary damping required to control movement of the bridge deck in the wind.

As fate would have it, Roebling – an immigrant, would design the major features of the bridge and, to a large extent, immigrant labor would build it. However, it would be a first generation American: Washington A. Roebling, who would inherit the task of actually building the bridge as a result of his father’s untimely death at the very outset of construction in 1869. Civil War hero and innovative bridge engineer in his own right, he was an able heir for the great task ahead that would take fourteen years to complete.

Among many innovations used in the construction of the Brooklyn Bridge is the first use of large-scale pneumatic caissons to support the tremendous dead-weight and compression load (transferred to the towers as compression from the tension in the main cables). Acting as sub-structure, the caissons carry the load from the towers into the earth below. Without a solid founding (via the caissons), all else would fail. The known dangers but unknown (at the time) causes of Caissons Disease (a.k.a. “The Bends”) would add to the drama of the sinking of the caissons and exact a heavy toll on the work force and, in particular, the Chief Engineer: Washington A. Roebling.

Though it wasn’t the first suspension bridge with wire cables, cable stays, stiffening trusses and masonry towers and anchorages, its great main span (nearly 1,600-feet) and use of steel (rather than iron) for the wire cables, suspenders and superstructure ushered in a new age of steel construction. The same year the Brooklyn Bridge was completed – 1883, would see the erection of the first “skyscraper” in Chicago (The Home Insurance Building). The age of steel had begun.

Course Content

The following links contain the reference materials and lecture handouts for this webinar:

Brooklyn Bridge - A Documentary Film (Video Part 1 of 3, to be viewed during the webinar)
Brooklyn Bridge - A Documentary Film (Video Part 2 of 3, to be viewed during the webinar)
Brooklyn Bridge - A Documentary Film (Video Part 3 of 3, to be viewed during the webinar)
Brooklyn Bridge: Epic of the Age (printable handout in PDF, 17 MB, see Note A below for downloading instruction)
Brooklyn Bridge: Epic of the Age (non-printable slideshow for screen-viewing only, 24 MB, see Note A below for downloading instruction)

Note A: Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right-clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader from your computer.

Because this course is offered as a "live" course, you are required to attend the webinar at the scheduled time and date. Please check the Webinar Schedule under course description on our website for currently scheduled meeting date and time. We will send you an invitation to the webinar through email approximately 24 hours before the webinar (confirmation of the receipt of the invitation is required). The certificate of completion will not be issued unless you attend the webinar and pass a quiz. Thank you for your cooperation.

Course Summary

Perhaps Paul Goldberger – Architectural critic, said it best in 1983 upon the celebration of the first one hundred years of the Brooklyn Bridge: “The thing about the Brooklyn Bridge, in the end, is that it is just so beautiful.” He also observed how the masonry towers were a reflection of the 19th century and the steel cables and superstructure were of the 20th century. Serving into the 21st century (and beyond), the Brooklyn Bridge remains the most trouble-free of all of NYC’s suspension bridges. It was so well built that, after a ten-year study and reconfiguration in the middle of the 20th century, the only suggestion for improvement that could be made was that it needed a fresh coat of paint.

Related Links

For additional technical information related to this subject, please visit the following websites:

Wikipedia - Brooklyn Bridge
YouTube - Roebling and Trenton Documentary (Part 1)
YouTube - Roebling and Trenton Documentary (Part 2)

Quiz

Before you attend the webinar, you need to print the quiz questions from your browser for your study during the webinar. At the end of the webinar, you need to complete the quiz and submit your answers to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.