who are those other guys and what did they do?

Who are those other guys and what did they do?Who are those other guys and what did they do?A look at Chicago bridge engineers at the turn of the 20A look at Chicago bridge engineers at the turn of the 20thth Century Century

byby

James S. PhillipsJames S. Phillips

Introduction

July 4, 2009 marked the centennial of The Plan of Chicago authored by Daniel H.

Burnham and Edward H. Bennett. The focus of The Plan was to create a city that would

achieve two major goals - provide an efficient environment for commerce and a

beautiful environment that would add to the quality of life for city residents.

Burnham and Bennett received many accolades for their vision of Chicago. In

addition, Edward Bennett was the architectural consultant for the Chicago Plan

Commission which meant that he had a great deal of influence on the major projects

built in the city between 1909 and 1930, including the bascule bridges in the Loop.1 Mr.

Bennett's name appears on plaques of eleven bridges built in this era (W. Washington,

W. Jackson, W. Lake, W. Monroe, N. Michigan, N. Franklin-Orleans, N. Wells, W.

Madison, W. Adams, N La Salle, and N. Wabash – see Illustration 1).

Mr. Bennett was instrumental in ensuring that the bridges were beautiful. While

there were some architectural considerations in the bridge components themselves, most

of the architectural attention was focused on the bridge tender houses, abutments,

staircases, and railings.

While Mr. Bennett had a major role in defining the appearance of the bridges, he did

not “design” these bridges. Other names appear on the bridge plaques. “Who are those

other guys and what did they do?”

1 The bridges of interest here are located on the Main and South Branches of the Chicago River between N. Lake Shore Dr. and W. Van Buren St. Illustration 1 shows the area and the location of the bridges.

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Some History

To answer that question, we need to look back at the 1890's, when all of Chicago's

movable bridges were center pier swing bridges. This type of bridge has a turntable on a

pier in the middle of the river (Illustration 2). Commercial vessels had grown large

enough that these center piers were a hindrance to navigation especially in the relatively

“tight” turn from the Main Branch to the South Branch (see Illustration 1). The need for

more room in the river channel made the shipping and marine interests push Chicago

and its engineers to develop a more navigation-friendly bridge.

Illustration 1: Location of Downtown Chicago Bridges (bridges marked with double asterisk were built between 1913 and 1930)

123

4

5678910

1112

13

14

1516

17

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1. N Lake Shore Dr2. N Columbus Dr3. N Michigan Ave**4. N Wabash Ave**5. N State St6. N Dearborn St

7. N Clark St**8. N LaSalle St**9. N Wells St**10. N Franklin-Orleans St**11. W Lake St**12. W Randolph St

13. W Washington Blvd**14. W Madison St**15. W Monroe St**16. W Adams St**17. W Jackson Blvd**18. W Van Buren St

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Three prototype bridge designs emerged that met the goal of adequate channel width

but with varying degrees of success meeting the operational criteria. These were the

folding-lift bridge, the vertical lift span, and the rolling lift bascule bridge. Each of these

designs was patented by their respective designers: the folding-lift by Captain William

Harman; the vertical lift span by J. A. L. Waddell; and the rolling lift bascule by William

and Albert Scherzer.

Illustration 2: Lithograph in James W. Sheahan, Chicago Illustrated (Chicago: Jevne & Almini, 1866). P&P,LC-USZ62-23805. (Library of Congress Digital image provided in

BRIDGES by Richard Cleary, copyright 2007, W.W. Norton & Company.)

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The folding-lift bridge had a dual action. It lifted vertically then folded mid-leaf to

allow for a fairly wide clear span (see Illustration 3). This particular concept proved too

complex and troublesome to operate and maintain. Only two of these bridges were built

in the 1890's. They were at Canal and Weed Streets. The Canal Street bridge was

replaced with a rolling lift bridge in 1903 and the Weed Street bridge was removed in

1905.

Illustration 3: The Harman Folding Lift Bridge (drawing taken from the Harman's 1888 patent)

Bridge upLeaf folded at hinge Bridge Down

Span hinge

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In the vertical lift span bridge (Illustration 4), all or a portion of the river span lifted

up via hoists and cables, similar to an elevator car. This bridge, while effective, was

expensive to build and maintain. It was also considered to be less than attractive by

some. Illustration 3 shows the drawing of this type of bridge as shown in the 1893

patent. No vertical lift bridges were built between N. Lake Shore Drive and W. Van

Buren Street. (Today, a vertical lift railroad bridge can be seen crossing the South

Branch near Canal Street – near Ping Tom Memorial park in Chicago's China Town.)

Illustration 4: The Waddell Vertical Lift Bridge (drawing taken from the Waddell's 1893 patent)

Bridge up

Bridge down

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Of these three concepts, the most promising was the rolling lift bascule bridge

(Illustration 5). This concept best met all of the design criteria - simple operation, easy

to build, and low construction cost. The rolling lift bridge opens by rotating vertically

on the river bank. A large counterweight on the shore end of the bridge aids the lifting

process as the bridge leaf rotates upward. The bridge is not tied to a single rotation

point, so the center of gravity of the leaf rolls back over a distance of twenty to thirty

feet on track girders. This amount of movement means that the foundation has to be

designed over an area large enough to handle the weight of the rotating leaf.

While the rolling lift bridge was the superior bridge design of the three bridge types

examined in the 1890's, John Ericson (Chicago City Engineer) was convinced that the

rolling lift bridge was an unsatisfactory solution to the city's bridge problems.

Two technical issues emerged from the city's experience with the early rolling lift

bridges. The first involved the relatively fast degradation of the track girders. This

degradation meant that the city faced a long-term, high-cost maintenance item on these

bridges. The second issue was in the bridge foundation. The early foundations did not

adequately support the bridge through the full range of movement of the bridge leaf.

Illustration 5: The Scherzer Rolling Lift Bridge (drawings taken from the William Scherzer's 1893 patent)

Track

Bridge “Rocker”

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Proper foundation design would increase the initial cost of the bridge, partially erasing

its low-cost advantage.

The most serious problem with the rolling lift bridge, however, was the fact that it

was patented. Each time one of these bridges were built, the Scherzer Rolling Lift

Bridge Company received a royalty. These royalty fees were a hardship on a cash-

strapped city budget.

In 1899, Ericson's engineers performed a literature review of bridge designs used in

the U.S. and Europe. The goal was to find a bridge design that would satisfy the design

criteria and not have the added cost of royalty fees.

Chicago engineers adapted the concepts of the 1894 Tower Bridge of London to their

situation. The Tower Bridge was a fixed trunnion bascule bridge. It was considered a

better option for Chicago because, it was simple to operate, the foundation design was

less complicated (when compared to a rolling lift bridge), and it was patent free.

Illustration 6: Fixed Trunnion Bascule Bridge (drawing from von Babo's 1911 patent)

Tail Pit

Trunnion

Rack

Counterweight

Pinion

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The Chicago-Type fixed trunnion bascule bridge (Illustration 6), as this design is

now known, operates in a manner similar to the rolling lift bridge. The major

differences between this design and the rolling lift design are that the fixed trunnion

bridge rotates about axles (trunnions) rather than rolling over an area and a rack and

pinion gearing system is employed to raise and lower the bridge (instead of a track for

the bridge to roll on).

This is the underlying design of all of the downtown bascule bridges. As with any

design, modifications and improvements were made along the way. Now, let's talk about

some of the other names on the bridge plaques and their contribution to the Loop bridges

built from 1913 to 1930.

The Engineers

John Ernst Ericson was born in Stockholm, Sweden on October 21, 1858. He

received his training in civil engineering from the Royal Polytechnic Institute in

Stockholm in 1880 and immigrated to the United States in 1881.

He worked in several areas of civil engineering before becoming the Chicago city

engineer in 1897, where he served for all but four years from 1897-1927. He was the

driving force behind the work that identified, implemented, and refined the fixed

trunnion bridge as the best design for Chicago's movable bridges. His name appears on

bridge plaques at W. Lake St., N. Franklin-Orleans St., N. Wells St., and W. Madison St.

Alexander F. von Babo was born on May 27, 1854 in Heidelberg, Germany and he

immigrated to the United States in 1886. Mr. von Babo was a part of the group of

engineers that selected the fixed trunnion bascule bridge as “Chicago's bridge” in 1900.

Although he worked directly on the W. Washington Blvd. bridge and his name appears

on the bridge plaque on the W. Lake St. bridge, the impact of his patented design

innovation is much wider than his connection to specific bridges. This patent (No.

1,001,800, August 29, 1911) was significant because it moved the rack from the outside

of the bridge trusses to the inside. Illustration 6 shows von Babo's patent drawings of

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the original Chicago-type bridge configuration (right hand side) and von Babo's

innovation (left hand side). This innovation paved the way for the use of more attractive

and varied trusses on bridges built between 1913 and 1930.

Thomas G. Pihlfeldt was born on October 11, 1858 in Vadso, Norway. He received

his engineering training in Germany and immigrated to the United States on August 25,

1879. His first jobs in the Chicago area were as a draftsman in different engineering

firms. In 1889 he began work for the Chicago Bureau of Maps. Pihlfeldt transferred to

the Division of Bridges in 1894. He became an Assistant Engineer of Bridges in 1896

and was promoted to Engineer of Bridges in 1901. He was awarded the Order of St.

Olaf by the King of Norway in 1932. He worked in the bridge division until his death

on January 23, 1941.

Probably his most innovative work came in the replacement of the double deck

center pier swing bridges at West Lake and North Wells streets. Both bridges carried a

large volume of train traffic on their upper deck. It was important to the economy of the

Illustration 7: Alexander von Babo's Major Contribution to the Chicago Type Bascule Bridge (drawing taken from the 1911 patent)

Rack

Pinion

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city that this train traffic not be interrupted for an inordinate period of time. His solution

was to maintain train traffic on the elevated tracks on the old swing bridge while the

bascule bridge leaves were constructed in the vertical position. When the bascule bridge

was completed, the old swing bridge was rotated open, cut up and removed via the river

and the bascule bridge was lowered. The decking on the upper deck was then installed.

On his first try at the W. Lake Street bridge, traffic was interrupted for seven days. On

his second try at N. Wells, the break in train service was only three days.

Mr. Pihlfeldt's long service in the bridge division is confirmed by the number of

bridge plaques around the city that bear his name. Of the bridges along Wacker Drive,

his name is found on ten plaques (W. Washington; W. Lake; N. Michigan; N. Franklin-

Orleans; N. Wells; W. Madison; W. Adams; N. La Salle; N. Clark; and N. Wabash).

Hugh E Young was associated with nine of the bridges built between 1913 and 1930

(W. Lake, W. Monroe, N. Franklin-Orleans, N. Michigan, W. Madison, N. Wells, N. La

Salle, N. Clark, and N. Wabash). His first association with a bridge along Wacker Drive

was in 1916 when the bridge at West Lake Street was built. He worked for the city

bridge division and the Chicago Plan Commission during his career.

His most innovative work was on the design of the W. Monroe St bridge. This site

was complicated in two respects. First, the railroad tracks on the west side of the river

interfered with the “normal” location of the tail pit. Secondly, tunnels running under

Monroe St. on both sides of the river that complicated the foundation design.

The railroad issue was addressed by using a different design approach on each of the

bridge leaves. On the railroad (west) side of the bridge, a shorter counterweight arm and

a cast iron counter weight was used to avoid the conflict with the railroad tracks. The

east leaf was built more “conventionally” with a longer counter weight arm and a

concrete counterweight. Illustration 8 shows the asymmetry in the two leaves. The west

leaf is on the right-hand side. This design solution allowed this bridge to maintain the

architectural goals of The Plan – a major requirement in this era.

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Foundation issues were handled through the use of sub piers that reached a depth of

117 ft which was deeper than most sub piers of the bridges in the area. The asymmetry

in the design of the superstructure was mirrored in the foundation design.

Donald N. Becker was born in Ithaca, NY on March 25, 1888. He received his

engineering degree from Rensselaer Polytechnic Institute in 1908. His early career

included time as an instructor at Rensselaer and as a draftsman in Chicago engineering

firms. He joined the Chicago Bridge Engineering Department in 1912 and worked there

until 1943.

His most significant contribution to the Chicago bridge story was his paper entitled

“Development of the Chicago Type Bridge” published in the February 1943 Proceedings

of the American Society of Civil Engineers. This well-written history is a valuable

resource. Mr. Becker's name appears on bridge plaques on the W. Adams, N. La Salle,

N. Clark, and N. Wabash street bridges.

Conclusion

Any project of size has many people involved in its design and execution. These

bridges are no different. The engineers discussed here were responsible for some

innovative features and improvements that may not be as visible as the architectural

features, but were just as important. So the next time you look at one of the Chicago

Loop bridges, remember that there is more than meets the eye.

Illustration 8: A view looking south at the W Monroe St Bridge

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ReferencesEngineering Biographical Data

● Bjork, Kenneth, Saga in Steel and Concrete: Norwegian Engineers in America, pp120-130 (Pihfeldt), Norwegian-American Historical Association, 1947 (http://newsarch.rootsweb.com/th/read/NORWAY/2003-04/1050683732).

● Leonard, John William and Marquis, Albert Nelson, The book of Chicagoans : a

biographical dictionary of leading living men of the city of Chicago, (Ericson), A.N.

Marquis, 1905-1917, 1911.

● Weingardt, Richard G., Engineering Legends: Great American Civil Engineers 32 Profiles

of Inspiration and Achievement, pp 63-66 (Waddell), ASCE, 2005.

● ___________, Who's Who in Chicago, (Pihlfeldt), A.N. Marquis & Co., 1926

● ____________, Who's Who in Chicago, (Becker), A.N. Marquis & Co., 1945.

Bridge Patents

● Harman, W, Bridge, Patent No. 383,880, U.S. Patent and Trademark Office, June 5, 1888.

● Scherzer, W. (Dec'd – A. H. Scherzer, Administrator), Lift Bridge, Patent No. 511,713, U.S.

Patent and Trademark Office, December 26, 2893.

● Scherzer, A. H. and Kandeler, C. F. T., Bascule Bridge, Patent No. 721,918, U.S. Patent and

Trademark Office, March 3, 1903

● Strauss, J. B., Bridge, Patent No. 995,813, U.S. Patent and Trademark Office, June 20, 1911

● Von Babo, A. F. L., Trunnion Bascule Bridge, Patent No. 1,001,800, U.S. Patent and

Trademark Office, August 29, 1911.

● Waddell, J. A. L., Lift Bridge, Patent No. 506,571, U.S. Patent and Trademark Office, October

10, 1893.

http://newsarch.rootsweb.com/th/read/NORWAY/2003-04/1050683732

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Bridge History

● Becker, D. N., Development of the Chicago Type Bascule Bridge, American Society of Civil

Engineers Transactions, Paper No. 2226, February 1943.

● Christensen, D., Editor, Chicago Public Works: A History Chicago, Rand McNally &

Company, 1973.

● Cleary, R. L., Bridges, W.W. Norton & Company, ISBN0-393-73136-7, 2007.

● Department of Public Works, Bureau of Engineering, The Movable Bridges of Chicago, A

Brief History, City of Chicago, 1983.

● Hess, J. A., Chicago River Bascule Bridges Development of Movable Bridge Technology in Chicago, 1890-1910, Historic American Engineering Record Library of Congress, HAER No. IL-111, 1999, http://memory.loc.gov/ammem/collections/habs_haer/.

● Pihlfeldt, T. G., “Bridges,” Civil Service News, Pictorial Story of Chicago's Public Works,

Engineering Wonders of the World Featuring Chicago's Charter Jubilee 1837-1937, 1937.

● Scott, C.; Alexander, F.; Nicolay, J., Chicago River Bascule Bridge, Clark Street, Historic

American Engineering Record Library of Congress, HAER No. IL-64, 1986,

http://memory.loc.gov/ammem/collections/habs_haer/.

● Scott, C.; Alexander, F.; Nicolay, J., Chicago River Bascule Bridge, West Adams Street,

Historic American Engineering Record Library of Congress, HAER No. IL-51, 1986,


● Scott, C.; Alexander, F.; Nicolay, J., Chicago River Bascule Bridge, Jackson Boulevard,

Historic American Engineering Record Library of Congress, HAER No. IL-55, 1986


http://memory.loc.gov/ammem/collections/habs_haer/

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● Scott, C.; Alexander, F.; Nicolay, J., Chicago River Bascule Bridge, La Salle Street,



● Scott, C.; Alexander, F.; Nicolay, J., Chicago River Bascule Bridge, Michigan Avenue,



● Scott, C.; Alexander, F.; Nicolay, J., Fitzsimons, G; Brucken, C., Chicago River Bascule

Bridge, Washington Street, Historic American Engineering Record Library of Congress,

HAER No. IL-38, 1992, http://memory.loc.gov/ammem/collections/habs_haer/ .

● Sneddon, M. T., Chicago River Bascule Bridge, Wabash Avenue, Historic American

Engineering Record Library of Congress, HAER No. IL-48, June 1999,


● Sneddon, M. T., Chicago River Bascule Bridge, Wells Street Bridge, Historic American

Engineering Record Library of Congress, HAER No. IL-52, 1999,


● Sneddon, M. T., Chicago River Bascule Bridge, Monroe Street, Historic American



● Sneddon, M. T., Chicago River Bascule Bridge, Franklin-Orleans Street, Historic American



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