postwar chicago skyscraper of the week–borg-warner

[Chicago Skyscrapers, 1934-1986, published by University of Illinois Press, is out now–available on Bookshop.org and Amazon.com, among other outlets.

Borg-Warner (A. Epstein & Sons/William Lescaze, 1955-1958)

Inland Steel and Prudential were new headquarters buildings funded by large corporations.  A more serious indication of faith in the Loop would be a purely speculative investment—developers constructing skyscrapers in anticipation of future tenants.  This had formed the bulk of the downtown real estate market before the depression, but the lack of demand throughout the 1940s and early 1950s discouraged such optimism.  It was notable, therefore, when Robert McCormick, Jr., representing the New York investment firm Collins Tuttle & Company, presented plans for a 20-story tall office building on the corner of Michigan and Adams in October 1955.  The Pullman Company, which had occupied a 10-story headquarters building on the site designed by Solon Spencer Beman since 1884, would sell the site and would take 35,000 square feet of space in the new building, but the remainder of the proposed 362,000 square feet would be speculative.  The Pullman Building was obsolete, the company’s spokesman emphasized, “erected…before the day of steel skeleton construction…its brick and granite walls are several feet thick.”[i] 

Pullman Building, Solon Spencer Beman, 1884.

The proposed replacement could not have differed more from the doomed structure’s masonry bearing walls and narrow arched windows.  Collins and Tuttle hired New York architect William Lescaze (1896-1969), best known for his PSFS building in Philadelphia, who responded with a horizontally striated curtain wall block with continuous spandrels of gold anodized aluminum, light inset strip windows, and a glazed lobby with black granite interiors.  Office space would wrap around a central core containing “air conditioning and high speed electronically controlled elevators,” all for an estimated $12.5 million.[ii]

WIlliam Lescaze’s initial scheme. (Chicago Tribune, October 5, 1955).

Automotive machinery manufacturer Borg-Warner signed a lease for the top five floors in January 1956, ensuring the project’s viability and lending it a new name.[iii]  The project also gained local backing from Samuel Banowit, a Chicago attorney who had launched his downtown efforts in 1952 by purchasing the Boston Store at Madison and Dearborn (Holabird and Roche, 1905).  Banowit retained Lescaze as a “consulting architect” but hired A. Epstein & Sons to lead the project.[iv]  Epstein produced a more restrained design, published in May 1956, that abandoned Lescaze’s gold anodized skin for “either aluminum or stainless steel vertical fins and window sash with spandrels…of navy blue porcelain enamel.”  The lobby evolved, too.  It would contain a showroom for Borg-Warner’s heavy machinery set against black and pink marble walls with more durable terrazzo floors.[v]  Architectural Record published the project in March 1957. By that time, Epstein and Lescaze had settled on aluminum mullions in a natural finish and blue porcelain-enameled steel for spandrel panels.[vi]  The blue spandrels would contrast with the Loop’s stone-and-brick surroundings, but Epstein thought it was less ‘faddish’ than the original gold and black and better aligned with Borg-Warner’s image.[vii]  The contrast between the new building’s construction and the Pullman’s drew as much interest.  The curtain wall, still a novelty at “only 1-1/2 inches thick,” compared with Pullman’s “massive stone walls, some of them 9 feet thick,” in the words of the Tribune’s Ernest Fuller.  This wall’s spandrel panels were still backed up with masonry fireproofing— “to comply with Chicago building regulations”—though these knee walls were no longer required.  Like the Prudential, Borg-Warner backed these spandrel walls with perimeter air conditioning cabinets that blanketed the curtain walls with seasonal hot or cold air and automatic elevators—still noteworthy in the building’s opening press for eschewing human operators—including a dedicated cab to Borg-Warner’s 21st-floor penthouse executive offices. 

Sumner Sollitt began construction on Borg-Warner in the summer of 1957.  Inland had proven that steel bearing piles were effective and economical for a structure of its size, but the noise and vibration of pile drivers on-site threatened to disrupt Orchestra Hall next door.  Steel remained scarce, too, with wait times of a year or more.  As a result, Epstein’s engineers specified concrete caissons, but efforts to keep groundwater out of these undermined Orchestra Hall’s north wall, leading its pile foundations to settle.  Caisson techniques in the city would evolve to deal with the constant threats of flooding and adjacent settlement.[viii]  As the building’s steelwork topped out in November 1957, Banowit reported that the building was fully leased, with some of the city’s major industrial firms—American Can and food company Libby, McNeil & Libby in particular—taking full floors.[ix]  Tenants moved in during the summer of 1958, and the building formally opened that August, with Borg-Warner’s chairman, R.C. Ingersoll, predicting that the “colorful new building” would be just the first of many “facelifts” along Michigan Avenue.  (Figure 4.15)  Banowit echoed this in his opening remarks.  He was, in fact, already at work on Borg-Warner’s sequel with his renamed company, National Properties, telling the press in January 1957 that he had purchased the site of Northwestern’s abortive 1935 skyscraper proposal at LaSalle and Jackson, adjacent to the Board of Trade.  “The city still needs more central area office space,” he told the Tribune, pointing to Borg-Warner’s rapid leasing. 

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[i] Ernest Fuller, “Announce Plan to Replace Historic Pullman Building.”  Chicago Daily Tribune, Oct. 5, 1955.  1.  .

[ii]  Ibid. 

[iii] “Skyscraper’s Main Tenant Will be Borg.”  Chicago Daily Tribune, Jan. 26, 1956.  D7.

[iv] “Borg-Warner Building, 200 South Michigan Ave., Chicago.”  Architectural Record, Vol. 121, no. 3.  March, 1957.  236.

[v] “Replacement for Pullman Building.”  Chicago Daily Tribune, May 23, 1956.  C7.

[vi] “Borg-Warner Building, 200 South Michigan Ave., Chicago,” op. cit.  236.

[vii] Ernest Fuller, “Choose a Color Plan—For a New Skyscraper.”  Chicago Daily Tribune, Aug. 10, 1958.  A9 and “New and Old Materials Give Life to Skyscrapers.”  Chicago Tribune, Feb. 20, 1966.  3-K1.

[viii] Clyde N. Baker, Charles W. Pfingsten, and John P. Gnaedinger, Task Force Report No. 13: History of Chicago High Rise Building Foundations, 1948-1998.  (Chicago: Chicago Committee on High-Rise Buildings, 1998).  41.

[ix] Ernest Fuller, “Borg-Warner Building is 95% leased.”  Chicago Daily Tribune, Aug. 25, 1957.  A7; “Borg-Warner Unit is Topped Out, Dedicated.”  Chicago Daily Tribune, Nov. 12, 1957.  C6.

postwar chicago skyscraper of the week–brunswick (part 2)

[Chicago Skyscrapers, 1934-1986, published by University of Illinois Press, is out now–available on Bookshop.org and Amazon.com, among other outlets.

Continued from last week:

Brunswick’s tightly spaced columns around its perimeter presented a ground-level architectural problem. Generous dimensions for office windows would be restrictive enclosing a lobby looking out onto a large civic plaza.  SOM thus faced a conundrum: how to open the building’s base in a structural system that relied on closely spaced columns.  Pei and Komendant’s walls at Kips Bay set narrowly spaced columns sit on deep girders, transferring loads over wider bays at ground level.  This made even more sense with Chicago’s difficult clay soil.  Fewer columns meant fewer caissons, saving excavation costs.  Other tall buildings in the Loop had used transfer girders below grade to spread loads from normally spaced columns above onto more widely spaced caissons below.  Graham and Goldsmith moved this element out of the ground to the lobby’s ceiling level.[i]  Kips Bay was just 20 stories tall, and its ground-level lobbies and entries were scaled to residential standards.  Carrying a building nearly twice as tall and with larger spans at ground level, Brunswick’s transfer structure had to be exponentially larger.  SOM’s preliminary designs showed a Vierendeel truss supported by nine tapering columns—like their New York office’s Beinecke Library at Yale.  However, as Brunswick’s scheme developed, its lobby grew taller and the Vierendeel truss deeper.  The expressive, tapering pin supports were simplified and enlarged into simple square columns.  In the final design, 24’ tall transfer trusses enclosed a double-height mechanical floor. They spanned 57’ from column to column—a colossal structural element articulated with expressed vertical chords matching the mullion-columns above.[ii]  To resist the enormous shear loads imposed by 36 floors above, the transfer truss also needed to be thick—7’-6”—leaving a large setback on its top surface.  Goldsmith resolved this with a curved taper to the mullion-columns, pronounced in the story above the transfer girder and smoothed into a gradual slope that matches each mullion-column’s cross-section to the diminishing loads it carries as it ascends.  To many, this geometry mimicked the Monadnock’s curved, tapering bearing walls, four blocks south.  Goldsmith denied a direct inspiration, but Graham suggested at least a philosophical continuity between the two.  “The Monadnock building could be called a tube too,” he argued, as its famous brick exterior carries gravity and wind loads, assisted by a lighter steel structure within.[iii]

Architectural Forum, April, 1966.

Brunswick’s exterior tube and interior shear walls are connected by stiff floor diaphragms.  One-way pan joists handle the 37’ spans from perimeter to core, supplemented by two-way waffle slabs at the corners.  This allowed the exterior frame to handle most of the lateral loads in the top portion of the tower and the core walls to take up shear loads as they increased toward the building base, a synergetic behavior Khan and Iyengar termed “frame-shear wall interaction.”[iv]  To accommodate up to 1-1/4 inches of thermal expansion in the outer tube, Khan developed hinge details at the junctions between floor and perimeter walls, restraining them horizontally while allowing them to expand and shrink during extreme weather.[v]

Brunswick opened to mixed reviews in April 1965.  Budget concerns eliminated travertine that Graham had intended to clad the entire structure, like the granite veneer at Hartford.  The exposed concrete structure had its own clarity. Still, it remained on the giant, seven-foot square piers at the lobby level, creating a material discontinuity that makes the base appear fragile compared with the solid structure above.  Architectural Forum compared the Brunswick to Eero Saarinen’s headquarters for CBS a year after its opening, noting that the two structures revived bearing wall structures for tall buildings, transforming their structural perimeters from “punctured walls” to “light columns” of reinforced concrete.  While Forum felt that Brunswick’s structural expression was purer than CBS’, which paired columns with vertical risers like the Equitable’s, Forum found the “enormous unity” of Saarinen’s stark, granite-clad shaft more satisfying.[vi] Brunswick’s structural innovations made Khan rethink tall building structures, turning conventional frames inside out.  The tube structure would become an SOM trademark. The challenging transition from a perforated bearing wall to a broad, open lobby would evolve through the firm’s work in Chicago and elsewhere.  The Brunswick was also a powerful re-interpretation of Chicago traditions, a concrete rejoinder to the fine steel grains of the Harris and Continental.  Carl Condit thought its concrete frame showed a “combination of the traditional masonry bearing wall and the articulated or cellular wall developed by the Chicago school for steel-framed construction” that brought back—in a new dialect— “the texture, depth, and mass that we miss in the featureless and brittle curtain of enameled steel and glass.”[vii]

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[i] “A Tale of Two Towers.”  Architectural Forum, April, 1966.  29-30.

[ii] Promotional Brochure, “Materialite® Lightweight Concrete Aggregate.”  General Dynamics Corporation, Chicago.  N.d.

[iii] Betty Blum [????], “Oral History of Bruce J. Graham.” Art Institute of Chicago Architects’ Oral History Project.  89.

[iv] “Brunswick Building, Chicago, Illinois (USA).”  IABSE Structures.  Vol. 6, 1982.

[v] “Brunswick Building, Chicago, Illinois (USA).”  IABSE Structures.  Vol. 6, 1982.

[vi] “A Tale of Two Towers.”  Architectural Forum, April, 1966.  28-37.

[vii] Carl W. Condit, “The New Architecture of Chicago.”  Chicago Review, 17:2/3, special issue on New Chicago Writing and Art.  1964.  115-116.

postwar chicago skyscraper of the week–brunswick (part 1 of 2)

[Chicago Skyscrapers, 1934-1986, published by University of Illinois Press, is out now–available on Bookshop.org and Amazon.com, among other outlets.

Brunswick (SOM, 1961-1964)

Planning for Chicago’s new Civic Center (see Chapter 7) gained renewed attention when Arthur Rubloff announced a project to transform Washington Street into Chicago’s “answer to Rockefeller Center” in October 1961.[i]  Rubloff’s client, Brunswick, had begun as a billiard table manufacturer in Cincinnati in 1845, moving to Chicago in the 1870s, expanding into factories on the River’s north bank in the 1880s, and opening corporate offices in the city in 1907.  In 1913, Brunswick moved into the former Studebaker Building on South Wabash, diversifying into real estate, small marine craft, and recreation and becoming a Fortune 500 company in 1957.[ii]  As part of its re-branding, Rubloff convinced Brunswick to become the principal tenant in his Washington Street project.

The project would replace the Chicago Title and Trust building, an 1892 building by Henry Cobb at the corner of Washington and Dearborn.  The quarter-block site was at the “crossroads of Chicago’s business and financial centers,” overlooking the site of the planned Civic Center.  Rubloff planned a huge development—800,000 square feet, with an estimated cost of 35 million dollars, pitching it as “the largest and tallest to be constructed in the heart of the Loop since the early 1930s,” carefully excluding the million-square-foot Prudential.  Rubloff signed Brunswick to a fifth of the building’s planned space, with the remainder of the structure to be rented out.[iii] 

Rubloff hired SOM, whose design would be influential, providing open, unobstructed floor plates while advancing the office’s interest in new structural strategies for building taller.  SOM’s team was led by Bill Hartmann, who paired Bruce Graham and Myron Goldsmith as design partners—one of the few times the two were credited on the same project—with Fazlur Khan leading the structural design.[iv]  Rubloff asked for column-free floors and a modular approach to services allowing flexibility in office layouts.  At the building’s base, Rubloff planned a subterranean retail mall connecting to the Civic Center’s concourse, linked by escalators to a ground-level lobby that would look out to its plaza.  The office floors were arranged in a single rectangular shaft with a ‘bustle’ on the lower nine levels providing large floor plates of 27,000 square feet toward the base and 19,400 square feet in the main shaft.^[v]

University Apartments, Hyde Park. I.M. Pei, 1961.

Supporting the building without interior columns led to its pivotal structural design.  Hartmann had been intrigued by I.M. Pei’s Kips Bay Plaza in New York City, which carried its floor loads on an exposed concrete exoskeleton that also enclosed the building.[vi]  Distilling the structure onto the exterior wall eliminated columns, making more efficient and flexible planning inside, but it also suggested re-considering the then-ascendant curtain wall.  SOM had completed the Hartford Building’s exposed concrete frame in 1961, as Pei’s designs were being published and his University Apartments in Hyde Park, engineered by August Komendant, were being completed—Khan and his family took an apartment in them after they opened.  The New York Times had noted that the exoskeletal approach revived the traditional idea of the exterior bearing wall—a seemingly reactionary structural development.  Steel reinforcing now allowed engineers to avoid the thick, heavy masses plaguing traditional masonry wall buildings like the Monadnock.  Kips Bay’s “honeycomb” structure, the Times reported, performed like a bearing wall structurally, but its stiffness and strength were so concentrated in its joints and structural mullions that it maintained the transparency of a glazed curtain wall.[vii] 

Digital model by Jack Strait

This integration provided more design freedom than what Pei called the “straitjacket of punching holes in a brick wall.” Still, SOM discovered structural potential beyond what Komendant and Pei had achieved.[viii]  Recalling the Equitable design that had found efficiencies in its stiffer exterior connections, SOM engineer Hal Iyengar realized that Pei’s “honeycomb bearing wall” could be combined with Equitable’s concentration on the exterior structure to suggest a new structural species.  Instead of designing the Brunswick as a “system of bays,” it would evolve as a “tubular building,” its structure condensed entirely onto the perimeter and core, creating two concentric tubes linked by stiff floor plates.  Shear walls enclosing plumbing, elevators, and fire stairs formed the inner core tube, while the outer tube would be made of four giant perimeter shear walls, each perforated, or “honeycombed,” as Pei had termed it, by large glass windows.  Replacing Equitable’s massive, widely spaced columns with a network of much smaller, closely spaced elements, Iyengar and Fazlur Khan balanced shear walls’ stiffness with a glass wall’s transparency.[ix]  The resulting tube structure provided the column-free interior space desired by Rubloff, with clear spans of 38 feet between the core and exterior wall, while deploying structural material where it best resisted wind loads.  Its exterior columns are located at 9’-4” centers, framing over 1,900 windows, each eight feet wide and nine feet tall.  The concentric tubes created impressive spatial efficiencies in plan and section; its floor plates have an 81 percent net to gross floor area ratio, and its exterior ‘bearing wall’ is 70% glass.[x]

(to be continued)

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[i] James M. Gavin, “How Brunswick Corp. was Sold on Building.”  Chicago Tribune, Nov. 3, 1961.  4-C6.

[ii] Promotional Brochure, “69 West Washington, Chicago.”  (Chicago: Brunswick Corporation, 1966). 

[iii] “New Office Skyscraper Set for Loop.”  Chicago Daily Tribune, Oct. 29, 1961.  A9, and “Beauty, Success Blended in Tower.”  Chicago Tribune, Dec. 5, 1965.  3A-H1.

[iv] “A Tale of Two Towers.”  Architectural Forum, April, 1966.  31.

[v] Promotional Brochure, “69 West Washington, Chicago.”  (Chicago: Brunswick Corporation, 1966) and Donald D. Hanson, “Structuring the Loop.”  Progressive Architecture, vol. 47, no. 8.  August, 1966.  104. 

[vi] Betty Blum [????], “Oral History of Bruce J. Graham.” Art Institute of Chicago Architects’ Oral History Project.  89.  Carl Condit also noted the connection to Pei’s work.  See Carl W. Condit, “The New Architecture of Chicago.”  Chicago Review, 17:2/3, special issue on New Chicago Writing and Art.  1964.  115.

[vii] Glenn Fowler, “Facade of Building Forms Structural Support for High-Rise Apartments.”  The New York Times, Apr 23, 1961. 449.

[viii] Glenn Fowler, “Facade of Building Forms Structural Support for High-Rise Apartments.”  The New York Times, Apr 23, 1961. 449.

[ix] Betty Blum [????], “Oral History of Hal Iyengar.” Art Institute of Chicago Architects’ Oral History Project.  36-37.

[x] Donald D. Hanson, “Structuring the Loop.”  Progressive Architecture, vol. 47, no. 8.  August, 1966.  104 and Promotional Brochure, “69 West Washington, Chicago.”  (Chicago: Brunswick Corporation, 1966).