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calculations for perpendicular winds (but not for quartering winds). Only
Weinstein was indicated as signing off on the copies of the calculations he provided to her, although she expected to see them initialed by a second person to confirm them, as was the usual practice in the industry. According to Hartley, she asked for calculations about quartering winds, and Weinstein said he would provide them but then didn't. Calculations for quartering winds were not required by the building code at the time, and were not common practice in the industry (although the design of the building was obviously unusual and would have justified special analysis). Weinstein assured her that the building could handle the necessary forces, and she did not further pursue the issue beyond writing about it in her thesis, which recorded her concerns and the response she received. In his feedback on Hartley's thesis, Billington questioned why her calculations weren't checked against figures from the firm.
380:: The steel framework subcontractor (Bethlehem Steel) proposed to use bolted joints instead of full-penetration welding, and the proposal was approved by LeMessurier's firm without LeMessurier personally reviewing the details. Kremer reported that Robert McNamara, "the managing principal for Citicorp in LeMessurier Associates' Cambridge office", stated that after he reviewed the proposal, he "presented the suggested change to Bill LeMessurier", who "discussed the technical implications and did calculations as to what effect the bolt extension in the connection would have on the movement of the tower ...", and that LeMessurier's firm then approved the details of the change without LeMessurier personally reviewing those details. This somewhat contradicts LeMessurier, who said he wasn't aware of the substitution until after the work had been completed.
402:: When Hurricane Ella threatened the city in August and September 1978, evacuation plans for the surrounding area were made in secret. Kremer cites the NSPE Board of Ethical Review (BER), which, although it was not commenting about the Citicorp Center specifically, said "withholding critical information from thousands of individuals whose safety is compromised over a significant period of time" is improper (although it could be argued that the Citicorp Center situation did not rise to meet that standard, when considering that no storms with high winds actually occurred in New York City during the period in question, and other steps had been taken to reduce the risk, and evacuation plans were ready if a high-wind storm were to occur).
242:
a 40 percent increase in wind loads and a 160 percent increase in the load at the bolted joints. Citicorp Center's use of bolted joints and the loads from quartering winds would not have caused concern if these issues had been isolated. However, the combination of the two findings prompted LeMessurier to run tests on structural safety. He concluded that the original welded-joint design could withstand the load from both straight-on and quartering winds, but the modified bolted-joint design could be vulnerable to a 70-mile-per-hour (110 km/h) near-hurricane force quartering wind. LeMessurier also discovered that his firm had used New York City's truss safety factor of 1:1 instead of the column safety factor of 1:2.
22:
367:(AIA) Trust, "many have viewed the actions of LeMessurier as nearly heroic, and many engineering schools and ethics educators now use LeMessurier's story as an example of how to act ethically." However, others have criticized LeMessurier for his lack of oversight that led to the issues and his lack of honesty toward neighborhood residents, architects, engineers, and other members of the public when the problems were discovered. Architect Eugene Kremer discussed the ethical questions raised in this case in 2002. Kremer listed six key points that he perceived as ethically problematic:
118:
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directly – she had spoken only to Joel S. Weinstein. According to one second-hand report, when one of LeMessurier's colleagues asked whether the student was female, "LeMessurier responded that he didn't know because he had not actually spoken with the student." However, in a lecture on the subject, LeMessurier himself said he had spoken directly and repeatedly with the student and referred to the student as male. LeMessurier died in 2007 without describing any communication with him about the interaction between
Hartley and Weinstein.
80:(NJIT), DeCarolis chose the building as the topic for a report assignment in his freshman class on the basic concepts of structural engineering. A professor Zoldos of NJIT expressed reservations to DeCarolis about the building's structure, and DeCarolis contacted LeMessurier, relaying what his professor had said. LeMessurier had also become aware that during the construction of the building, changes had been made to his design without his approval, and he reviewed the calculations of the building's stress parameters and the results of
513:(tuned mass damper discussion starting at 14:08, reference to the building as the first and to LeMessurier as the "father of the tuned mass damper" at 25:50, phone call with student described at 28:34, finding out about bolt substitution 27:30 (when he learned of it 31:25), wind tunnel experiments 34:10, 16-year failure period if damper was not functioning 35:10, brief thought of suicide 38:15, insurance company interaction and conventionality of diagonal wind analysis 40:40 and 55:40, evacuation plan at 49:30)
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a power failure, the building could be toppled by a wind of about 70-mile-per-hour (110 km/h) from a particular direction, with possibly many people killed as a result. The reinforcement effort was kept secret until 1995. The tuned mass damper has a major effect on the stability of the structure, so an emergency back-up generator was installed and extra staff was assigned to ensure that it would keep working reliably during the structural reinforcement.
374:: Although quartering wind loads were considered early in the design process, LeMessurier initially reached the conclusion that they were not the critical case for the building's structural analysis, and came to rely primarily on the calculations for perpendicular winds, as required by building codes, rather than checking all calculations and scenarios thoroughly.
218:, and a potential contractor questioned the expense of using welded rather than bolted joints. LeMessurier asked his office how the welds went at the Citicorp construction and was then told that bolts had been substituted for the welded joints he had prescribed. LeMessurier had not seen the analysis that had been performed when this substitution was done.
386:: Before LeMessurier decided to make Citicorp aware of the design defects, he briefly considered concealing the issues instead, or even committing suicide. Kremer said he should not have entertained such thoughts, even briefly. In contrast, the AIA study reports that it is clear LeMessurier never really considered the other options seriously.
294:. Officials barely acknowledged the issue, instead describing the work as a routine procedure. Henry DeFord III of Citicorp claimed the Citicorp Center could withstand a 100-year wind and that there were no "noticeable problems in the building at all". As precautions, emergency generators were installed for the mass damper,
241:
On July 24, 1978, LeMessurier went to his office and conducted calculations on
Citicorp Center's design. He had thought that perpendicular winds were the critical case for the building rather than quartering winds. He found that, for four of the eight tiers of chevrons, quartering winds would create
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against the side of the building. Although he had initially studied winds from various directions, he had concluded that quartering winds were not the critical case, and came to rely primarily on the calculations for perpendicular winds. Perpendicular winds were the only calculations required by New
173:
As part of
Citicorp Center's construction, a new building for the site's previous occupant, St. Peter's Lutheran Church, was erected at the site's northwest corner; by agreement, it was supposed to be separate from the main tower. To avoid the church, the tower is supported by four stilts positioned
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The reinforcements were made stealthily at night while the offices in the building were open for regular operation during the day. The scenario of concern was for the integrity of the building structure was high wind conditions. Estimates at the time suggested that if the mass damper was disabled by
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Repairs were completed in
October 1978, and most of the newspapers remained out of production for weeks after it was completed. LeMessurier claimed a wind strong enough to topple the repaired building would occur only once every 700 years. Stubbins and LeMessurier's insurance carrier covered all of
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and heading for New York. The reinforcement was only half-finished, with New York City hours away from emergency evacuation, but at that point the backup generators were in place and the mass damper was being continually monitored by special staff, and enough of the bracing had been completed that
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reassessment using modern technology later determined that the quartering wind loads were not the threat that LeMessurier and
Hartley had thought. They recommended a reevaluation of the original building design to determine if the retrofitting had really been warranted. It is not clear whether the
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However, another student at a different institution later identified himself as the student that LeMessurier spoke to by phone identified himself as Lee DeCarolis in an article published on the Online Ethics Center website. He said he learned in 2011 how he played a part in the
Citicorp Building
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active, LeMessurier estimated that a wind capable of toppling the building had a one in fifty-five chance of happening any year. But if the tuned mass damper could not function due to a power outage, a wind strong enough to cause the building's collapse had one chance in sixteen of happening any
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were placed on critical beams and weather forecasters were engaged. Citicorp and local officials created emergency evacuation plans for the immediate neighborhood. However, these evacuation plans were not publicized at the time, although thousands of people could have been killed in a potential
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LeMessurier agonized over how to deal with the problem. If the issues were made known to the public, he risked ruining his professional reputation and causing panic in the immediate area surrounding the building and the occupants. LeMessurier considered never bringing the issue up, and he also
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from quartering winds, finding them higher than the maximum expected stress values provided to her by LeMessurier's firm. Hartley asked her contact at the building design company, Joel S. Weinstein, a junior member of its staff, about the issue, and he provided her with a copy of the firm's
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underneath the centers of each of the tower's edges. (Early plans called for the supports to be placed under the tower's corners, but the agreement with the church prevented that.) To allow this design to work, Bill LeMessurier specified that load-bearing braces in the form of inverted
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described the student as a "young man, whose name has been lost in the swirl of subsequent events" who called LeMessurier saying "that his professor had assigned him to write a paper on the
Citicorp tower". However, it was clear that Diane Hartley had never contacted LeMessurier
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In June 1978, LeMessurier was answering questions via phone with a young architectural student, self-identified more than 40 years later as Lee DeCarolis. Those phone calls and the bolt substitutions convinced him to recalculate the wind loads, including the diagonal wind loads.
253:. Davenport's team conducted calculations on the building and concluded not only that LeMessurier's modeling was correct but also that, in a real-world situation, member stresses could increase by more than the 40 percent LeMessurier had calculated. LeMessurier then went to his
25:
Citigroup building with a sketch of internal framework superimposed on one side. The same design is used on all four sides and transmits wind and gravity loads to the four support stilts. There is also a fifth support column in the
408:: Kremer argues that concealing the crisis for almost 20 years prevented some of the ethical and engineering analysis and learning that could have taken place if information had been released about the Citicorp Center case.
350:
Steve
Silverman. By that time, LeMessurier had died. While he had mentioned his role to acquaintances and even written a play about it, DeCarolis revealed himself to the public at large only after a reassessment by
121:
St. Peter's
Evangelical Lutheran Church is visible on the left-hand side, below the skyscraper. The church's location necessitated the unusual placement of columns in the center of each face instead of at the
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joints. To save money, Bethlehem Steel proposed changing the construction plans to use bolted joints, a design modification accepted by LeMessurier's office but unknown to the engineer himself until later.
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before anyone else found out about the defect. LeMessurier ultimately contacted Stubbins's lawyer and insurance carrier. LeMessurier then contacted Citicorp's lawyers, the latter of which hired
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with a 400-ton concrete weight floating on oil to counteract oscillation movements. It was the first building that used active mechanical elements (the tuned mass damper) for stabilization.
69:, Diane Hartley, investigated the structural integrity of the building and found it wanting. However, it is not clear whether her study ever came to the attention of LeMessurier, the chief
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Construction crews started installing the welded panels at night in August 1978. Officials made no public mention of any possible structural issues, and the city's three major newspapers
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had determined that the wind loads had not been the threat that Hartley and LeMessurier had determined, stating that he could therefore not be accused of seeking or stealing glory.
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Concerned about "quartering winds" (wind directed diagonally toward the corners of the building rather than perpendicular to a wall) an undergraduate engineering student from
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experiments. He concluded there was a problem. Worried that a high wind could cause the building to collapse, LeMessurier directed that the building be reinforced.
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At around the same time as Hartley was studying the question, according to a 2022 article by Lee DeCarolis, who in 1978 was a first-year architecture student at
42:. Workers quietly made repairs over the next few months. The building, now known as Citigroup Center, occupied an entire block and was to be the headquarters of
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the tower was estimated to be able to survive a 200-year storm. Ella eventually turned eastward and veered out to sea. The weather watch ended on September 13.
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about Citicorp Center's design at the suggestion of her professor, David Billington. As part of that work she analyzed the structural design and calculated
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206:. Such winds are normally the worst case, and typically a structural system capable of handling them can easily cope with wind from any other angle.
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392:: In press interviews and releases of information at the time, officials either omitted or lied about details of the defects. Kremer cites the
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Implications of a Major Urban Office Complex: The Scientific, Social and Symbolic Meanings of Citicorp Center, New York City – V. 1 and 2
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NIST recommended reevaluation was ever conducted, although the question is only an academic one, since the reinforcement had been done.
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in sections and assembled on-site, requiring five joints in each brace. LeMessurier's original design for the chevron load braces used
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965:"At New York's Citicorp Center, a structure of masterly invention underlies the urbane face of a skyscraper in the grand manner"
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In May 1978, after the building structure was completed, LeMessurier was designing a similar building with wind braces in
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396:(NSPE) Code of Ethics, which says engineers shall "Issue public statements only in an objective and truthful manner."
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was hired for the welding process. Very few people were made aware of the issue, besides Citicorp leadership, mayor
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554:"Wind Effects on a Tall Building with Cross Section and Mid-size Base Columns: A Database-assisted Design Approach"
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Since no structural failure occurred, the work was not publicized until 1995, when a lengthy article appeared in
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as an expert adviser. Citicorp accepted LeMessurier's proposal to weld steel plates over the bolted joints, and
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The city had plans to evacuate the Citicorp building and other surrounding buildings if high winds did occur.
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For his original design, LeMessurier focused primarily on the wind load on the building when the wind blew
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Hartley identified herself as the probable engineering student in 2011, more than fifteen years after the
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be stacked above the stilts inside each face of the building. These braces are designed to distribute
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Access Restrictions: Walk-in Access. This thesis can only be viewed on computer terminals at the
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437:"William LeMessurier – The Fifty-Nine-Story Crisis: A Lesson in Professional Behavior"
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900:. Old York Foundation Distributed by David R. Godine, Publisher. p. 116.
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719:"Manhattan's Fifth Tallest Building Is Designed for Energy Conservation"
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130:, originally known as Citicorp Center, is a 59-story skyscraper at 601
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Park, Sejun; Duthinh, Dat; Simiu, Emil; Yeo, DongHun (March 6, 2019).
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1978 discovery of a major structural flaw in a Manhattan skyscraper
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692:(5th ed.). New York: Oxford University Press. p. 320.
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during the retrofitting, but it changed course before arriving.
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created by the wind from the upper stories down to the stilts.
1426:"Citicorp Tower Gets More Steel Bracing As Added Precaution".
802:. American Institute of Steel Construction. 1978. p. 17.
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Stern, Robert A. M.; Mellins, Thomas; Fishman, David (1995).
1312:"(Re)Examining the Citicorp Case: Ethical Paragon or Chimera"
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759:"Plan for Skyscraper On Lexington Ave. Detailed by Citibank"
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Ultimately, the retrofitting may not have been necessary. A
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and a column in the center, diagonal bracing which absorbed
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the repair costs, estimated to be several million dollars.
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Beyond Failure: Forensic Case Studies for Civil Engineers
1029:"The Design Flaw That Almost Wiped Out an NYC Skyscraper"
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summer home on July 28 to analyze the issue. With the
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The Ethical Engineer: Contemporary Concepts and Cases
638:. Emporis. Archived from the original on May 12, 2018
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170:. The building was dedicated on October 12, 1977.
38:, a skyscraper that had recently been completed in
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225:engineering student Diane Hartley was writing her
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1209:"Citicorp Building: Who Was the Mystery Student?"
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525:"Citicorp Building: Who Was the Mystery Student?"
435:Whitbeck, Caroline; Plosky, Eric (May 29, 1995).
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150:(later Citibank), along with associate architect
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529:Online Ethics Center for Engineering and Science
185:The long, multi-story diagonal braces had to be
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1131:. Princeton University Press. p. 82.
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686:; Willensky, Elliot; Leadon, Fran (2010).
614:"Citigroup Center – The Skyscraper Center"
483:LeMessurier, William (November 17, 1995).
394:National Society of Professional Engineers
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1583:Postal, Matthew A. (December 6, 2016).
1508:Delatte, Norbert J. (January 1, 2009).
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896:Alpern, Andrew; Durst, Seymour (2011).
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489:MIT Mechanical Engineering Colloquium
1565:Morgenstern, Joseph (May 25, 1995).
797:"Architectural Awards of Excellence"
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1668:1978 disasters in the United States
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570:10.1061/(asce)st.1943-541x.0002328
78:New Jersey Institute of Technology
14:
1684:
1653:History of structural engineering
1207:DeCarolis, Lee (August 7, 2022).
1004:Stern, Mellins & Fishman 1995
929:Stern, Mellins & Fishman 1995
884:Stern, Mellins & Fishman 1995
558:Journal of Structural Engineering
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447:from the original on July 9, 2021
363:According to a case study by the
93:A hurricane did threaten New York
1658:Ethics of science and technology
406:Advancing professional knowledge
365:American Institute of Architects
271:briefly contemplated committing
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1403:. August 9, 1978. p. 271.
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1027:Werner, Joel (April 17, 2014).
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493:National Academy of Engineering
142:. It was designed by architect
1430:. August 9, 1978. p. 15.
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113:Citigroup Center § Design
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1607:. New York: Monacelli Press.
1568:"The Fifty-Nine-Story Crisis"
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251:University of Western Ontario
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46:. Its structure, designed by
1310:Kremer, Eugene (Fall 2002).
209:
7:
1516:. ACSE Press. p. 340.
1415:– via newspapers.com.
1164:Hartley, Diane Lee (1978).
732:(4): 11, 61. October 1973.
384:Professional responsibility
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689:AIA Guide to New York City
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58:from upper stories, and a
656:: CS1 maint: unfit URL (
30:In July 1978, a possible
148:First National City Bank
146:as the headquarters for
1428:The Wall Street Journal
1190:Mudd Manuscript Library
1125:McGinn, Robert (2018).
978:(E3): 69. August 1978.
344:Einstein's Refrigerator
338:article was published.
34:flaw was discovered in
636:"601 Lexington Avenue"
372:Analysis of wind loads
247:Alan Garnett Davenport
156:LeMessurier Associates
123:
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1648:1978 in New York City
342:history from reading
152:Emery Roth & Sons
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24:
1213:Online Ethics Center
1172:Princeton University
1097:on November 12, 2020
972:Architectural Record
843:(October 12, 1977).
441:Online Ethics Center
326:. The 1995 story in
223:Princeton University
67:Princeton University
1401:New York Daily News
1324:(3). Archived from
277:Leslie E. Robertson
71:structural engineer
48:William LeMessurier
1673:1970s in Manhattan
1085:Vardaro, Michael.
851:The New York Times
763:The New York Times
292:had gone on strike
281:Karl Koch Erecting
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1585:"Citicorp Center"
1577:. pp. 45–53.
1523:978-0-7844-7228-6
1468:, pp. 52–53.
1285:, pp. 48–49.
1270:, pp. 47–48.
1240:, pp. 46–47.
1138:978-1-4008-8910-5
907:978-1-56792-443-5
765:. July 25, 1973.
699:978-0-19538-386-7
624:on June 15, 2012.
390:Public statements
359:Ethical questions
259:tuned mass damper
136:Midtown Manhattan
73:of the building.
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662:
661:
655:
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632:
626:
625:
620:. Archived from
610:
604:
603:
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599:
581:
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535:
523:DeCarolis, Lee.
520:
514:
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480:
457:
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432:
138:neighborhood of
132:Lexington Avenue
128:Citigroup Center
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1328:on May 23, 2007
1308:
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1123:
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935:
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878:
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834:
826:
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812:
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806:
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752:
742:
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681:
677:
669:
665:
649:
648:
641:
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633:
629:
612:
611:
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564:(5). New York.
550:
543:
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531:
521:
517:
502:
500:
481:
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448:
433:
420:
415:
361:
318:
268:
212:
199:perpendicularly
164:Bethlehem Steel
115:
109:
36:Citicorp Center
17:
12:
11:
5:
1686:
1676:
1675:
1670:
1665:
1660:
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1636:
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1613:
1596:
1580:
1574:The New Yorker
1560:
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1541:
1522:
1500:
1485:
1470:
1449:
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1388:
1371:
1354:
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1317:Cross Currents
1287:
1272:
1257:
1242:
1230:
1196:
1170:(BSE thesis).
1156:
1137:
1108:
1052:
1008:
1006:, p. 493.
996:
956:
933:
931:, p. 492.
921:
906:
888:
886:, p. 490.
876:
832:
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750:
705:
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663:
627:
605:
541:
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417:
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397:
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378:Design changes
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328:The New Yorker
323:The New Yorker
317:
314:
301:Hurricane Ella
267:
264:
221:In June 1978,
211:
208:
166:was the steel
160:James Ruderman
111:Main article:
108:
105:
15:
9:
6:
4:
3:
2:
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1551:, p. 51.
1550:
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1504:
1498:, p. 45.
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1369:, p. 50.
1368:
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954:, p. 46.
953:
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731:
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695:
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684:White, Norval
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534:September 12,
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349:
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305:Cape Hatteras
302:
297:
296:strain gauges
293:
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286:
282:
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256:
252:
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243:
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227:senior thesis
224:
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207:
205:
204:building code
200:
195:
192:
188:
183:
181:
180:tension loads
177:
171:
169:
168:subcontractor
165:
161:
157:
153:
149:
145:
144:Hugh Stubbins
141:
140:New York City
137:
133:
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119:
114:
104:
101:
96:
94:
89:
85:
83:
79:
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45:
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40:New York City
37:
33:
23:
19:
1602:
1572:
1544:
1532:. Retrieved
1511:
1503:
1427:
1421:
1409:. Retrieved
1400:
1391:
1386:, p. 9.
1330:. Retrieved
1326:the original
1321:
1315:
1233:
1221:. Retrieved
1212:
1187:
1180:. Retrieved
1166:
1159:
1147:. Retrieved
1127:
1101:November 29,
1099:. Retrieved
1095:the original
1090:
1043:. Retrieved
1032:
999:
987:. Retrieved
975:
971:
959:
924:
897:
891:
879:
867:. Retrieved
850:
835:
830:, p. 7.
823:
811:. Retrieved
791:
779:. Retrieved
762:
753:
741:. Retrieved
729:
725:
687:
678:
673:, p. 1.
666:
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630:
622:the original
617:
608:
596:. Retrieved
561:
557:
532:. Retrieved
528:
518:
507:– via
501:. Retrieved
488:
449:. Retrieved
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125:
97:
90:
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75:
64:
29:
18:
726:AIA Journal
316:Publication
82:wind tunnel
1642:Categories
642:January 1,
413:References
336:New Yorker
303:) was off
216:Pittsburgh
202:York City
187:fabricated
107:Background
56:wind loads
32:structural
1534:March 13,
1444:134301488
1436:0099-9660
1223:August 7,
1091:AIA Trust
1045:April 17,
916:722452921
859:0362-4331
771:0362-4331
598:August 7,
503:August 7,
348:podcaster
210:Discovery
1631:1130718M
1623:32159240
1528:Archived
1440:ProQuest
1411:April 6,
1405:Archived
1332:July 21,
1217:Archived
1182:July 21,
1176:Archived
1149:July 21,
1143:Archived
1039:Archived
989:July 24,
980:Archived
869:April 5,
863:Archived
813:April 6,
804:Archived
781:April 3,
775:Archived
743:July 21,
734:Archived
652:cite web
592:Archived
588:33642672
497:Archived
445:Archived
231:stresses
176:chevrons
122:corners.
44:Citibank
1559:Sources
579:7909585
509:YouTube
451:July 8,
285:Ed Koch
273:suicide
266:Repairs
249:at the
134:in the
26:center.
1629:
1621:
1611:
1520:
1442:
1434:
1135:
914:
904:
857:
769:
696:
586:
576:
262:year.
191:welded
52:stilts
1588:(PDF)
1034:Slate
983:(PDF)
968:(PDF)
807:(PDF)
800:(PDF)
737:(PDF)
722:(PDF)
255:Maine
1663:Wind
1619:OCLC
1609:ISBN
1536:2019
1518:ISBN
1432:ISSN
1413:2021
1334:2021
1225:2022
1184:2021
1151:2021
1133:ISBN
1103:2020
1047:2014
991:2021
912:OCLC
902:ISBN
871:2021
855:ISSN
815:2021
783:2021
767:ISSN
745:2021
694:ISBN
658:link
644:2021
600:2022
584:PMID
536:2024
505:2022
453:2021
353:NIST
158:and
126:The
100:NIST
976:159
574:PMC
566:doi
562:145
1644::
1627:OL
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993:.
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660:)
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602:.
568::
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511:.
455:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
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