1 The Citicorp Center Project: LeMessurier Stands Tall by Michael J. Vardaro, Esquire and Timothy F. Hegarty, Esquire When the Citicorp Center opened in 1978 it instantly became one of the defi ning icons of the New York City skyline. However, the engineering marvel had a dark secret—it would likely collapse if exposed to 70 mph winds. Once this secret became known, the structural engineer set into action a remarkable chain of events to stabilize the tower, preserve the client relationship, avoid litigation, and possibly save the lives of many. Perhaps even more remarkable is that all of this was done without the public’s awareness. What can be learned from what happened, and what never did? Introduction The Citicorp Center (now known as the Citigroup Center) is one of the most recognizable features of the New York City skyline.1 The distinctive 45° angled top rises 915 feet into the air. What many do not realize is that the base of the building is arguably even more distinct. The building sits 114 feet in the air, supported by an unusual placement of four huge columns centered, not on its corners, but rather on each of its sides that make the 59-story tower appear as if it is gracefully levitating above Lexington Avenue.2 The columns or stilts were anything but ordinary when they were designed to support what was then the seventh tallest building in the world.3 By all accounts, the use of the huge columns was a creative engineering marvel. However, they also led to a series of unforeseen events that nearly caused a catastrophe of monumental proportions. Capitalizing on good fortune, the disastrous end of a respected engineer’s career was avoided and, instead, his reputation was enhanced in the eyes of many. The story of Citicorp Center’s structural engineer, William LeMessurier,4 is both interesting and instructive to those in, or representing, the design industry. It is a lesson that demonstrates the need for proper communication, delegation, and supervision in the design process, and how risky legal strategies such as unequivocal forthrightness must be formulated without compromising an engineer’s ethical obligations. Michael J. Vardaro, LEED AP, is a partner with Zetlin & De Chiara and focuses his practice on construction litigation, drafting and negotiating construction contracts, and providing advice to architects and engineers. A former construction worker with a degree in civil engineering, Michael’s background gives him the ability to understand the intricacies and nuances of the construction process and to provide focused and innovative counseling. He is admitted to practice in New York, Florida, and New Jersey. Timothy F. Hegarty, a partner at Zetlin & De Chiara, focuses his practice in the area of construction law and litigation with an emphasis on construction claims, arbitration, mediation, surety law, and contracts. For more than 16 years, Mr. Hegarty has litigated many construction cases in federal and state courts and counseled owners, developers, construction managers, trade contractors and design professionals regarding the prevention and resolution of large construction claims for projects located across the U.S. and internationally. Since 2007, Mr. Hegarty has served as an adjunct professor at Columbia University in the graduate program in construction administration where he teaches “Legal Issues in Building Construction.” In addition, Mr. Hegarty is General Counsel to the American Council of Engineering Companies of New Jersey. Copyright 2011 by Victor O. Schinnerer & Company, Inc. 2 The Citicorp Center Design In the early ’60s, Citicorp’s headquarters, located at 399 Park Avenue, became too small for its continued growth and expansion plans. At the same time, St. Peter’s Lutheran Church was experiencing fi nancial diffi culties and began to consider selling its valuable property on the northeast corner of Lexington Avenue and 54th Street. The church was constructed in 1905 and was in need of serious repair. As fate would have it, the church was located across the street from the bank’s existing offi ces. Citicorp took notice and began planning to build a new building on the church’s block. The bank spent fi ve years and approximately $40 million to purchase all but one portion of the entire block.5 There was one important condition of the church’s sale of its property to the bank: the bank would have to build a new church on the same corner of the block with no connection to the Citicorp building, and no columns were permitted to pass through the new church to support the bank’s building. In the early ’70s, Hugh Stubbins was retained by the bank to be the architect of the new building.6 Hugh Stubbins started his fi rm roughly 20 years earlier and had already had experience designing high-rise projects when his fi rm was retained by Citibank. Stubbins’ fi rst high-rise building was the State Street Bank Building in Boston, which is also where Stubbins’ retention of, and relationship, with William LeMessurier as his structural engineer was solidifi ed.7 The conditions imposed by the church on the Citicorp project presented a signifi cant architectural and engineering obstacle to constructing a well-designed high-rise building on the site. Like many stories involving design professionals, this one also begins with a simple paper napkin. In a Greek restaurant close to his fi rm’s offi ces in Cambridge, LeMessurier pondered how to structurally deal with the inability to place columns in their traditional corner placement. He sketched a chevron pattern of structural bracing to transfer loads to columns placed at the mid- span of the building’s exterior walls. LeMessurier’s remarkable solution permitted each corner of the building to cantilever out 72 feet, which allowed Stubbins to delicately nestle the new church building into the northwest corner of the property. Put another way, the columns would act as stilts raising the building 114 feet in the air and, at the same time, provide the necessary clearance for the new church building.8 Although the 160-foot angled top was originally conceived to face west and provide for residential penthouse setbacks, the city refused to grant a permit for residential use.9 As a result, the confi guration was reoriented to the south to maximize the potential for generating solar power. Unfortunately, due to the lack of technological advancement of solar collectors at that time, the solar plan was abandoned. However, the unique angular top had become a signature of the design and it was retained by re-purposing it to provide space for most of the mechanical equipment. The Citicorp Center was completed in 1977, reportedly cost approximately $195 million, and at approximately 25,000 tons, the steel superstructure is considerably lighter than other skyscrapers of similar size. Due to the relatively light weight, a serious concern that LeMessurier addressed in the design phase was building sway. At the cost of $1.5 million, a “tuned mass damper” was installed in the angled top, which was the fi rst of its kind implemented on a building in the United States. This 400-ton block of concrete, which fl oats on a fi lm of oil, is computer- controlled to absorb the energy of the swaying structure and reduce the building’s movement due to wind by as much as 50 percent.10 At the time it was designed and installed, no one foresaw that the tuned mass damper would prove to be a signifi cant and valuable safety device during a tense period a year after the project was completed. The Citicorp Center Project: LeMessurier Stands Tall PROCEEDINGS OF THE 50TH ANNUAL MEETING OF INVITED ATTORNEYS 3 A Student’s Inquiry The plot to this story begins with an engineering student at Princeton University who was studying structures and the urban environment. The Citicorp Center was carefully considered by the student, Diane Hartley, and her professor, in her undergraduate thesis entitled, “Implications of a Major Offi ce Complex: Scientifi c, Social and Symbolic Implications.” In addition to allowing the preexisting church to remain in place, the innovative design also left considerable open space at the ground level enabling the height of the building to rise above what would otherwise be permitted by the zoning laws.11 In June 1978, Ms. Hartley contacted LeMessurier’s fi rm and she spoke with one of their junior engineers.12 Shortly thereafter, the plans and engineering calculations were sent to Ms. Hartley for use in her thesis. She performed her own calculations and discovered that quartering winds produced signifi cantly higher stresses than those produced by winds hitting just one face of the building. This structural behavior was different from a conventional building with columns placed at the four corners, where wind perpendicular to one face presents the worst loading case.13 Moreover, Ms. Hartley’s calculations suggested that the structural design was not suffi cient to withstand the quartering winds. Ms. Hartley questioned LeMessurier’s junior engineer about her fi ndings, but was assured that the building was “more effi cient” then her calculations suggested.14 Ms. Hartley submitted her thesis, which included both the inconsistency noted in her calculations and the response from the junior engineer. She was not the only one to question the calculations. Her professor, David Billington, also questioned this inconsistency in his comments on Ms. Hartley’s thesis.15 In deference to the reputation and expertise of LeMessurier’s fi rm, Ms. Hartley, who was an undergraduate student, accepted the response from the engineering fi rm.16 LeMessurier passed away in June 2007, and it is unclear exactly what portion of the exchange between Ms.