Civil & Environmental Engineering

Professor Emeritus Robert J. Hansen Sc.D. ’48, whose Cold War research in atomic-bomb-resistant structures helped lay the foundation for the field of structural dynamics, has died at age 91. He was on the faculty of MIT’s Department of Civil and Environmental Engineering (CEE) for 27 years.

“Bob Hansen was a pioneer in bringing research grants supported by the [U.S.] Department of Defense to the MIT civil engineering department,” the late CEE Professor Robert Whitman said in a 2009 interview appearing in a publication of the Earthquake Engineering Research Institute. “This work was motivated by the challenges of defense against nuclear attack. It involved basic theoretical and experimental work at MIT and also designing test structures that were later exposed to nuclear explosions in Nevada and on Eniwetok Atoll in the Pacific. This was the origin of the important growth in structural dynamics work at MIT after World War II.”

Born in Tacoma, Wash., Hansen received his bachelor’s degree from the University of Washington in 1940 and headed to MIT for graduate school. However, he quickly changed plans and accompanied MIT administrator John Burchard to Washington, D.C., to join a program researching the effects of high-powered explosives on targets and developing resistant structures. After Hansen returned to MIT in 1945, CEE department head Professor John Wilbur asked him to spearhead a government study designing structures to withstand nuclear blasts. The two created a special testing laboratory for this purpose in the basement of MIT’s Building 1.

Hansen joined the CEE faculty in 1948 and continued to oversee the MIT-U.S. Army Corps of Engineers collaboration to design bomb-resistant military and civilian structures throughout the 1950s. This work provided the material for the groundbreaking 1959 book, Structural Design for Dynamic Loads, written by CEE Professors Charles Norris, Hansen, Myle Holley ’39, S.M. ’47, John Biggs ’41, S.M. ’47 and others.

In 1951, Hansen and a group of students spent several months on a tiny Pacific island preparing structures to be tested in an actual atomic bomb explosion. After the blast they collected and analyzed information on the remains of the structures. “This was the first experiment in which meaningful structural response results were obtained,“ Hanson wrote. “The results of the detonation on the Army structure were much in accord with the design planning.” For several years groups traveled to nuclear test sites to observe, record and analyze the blasts impacts on structures. Based on these data, Hansen and students prepared a design manual in the late 1950s, Design of Structures to Resist the Effects of Atomic Weapons.

Moving from blast-resistant structures to earthquake engineering

In later years, Hansen was instrumental in moving the emphasis of CEE research from bomb blasts to earthquakes. He served as editor of Seismic Design for Nuclear Power Plants (MIT Press, 1970), a collection of papers from an MIT conference focused on protecting nuclear plants from earthquake damage. MIT CEE went on to become a major player in earthquake engineering research.

In addition to his work at MIT, Hansen was a member of the consulting firm Hansen, Holley and Biggs Inc., which consulted on the construction of many skyscrapers and other large structures. The firm is often remembered for its work conducting tests that replicated the windows and tower of Boston’s John Hancock Tower after windows in the new structure notoriously began popping out and crashing to the streets below. The structural problems resulted in lawsuits and the results of Hansen, Holley and Biggs’ tests remain secret as mandated by the legal proceedings. In the 1970s, the firm also conducted a study of a radical new design proposed for the Standard Oil of Indiana Building in Chicago, which would become the tallest in the city. The study concluded the design was sound, and the work earned Hansen and colleagues the 1974 Moisseiff Award from the American Society of Civil Engineers. He retired from MIT in 1975.

Outside the field, Hansen was known by many for an essay he wrote with Holley for the July 1967 issue of Technology Review that recommended scientifically engineering smaller people to relieve the problems associated with population growth. Many readers responded angrily, and Hansen was amused that people didn’t recognize the work as satire. Summarized in another Technology Review column in its September/October 2011 issue, the essay roiled a much greater audience as it traveled around the Internet.

A resident of Winchester, Mass., for over 50 years, Hansen died on Nov. 30, 2009. He was survived by his wife, the former Eleanor Welch, who died in 2011, and two children, Eric Hansen and Karen Puffer.