Charles J. McMahon Jr., professor emeritus at Penn, veteran, author, and mentor, has died at 89

Charles J. McMahon Jr., 89, of Philadelphia, professor emeritus at the University of Pennsylvania, former chair of the school’s materials science and engineering department, veteran, author, and mentor, died Saturday, Dec. 10, at his home of complications after a fall.

Dr. McMahon was a leading authority on steel fracture, and his research led to construction and safety improvements in bridges, ships, and countless other engineering projects. He chaired Penn’s department of metallurgy and materials science, now the department of materials science and engineering, from 1987 to 1992, and spent nearly 40 years training two generations of undergraduate and graduate students, and postdoctoral fellows.

A pioneer of electronic and online learning initiatives, he created video lectures and animated tutorials that students used to augment his dynamic classroom instruction. Former students said he was inventive and creative in class, and taught them how to think, not what to think. One said Dr. McMahon smoothed over a rough patch in class by telling him: “I don’t care where you start out. I care where you finish.”

He attended conferences around the world and wrote many papers on the destructive effects of temperature, material embrittlement and cracking, and other topics related to engineering. He also published two text books, Introduction to Engineering Materials: The Bicycle & the Walkman in 1995, and Structural Materials in 2006.

He earned grants, chaired committees on the University Council and Faculty Senate, and wrote opinion pieces on athletics for Penn’s Almanac. He also spent three years on sabbatical research in New York, England, and Germany.

Among his many awards are the 1975 Marion Howe Medal from the American Society for Metals, the 1976 Mathewson Gold Medal Award from the American Institute of Mining, Metallurgical and Petroleum Engineers, and Penn’s 1992 S. Reid Warren Jr. Award and 2001 Lindback Award, both for distinguished teaching.

In 1980, Dr. McMahon was inducted into the National Academy of Engineering for his “contributions to the understanding and mitigation of grain boundary embrittlement of alloy steels.” He retired in 2002.

In a tribute, a colleague said: “Charlie had a knack for instilling such an absurdly high level of trust in you that you didn’t have any choice but to live up to it.”

Charles Joseph McMahon Jr. was born July 10, 1933, in Philadelphia. He grew up in Germantown and East Mount Airy, won a scholarship to La Salle College High School, went to Penn on a Naval Reserve Officers Training Corps scholarship, and earned a degree in metallurgical engineering in 1955.

He then served on the USS New Jersey and three years of active duty on the USS Thuban. Afterward, he received a doctorate in metallurgy at the Massachusetts Institute of Technology in 1963.

He met Helen O’Brien at the wedding of mutual friends, and they married in 1959, had daughters Christine and Elise, and sons Charles III, Robert, and David, and lived in West Mount Airy, Lafayette Hill, and Chestnut Hill. He became a postdoctoral fellow at Penn, joined the faculty in 1964, and was promoted to full professor in 1974.

Dr. McMahon was a lifelong physical fitness and sports enthusiast. He swam the backstroke for his high school and college swim teams, and worked summers as a lifeguard in Ocean City. He began rowing in college, resumed in his 50s, and stayed on the Schuylkill into his 80s.

He enjoyed plays at the Lantern Theater, liked to host parties at his home, and a colleague called him “thoughtful, amusing, and warm” and “a very special man, full of ideas and humanity.” He was a devout Catholic, a student of early Christianity and church history, and an advocate for the ordination of women, married clergy, and other reforms.

In 2011, he talked to The Inquirer about the Catholic clergy sex-abuse scandal and said: “The only way to get all of the facts out in the open is through discovery. And the only way to do that is in the courts.”

In 2022, he published The Rocky Road of Roman Catholicism: Women, Compassion, and the Salvation of the Catholic Church. In a tribute, his family said: “He will be remembered by family, friends, and colleagues for his lifelong commitments to charity, integrity, self-discipline, and to realizing a just and thriving society.”

In addition to his wife and children, Dr. McMahon is survived by two granddaughters, one sister, three brothers, and other relatives. His daughter Christine died earlier.

Visitation with the family is to be at 10 a.m. Saturday, Jan. 21, at Our Mother of Consolation Parish, 9 E. Chestnut Hill Ave., Philadelphia, Pa. 19118. A memorial service is to follow at 11.

Donations in his name may be made to the Lantern Theater Company, P.O. Box 53428, Philadelphia, Pa. 19105, and the Sisters of St. Joseph, Mount St. Joseph Convent, 9701 Germantown Ave. Philadelphia, Pa. 19118.