Enrique Aragon interviews Thomas C. H. Lum
Enrique Aragon is a CEE senior with a primary in construction management and a secondary in structural engineering. He is a tutor for CARE and the engineering council representative for the student chapter of the Structural Engineers Association. Aragon has interned at Tribco Construction Services as a field engineer. Tribco is a concrete subcontractor in Chicago, and Aragon was working on a residential high-rise building in Lakeview during summer 2016. Upon graduation, he will be working full-time with Tribco Construction Services.
Thomas C. H. Lum (MS 59) is a retired structural engineer whose career involved serving in the U.S. Army and private practice. His projects included working on the team that designed the first Polaris missile submarines and serving as lead engineer in the design and construction of the memorial over the wreck of the USS Arizona in Pearl Harbor. In addition to his degree from Illinois, Lum holds a bachelor’s degree in architecture from Washington University in St. Louis and did additional graduate work at the University of California at Berkeley and at George Washington Unversity.
Please tell me more about your background and how you got interested in Civil Engineering?
I was born and raised in Hawaii and served in the army before attending college. I graduated from Washington University, St. Louis, Mo. with a degree in Architectural Engineering. Upon graduation, I was employed by an architectural company is St Louis. With apparent good grades in structures, I was asked to work in the special structure division of the company. The work was highly unusual and required a thorough knowledge of energy methods for solving problems.
After two years, I returned to Hawaii and was hired as a Naval Architect doing structural work on Naval vessels. I was then sent to the graduate school at the University of California at Berkeley to study ship design, with the emphasis on submarine design. I was then sent to Washington, D.C., to work on the design of the first Polaris Missile submarine. I was also sent to the graduate school at George Washington University, for further studies in structures.
It was then that I decided to attend a graduate school to work on a degree in structures. It was now June; I had a discussion with my professor on which graduate school. It boiled down to three schools; Massachusetts Institute of Technology, Stanford University and the University of Illinois at Urbana-Champaign. Although it was June, he promised to get me into all three schools. He kept his word.
How did you come to pick Illinois to get your master’s degree?
I now had a very difficult decision: Which university? I finally decided on Illinois. I decided to get married just prior to leaving for graduate school and selected Illinois because of the curriculum and research facility; there would also be no other distractions. My new wife was also able to get a teaching job in Urbana.
How did that decision to come to Illinois impact your career and your life?
In retrospect, I strongly believe that was the best decision I have ever made. The education has enabled me to achieve a lifetime of many accomplishments.
What is the most memorable project you have been a part of during your career?
The most memorable of all projects was the Arizona memorial in Pearl Harbor, Hawaii.
Describe how you first approached designing the memorial for the bombing of Pearl Harbor.
It was less than six months after I had received my M.S. from Illinois. Fortunately, I had acquired knowledge of prestressed concrete – pretension and post-tension – and behavior in research at Talbot lab. Bear in mind that prestressed concrete had only been introduced in the U.S. about four years prior to my studies at Illinois. When this project was proposed, I was only a junior engineer. Fortunately, only a few in the company had knowledge of prestressed concrete. The design indicated that prestressed concrete was the only possible solution.
What aspects of the design were most important to you?
The memorial would be straddled over remains of the battleship and supports could only be placed clear of the remains; a clear span of 110 feet. In addition, the memorial would be cantilevered 37 feet from both supports – a total of length 184 feet.
What aspects of that project were the most challenging?
The foundation was a problem. The water depth was about 40 feet. There was soft mud for another 40 feet with denser mud for another 40 feet. The mud was stiffer after that depth. Also, there was no bedrock or coral.
Pretensioned, prestressed concrete piles driven to a depth of about 150 feet were used for the foundations. Sample piles were used to have loads tested to 200 percent of design capacity. Some piles were battered. The main supports for the structure were two post-tensioned and grouted girders spanning the entire distance. These girders support the entire concrete structure. The girder and foundation design were the most important ingredients in the design. The memorial has since been remodeled and celebrated its 50th anniversary in 2012.
Are there any other projects you’ve worked on that you’re particularly proud of?
I have since done many other structures, including high-rise buildings, freeway viaducts, airports, etc. Completing these projects has been very satisfying.
What advice would you give students in CEE at Illinois today?
The only suggestion I would give to students is: to solve any problem, always ask yourself: “What do I expect for an answer?” Doing the calculations is only to confirm your expectations. If it doesn’t you must ask yourself, “WHY?”