As I mentioned in my earlier post, (see July 18, 2008 post), in 1971 I was a design development draftsman working at Yamasaki's architectural office in Troy, Michigan...forty years ago now. I was honored to be working for such a distinguished firm bursting at the seams with talent and creativity. I am still proud to have been part of that team. It was an exciting time.
One of the assignments I had at that time was to detail the study drawings for the aluminum cladding system for one of the other projects* awarded the firm after the WTC. These projects shared many of the fenestration design features used on the WTC. The elaborate aluminum cladding system, (elaborate because it performed a three-dimensional seal between the glazing, spandrels and other finish materials that expanded at different rates based on thermal variables, while still providing weather integrity and effective moisture drainage). It was an elaborate detail, yet functionally effective and beautiful at the same time.
In retrospect, I remember questioning the direct connection detail of aluminum to steel, and aluminum to concrete, that was, apparently going to be used on these new projects. This was a detail that flew in the face of everything I knew about the reaction that occurs between disparate metals, like steel and aluminum. That is, an electro-galvanic reaction which will corrode and ultimately compromise the strength of the connection over time as oxidation takes place. I asked several of the senior architects and even brought it to the attention of the department head. My questions were not answered, really, and If I recall correctly, I was told that it would not be a problem because it had been tested in other structures and was a non-issue. Perhaps, ultimately, the aluminum-to-steel connection detail was not used on the project I was working on--I never saw the shop drawings or inspected the actual field connection. Nevertheless, I left the firm a few months after that, (not for that reason but for other personal reasons--I wanted to travel the U.S.).