DB: Well, there's, first of all, the geology of the foundations which indicate that in order to build the bridge economically, one wants to get the towers out of the main channel and out of the deep water. They will be much more easily built. So there was a basic reason for making a span of the order of 3,000 feet. That's the first and more or less basic idea. The second idea which Ammann spoke about was the fact that by having the back spans short, that aided in stiffening the main span. That was a consequence, I believe, of the geological reason for moving the, moving the, the towers out widely. So I think the first reason is because of the channel, but a, a second reason is because it does provide more stiffness.

DB: Ammann chose the dimension of 3,500 feet not on the basis, I believe, of strictly rational factors. The span had to be of that order, clearly, but the fact that 3,500 feet was exactly double the span of the Delaware Memorial Bridge, then the longest spanning bridge in the world when he set out to design his bridge, seems to me to be a determining factor in the exact number he chose. It's a little bit like the Eiffel Tower, which is exactly 300 meters or, later on, Ammann's decision to make the Verrazano Bridge just 60 feet longer then the Golden Gate Bridge or the Bayonne Bridge just 2 feet longer than the longest spanning arch then, which would have been the Sydney Harbor Bridge. So I believe engineers are motivated in this kind of effort by certain emotional factors. It is, after all, world's records and world's records are usually set by small differences and that means that this was not out of the consciousness of the designer when approaching such things. But surely the Golden, the George Washington Bridge is unique not just in being the longest span, he would have had that with 3,400 feet, but in picking this exact number.

DB: The towers of the George Washington Bridge are surely unique. My own view of them is that it was basically a mistake to design them in that way. That is to say, to conceive of them as masonry towers built, in fact, structurally as steel towers. So that had they been covered, I think they would have, it would not have been as striking an effect as could have been done, as Ammann did do in his later bridges when he accepted the discipline of steel and then attempted to make them and did make them quite elegant. George Washington Bridge, as it is now, uncovered, the towers are surely very strange. There's no other suspension bridge in the world that has towers that are even close to looking like the George Washington Bridge. Now, of course, we're used to it. It's an old friend, and, therefore, since the bridge is a marvelous bridge in any case, I like it. But if you ask me is it appropriate, is it really an esthetic delight, those towers, I say no, it is not. They are not that, they are not at that level. They are not like the Brooklyn Bridge towers, which we know to have been appropriate from a constructional point of view. It's not like the Verrazano Bridge towers, which are appropriate from a design point of view of taking the material steel and doing something with it in a very simple, spare, but quite elegant way. So I think Ammann in a way was his own best critic. His later bridges, the towers of the Bronx-Whitestone and the Verrazano Narrows Bridge, are the best critique we have of the towers of the George Washington Bridge.

DB: There seems to be some kind of contradiction between the fact that starting with the George Washington Bridge and moving up all the way through to Golden Gate and so forth, there were these very large projects, and in New York also other projects, infrastructure projects, built at a time of depression, of economic depression. But I think there's, at least from the point of view of New York, I think the argument is, is better understood if we realize two things. First of all, that works like the George Washington Bridge, the Bayonne Bridge were all conceived, planned, and financed in the '20s, before the Depression. So that's one aspect. Even the Empire State Building is part of that same thing. That's one aspect of it. The other aspect is that the bridges we're talking about were toll bridges. Therefore, they were conceived of in a new way. It really wasn't as if somehow the government was pouring money into it, although they did pour lots of money into certain things, but at least in these bridges they were supposed to be self-sufficient. And initially they showed themselves to be very profitable. Of course, as the Depression wore on, they did have difficulties, but at the same time it was the concept that they would be toll bridges, that they would retire the bonds, that they would be done by an authority which was removed from the basic municipal issues that had clouded design and had, in the minds of many people, made government seem to be inefficient in these things. So new mechanisms went together with that, such as TVA, Bureau of Reclamation. So even though money was poured into them, they were special mechanisms removed from the direct political control of local bodies and even the Federal government.

DB: The failure of the Tacoma Narrows Bridge in late 1940 was surely a shock to the engineering profession. There was little preparation for that. Indeed, the year before, Leon Moissieff, the designer of the bridge, had written an article with a title something like "We Know So Much Now About Suspension Bridges." It was a very positive article and it indicated the confidence of the profession and all the major designers, Ammann and Steinman and Moissieff, all of them had been designing bridges in this same mold. Moissieff was just the unluckiest of the group. So it was a, a great shock, a great surprise.

I don't know Ammann's immediate response, but surely we know his basic response because he was one of the three people chosen to write a detailed report of the failure of the Tacoma Bridge. And his response was that, of course, all of these bridges had been designed under the wrong ideas about wind. And he even went so far as to indicate that the George Washington Bridge has started that trend. And he even noted, when asked, that he would "do it differently today," he said. He didn't say exactly what he meant by that, but we know what he meant by that because we know how he designed the Verrazano Bridge and it is different than the way he designed the George Washington Bridge and it is very successful from that point of view. So his response was, of course, based on a very careful study of it and, in particular, based on the work of Professor Farquharson at University of Washington Seattle, who took, it seems to me, the exactly correct approach. And what Farquharson did in his report was to start with a detailed study of all those 19th-century bridges that had failed and he called the attention of the profession to the historical record and implied, and even stated, that had they known the record, had they realized that the Brighton Chain Pier and the Menai Straits Bridge problem, not total failure, but problems, were of a very similar nature to the problems of the Tacoma Bridge, had the profession realized that, they would have thought differently about these early designs.

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