Something I said yesterday seems to have struck a chord. The last paragraph of yesterday’s post was “The most important advice I can give about dealing with oddball structure like this is to assume the people who built it were at least as smart as you. They had good reasons for doing what they did, just like you do. It’s your first job, today, to understand what they did. Then you can assess if their work is okay or not.” David West felt that thought was worth more discussion, so here we are…
Engineers today have a large assortment of tools available to us. There are many different forms of structural analysis, design, and drafting programs available – not just different programs but different types of program. For example, thirty five years ago I set up a spreadsheet‡ to perform moment distribution, which is a crude tool by current standards, but a useful check on more polished and more advanced forms of frame analysis. We have many material choices – off the top of my head, I’ve used natural lumber, manufactured lumber, light-gage steel, reinforced and unreinforced masonry, reinforced concrete, and structural steel in the last few months – all with well-defined‡‡ properties and libraries of details. We have instantaneous photos thanks to digital cameras, thousands‡‡‡ of material and procedure specifications from organizations like the ASTM, and databases to help us organize all of this information.
The picture above shows the sophomore class at Rensselaer Polytechnic in 1908, wearing what I assume are lab coats. They’re posed on The Approach, a monumental stair connecting the campus to downtown Troy; the big building behind them on the right is the Carnegie Building paid for by a donation from Andrew Carnegie, the big building on the left is the Pittsburgh Building paid for by a donation from, you guessed it, alumni from Pittsburgh. Maybe 20 percent of those men were studying civil engineering, and they were lacking most of the tools I’ve mentioned. They had structural steel, with eight-year-old ASTM specs giving some order to the material, and hand drafting, and hand calculations possibly aided by slide rules. The method of moment distribution did not yet exist, and while the theory behind finite-element analysis existed, the onerous amount of math it requires meant it was not used, leaving only the portal method for frame analysis. They were, compared to us today, quite poor in engineering tools.
Now, think of what engineers of that era accomplished with the poor tools they had: 1908 saw the completion of the 612-foot, 41 story Singer Tower. The Manhattan Bridge was in construction and would open the next year, carrying four subway tracks over a 1480-foot main span. The Hudson and Manhattan Railroad (now the PATH train) opened that year with underwater tunnels more than a mile long. Those three examples are projects that are still impressive today, and were performed with the primitive tools of that era. Or go back thirty years earlier, and think about the Brooklyn Bridge and the Tribune Building being constructed without electric lights available.
We think that our engineering is more advanced, and in terms of its theoretical foundations it is, but engineering has never been about just theory. Despite lacking the more than 110 years of research separating their time from ours, they accomplished great designs that are still in use today – not just the ones I mentioned above, which were built by older engineers than those in the photo, but literally thousands of other structures. They were ignorant compared to us, but, judging by their work, quite smart. I’d like to think that I could still design useful structures if I were deprived of all my modern tools, but I honestly don’t know.
TL;DR: Don’t ever assume that people in the past were guessing, or were dumb. They may have known less than us measured in the narrow sense of scientific theory, but they knew how to build great and safe structures with the theory they had. Respect that, and you’ll find it easier to work with their built legacy.
‡ I know, you should never use spreadsheets for engineering work. I learned that later.
‡‡ Some better defined than others.
‡‡‡ I don’t want to think about how many tens of thousands there are.
You must be logged in to post a comment.