Self-Contradictory Structural Decoration

I thought I was done looking at the Pearl Street bridge that is part of the Brooklyn Bridge approach, but apparently not.

This is another view of the new steel of the arch structure that was installed to resupport the original truss bridge. The big beam at the bottom and the two diagonal braces above it are all “new,” which is to say twentieth-century additions to the original 1880s steel. The cut-outs in the webs of these three pieces of steel are, as I mentioned before, purely decorative and meant to visually invoke the lacing of nineteenth-century built-up steel members. So far, so good meh.

The vertical plates projecting from the big beam’s web and from the gusset plate above, where the braces are attached, are stiffeners, there to make sure that compression in the web and gusset plate from the bracing connections don’t cause local out-of-plane buckling. This is good design. However, those stiffener plates are welded, which is twentieth-century technology. Similar stiffeners in the nineteenth century were angles riveted in position.

In other words, the proper parts of the steel design clearly show their era of construction, directly contradicting the nearby attempt to make the steel look oldey-timey. I’ve argued against “structural honesty” as a concept in architecture, but I’m also arguing against decorating structure. Structure is there to do a physical job and it should neither be decorated nor fetishized: in buildings it is mostly covered by “architecture,” which is to say the portions of the building designed for human comfort and use rather than simply resisting gravity and other forces. In this example, in a bridge, the structure should have been left alone to appear as what it is, a mid-1900s intervention on a late-1800s truss.