Smithfield Street Bridge Sculpture

When making photos of the Smithfield Street Bridge, I was surprised to find the metallic sculpture below incorporated into one of the steel beams.  I have been across the bridge in my car many times and had never noticed it.  I guess that is what photography is supposed to do.....make one see clearer and deeper! I have been trying to learn more information about this sculpture and what it represents, but no luck thus far.....

Sculpture On Smithfield Street Bridge

Copyright Howard Grill