The Walkway to the Lower Level

A couple of weeks ago, I tried sketching a portion of the towering columns and the arched ceiling in Grand Central Terminal.  This time, I became ambitious to sketch a little bit of Grand Central Terminal.  This was at the walkway to the Lower Level.  Since I started the sketch a week ago, I've added three more sittings for the 10-15 minutes I have left before catching my train home.