This is a temporary (I think) trestle built for a municipal drainage project about one block inland. Trucks bring the debris from the project down to land end of this trestle, behind me in this view, where it is loaded on a small hopper car similar to what you would see in a mine. The car then clanks, literally, out to the end of the trestle where the contents are dumped into the ocean with the assistance of the crane which you can see here. I estimate the trestle is about 300 yards (275m.) in length.
(Submitted to the 2013 September TTT contest as entry #134.)