The steam paddle wheeler Portland, that is currently moored by the seawall at Tom McCall Waterfront Park, was used for many, many years as a tug. Now it serves the community as a really wonderful maritime museum, but it wasn't too very long ago it was a river work horse. The ships that load at O Dock (the grain dock by the Steel bridge, AKA LDC or Globe) need to be turned around in the wide section of the river between Alber's Mill and Irving Dock. They need to have the "pointy end" turned so it will be aimed down river when the ship goes under its own steam.
One day in the 1980s my brother gave me a Polaroid camera for my birthday. I happened to have it with me one day when I was working at LDC (as it was called then). The ship was being moved by tugs, including the tug Portland. It occurred to me that this tug might not be used very much longer, so I went to various places in the elevator and snapped away. These pictures I thought were lost in the river of time, like so many other things, but the other day my dear daughter brought over some albums for me to scan and—hurray!—my old Polaroids!