Check this thing out! The piece is four feet tall and 51 inches long. Incredible.
From the video description:
Battleship train ship model with cannons and lasers that fire. It has many handmade moving parts that are driven by a live steam engine. The video is a depiction of it's first trial run, with some animation and effects thrown in. It was made from over 50 found parts and took over 2500 hours to construct. Except for the steam engine, which was modified, it is totally hand built using ordinary home tools.
Here is where you can see and learn more about the Steampunk Machine "Barnum's Dream".
[ Thanks Willem!]