It is stunning to see a machine in the Civil War that embodies all the elements still used in dredges today. The vertical timbers are called spuds, which are lowered to the bottom to hold the machine in place. There were three of them, one at the stern (right end of photo) and two port and starboard at the bow, only one visible. Same as today. The angled timber at the left is the dipper stick, which has the bucket or dipper at the other end. Note the gear teeth for the bucket crowd.

It's a steam shovel, very like the ones that built the Panama Canal.

I believe that's the monitor USS Onondaga in the upper right. Your earlier post shows what could possibly be a wrecked ship on the river bank (look over the stern). Could these two photos be from the same area of the James River on the same day?

[The sunken ships look to be two different boats. - Dave]

I am wondering where this picture was taken. The tower in the top left corner of the picture seems very unusual. It hardly resembles any type of structure that I have seen in other pictures taken during the Civil War.

Can anyone help identify this structure?

[It's a signal tower. Made of wood, not steel. Click below to enlarge. - Dave]

My guess is the square "pole" in the rear is cranked down to anchor the stern of the dredge in the while the front end scoops.