What The Heck Was Floating Down The East River On Barge Sunday Afternoon – A Space Capsule, Submarine Part, Underwater Turbine?

Roosevelt Island resident Dave Rosenberg noticed something unusual being barged down the East River Sunday afternoon. Mr. Rosenberg shares this photo he snapped

Image From Dave Rosenberg

and asks:

What the heck is that?

Any ideas?
Here’s more East River Traffic from previous posts.