Far from the top expert here, or at all, LOL
Maybe it is a Carronade type Barrel? That is what it looks like to me. Carriage is likely someones homemade project it looks like. Maybe that Barrel should be in a more of a Naval type Carriage?
I find the boxes on the side interesting though. Maybe a older Hern Iron Works made Barrel?
I am sure others with more answers will be along.