RE: tug
There was an article a long time ago that detailed a recovery boat. It consisted of 2 elongated hulls set up like a " U " with an electric motor drive system in each. No rudders just controlled each motor independent of one another. The hulls could be adjusted in width.
You could build a barge like this also and push it with just about any tug.
A little foam for padding might be a good idea.
Mike