Towmasters has a post up: Extreme ATB’s: Towing Vessels Or Something Else?
I can answer this. It is not a tow vessel, it is the house and engine room of a ship. Basically the designers and builder of this vessel have built a ship, broken it in half and then made arrangements to pin it back together. The reason they did this was to dodge regulations. The question is why does the Coast Guard approve it?
Crowley's AT/B - Rule Beater