Thank you for the link! We have fishing tugs leave here daily now that the ice is thinning up and some nights they dont come back. With the state of most of there equipment and lack of liferafts always makes for discussion as to where they are. I was under the impression that fish tug came from the fact that the builders used a tug based hull and added a fishing superstructure to the top. This is the same boat.
That is my "tug" as a fishing vessel then to give it perspective this is what it looks like as a "tug". It has an ice-breaking bow with an angle to climb the ice and thicker steel.
And if the cabin was shorter it would look very much like a tug. It was built to look like a common tug of the early 1900s. She was built in 1934. Worked until the 80s then became this.