Tubby Tug by Bill Hodgdon, Strafford, New Hampshire

June 25, 2009

This recently completed project (Launched Aug 1, 2008) involves a modified Tubby Tug, which is different from the standard version in that it is electric power, has a folding top, and a fantail stern.

I have built about a dozen boats, the first being a Glen-L Squirt in 1960 with my Dad. I was also a draftsman and later an engineer before I retired. I only point this out because the faintail stern modification I did, involved complex full-size lofting that I do not recommend to anyone without the experience to do so (not recommended for new boatbuilders). That said...here's my story.

My wife wanted a small electric boat to go out on the lake early in the morning as the sun rose, to watch the Loons, and just quietly look at the peaceful morning. When she asked me to build her one, I took her to the Glen-L site and asked her which of the special purpose electric boats she wanted me to build. Unexpectedly, the Tubby tug was also in that category, and she said for sure, that was the one she wanted. Unfortunately, we have a low bridge (42" clearance), so the top would need to be retractable, somehow (leaving the top off was not an option). My 88 year old Dad spent lots of time helping aboard the local harbor tugs as boy, and we both thought that even though it would make the job much more difficult, the transom should be a traditional fantail stern. (I think I spent as much time on the fantail stern as on the rest of the boat, all considered). Since there are many excellent articles on building the Tubby Tug, I will just focus on these different modified areas of my Wife's Tubby Tug.

A sketch on the study plans showed that the fantail stern was possible, and would not look unreasonable, so I proceeded to design a new stern for the Tubby Tug. This was done full-size on some of the plywood that would become the hull (and so there are no remaining plans for the design change). A quick check of moments showed that the two AGM batteries mounted at the front seat area would effectively offset the approximate weight of the new stern, taking into account the minor increase in displacement. The fantail was developed to be circular from directly overhead, with the hull sides and bulwarks being conical. Note that the circular appearing rings used to form the fantail are actually not exactly circular, since they are not in the horizontal plane. There is nothing truly circular in any of the framework for the transom.

So, the first set of parts were cut out from the plans and the lofting. The hull sides were scarf joined in lieu of using a butt block. It wasn't until after I took this picture that I realized I had made a little space man out of the parts...totally by accident. You can see many of the parts that form the fantail stern in this shot.

Here we have begun construction. The inclined bottom of the fantail stern begins where the true transom should be located. The rear seat supports are angled slightly to provide a better drainage to the center of the rear seat area, where a bilge pump will be located. (Length and side angle requires adjustment with this change). The rectangular center well for the trolling motor has a vertical forward face to allow retraction of the trolling motor for trailering or beaching. The motor and propeller will completely retract above the bottom of the boat. The front seat has been cut down for a cushioned swivel chair, and the forward front seat support has been moved forward to allow room for the AGM batteries to sit in a fore and aft orientation. This requires changing the forward seat supports to fit the hull in the new location. The front seat will swivel 360 degrees when installed, making it easy to get in the pilot house.

The lower ring has been attached to the normal Tubby Tug modified transom and will define the joint location between the hull and bulwark. The normal transom portions are actually angled back per plan, although they do look vertical here.

Here's another view for reference. The two stiffeners attached to the bottom are temporary.

Here is one-half of the fantail hull panel (they are butt block joined on centerline). The 5-ply 1/4" plywood was too stiff to bend around the curve without breaking, so 1/8: cuts were made approx 3/4" apart along the panel. Note that since this is a conical panel, the cuts are not parallel. (After installation, the grooves were filled with epoxy paste and then the panel was epoxy fiberglassed over.)

Here is the panel, clamped in place for a trial fit.

The fantail stern hull panels are installed and the ring that defines the top of the fantail bulwarks has been installed. You can see the white outlet for the bilge pump in this view. The hull panel overlaps the bottom here, and it has not been trimmed yet.

Now we have installed the fantail bulwarks as well. These panels also required relief cuts to prevent breakage.

Well, now it's beginning to look like a fantail stern!

This is a trial fitting of the cabin, note the cut off posts where gussets will be added for the cabin top pivots. The posts are all aligned fore and aft, not aligned with the cabin sides. Tapered shims were used for proper alignment. This is so there will be no binding when the roof pivots down.