Tiny Tug

The Little Tug

The first iteration of this design looked like this,

It was obvious to me that there was too little bearing aft to make this a successful little tug. Working from the original concept I redrew the lines to give the boat more bearing aft, to place the center of the deeper box keel under the steering position and give a little more room for the propulsion system.

The original lines lines looked like this,

The redrawn lines like this,

As you can see the stern is wider as is the box keel, there is more bulk in the box keel closer to the fore and aft centre of the boat giving more space for the propulsion system.

We discussed the propulsion system here  and here . The little tug with the propulsion system fitted looks like this,

The two wheels at the helm station control the direction of travel, the smaller wheel controls the forward and aft motion of the Kitchen rudder clamshells given reverse, neutral and forward and the larger wheel moves the rudder arm from port to starboard. Here is the rudder layout.

You can see from this drawing that the bulk of the box keel falls right under the helmsman, the towing point and the motor.

Here's the tug in profile and plan. I'm pretty happy with it.

In the Kitchen

In the Kitchen

Rather than go one at great length about how the Kitchen rudder actually works you can actually see the operation of it here and here.

Why I am so enamored of the Kitchen rudder? Because it gives you twin engine manoeuverability with a single engine, watch here. The vessel you see in the video is single engine and the inner wheel in the wheel house controls the angle of the Kitchen rudder and the outer wheel is the helm or steering wheel. You can only get that sort of manoeuverability normally in a twin screw vessel with opposed outward turning wheels.

For that reason the Kitchen rudder eminently suited to our small tug not only can you run the engine a constant level of revolutions but you can vary the speed, stop within a boat length and quickly manoeuver to avoid girding or girting. (depending upon where you are in the world)

The controls for the Kitchen rudder could be hydraulic, Bowden or Morse cable or line on a drum. For one of my designs, much larger that the little tug, I designed an hydraulic system. However for the little tug a simple drum and rope system is more than adequate.

More on the little tug to come.