Below is his steering which he experimented with windshield wiper motors, fan motors, water pump bearings, and other auto 12 volt motor applications. Using automotive parts and electrical components works well for this size tug. Understand that using the electric outboard motor is not for the faint of heart to design and build.
Below, the latest from "ABB" Azipod. . .for real tugboats: 2016
Below is the work of master craftsman, "BJ". He used the tugboat tracing drawings from the site here and changed the stern to match his "Inspiration Tugboat" that he is modeling. He designed steering gear for the installation of his 50 bound thrust electric outboard motor.
To watch the "Mary Ann" in some rough water CLICK HERE. Note that the video camera has made the tug look much shorter that it is. This tugboat is 65 inches long. . .
Above, I worked with "Bilge Pumps" for a couple of years. They work out just fine for thrusters. Below, is the tried and true running gear setup. A little "spendy" but excellent control and pull. Twin 800 motors, 3 to 1 reduction from "Harbor Models.com".
I'm building this site as I type away here 06/06/16
Below is "Doc's" tugboat the "Mary Ann". Click on the picture to watch it cruise the pond. Doc used an electric outboard motor, steerable "pod drive" he also modified. 55 pounds thrust.
Above is a "Steerable Pod Drive" made from an "electric outboard motor". Any brand will do that has at least 40 pounds thrust.
Right after, "where will I build and keep my tug", come the questions, "how do I build my tug" and
"what kind of motors do I install?" To this day, and after building five tugs, I still deal with these three
stages of building and so I understand your asking the questions. Let's talk "running gear" for your tug.
Because this tugboat design is large, it is very forgiving with regards to what ever kind of motors and running gear you choose. It will accommodate conventional drive, that is, single screw and any kind
of motor you choose. Auto fan or Air Conditioning motors, robot motors, and model motors if they are large. Series 800 motors at a minimum. Below is a picture of a single screw fine old tugboat's bottom stern.
11/07/16 For a free drawing plan of the keel, PDF #1 of 7, email me anytime, Michael, at: email@example.com