In 1978, Doug Aron, founder and President of Shipwrights Inc., designed a Bow Thruster
suitable for small craft. Motivated by the need for a small, but powerful unit for his own
boat, and an engineer in his own business since 1968, he created the original TwinProp
Thruster. Designed to be hydraulically driven at a continuous 5 hp in a 6
inch tunnel, this thruster was the first commercially available thruster to realize the
advantages of two propellers. Operating in an 8 inch tunnel, it has been transmitting up to 50 HP since 1990. 10 and 12 inch tunnel sizes are available as an option
in the original TwinProp series.
In order to reach 50 HP, the thruster was continuously improved and tested in our own facility, using diesel hydraulic power sources and our own custom test tank. Our test tank is fitted with a strain gauge connected to a digital indicator which gives us thrust readings. Our power source is monitored with other instrumentation which indicates HP. Other infrastructure involved in the process is our CNC Machining Center and CNC Lathe and 4 CAD and one Cam System.
Due to the evolutionary process of development that refined our thruster, a significant advantage was created that has yet to be duplicated by our competitors for a thruster with a 50 hp capacity rating. This is a remarkably small obstruction to flow in an 8" tunnel capable of 50 hp. Our 8 inch thruster blocks only 27% of the tunnel cross-sectional area.
Our thruster has gone through 31 years of continuous development and is many times stronger than other units in its size range, proven by its ability to transmit horsepower.
If this is compared to our competitors, it will dramatically show one of the many reasons our 8 inch unit has been successful in installations aboard vessels up to 100 feet in length, operating at up to 50 HP. Our 6 inch thruster has been successful in installations aboard vessels of up to 50 feet in length operating at up to 25 HP.
Many of the other reasons for our success are related to subtleties in the relationship of propeller pitch, diameter and RPM developed in our laboratory. This information is proprietary and is partially responsible for the fact that there are no other thruster products on the market that can reach the level of power our units demonstrate for a given tunnel diameter.