Neither ship nor submarine , the advantages of sailing neither above nor under water

A curious aquatic vehicle takes advantage of the advantages of a ship and a submarine without belonging to either of these two categories.

 

This unmanned vehicle, developed at Washington State University in the United States, may prove that the best way to travel undetected and energy-efficiently through water is not over it or under it, but through the middle. .

 

The roughly half-meter-long prototype, built with off-the-shelf and 3D-printed parts, proved its seaworthiness in water tests, moving quickly with little drag and not attracting attention.

 

This type of boat is not new. It is known that in recent years, semi-sunk vehicles have been used for illegal activities. But the line of research and development undertaken at the Washington State University has the goal of demonstrating how vessels of this type, definable as semi-submarines and developed by engineers, can efficiently serve legal purposes, in the area of ​​scientific research, in the military and even in the commercial.

 

A semi-sub is relatively cheap to build, difficult to detect and can travel great distances, notes Konstantin Matveev of the research and development team. It is not as susceptible to waves compared to ships, since most of the body is under water, so it also has some economic advantages.

 

Since the semi-submarine primarily sails on the waterline, it does not need to be made of materials as strong as those of a submarine, which has to withstand the pressure of being underwater for long periods of time. The semi-submarine also has the advantage of having a small area in contact with the atmosphere, which facilitates the reception and transmission of data

For this study, Matveev and Pascal Spino tested the semi-submarine in Wawawai Bay of the Snake River in Washington state. They tested its stability and maneuverability. The semi-submarine reached a maximum speed of 1.5 meters per second. At higher speed, it rises above the water creating a more obvious wake and expending more energy. At lower speed, it is almost completely submerged.

 

The researchers also equipped the semi-submarine with sonar and mapped the bottom of a reservoir near Pullman, Washington to test its ability to collect and transmit data.

 

Matveev and Spino present the technical details of their latest advances and the results of their latest experiments in the academic journal Unmanned Systems, under the title "Development and testing of unmanned semi-submersible vehicle".

 

For now, Matveev's lab continues to work on optimizing the shape of prototype semi-subs to make them fit for specific purposes.