Ocean ridges where lithospheric plates are being produced, has been fascinating geologists, biologists and engineers. While dynamic structures in seabed are being investigated by utilizing manned submersibles and remotely operated vehicles, the operation of these vehicles involves a huge support system and consumes enormous amount of money resulting in pointwise expeditions. To establish a new system for scientific and marine engineering survey of the wide area of seabed, an unmanned and long endurance system has been investigated based on Autonomous Underwater Vehicles (AUVs). Many projects are currently promoted to construct prototypes of vehicles which can dive freely in a deep sea (Ura, 1989).

The University of Tokyo and Mitsui Engineering & Shipbuilding Co.Ltd. have been working jointly on a project for "Development of autonomous underwater robots for survey of mid-ocean ridges", in short, the "R1 Project" (Ura, Tabuchi, Obara, Maeda, 1992) (Obara, Yamamoto, Ura, Maeda and Yamato,1993).

R1 project

The target of the R1 Project is to construct a long endurance autonomous underwater free swimming vehicle called the "R1 robot". The robot swims for one day without terminating its mission and surveys a wide area of ridge systems including measurement of CTDO in the vicinity of the seabed. It is anticipated to make detailed research when abnormalities in temperature, etc., are detected(see Fig.1). The survey of gravity field is also a suitable mission for the R1 robot.

Fig.1 R1 in mission

The schedule of the project is divided into two stages. In the first stage of the 6-year program which started in 1990, a prototype R1 robot, whose operating depth is 400m with one day duration, has been constructed to investigate the practical CCDE system. (see Fig.2) The robot is anticipated to be launched by the fall of 1995.

Fig.2 R1

In the following second stage of a 3-year program, a practical R1 robot which dives to the depth of 3,000m and surveys the mid-ocean ridge system, will be constructed on the basis of the technology from the first stage. The CCDE system developed through the first stage can be adopted to the vehicle of the second stage.

Last modified: Mon Jun 5 18:38:27 1995