Mechanization of Underwater Civil Engineering Work and Development of Unattended Robot

摘要

Divers have chiefly carried out underwater work in ports and harbors. Such work included mainly sea bottom surveys, measurements, riprap mound construction for breakwaters, and giving instructions to the workvessel for placement of sand and rocks over the seabed. Some of this work has already been automated. Riprap mound construction is mostly depended on divers and a diver support ship to place the rocks one by one. Directly grasping a rock with the hands has often caused accidents to the hands causing a loss in work efficiency. To mechanize manual work of divers and ensure the safety and efficiency of divers, a new underwater backhoe operated by a diver has been developed. The vehicle uses a backhoe available in the market as a base machine retrofitted as an underwater vehicle by providing watertight equipment able to work to a water depth of 50m. The machine is normally required to perform underwater work down to 30m. The vehicle is supplied with electric power via a cable from a support ship and the operator-diver is able to use all his senses in the control of the vehicle under water. The first vehicle with a bucket capacity of 0.5m~3 was constructed in 1994. Since then, 15 vehicles have been built with increased safety and work efficiency features. Areas of riprap mound construction carried out by these vehicles totaled over 123,000m~2 during the period from 1995 to January 2000. Moreover, R&D on unattended operation for deep-sea use were started by joint efforts of the government and private sector in 1999. The verification tests for unattended operation will be conducted in an actual sea area at the end of 2000. The present situation of divers and diver operating backhoe, construction by diver-operated backhoes, development of remotely controlled backhoe, and future development of underwater work are discussed.