Taisei Corp. unveiled a new underwater robot that it says can reduce work time and costs on dams by 30 to 40 percent compared to conventional methods using divers, even in muddy waters.
The robot relies on ultrasonic sonar and uses an 11-meter-long arm to do repairs, the company said.
Taisei developed the robot jointly with other companies. The total cost was around 600 million yen ($5.8 million).
It can perform various tasks by changing the component on the tip of the arm. Resembling an excavator, the robot is installed on a pillar with a diameter of 91 centimeters that is lowered to the bottom of the dam lake. It is able to work in depths up to 50 meters.
An operator remotely controls the robot from the barge using a video monitor. Tasks the robot can perform include dredging mud, cutting and manipulating concrete, and removing sunken logs and debris from the bottom of the river.
Taisei said the robot will go into service in February when it will be used to cut a hole in the side of Amagase Dam in Kyoto Prefecture to create a new floodway. The repairs to the dam, which until now would normally take seven months, are expected to take just four and a half months.