Caisson Automatic Water Injection Control System

Automated Pump Control for Caisson Water Injection Operations

In construction operations involving caissons it is essential to constantly monitor the amount of water being injected into each section. Because the scaffolding above the caisson is usually narrow, there are safety concerns if operators have to keep watch on the amount of water being injected for long periods.
The caisson automatic water injection control system provides increased safety, better energy conservation and improved installation quality for construction operations involving caissons.


  • Automatic measurement and display of the amount of water injected into each caisson section (water-level sensor).
  • Monitoring of the orientation of the caisson using a tilt sensor.
  • Automatic pump control based on the water level of each caisson section and the tilt sensor.

System Configuration


Automatic Measurement and Control of Water Injection Volume to Each Section

When the caisson is installed, an underwater pump and water-level sensor are set up in each section. A tilt sensor is also installed in order to check the tilt of the caisson itself.
The values from the water level sensor in each section are sent from the control board to the computer on the works vessel via wireless LAN, and displayed on the screen.

Automatic Pump Control Regulates the Water Level Difference between Sections

If the difference in water levels between two adjoining sections exceeds the prescribed value, the underwater pump is stopped in order to prevent the water level rising any higher.
A three-stage flashing light alarm according to the water-level difference, is activated on the works vessel.

Tilt Sensor

If the tilt sensor installed on the caisson indicates tilt to a value greater than prescribed, the pump on the tilted side (the heavy side) is stopped, preventing the caisson from tilting any further. At the same time, a three-stage flashing light alarm is activated according to the degree of tilt.
Refer to GPClino

Advantages in Installing the System

  • With automatic control of the underwater pump, prompt water-level measurement and secure water level management can be obtained, preventing tilting of the caisson and improving operational efficiency.
  • The system improves quality by preventing damage to partition walls caused by unbalanced loading as a result of differences in water-head level between adjoining sections.
  • The water injection can be checked on a monitor set up on the crane barge, allowing crew members and operators to share information in real time, which leads to greater operational efficiency.
  • Operators do not need to move around on the caisson to check the water levels in each section, resulting in improved safety.

Utilization Scenarios