Modernization of the control technology of 4 Liebherr CBW 32/24 deck cranes from 1994

The goal of the retrofit was to replace the control technology—which was over 30 years old—with a modern, reliable solution that could be maintained over the long term.

Measures implemented:

• Modern PLC Control:
  The existing circuit board system and the old control relays were replaced with a modern PLC control system featuring new 24-V DC components.
• Touchscreen operation:
  A new HMI touchscreen allows for a clear display of operating statuses, pressure values, end positions, and system messages.
• New CAN Bus Joysticks:
  The previous controls have been replaced with modern CAN bus joysticks. This enables precise and reliable control of all crane movements.
• Modernized End-Position Monitoring:
  The old mechanical cam limit switches for the lifting and rocking mechanisms have been supplemented with CAN bus encoders. Separate cam limit switches remain in place as an additional safety measure.
• New pressure sensors
  Modern pressure sensors were installed for the lifting mechanism, the tilting mechanism, and the rotating mechanism, and integrated into the new control system.
• Commissioning and Training
  After the wiring was completed, all digital and analog signals, crane movements, limit switches, and emergency stop functions were tested. In addition, the ship’s electricians and the responsible crew members were trained in the operation of the new system.
• Inspection by the classification society:
  The modifications made and the safety features were explained to the responsible RINA expert and successfully demonstrated as part of a comprehensive functional test.

Result:

Thanks to the modernization, all four cranes now feature a standardized, modern, and maintenance-friendly control system. The new technology improves operability, diagnostic capabilities, and spare parts availability, thereby laying the foundation for reliable operation for many years to come.

This project demonstrates how proven crane systems can be brought up to the current state of the art in a cost-effective and sustainable manner through targeted modernization measures.