What is the Dry Box Technique in Ship Hull Plate Repair? | Underwater Application Details
What is the Dry Box Technique in Ship Hull Plate Repair? | Underwater Application Details
The dry box technique used in ship hull plate repair enables safe underwater welding and cutting operations. It is commonly used to repair structural damages such as cracks, holes, or deformations in the submerged parts of a vessel. This method allows for significant repairs without the need to dock the ship in a dry dock, offering a time-efficient solution.
What is the Dry Box Technique?
A dry box is a temporary, sealed underwater chamber. The interior is dewatered to create a dry working environment for divers. Welders can then perform operations inside this chamber as if working in a surface-level dry area. It is typically installed over the damaged section of the hull and supported with pressure control and air evacuation systems.
When Is It Used?
The dry box technique is used when there are structural issues such as cracks, punctures, or bent plates on the hull. It is especially effective for emergency repairs where docking the vessel is not an option. The method is recognized and approved by major classification societies and ensures minimal downtime during operations.
Dry Box Setup Steps
First, a dive plan is prepared and necessary permissions are obtained. After damage assessment, the dry box system is mounted over the affected area by divers. Air is pumped in to displace the water, creating a dry interior. A diver then enters the chamber and begins welding. Once the repair is complete, the system is dismantled and the area is cleaned. Every step is documented thoroughly.
Advantages
- Allows repairs without dry docking
- Minimizes operational downtime
- Approved and safe by international standards
- Enables precise underwater welding and cutting
- Delivers long-lasting and durable repair results
Equipment Used
- Dry box chamber system
- Underwater welding machines and electrodes
- CCTV and communication systems
- Diver air tanks, compressors, generators
- Air evacuation and sealing equipment
Conclusion
Hull plate repair with the dry box technique combines professionalism and safety in underwater repair operations. Welding in a dry environment overcomes the limitations of underwater work and ensures high-quality, permanent results. It is a frequently used method in modern marine maintenance, minimizing disruption to vessel operations.