PROBLEM

A major marine contractor required expert diving support for the installation of a structural cap at a floating drydock mooring facility located within a restricted-access naval base in San Diego. The operation involved precision underwater cutting, structural steelwork placement, and integration with concrete construction, all under tight schedule and engineering constraints.

Subsea Global Solutions was selected for our proven record in underwater marine construction, our ability to coordinate complex, multi-stakeholder projects, and our adherence to rigorous safety and quality standards, including full compliance with EM 385-1-1 safety protocols.

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SOLUTION

Scope: Cap installation, pile preparation, structural steel placement, splash zone sealing, and final survey verification.  

Subsea Global Solutions executed a highly coordinated underwater construction operation that included:  

• Cleaning and precision cutting of three piles to design elevation  

• Installation of custom-designed friction and horse collars  

• Placement of structural beams and steel panels with precise alignment  

• Hyperbaric welding of formwork components  

• Application of splash zone sealants to ensure watertight integrity  

• Underwater grout injection into annular spaces  

• Final cap placement with survey verification and underwater video documentation  

All work was performed in coordination with the contractor’s engineering team and in strict compliance with naval base access requirements, EM 385-1-1 safety standards, and Subsea Global’s internal diving safety protocols.

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EXECUTION

Subsea Global Solutions’ divers began by cleaning and cutting the piles, setting wooden templates and installing steel friction collars to the required elevations. After torquing and verification, the team installed structural formwork, including beams and horse collars. Plate installation was performed from the center outward, with continuous alignment checks.  

Steel plates were welded per the direction of the prime contractor, and the complex interfaces were sealed with a splash zone application. The final concrete cap was installed and verified through video inspection and gasket integrity testing.  

Following a specified cure period, the Subsea Global team returned to strip the formwork and complete final grout placement to bring the structure into service. Daily coordination meetings ensured alignment of scope, personnel, and progress tracking throughout the multi-week operation.

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CONCLUSION

Subsea Global Solutions successfully completed all underwater elements of this critical cap installation, delivering the project on time and in full compliance with engineering specifications and the contract documents. Our team’s adaptability, close collaboration with the contractor’s field and engineering teams, and commitment to safety contributed to a smooth and successful execution.

This project highlights Subsea Global’s ability to provide complex underwater construction support in demanding environments and further reinforces our position as a trusted partner providing competent underwater support services for critical infrastructure and marine construction operations.

MARINE CONSTRUCTION SERVICES

Subsea Global Solutions delivers expert marine construction and infrastructure support for waterfront developments, industrial installations, and critical defense assets. From underwater demolition and pile cutting to structural steel assembly and concrete placement, our certified commercial diving teams bring unmatched precision, safety, and reliability to every project. We specialize in complex marine scopes, including mooring system installations, underwater inspections, and structural repairs, all executed to engineering and regulatory standards.

With global reach and local responsiveness, Subsea Global Solutions integrates seamlessly with engineering firms, prime contractors, and government stakeholders to deliver efficient, high-quality results in demanding environments. Whether in a drydock, port, or remote coastal location, we are the trusted partner for turnkey underwater construction solutions.

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