Shearwater Marine Services successfully addressed the ongoing challenge of underwater acoustic tiling for the Ministry of Defence (MOD). With dry docking not an option and temporary fixes insufficient, Shearwater Marine Services developed a novel solution to control the underwater environment and ensure tile adhesive curing. The solution involved the creation of an underwater 'dry space' for divers to work in, with environmental monitoring and CCTV surveillance to ensure optimal application conditions. The outcome was a significant improvement in adhesion strength over conventional in-water applications, offering a new standard for underwater acoustic tiling.
The MOD faced a persistent problem: the application of acoustic tiles underwater. The traditional practice of dry docking was impossible, and temporary repairs were not durable. The task was to devise a solution that would control the environment and maintain stability during the adhesive curing process. This was a novel task, with no previous baseline statistics or established methodologies to follow.
The project faced several obstacles, including limited information on tiling application, restraining methods, environmental parameters, availability of testing facilities, and requisite training. The principal challenge was creating and maintaining an environment suitable for tile application that had never been attempted before. Testing parameters were challenging to define, but Shearwater's in-house testing facility, dive tanks, 30m dive sites, and training vessel enabled the exact testing conditions required on-site to be replicated.
After exploring various solutions, including industry-standard hydro boxes, Shearwater decided to construct a dry space for the diver to work in a controlled, dry environment. This dry space was equipped with an environmental monitor and CCTV, allowing certified trainers and supervisors to oversee the application process. The dry space was designed and built in-house using aluminium and CE-approved in the company's execution-class workshop. This innovative approach, combined with appropriate planning for the right equipment, helped address the cost implications of the project.
The dry space was successfully constructed, and initial tests were conducted on the surface with a qualified applicator before progressing to sea trials. Subsequently, the testing was moved to the Professional Diving Academy facility, where a cage was built to simulate the vessel's hull, enabling attachment of the dry space and lowering it to the required testing depth. With QinetiQ onsite to ensure procedural compliance and data collection, the testing results were nearly identical to those of surface application. In contrast, in-water trials showed significant loss in adhesion strength compared to surface application, highlighting the effectiveness of the dry space solution.
The innovative solution provided by Shearwater Marine Services sets a new standard for underwater acoustic tiling. By creating a controlled dry space underwater, the company has not only overcome the limitations of traditional tiling methods but also demonstrated a potential model for other underwater engineering tasks. This case study provides a testament to Shearwater Marine Services' ability to think outside the box and devise creative solutions to seemingly insurmountable challenges.