.truncate { white-space: nowrap; text-overflow: ellipsis; }

Underwater Blankings & Cofferdams

Hull Cleaning

Subsea Global Solutions (SGS) has 30 years of experience in designing and building hull blanks, cofferdams, and hyperbaric habitats. All SGS locations around the world maintain various types of closed and open cofferdams for fasts response to any hull repair. Renewing wasted/damaged shell plate or spool pipes afloat eliminates the need for a dry dock.

The use of cofferdams to replace damaged shell plate or spool pipes is not new in shipping—however, what SGS has focused on for the past 10 years is developing and qualifying in-house welding procedures for both dry and wet applications using class A underwater wet welding procedures in combination with topside procedures. This unique approach has enabled SGS to provide turn key repair solutions for doing permanent—no condition repairs afloat. The gouging and welding of root one sided welds can now be done underwater after the dry repair is completed with the underwater wet welds meeting class approval, as per the Class A requirements of AWS D3.6M: Underwater Welding Code.

In-house built drawings can be provided for thermal heat barrier type blanks and tailored cofferdams with complex shapes/contours that SGS can typically design on the job site. With built drawings, class approval can be obtained for any cofferdam at the customer’s request, as we have the equipment and design expertise to allow any repair types to be executed without fit up concern.

In some cases, SGS installs hull blanks that are designed to remain on the hull while the vessel is in transit undergoing repairs. We have various options for enclosed cofferdams, open-top cofferdams with man entry, and open-bottom cofferdams (or hyperbaric cofferdams) for repairs that are required beneath the surface. If we do not have one shaped and sized for your unique requirements, we will design one to ensure a proper fit with safe execution.

Whether your vessel is an offshore marine asset or transiting globally, SGS can provide custom hull blanking/cofferdam solutions that will allow repairs to happen in-situ, keeping your vessel on its planned itinerary without expensive deviations to a dry dock while minimizing off hire time.

Common Use Cases for Blankings/Cofferdams

For underwater repairs or underwater exchanges on tunnel thrusters, tunnel thruster seals, tunnel thruster blades, stabilizers fins, propellers, propeller blades, stern seals, rudders, and rudder seals—please see our unique underwater ship repair options here.