Air Lift Bags for Marine Salvage

Open bottom air lift bag

Open bottom air lift bag commonly used for marine salvage

Marine salvage involves recovering a ship and/or its cargo from the seabed following a shipwreck or other maritime accident. Obviously, ships and cargo are heavy objects which cannot be recovered without specialist equipment and knowledge.

Underwater air lifting bags are specifically designed for the recovery of underwater objects that need lifting to the surface. They can also be used as static buoyancy in underwater engineering as they only need a single attachment point and are stable and easy to handle underwater.

Air Lift Bags

Air lifting bags are available in various designs and capacities, so that salvage operators can choose the appropriate level of buoyancy required to lift objects in a controlled fashion. For recovering heavy objects, such as a ship, multiple bags will be necessary to provide a balanced and controlled lift. This is important as objects that are lifted too quickly can reach the surface out of control, posing a risk to the operators and the vessel being salvaged.

Closed or Open?

There are two basic types of lifting bag:

  • Closed air lifting bags typically include a safety valve that allows air to be released for a steady, controlled ascent.
  • Open bottomed air lift bags work differently as their open bottom allows expanding air to vent freely during an ascent to the surface as pressure decreases.

For this reason, and the ease of handling, open bottomed air lift bags are usually the preferred choice for marine salvage. Their strength, ease of use underwater and predictable behaviour make them the most effective and safest option for most marine lifting operations.

Jean Ricciardi

Salvage of the Jean Ricciardi

When the trawler Jean Riccardi suffered a power failure, flooded and sank near the port of Sete, on the French Mediterranean coast, twelve open bottom air lift bags, capable of lifting 20 tonnes each, were used to complete the salvage operation quickly and safely.

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