The Use of a Diving Wet Bell Launch and Recovery System

What is a Diving Wet Bell?

A diving wet bell is a type of underwater platform that allows divers to be transported to and from the work site underwater. Unlike a dry bell, which is a sealed chamber that keeps divers dry, a wet bell is open at the bottom, allowing water to enter. It typically has a canopy to provide an air space where divers can breathe.

Components of the Launch and Recovery System

The launch and recovery system (LARS) for a wet bell consists of several key components:

• Winch System: This includes the winches and cables used to raise and lower the wet bell. The winch system must be robust and capable of handling the weight of the bell, divers, and any additional equipment.
• A-frame or Crane: The structure from which the wet bell is suspended during launch and recovery. This structure must be stable and able to withstand harsh marine conditions.
• Umbilical Management System: Ensures the diver's umbilical (a lifeline that supplies air, communication, and sometimes hot water) is managed correctly to avoid entanglement.
• Control Panel: Used to operate the winch and manage the entire launch and recovery process. This panel allows for precise control over the bell's movements.
• Safety Features: Including emergency stop mechanisms, backup power supplies, and redundant systems to ensure diver safety in case of primary system failure.

Operation of the System

The operation of a wet bell launch and recovery system involves several stages:

• Preparation: The wet bell is prepared on deck, with all systems checked for functionality. Divers are briefed, and all safety checks are completed.
• Launch: The wet bell is lifted from the deck using the A-frame or crane and lowered into the water. Divers enter the bell, and it is further lowered to the desired depth. The winch system must be controlled precisely to ensure a smooth descent.
• Diving Operations: Once at the working depth, divers exit the bell to perform their tasks. The wet bell remains at the depth, providing a safe haven for divers to return to if needed.
• Recovery: After the dive, divers re-enter the bell, and it is carefully raised to the surface. The ascent must be controlled to avoid rapid changes in pressure, which can be harmful to the divers.

Advantages of Using a Wet Bell

• Safety: The wet bell provides a secure environment for divers, reducing the risk of decompression sickness by allowing controlled descents and ascents.
• Efficiency: Divers can spend more time on task as the wet bell offers a nearby refuge, reducing the time needed to travel back to the surface for breaks.
• Versatility: Suitable for a wide range of underwater tasks, from inspection and maintenance to scientific research and underwater construction.
• Support for Extended Dives: The air space in the wet bell allows divers to take breaks without needing to surface, supporting longer and more productive dives.

Conclusion

The diving wet bell launch and recovery system is an essential component in modern underwater operations, combining advanced technology with rigorous safety protocols to ensure divers can perform their tasks efficiently and safely. Its use is integral to a variety of industries, including offshore oil and gas, marine research, and underwater construction, underscoring its versatility and importance. As technology advances, we can expect these systems to become even more sophisticated, further enhancing the capabilities and safety of underwater diving operations.