Closed bell

Closed bell is a term used in underwater diving to refer to a type of diving bell that is sealed against the water. Unlike an open bell, which is open at the bottom and allows direct contact with the water, a closed bell is completely sealed and allows divers to be transported to and from the surface in a dry environment.

History

The concept of the closed bell has been around for centuries, with early designs dating back to the 16th century. However, it was not until the 20th century that closed bells became a practical tool for underwater work, particularly in the oil and gas industry.

Design and Operation

A closed bell is typically made of a strong, corrosion-resistant material such as stainless steel or titanium. It is designed to withstand the high pressures found at depth, and is equipped with a number of safety features, including a locking door, an emergency release system, and a life support system that provides air, heat, and light.

The bell is lowered from a surface vessel using a winch and cable, and is guided to the work site by a diver or remotely operated vehicle (ROV). Once at the work site, divers can exit and enter the bell through the bottom hatch, which is designed to seal tightly when closed.

Uses

Closed bells are used in a variety of underwater applications, including construction, salvage, and scientific research. They are particularly useful in deep diving operations, where they allow divers to work at depth for extended periods without the need for lengthy decompression stops on the way back to the surface.

See Also

• Diving bell
• Underwater diving
• Saturation diving