{"id":3168,"date":"2021-12-04T17:01:14","date_gmt":"2021-12-04T17:01:14","guid":{"rendered":"https:\/\/divingcorner.com\/?p=3168"},"modified":"2021-12-04T17:02:48","modified_gmt":"2021-12-04T17:02:48","slug":"what-is-a-diving-bell","status":"publish","type":"post","link":"https:\/\/divingcorner.com\/what-is-a-diving-bell\/","title":{"rendered":"What Is A Diving Bell? (Types & History)"},"content":{"rendered":"\n

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When we think of stays underwater, beyond a breath hold, we may think of scuba diving, surface provided air systems, underwater habitats, and even submarines. <\/p>\n\n\n\n

The first device to allow prolonged stays underwater was the diving bell, a device that is still in use today in an upgraded version. <\/p>\n\n\n\n

The writings of the Greek philosopher Aristotle from the 4th century B.C. mention a device that could be considered the forerunner of today’s diving bells.<\/p>\n\n\n\n

What is a diving bell?<\/em><\/p>\n\n\n\n

A diving bell is a chamber used to transport divers from the surface to depth and back in the ocean, for the purpose of performing underwater work. The most common types are the wet bell with an open-bottom and the closed bell.<\/strong><\/p><\/blockquote>\n\n\n\n

Unlike a submarine, a diving bell is attached by a cable to a surface support vessel. The cable is used to lower and raise the diving bell. <\/p>\n\n\n\n

Along with the cable are communication lines, power lines, and air hoses. <\/p>\n\n\n\n

There are three types of diving bells, the wet bells, closed bells and rescue bells.<\/p>\n\n\n\n

The Original Diving Bells- Wet Bells<\/em><\/strong><\/h2>\n\n\n\n
\"wet <\/picture><\/figure>\n\n\n\n

The original concept is simple to understand. <\/p>\n\n\n\n

One of the early usage was to recover items from the ocean floor. There are records of salvage operations using diving bells as far back as the 15th<\/sup> century<\/a>.<\/p>\n\n\n\n

A person or two would get into a device open at the bottom with a bench inside. The people and the device would be lowered into the water. <\/p>\n\n\n\n

As the device sank, water would enter the bottom, compressing the air inside and trapping it. <\/p>\n\n\n\n

When the device reached the desired depth, the swimmer would exit the device, look for items to retrieve and return to the device for a fresh breath of air. <\/strong><\/p>\n\n\n\n

They could do this a number of times before the carbon dioxide became to high within the device. <\/strong><\/p>\n\n\n\n

The people, salvage and device would be hoisted back to the surface. The operation could then be repeated. <\/p>\n\n\n\n

While original designs had many shapes, a bell shape became the most common due to its stability. <\/strong><\/p>\n\n\n\n

You can test the principle for yourself by submerging a piece of paper in a glass in a sink full of water.<\/p>\n\n\n\n

Take a sticky note and place it on the inside bottom of a drinking glass. Fill a sink with water deeper than the height of the glass. <\/p>\n\n\n\n

Place the open end of the glass on the surface of the water and slowly press down, keeping the opening level. As you do so, you should notice two things.<\/p>\n\n\n\n

First is that it become harder to push the glass down and second the water level inside the glass is lower than the level outside. The air pressure inside will be equal to the pressure of the water. <\/p>\n\n\n\n

If you slowly reverse the movement, when you get the glass clear of the water, you will find the paper is still dry. If you have children, you can amaze them with this science-magic trick.<\/p>\n\n\n\n

Wet Diving Bell Advancements<\/em><\/strong><\/h2>\n\n\n\n
\"Charles <\/picture>
Charles Babbage’s proposed design for a diving bell, 1855<\/figcaption><\/figure>\n\n\n\n

While a great concept, it had some severe limitations. The first would be when the swimmer exhaled they would add carbon dioxide to the air they were rebreathing, which limited the time they could stay below. <\/p>\n\n\n\n

The second would be the space the air occupied. <\/p>\n\n\n\n

As the water pressure increased and the air pocket compressed, it had a smaller volume to be inhaled as well as less space for the swimmers head. <\/p>\n\n\n\n

Denis Papin in 1689 theorized<\/a> that a set of blacksmith bellow could force air down a hose into the bell. <\/p>\n\n\n\n

This would provide fresh air as well as increase the volume of air. While the concept was good, the equipment of the time was inadequate. <\/p>\n\n\n\n

It was almost a hundred years later that John Smeaton invented an air pump able to complete the task.<\/strong><\/p>\n\n\n\n

Wet diving bells are still used in commercial diving today. They are often used to take divers with heavy equipment to a depth to complete some work. <\/p>\n\n\n\n

The concept of the diving bell also lead to the development of the dive helmet and armor diving suit. <\/p>\n\n\n\n

A moon pool uses the same principle of air pressure against water pressure. <\/p>\n\n\n\n

Found in research vessels, commercial diving platforms and oil rigs, a moon pool allows divers direct access to the water, often at depth.  <\/p>\n\n\n\n

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