Monday, August 16, 2010

The U.S. Navy Mark V

It's hard to believe, but the History of Diving Museum Collections Blog is entering into its third month of online diving history! The focus of this blog has been to inform readers on the history of artifacts within the collection. So far, I have chosen only those items with great significance to diving and Florida Keys history. Although diving bells, Art McKee, the first American diving helmet and the last petroleum lamp are very important, I have somehow neglected quite possibly the most important piece of diving history...

The U.S. Navy Mark V is the most coveted and recognized diving helmet in the world. It embodies helmeted diving with its bold look, functional design and long-standing history in American diving. Navy Dive Master Carl Brashear (his story was the inspiration for the movie Men of Honor) used a Mark V during his career. Today, it symbolizes not only an important segment in diving history, but also stands as one of the most important technologies in the history of the world.

On to the history...

The U.S. Navy discovered a growing need for a standardized diving program. To the surprise of many, at the turn of the century the Navy had neither a standardized procedure or equipment for the diving program. Consequently, they were diving any and all equipment available, often with little knowledge of the dangers associated with diving.

In 1912, Navy Gunner G.D. Stillson wrote a letter to the Bureau of Construction and Repair (Bureau of Ships as it is called today) concerning the current diving program or lack thereof! He assembled a team and began a critical analysis of existing diving procedures. In the following years, Stillson and his team were commissioned to evaluate, improve and redesign every part of the diving program.

This evaluation produced two major developments. By 1915 G. D. Stillson, through the intercession of the Bureau of Construction and Repair, completed the first U.S. Navy guideline for diving known as the Report on Deep Diving Tests. This report served as the framework for Navy diving in the years to come. In it, Stillson discussed the necessary decompression times for deep dives, principles of pressure and most importantly, the equipment fostered through the program.

In Stillson's evaluations, he tested a wide variety of diving equipment, mostly those from the Schrader and Morse Companies, but also equipment from Draeger and Siebe. In the two years leading up to the completion of the Report on Deep Diving Tests, a standardized equipment would be developed for the U.S. Navy, giving birth to the Mark I!

The Mark V helmet, the standardization of the diving program and the self evaluation of the program, symbolizes the future of the U.S. military as we know it. Mark, a work frequently associated with military hardware, simply means a 'standard' or 'variant.'

Stillson and the Navy experimented with four versions of the Mark helmets, the Mark I, II,III and IV. The Mark V combined the best aspects from the previous four helmets. The final version was completed in 1917 and remained largely unchanged until its decommission in 1984. It is believed that only a mere 7,000 to 10,000 were ever constructed.

Four companies were commissioned to build the Mark V. The first Mark V helmet was made by the Morse Company; it is also the most common. Schrader, Desco and Miller-Dunn were also commissioned to build the Mark V. The Miami based Miller-Dunn Company produced the fewest helmets making them the rarest by today's standard. Out of the hundred or so helmets manufactured by the Miller-Dunn Company, the History of Diving Museum has two on display.

A Mark V helium rebreather version was also developed. The helmet has a large helium scrubber on the back. Of course, adding a large helium scrubber serves as a reservoir for more air, adding increased force buoying the apparatus and diver to the surface. To offset this affect, the helium Mark V needed increased weight to compensate for this added force. The boots are larger and lace just below the knee (a rather stunning look for those who have seen the design). The 'Banana Exhaust' was moved from the back of the helmet to the top where it was excluded from its original placement due to the scrubber. Lastly, the dumbbell lock was moved from the rear of the helmet to the front.

In the late 1970's, the Mark helmets changed completely. No longer a metallic base, the Marks are now fiber glass which changed the identity forever. HDM displays a newer version from the Mark line. The Morse Mark XII is the successor to their line of copper helmets. The top part of the helmet can be used alone for swim diving with air supplied by a hose from the surface, or a backpack or used with a 12-bolt attachment. It is much lighter than the original Mark V diving dress.

The Mark V is the icon of helmeted diving, thus this blog cannot be completed without a more in depth look at the helmet. This will be a two-part blog; the second part will provide an overview of the components on the Mark V. If you would like to learn more about what made this helmet one of the best manufactured technologies of the twentieth century, stay tuned for our next blog! The History of Diving Museum is the largest collection of historical diving apparatus in the world, we're proud to be your source for diving history!

Sources: (accessed 08/28/2010)

Monday, August 2, 2010

Petroleum Underwater Diver's Light, Cabirol, France c.1860

The History of Diving Museum (HDM) displays many artifacts that are one of a kind, the first or simply the rarest in existence. However, out of the many priceless artifacts, the Cabirol Petroleum lamp is extremely rare and cannot be found anywhere else in the world.

Significant from both a technological and conceptual standpoint, the Cabirol Petroleum lamp was designed in 1860 by Joseph Cabirol in France. This grand petroleum lamp was made before electricity was used in underwater lighting! The Cabirol lamp predated the transition from open flame to electricity.

Now, to take a step back, it is best to understand the history of electricity to appreciate the significance of the Cabirol lamp. A late 19th century design, it barely missed the jump from oil lighting to electricity (a fuel that would be outsourced shortly thereafter). The discovery of electricity dates back to 3rd century B.C.E. during the time of the Ancient Egyptians. Texts confirm an understanding of electrical charge created by fish. However, electricity and positive energy would remain an intellectual phenomenon for the next two-thousand years. Many credit Benjamin Franklin with the first discovery and application of electric charge in his famous, 'kite in a thunderstorm' experiment, but truthfully, it wasn't until the 19th century that Nikola Tesla, Thomas Edison, Otto Blathy, Anyos Jedlik, Sir Charles Parsons, George Westinghouse, Ernst Werner von Siemens, and Lord Kelvin transformed electricity from an intellectual curiosity to an essential tool for everyday life.

From a design standpoint, the fuel source (petroleum) was held in the bottom canister. To keep the flame burning in the crystal sphere, a steady supply of oxygen was needed -- just as a diver would need fresh air. The air was provided by a dedicated 2-piston air pump contained in the pump box. The air was pumped through a set of rubberized hoses (in 1860!), down the lamp. The hot gases were then channeled out the top and through the pipes surrounding the crystal globe, where the hot fumes were coolest to prevent scorching rubber return hoses.

Due to a fortuitous accident, this rare lamp was preserved for 150 years! The petroleum flame was lit and the lamp was quickly closed to make it watertight. But before the lamp was lowered into the water, the crystal globe became too hot and cracked -- as can be seen on the lamp! Because the lamp was broken, it was condemned to a removed warehouse, where it was forgotten for a century and a half.

The lamp is displayed in the "Abyss" exhibit at HDM.

The Cabirol Company

Cabirol is also known in the historical diving community for its contribution to helmeted diving. Around 1842, the company began producing helmets; their inclusion of a top window separated their design from that of the Morse Company. Although few still remain, the HDM collection owns a Cabirol helmet. An extremely rare artifact in its own right, missing the front port and brails, its dull color suggests the uncommon nature of the item.

At the time, the Cabirol Company was highly regarded in France and respected for their contributions in diving. The French, in their typical decadent fashion, prominently displayed divers etched in stone with the inscription "Famille Cabirol-Ferrus" on the steps of the Cabirol factory. To our dismay, two larger divers surrounded the doors of the factory, carrying none other than the Cabirol petroleum lamp.

Today, the Cabirol Company is no longer in existence. Once a small company in France, Cabirol was almost forgotten in diving history. HDM serves as the company's greatest monument and appreciation for their contribution to diving history.