Standard diving dress
A standard diving dress consists of a metallic (copper and brass or bronze) diving helmet, an airline or hose from a surface supplied diving air pump, a canvas diving suit, diving knife and weighted boots. An important part of the equipment is the lead weights, generally on the chest, back and shoes, to counteract the buoyancy of the helmet and diving suit. Weighted boots may use brass, iron or lead for soles. The uppers are often made of oiled leather or canvas.
This type of diving equipment is also known as hard-hat equipment or a "John Brown" rig, so-called after the British company that built many of the helmets (Siebe Gorman and Heinke). In the United States, the dominant makers were DESCO, Morse, Miller-Dunn and Shreader and it is sometimes known as a "Diver Dan" outfit, from the television show of the same name. It was commonly used for underwater civil engineering, commercial diving and naval diving.
The diving suit is called a diver's dress. The earliest dresses were made of waterproofed canvas. From the late 1800s and throughout most of the 20th century, most Standard Dresses consisted of a solid sheet of rubber between layers of tanned twill. Their thick vulcanized rubber collar is clamped to the corselet making the joint waterproof. The inner collar (bib) was made of the same material as the dress and pull up inside the corselet and around the diver's neck. The wrist cuffs are also made of vulcanized rubber. The twill was available as heavy, medium, and light with the heavy working best against rough surfaces like barnacles and rocks. Three sizes were available; however, there was only one size corselet. Different types of dress are defined by the clamping of the outer collar clamps to the corselet. The legs are laced to prevent gas from getting trapped in the legs and dragging the diver to the surface. In normal UK commercial standard dress diving activities, the dress often did not have the lace up option.
The helmet is usually spun copper, with brass fittings soldered to it. The windows are known as lights or ports. The front port usually opens on the surface by being screwed in or has a hinged closure. The back of the helmet has two goose neck fittings. One has a non-return valve and is the connection for the air line. The other is for the diver's telephone. The difference in pressure between the surface and the diver can be so great that if the airline were cut on the surface and there was no non-return valve, the diver would be crushed and possibly killed. Helmets have an exhaust valve which is spring closed and allows the air to leave the helmet. It is diver adjustable and prevents the diver's dress from over inflating and the diver being floated violently to the surface. Helmets may have an extra manual exhaust known as a spit cock. This allows the diver to vent excess air when he is in a position where the main exhaust will not function correctly.
This is an oval copper and brass collar-piece resting on the top middle parts of the chest and back, for the helmet to be screwed to. Most helmets are joined to the corselet (also known as a breastplate) by 1/8th turn thread. The helmet is placed on the breastplate facing the divers left front and then turned forward, seating on a leather gasket. The helmet usually has a safety lock which prevents it from rotating back and thus separating underwater. However, other styles were used and the joins may be by clamp or bolts. Some helmets and breast plates are one piece and the dress are secured in other ways.
The breast plate is in turn, joined to the diver's dress by having the holes in the collar placed over bolts on the breastplate, and then being made water tight with wing nuts which compress brass rails (also known as brailes or brass straps) against the collar.
The helmet divers used heavily weighted shoes to steady them on the sea floor. Japanese divers often used iron soled shoes. The weighted sole is bolted to a wooden insole, which in turn has a leather, canvas or rubber upper. Lead was the most common sole and a pair could weigh up to 34 lb. Brass soled shoes with canvas uppers were introduced in WWII and are still in use. Some early brass shoes were called sandals because the were a casting held to the diver's feet by simple straps. The diver tends to lean forward as he pushes the weight of the water against him. For this reason the toes are capped, usually with brass.
The diver's knife is more a tool than a knife. It is not used to fight sea life. The diver can pry and hammer with it. It usually has one side of the blade serrated to cut heavy lines such as rope, and a sharper side for fine lines such as monofilament fishing line. There are two general knife sheaths, one is flat with a spring retention. The other is tube shaped and has an ajax triple thread. It is made as a tube so the diver can insert his knife in it from any direction. He then rotates the knife engaging the threads.
There are two general weight types. The earliest is still in use. It is the helmet weight. They are used in pairs. The large horse shoe type weights hold the helmet down and are attached to the corselet with figure eight hooks that go over breast plate weight studs. The Greek sponge divers simply joined the weights with ropes which went over the corselet like saddle bags. The second weight type is the weight belt. It has shoulder straps which cross and go over the breast plate. The US Navy Mk V weight belt weighed 83 lb. However, commercial belts usually were about 50 lb.
Air control valve
Most divers have an air control valve which is a lot like a common water tap. Air which is sent down the air hose can be controlled by the diver. The early helmets, like Siebe Gorman did not have air control valves and the diver signalled the surface with pulls on his rope or air line, indicating that he needed more or less air.
|This article has statements which are anachronisms.|
In 1405, Konrad Kyeser describes a diving dress that is made of a leather jacket and metal helmet with two glass windows. The jacket and helmet were lined by sponge to "retain the air" and a leather pipe was connected to a bag of air.
Borelli published a dress that consisted of self-contained underwater breathing apparatus consisting of a metal helmet, a pipe to "regenerate" air, a leather suit, and a means of controlling the diver's buoyancy.
In 1690, Thames Divers, a short lived London diving company, gave public demonstrations of a Vegetius type shallow water diving dress.
Klingert designed a full diving dress in 1797. This design consisted of a large metal helmet and similarly large metal belt connected by leather jacket and pants.
A diving helmet was designed by Charles Anthony Deane, a ship's caulker, in 1820 in England. It was originally intended as a fire fighter's breathing apparatus, but was not well received and underwater use was an after thought. The prototype was used in the salvage of the wreck of the Carn Brea Castle off the Isle of Wight, and the proceeds used to commission Augustus Siebe 5 Denmark St, London to make the dedicated diving helmet as he had made the prototype
In 1825, the first self-contained diving dress with a compressed air source was designed by William H. James. The helmet was a "thin copper or sole of leather" with a plate window. The air was supplied from an iron reservoir.
Augustus Siebe a jeweller who could make castings, was commissioned to make the first commercially successful diving helmets. The helmet, when joined to a diver's dress could not flood no matter how the diver moved, resulting in safer and more efficient underwater work.
The overall design of the helmet and dress changed little over the years until superseded in the 1950s with the Aqua-Lung being adapted to surface supplied air, known as hookah. The Aqua-Lung is now called scuba. The modern fiberglass helmet and other lightweight designs now fill the role. Helmets are used primarily for commercial and industrial purposes which includes special uses such a deep saturation diving.
The standard diving dress has been used to depths of 600 feet of sea water. Air comes from hand pumps, compressors, and banks of high pressure storage cylinders. Some models were autonomous, with built-in rebreathers or compressed gas supplies. A diving helmet is described by the number of bolts which hold it to the dress, and the number of vision ports, known as lights. For example a helmet with four vision ports, and twelve studs securing the dress, would be known as a "four light, twelve bolt helmet". When the telephone was invented, it was applied to the diving dress. The helmet diver remains dry and has a dry head, a big advantage during long dives.
In the diving helmet, a principle similar to that of the wet diving bell is used, where compressed air is provided to the helmet. The air lets the diver breathe normally and equalizes his internal pressure with the water pressure outside. The helmet must have a non-return valve at the rear air input port of the helmet, to prevent massive and fatal squeeze, should the air line be cut at the surface. Diving helmets, while very heavy, displace a great deal of water and combined with the air in the dress, would make the diver float with his head out of the water. To overcome this, some helmets are weighted, while other divers wear weighted belts which have straps that go over the base of the helmet. The diver may have an air inlet control valve, while others may have only one control, the exhaust.
A full diving dress can weigh over 80 kilos. Helmet diver's boots have canvas or leather uppers, and soles of iron, brass or lead.
While Siebe Gorman became the standard from which all helmets developed, the U.S. Navy Mk V helmet of 1915, has become the iconic helmet. It was based on the Gunner George Stilson design. Diving helmets were made all over the world. However, in the traditional form are still used to a lesser extent. China makes about 8,000 diving helmets annually and about 12,000 diver's dresses. The Aqua Lung type breathing apparatus conserves air when applied to a helmet. However, the well known scuba cannot replace the helmet because a worker needs to have his feet planted on the sea bed to work. The modern commercial diver selects his equipment based upon the job at hand. Diving helmets have progressed to modern materials, but the principle of walking on the sea bed while working remains. The swimming diver cannot hold his position while working. The traditional copper helmets of the past are now primarily used in the west by historical diving groups and collectors, but are still widely used in Asia.
- While searching for Red Rackham's Treasure, Tintin, Captain Haddock, and the Thompson Twins used diving suits, with varying levels of success.
- "Big Daddies" from the video game BioShock wear Standard Diving Dress, with each variation wearing a different style of suit and helmet; "Bouncers" (close-combat with a mining drill) wear Carmagnolle helmets, while "Rosies" (long range with a rivet gun) wear a more traditional three-port helmet.
- The 2000 film Men of Honor, which was set in the 1950s, prominently featured divers in Standard Diving Dress. The film depicts US Navy divers, supposedly using the Navy Mk V helmet and dress. The helmets actually used were commercial helmets on a Mk V corselet, which gives the camera a better view of the actor inside.
In at least two fictional scenarios, standard diving dress is used out of water as a spacesuit:
- In the 1964 film First Men in the Moon in the events set in the year 1899.
- In Stargate SG-1 (season 1) episode 11, by a man sent through the Stargate experimentally in 1945.
- Stillson, GD (1915). "Report in Deep Diving Tests.". US Bureau of Construction and Repair, Navy Department. Technical Report. Retrieved 2008-08-08.
- Davis p. 56
- Davis p. 551
- Davis p. 554
- Davis p. 556
- Davis p. 557
- Davis p. 560
- Newton, William; Partington, Charles Frederick (1825). "Charles Anthony Deane - 1823 patent". Newton's London Journal of Arts and Sciences (W. Newton) 9: 341 p. 297
- Davis p. 563
- Davis p. 406
- Acott, Chris (1999). "JS Haldane, JBS Haldane, L Hill, and A Siebe: A brief resume of their lives". South Pacific Underwater Medicine Society Journal 29 (3). ISSN 0813-1988. OCLC 16986801. Retrieved 2011-01-03.
- Davis p. 33
- Davis p. 1-2
Historical Diving Society diving at Stoney Cove, England
Cave diving equipment from 1935 in the museum at Wookey Hole Caves
|Wikimedia Commons has media related to Standard diving dress.|
- The Historical Diving Society
- US Naval Undersea Museum
- Mixed Gas Diving Helmets
- "Iron Men Under The Sea", January 1931, Popular Mechanics detailed article on salvage divers and diving school in Bremen, Germany
- "Undersea Acrobatics The World Never Sees", December 1931, Popular Mechanics training given divers to go against current on ocean floor pages 974/975
- History of Diving Museum