Rouquayrol-Denayrouze
Rouquayrol-Denayrouze is the name for a compressed air diving device , which was in use from 1864 until well into the 20th century. It is named after its inventors, the mining engineer Benoît Rouquayrol , the naval officer Auguste Denayrouze and his brother Louis Denayrouze .
prehistory
In 1860, Rouquayrol completed the development of a breathing apparatus for the mining industry. This device, called aérophore , was primarily used to get to the miners who had had an accident through the accumulation of non-breathable gases in mine sections . In collaboration with Auguste Denayrouze, the device was modified so that it could also be used as a diving device.
Technical elements
The essential component is a regulator , which consists of two cylindrical pressure vessels made of sheet metal, a diaphragm-controlled reducing valve, a breathing tube with a mouthpiece and an outlet valve.
The breathing air is pumped into the first pressure vessel, the so-called air reservoir, using an air hose. The second pressure vessel, the air chamber, sits on top of this air reservoir. The top of the air chamber is made of a rubber membrane. Inside the air chamber, a linkage leads down from the center of the membrane to a reducing valve that regulates the flow of air from the air reservoir into the air chamber. The breathing tube leads laterally from the air chamber to the mouthpiece, which the diver holds in his mouth. A branch of the breathing hose leads to the outlet valve (a rubber lip valve ).
It is particularly noteworthy that the device could be supplied with a hose and used autonomously, i.e. without a hose. In this respect, the Rouquayrol-Denayrouze is the ancestor of today's independent diving devices, which are commonplace in diving.
Mode of action
The diver carries the device on his back like a knapsack .
Depending on the strength of the pump on the surface, the air in the air reservoir is at a pressure that is 3 to 4 bar above the ambient pressure. With the autonomous device, the diver carries a container in which the air is compressed to 30 to 40 bar.
If the diver inhales, a negative pressure is created in the air chamber compared to the ambient pressure. The membrane on the top gives way to this pressure and is thereby pressed inwards. This movement is passed on to the reducing valve via the linkage so that it opens. The air under positive pressure in the air reservoir flows through the air chamber into the breathing tube to the diver.
As soon as the diver exhales, the membrane is pushed up again against the water pressure and closes the reducing valve via the rods. The exhaled air flows through the outlet valve into the water.
Other pieces of equipment
If the diver carries enough weight to overcome the buoyancy (lead weights and lead shoes), the device can in principle be used without additional equipment. However, its use can be facilitated:
Nose clip
Breathing only through your mouth with your nose open takes a lot of practice. Therefore, the diver could wear a nose clip that allowed inhalation only through the mouth.
Eye protection
Man cannot see clearly underwater with the naked eye. In addition, seawater or lime attack the eyes severely in the long term when working on walls. Therefore, the diver could wear glasses that are similar to today's swimming goggles .
Alternatively, the diver could put on a helmet with a viewing window. He continued to breathe through the hose. There was no exchange of air in the helmet.
After all, there were two types of full face masks for the device . One model consisted of a rubber mask that reached from the chin to almost the back of the head and also covered the ears. There was a small glass window in front of each eye; the tube was firmly attached to the mask. The second mask model was made of metal and had one or more windows. It was worn by the diver in front of the face, resembled a diver's helmet cut in half and was called "le groin" ( pig's snout ) in jargon
From 1867 there is also a real diving helmet. However, the mouthpiece in the diver's mouth remained unchanged.
Advantages and disadvantages in handling
This principle, in which the diver does not breathe the air in the helmet, but constantly receives fresh air directly into the mouth, is referred to in contemporary sources as a French diving device (here: FTG), in contrast to the English diving device (here: ETG) with free helmet breathing . While the divers at the ETG had to struggle with considerable accumulation of CO 2 in the breath in the early days , the CO 2 content at the FTG remained at a permanently low level.
It was difficult to buoyancy the diver. With the ETG, air flows continuously into the suit, which the diver has to let out from time to time. The FTG works the other way around, so to speak. In order to get air into the suit, the diver has to inflate it, so to speak, by inhaling from the tube and exhaling into the suit.
Another problem arose when the diver had to work in unfamiliar body positions. If he was lying on his stomach, the diver had to suck harder on the breathing tube before there was enough negative pressure in the air chamber for air to flow in from the air reservoir. The other way around, more air came in than the diver would like if he was in a position in which the diving device was lower than himself.
Significance for the development of diving technology
Despite its disadvantages, the device was a technical and commercial success in its time. The French Navy procured it in large numbers and it was also widely used in sponge diving. The autonomous model of the diving device was downright revolutionary. Due to the low overpressure in the storage tank, the diving depth and time were limited, but it was not until 1911 that the Drägerwerk brought out a competitive hose-free helmet diving device.
Jules Verne insisted on “equipping” the crew of the Nautilus with the Rouquayrol-Denayrouze devices in his novel 20,000 Leagues Under the Sea of 1870. The production of the Rouquayrol-Denayrouze devices was not stopped until 1922, around 1,500 units were built. The Musée du Scaphandre in Espalion in the Aveyron department , where Rouquayrol and the Denayrouze brothers worked, preserves the memory of the devices and their inventors.
literature
- Hermann Stelzner: Tauchertechnik , Lübeck 1943
- Robert Sténuit : History of Diving - The Real Pioneers . In: diving , Issue 8/1989
- Julius (sic!) Verne, Twenty Thousand Miles Below the Sea , Collection Verne Vol. 6 and 7, Vienna, Pest and Leipzig around 1880