In 2002 I was lucky to find an original Denayrouze 3-bolt helmet in a antiques shop in the south of France. The helmet was made to be used either with a ‘regulator’ or as a ‘ventilated’ (free-flow) helmet (see photographs below):

In 1873 Denayrouze introduced a ‘ventilated’ 3-bolt diving apparatus. The main difference with the regulator unit is that with a ‘ventilated’ system, the air is pumped into the helmet on one side and escaped through an exhaust-valve on the other side, thus allowing the diver to breathe freely inside the helmet (see photographs below).

Over the following years I managed to slowly acquire the various parts to complete the set of apparatus. However the apparatus shown here has a ‘replica’ regulator back-pack. The hose shown on top of the helmet at to the right of the diver is the speaking tube: in 1874 Auguste Denayrouze’s brother Louis Denayrouze, patented this system which is simply a tube (identical to an air-hose) with a membrane on either side. The membrane inside the helmet covers a large part of the back and top of the helmet, so when the diver speaks to the surface assistant his voice can be heard through the membrane at the tender’s end of the speaking tube. The diver can also hear the tender when he speaks from his end. To date, I have not been able to find the exact date when the second model ‘Pompe Hydraulique’ air-pump was introduced, but it was probably around 1870. The difference between the ‘first model’ air-pump and the ‘second model’ is the shape of the cylinders: the early pump has cylinders with a ‘bell shape’ top, while the second model has flat top cylinders. The pump used with the ‘pig-snout’ mask apparatus by the Danish Navy is of the second model and it has the company name ‘Rouquayrol-Denayrouze’ cast into the iron base plate. Most pumps of this second model only have the name ‘Denayrouze’ casted into the base plate. Photographs, David L.Dekker

In the photographs below, the ‘regulator’ back-pack has been replaced by a normal lead weight and the air-hose has been connected directly to the helmet for diving use as a ‘ventilated’ (free flow) system.

Another interesting detail is the fact that where the equipment with the regulator only has a gauge at the junction where the two hoses from the pump are connected to the air-hose going to the regulator, the ventilated equipment shown here above has a tank at the surface between the pump and air-hose, this tank is in diameter identical to the tank of the regulator and was called the ‘reservoir intermediair’. Due to the lack of the tank incorporated in the regulator back pack an identical tank was placed on a tripod and the gauge has been fitted to it. This separate tank was important for several reasons: it allowed the water to condense (be trapped and held) inside the separate tank, so the condensate water could not pass down the diver’s air-hose and into his helmet. The ‘reservoir intermediair’ also allowed for a more even, regulated air supply to be fed to the diver. Later models incorporated an air-filter built inside the tank which provided a cleaner air supply to the diver. When using the regulator the gauge shows the pressure provided to the regulator which has to be held at a more or less constant pressure of one atmosphere above the ambient pressure for the regulator to work properly. With the ‘ventilated’ system the gauge would also indicate the depth the diver was at. Photographs, David L.Dekker

In 1874 Auguste Denayrouze established a new company which was formed through the merger of two previous companies in which he held partnerships. The two old companies included Rouquayrol-Denayrouze (established in 1865 and both men were partners) and the other was a sponge diving company that Auguste and his brother (Louis Denayrouze) were directors of. The newly amalgamated company of 1874 was called ‘Specialites Mecaniques Reunis‘. A year later in 1875 Benoit Rouquayrol died, followed in 1883 by Auguste Denayrouze. The remaining partner, Louis Denayrouze remained in charge of the company until it was taken over three years later in 1885 by Charles Petit.

Cabirol appears not have exported any diving apparatus to the Netherlands, probably because his apparatus was very similar to that of Augustus Siebe from England. After Cabirol died in 1874 his company was taken over by his nephew Charles Ferrus. What became of Charles Ferrus is not known but his company disappeared from its working address in 1880. During this period the ‘Specialites Mecaniques Reunis’ introduced their 12-bolt helmets and diving dress. It is possible that ‘Specialites Mecaniques Reunis‘ bought the remaining stock of the Cabirol / Ferrus company in 1880. This is supported by the fact that there are air-pumps known to exist which are built with Cabirol parts but have been given the company badge of the ‘Specialites Mecaniques Reunis‘, or that of Charles Petit.

A fine Cabirol helmet with various markings: Cabirol often stamped the breastplate of his helmets with the information about the prizes that he won at the 1855 World Exhibition in Paris. However, his nephew Ferrus soldered a badge over the text after he took over his uncles business in 1874. This helmet is from the collection of Leon Lyons, St. Augustine Florida. Photographs, David L.Dekker

Charles Petit’s new air-pump, the ‘Modele 1888 a joints Giffard’ Photographs David L.Dekker

Above: one of the first 12-bolt helmets made by ‘Denayrouze’ (by then the company name had changed to ‘Specialites Mecaniques Reunis’). The helmet has lost its badge therefore it could have been made after 1885 when Charles Petit bought the company. Two later versions of this helmet would be used in production which were slightly larger and smaller in size and volume, but otherwise looked the same as the previous helmet. Helmet above from a private collection; photographs, David L.Dekker

In 1885 Charles Petit bought the ‘Specialites Mecaniques Reunis’ company. The company name remained the same until 1895 when it was changed to ‘Societe Charles Petit’. Three years after Petit bought the company he introduced a new air-pump: the ‘Modell 1888 a joints Giffard’. The new air-pump was redesigned and now had its cylinders fixed at the base plate and included moving pistons (the two earlier models had fixed pistons and moving cylinders). The ‘reservoir intermediair’ (the tank which was placed between the pump and the air-hose in the previous model air-pump) was now integrated into the base and central column of the pump. The gauge was also fixed to the central column.

In 1889 Louis Denayrouze (brother of company founder Auguste Denayrouze) brought out a new style of helmet known as the ‘Scaphandre Denayrouze Charles Petit Modele 1889’  diving helmet which is also called the ‘Clampage’ (‘lock’) helmet or ‘Sans Boulons’ (without bolts) helmet.

A genuine ‘Denayrouze Charles Petit Modele 1889’ helmet. The brass straps which enforce the breastplate indicate that this helmet has been supplied to the French navy. Helmet collection Philippe Caresse. Photograph,  David L.Dekker

The above engraving of the ‘Denayrouze Charles Petit Modele 1889’ is illustrated in the Bikkers sales catalogue of 1902, but there is no catalogue information given about the helmet. only one single photograph exists showing a dutch navy diver with a Bikkers Lock Helmet (see chapter: ‘1841 BIKKERS HELMET’) which might indicate that only very few of these helmets were actually manufactured in Holland. The helmet (right hand photograph above) also shows the ‘Denayrouze Charles Petit Modele 1889’ helmet design, but this one was made by the English firm of ‘Siebe, Gorman & Co Ltd’. Only three of these English ‘copies’ are known to have survived which does confirm that these catalogued helmets were being built and sold by the Siebe, Gorman company. I acquired the helmet in Spain (photo above) in the 1990s. (See chapter: ‘1904 Siebe, Gorman & Co Ltd.‘). Photograph, David L.Dekker

Catalogue information from this time period is scarce therefore I can only assume that the new model 3-bolt helmet was the same as the new ‘lock’ helmet of 1889, but with the old 3-bolt locking system. The new 3-bolt helmets from the company of ‘Societe Specialites Mecaniques reunis’ / Charles Petit has a different shape and the entire helmet is taller when compared to the earlier 3-bolt helmets.

Charles Petit continued his diving apparatus manufacturing business into the 1920s. In 1926 his daughter married Rene Piel who came to work for the company. For some time both family names (Charles Petit & Rene Piel) were marked on the diving apparatus, but when Charles Petit died in 1930 the company was renamed ‘Rene Piel’.  Diving apparatus with both names on the company badge are rare but still occasionally seen (see pictures below).

The above helmet does not have a badge but it is a 3-bolt helmet made by Charles Petit. The helmet is taller than the 3-bolt helmets made by Denayrouze. Helmet: private collection. Photographs, David L.Dekker

After Rene Piel took over the business from his father-in-law, he continued the production of all models of air-pumps and helmets.

This Modele 1889 ‘Clampage’ helmet was made during the time when Charles Petit and Rene Piel works together, as the company badge has both names stamped on it. Helmet: private collection. Photographs, David L.Dekker

The 3-cylinder Denayrouze air-pump exists in three versions: the Modele ‘Fluviale’ (‘river pump’) is the smallest version. The pump shown in the above photographs is the Modele ‘Moyenne profondeur’ (‘medium depth’ type) and the third version is the large Modele ‘Grand Profondeur’ (‘great depth’ type; also known as the modele ‘Marine’, or ‘Navy’ type). The pump in the photographs above was manufactured at the time when Charles Petit and Rene Piel worked together as it has both names on the company badge. I found this pump last year (2010) in Belgium. Photographs, David L.Dekker

Above: a Piel 3-bolt helmet. This helmet was built between 1930 to 1940 or after 1945. This is because the company badges were made of aluminum during WW2 and this one has a brass badge. The telephone connection on this helmet is an early electric one and not the acoustic version. Photographs, David L.Dekker

The photographs below show a 12-bolt helmet made by Rene Piel. It is a relatively recent helmet as evident by the telephone, which is no longer ‘acoustic’ but ‘electric’ instead.

Helmet collection www.pieds-lourds.com   Photo’s David L.Dekker

Above: a Piel 3 bolt helmet. This helmet was built between 1957 and 1965 for the french navy. The telephone connection on this helmet is the last version of the electric one, it has no acoustic telephone. Photo’s David L.Dekker

The above drawing was produced in 1957 by the ‘technical service’ of the French navy in order to register the helmet as the standard diving apparatus for naval use. It is part of a set of genuine drawings which I bought several years ago. I am currently looking for a printer who can reprint it as a poster on heavy paper as it would make a high quality reproduction, quite suitable for framing. When they are available for sale I will announce it in the ‘For Sale and Wanted’ chapter.

Questions? Suggestions? Diving Equipment or Documentation for sale?