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You can now download “The Little story of the Underwater Cutting” in one single printable document at: https://www.academia.edu/24883704/The_Little_Story_of_the_Underwater_Cutting
As you may have realized from reading some of my stories I have since the beginning of my career always loved the underwater cutting jobs and so what more normal if today as a retired commercial diver that is having a bit more free time, I took it to interest me a little more in detail in the development of this technique.
Currently the commercial divers have at their disposal various tools and methods to accomplish such a mission such as:
- The gas burning torch.
- The electric cutting with plain electrode.
- The electric cutting with oxy-arc electrode.
- The electric cutting with ultra-thermic electrode.
- The thermic cutting lance.
- The Kerie cable.
- The arc plasma.
But as you can imagine this has not always been the case. I therefore invite you to follow me through a few articles to discover the history of these great tools.
Since John and Charles Deane brothers invented the first modern diving helmet with which they would create the diver profession in 1832 our elders have been faced with situations where they had to make use of a tool capable of cutting.
For these pioneers of underwater work the range was not very big and it was generally limited to a knife, a saw, an ax or a hammer with his chisel.
At the time many of the underwater works was done on wrecks and consisted to recover their cargo. Sometimes when the wreckage hampered the traffic it was destroyed and in this case the tools used were of course not these hand tools but rather black powder and later in 1864 the famous dynamite invented by Mr. A. Nobel.
Figure n° 1: Wreck demolition with black powder (1)
Towards the end of the 19th century things were deteriorating a bit for our divers with the appearance of the first steel hull ships and the various port structures made of the same metal. The steel cutting using strands of explosives continues to be used but this technique was not always well controlled.
Either the charge was too small and nothing was cut, or she was too high and much more was destroyed that planned.
Fortunately for small cutting jobs, in addition to the hammer and chisel our elders now had at their disposal the pneumatic drill which was invented by Mr. Simon Ingersoll in 1871 which was followed a little later with the chipper.
With these tools they could now by making a series of contiguous holes cut short lengths of steel. This is also the method that was used on the wreck of H.M.S Gladiator which sank in April 1908 following a collision with the St. Paul (the same that we will find later in another article).
Indeed, to avoid certain structures to hinder the salvage, the 15 tons guns, the 3 chimneys the masts and all other disturbing structures were cut using pneumatic chisels.
Photo n° 1: H.M.S Gladiator before sinking (2)
Photo n° 2: H.M.S Gladiator during salvage (3)
Needless to say that in those days the cutting of a steel structure was particularly laborious and tedious and it was therefore necessary to find some other more suitable equipment.
The first effective tool that would be available to divers in the early 20 Th centuries was the underwater gas burning torch, but this fabulous machine that would revolutionize the underwater works would however never have been possible without the genius of some men.
The first named Edmund Davy was an Irish professor of chemistry who in 1836 discovered the C2H2 (acetylene) and imagined that this gas could when burned in air be used as lighting.
Then comes Henry le Chatelier a French chemist who in 1895 discovered that the burning of an oxygen / acetylene identical volume generates a flame whose temperature reaches about 3130 ° C which exceeds the temperature of combustion of other known mixtures. Three years later this same chemist suggested inventing a device capable of exploiting this gas mixture so that it can be used for the welding and the cutting of ferrous metals gas.
In 1896 two other French scientists Albert Claude and George Hess invented a method for storing acetylene in cylinders under pressure without risk of explosion.
Another key figure who promoted this invention: Carl von Linde a German engineer who in 1902 built the first factory for the industrial production of oxygen and nitrogen with an air liquefaction process.
And finally, last but not least, Edmond Fouché and Charles Picard, who in 1902 invented the first oxyacetylene torch for welding metals (Patent No. 325,403, filed October 18, 1902) then followed in 1904 by the first cutting torch.
Figure n° 2: The first oxyacetylene welding and cutting torches (4)
Obviously, this new invention quickly goes round the world and many countries buy the rights to this patent to also manufacture this tool.
Unfortunately for our divers despite the rapid implementation of this cutting device on demolition sites in the open air they had still to wait until 1909 for that someone get interested in it and starts to transform the torch for underwater works.
Previously it had been tried to let the torch burn under water, but the flame extinguished constantly because of turbulence caused by the flow of residual gas bubbles.
How then do about it? Why not create an artificial atmosphere allowing the flame to burn in an air bubble insulating it from contact with water.
It seems that this idea was born more or less simultaneously in the head of two.
That of Charles Picard who works for the acétylène dissous plant in Champigny and the other, the engineer A. Heckt of the German company der Deutsch-Luxemburgischen Bergwerks und Hütten-A-G.
The latter, however, takes a small lead over the French since 1909 the company buys 4 German patents through which it will be able to manufacture the first underwater gas burning torch (5).
To protect the flame of his blowtorch our engineer invents a kind of iron collar which surrounds the nozzle of the torch in which compressed air is sent.
Photo n° 3: The first underwater gas burning torch (6)
Photo n° 4 : Detail iron carcan (7)
In addition to the oxyacetylene gas mixture he also uses very rapidly an oxy-hydrogen mixture. The first tests are carried out in a tank equipped with portholes in the presence of many engineers and representatives of the Kaiser Wilhelm Canal department and on this occasion a diver cuts a flat iron 100 x 20 mm with an oxyhydrogen cutting torch (8).
On another occasion a diver goes down to 5 meters deep in the port of Kiel and cut a square 60 mm iron bar in thirty seconds which is then followed by a plate 300 x 20 mm that he manages to cut in 90 seconds ( 9).
Photo n° 5: German diver with his gas burning torch (10)
In 1914 this German torch starts to be used to cut sheet piles, pieces of metal structures, pieces of wreckage and from the writings the cutting speed can reach 1.45 meters of sheet pile at a time while the thicknesses that may be cut with this first tool can reach 150 mm (11).
Photo n° 6 : Sheetpiles cutting 1914 (12)
In 1915 a second German torch made its appearance, that of W. & BRUSCH WFJ BEYER but apparently extinguishing problems seem to exist because a few months later the two inventors are developing an electric ignition system in which the current is delivered by a small portable transformer that saw his weight also serves as ballast.
Figure n° 3: W. BRUSCH & W. F. J. BEYER Patent (13)
Photo n° 7: Diver holding his portable transformer (14)
In 1932 a new torch made its appearance, that of the Berliner Mr. H.Töpper.
The special feature of this device is that the heating flame is not fed with a combustible gas but rather with a conventional liquid fuel such as gasoline, benzene or other.
This liquid fuel is sent to the torch by a bottle of compressed air or nitrogen where it will be heated and then vaporized by the heating resistor that is incorporated into the body of the torch.
Photo n° 8: H. Töpper gasoline torch (15)
Photo n° 9: H. Töpper Torch detail (15)
Figure n° 4: Sketch installation (15)
With this torch the diver could in function of the thickness (10-40 mm) cut a steel sheet of 1 meter between 160 and 220 seconds (16)
A year later it is the turn of Messer Griesheim to arrive on the market with its underwater cutter. It was developed to be used on wrecks lying up to 60 meters deep.
Photo n° 10: Messer Griesheim gasoline torch (17)
The operating principle is more or less identical to its predecessor; it is - to - say that the gasoline is also send the torch head via compressed nitrogen where it is then sprayed in the oxygen.
The torch body consists of three valves: one for the supply of the cutting oxygen, one for the heating oxygen and the last one for the nitrogen - gasoline mixture.
Photo n° 11 : Messer Griesheim gasoline torch (18)
Three tubes then bring the gas and liquid to the torch tip. The tubes as well as the torch head are interchangeable thereby obtaining a different inclination of the nose, which facilitates the handling of the tool according to the cutting work.
One big advantage of this torch is that it has no bubble skirt, it has been replaced by a combustion chamber (see Picard H7) allowing therefore to better seeing the cutting flame if there is a little visibility.
Since its commissioning the performance of the device are such that it will quickly become the most powerful burning torch of the market because depending on the thickness to be cut (10 mm to 100 mm) it can reach a cutting speed of 30 to 6 meters per hour (18).
For the common contemporary professional divers, these cutting speeds are quite unimaginable, yet in a cutting made in Paris during the seventies, I witnessed the daily performance of an Old Dutch hard hat diver who with this torch managed to cut between 145 and 160 meters of sheet piles in six hours of diving.
To achieve such a performance the torch needed to use high oxygen pressure which in the cold period tended to cause freezing of the gas.
To avoid this, the manufacturer had planned to send the oxygen through a tank of heated water.
Figure n° 5: Sketch Messer Griesheim installation (20)
Widely used in the years 40-45 for the cutting of numerous wrecks, it employment then declined sharply because despite its high performance this torch had also some serious drawbacks:
Indeed the noise generated by the combustion flame was comparable to that generated by a jet and was widely exceeding 100 decibels.
Secondly as with all torches, the flame does not fully consume the gas or in this case the liquid fuel which tended to rise to the surface with the resulting pollution of the environment.
All this equipment was quite laborious to implement and could become dangerous if all safety rules were not respected, and finally this torch consumed a lot of fuel (25-40 liters / hour) and therefore it became less and less profitable because of the fuel price increase.
To follow: The French gas burning torches.
(1) Diving apparatus with instructions for submarine opérations by Siebe & Gorman 1870 page 26
(4) https://www.cganet.com/docs/100th.pdf page 7
(5) Das Acetylen:Seine Eigenschaften seine Herstellung und Verwendung by J.R.Vogel 1923 page 267
(6) Das Acetylen:Seine Eigenschaften seine Herstellung und Verwendung by J.R.Vogel 1923 page 268
(7) Das Acetylen:Seine Eigenschaften seine Herstellung und Verwendung by J.R.Vogel 1923 page 268
(8) mémoires de la société des ingénieurs civils volume 102,1914,page 235
(10) Der Grundbau: Ein Handbuch Für Studium und Praxis Par Schoklitsch Schoklitsch 1932 , page 150
(11) Der Grundbau: Ein Handbuch Für Studium und Praxis Par Schoklitsch Schoklitsch 1932 , page 151
(12) Das Acetylen:Seine Eigenschaften seine Herstellung und Verwendung by J.R.Vogel 1923 page 270
(13) F.W.Brusch & W.F.J.Beyer Patent 1,298,880
(14) Praktisches Handbuch der gesamten Schweisstechnk by P.Schimpke & H.Horn 1924 page 129
(15) Le génie civil.Revue générale des industries françaises et étrangères (1932/12/17) page 612
(16) Le génie civil.Revue générale des industries françaises et étrangères (1932/12/17) page 612
(19) Die Schweisstechnik des Bauingenieurs: Einführung in Entwurf, Berechnung Par Bernhard Sahling 1952 page 209
(20) Manuel de découpage sous-marin par F. Hermans 1995 page 34