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5 avril 2016 2 05 /04 /avril /2016 12:47
Underwater cutting tools history (part 4)

Hi every one,

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

And with our English colleagues?

It is difficult to say who made the first underwater gas burning torch in England.

What is certain is that in 1919 two underwater oxyacetylene torches arrived in England following the acquisition by the Maritime Salvors LTD Company from New Haven of two salving vessels the Restorer and Reliant brought to the US Navy. The trademark of these torches is not clear but they were part of the equipment and items sold with boats (83).

In the early twenties, Siebe Gorman began designing an underwater cutting torch and to do so the firm decided to test several including the second generation Picard AD-8 cutting torch which was tested in November 1924

Photo n° 42: Cutting test with the 2nd generation Picard AD-8 torch in the Siebe Gorman tank in 1924 (84)

Underwater cutting tools history (part 4)

Photo n° 43: Cutting test with the 2nd generation Picard AD-8 torch in the Siebe Gorman tank in 1924 (84)

Underwater cutting tools history (part 4)

Photo n°44: Cutting test with the 2nd generation Picard AD-8 torch in the Siebe Gorman tank in 1924 (84)

Underwater cutting tools history (part 4)

Apparently the French torch seduced since the model they will create incorporates their principles that is to say, the combustion chamber and the pilot flame.

Figure n° 17: Sketch of the first Siebe Gorman underwater burning torch (85)

Underwater cutting tools history (part 4)

In 1933 another oxy-hydrogen torch is marketed by the firm Underwater Cutters LTD (86) and in 1938, an article published in "The Electrical Journal" (87) mentions that this torch was used to cut 30 meters of sheet piles at 3 meters depth.

Photo n°45: Underwater Cutters LTD torch (88)

Underwater cutting tools history (part 4)

Figure n° 18: Underwater Cutters LTD arrangement (89)

Underwater cutting tools history (part 4)

Then comes the torch made by B.O.C & Siebe Gorman. It was a very powerful torch with which the diver could have a cutting speed of 60 cm per minute.

As can see from the photo n° 46, the company has removed the pilot flame and the combustion chamber she had used on her first torch and this time uses the principle of the air bubble as used on US torches.

A first mention of the use of this torch is reported in an article describing one of the most famous oxy-hydrogen cutting in history (90).

Photo 46: B.O.C & Siebe Gorman torch (91)

Underwater cutting tools history (part 4)

This one takes place in 1944 on the British warship H.M.S Valiant. This battleship which was engaged in the battle against the Japanese fleet had suffered some damage that had forced her to go into dry dock in Ceylon, but following a false move during the dry setting the dry dock breaks and sinks.

Fortunately, the H.M.S Valiant remained afloat but during the sinking the end of the dock severely damaged one of her rudders two of her inner screws as well as the cast iron A frames holding them to the hull.

As there were no other dry dock installation likely to receive a vessel of this size in the Pacific it was decided to send her to Alexandria. Despite her damage, the battleship could still navigate but only at the reduced speed of 8 knots because the vibrations generated by the inertia of the two central propellers were enormous.

Arriving in the Suez Bay, Commander in Chief Sir John Cunningham called one of his good acquaintances the Lt Commander Peter Keeble, a salvage expert an experienced diver and asked him how to eliminate this problem. It's simple; Peter Keeble replied cut and drop the defective parts on the harbor floor.

Cunningham did not take long to decide and gave Keeble a week to perform this job (92).

Figure n°19: Stern of the H.M.S Valiant (93)

Underwater cutting tools history (part 4)

Him in turn contacted the petty officer Nichols another underwater work specialist, and between them they will undertake this cutting job which is far to be simple.

It must be said that the total weight of each items to be removed weighted around 26 tons.

During 2 days Nichols beefed up the existing torch and gave it an awesome strength. Then once ready he volunteered to do the first dive.

Sitting astride on the starboard shaft he began the cutting at 1.5 m from the gland. Four hours later he is forced to come to the surface because of a technical problem.

Then wanted to go down again despite a burned thumb but his chief took over and finally 6 hours later the first shaft was through.

A little bit too long we may think? Certainly not if we know that these shafts were 47 cm (18, 5 inches) in diameter.

It remained to cut the A frame that in section were 107 cm (42 inches) wide and 36 cm (14,5 inches) thick.

Nichols cut the first side of the port A frame in 4 hours.

Keeble cut the other side for about 70 cm (27 inches) and then stopped when he realized that the cut began widening. For security it was decided to cut the remainder of the metal with a plaster charge of 7.5 kg.

Bang! The entire starboard assemblage fell on the harbor bottom. It remained to do the same thing on the other propeller which took about the same time.

Figure n°20: Removal of the starboard side (94)

Underwater cutting tools history (part 4)

Finally thanks to the cutting the vibration completely disappeared and the dry docking wasn’t necessary anymore.

Figure n° 21: British Gas and Torch (95)

Underwater cutting tools history (part 4)

Photo n° 47: B.G.T underwater torch equipment (96)

Underwater cutting tools history (part 4)

As shown in Figure n° 21 a submarine oxyacetylene gas torch was also manufactured by the British Gas and Torch Company from Camberley but no reference is found regarding the date of manufacture.

1945 saw the arrival of the Seafire (97). It is a small oxy-hydrogen torch where the diameter of the mixing nozzle is reduced which has the advantage of using significantly less gas and makes it very convenient for small cutting jobs.

Photo n° 48: Seafire torch (98)

Underwater cutting tools history (part 4)

The handle comprises two valves for the supply of the heating flame and a trigger for the cutting oxygen supply. The head is connected to the handle by 4 tubes. The top tube that leads the cutting oxygen, the lower tube the shield oxygen, the left tube the hydrogen fuel, and the right tube the heating oxygen.

Figure n°22: Seafire description (99)

Underwater cutting tools history (part 4)

The head is provided with an outer removable nozzle in which the flame burns.

The particular design of the chamber allows an additional supply of oxygen to the base of the flame, thereby promoting combustion. The mixture of the two gases is done in the same nozzle of the torch.

Two models with head orientation at 45 ° or 90 ° are available.

Photo n°49: Diver with a Seafire torch (100)

Underwater cutting tools history (part 4)

And finally in 1968 (101) we find the Vixen Kirkham M2, which was the last torch being manufactured by our English friends.

As can be appreciated, with the exception of the locking system of the trigger this torch resembles the model of the Seafire.

Photo n°50: Vixen Kirkham M2 torch (102)

Underwater cutting tools history (part 4)

Other countries also had their torch, but like everywhere else these have gradually been abandoned in favor of the electric cutting.

One of the main reasons is due to the fact that learning this technique is longer and more difficult.

Photo n° 51: Loosco Dutch torch (103)

Underwater cutting tools history (part 4)

Photo n° 52: Hungarian torch from the twenties (104)

Underwater cutting tools history (part 4)

Figure n° 23: Hungarian torch (105)

Underwater cutting tools history (part 4)

Photo n° 53: Italian torch with the automatic gas control unit (106)

Underwater cutting tools history (part 4)

The problem with the underwater gas burning torches is that they sometimes need to be turned off (or sometimes go out from themselves) for a few minutes.

If the diver is working in shallow water, this does not pose much problem because all he had to do is ascend a few meters to reignite.

But this can quickly become annoying or impossible to do on deeper sites. As we have seen, Mr. Corné Mr. Picard and the Fabbrica italiana d'apparecchi per saldatura, Milano had solved this problem by inventing the pyrotechnic igniter and the pilot flame.

Elsewhere the electric ignition was privileged. In the early twenties (1920) two ignition systems appeared.

The American system that worked from a 110 volts DC power source and the English system that was rather using a 12-volt battery.

The implementation was more or less identical. When the diver wanted to light his torch, he first settled the length of the gas bubbles and then once done asked for juice. This depending on the system caused a spark which in turn lit the torch. Once it burned correctly the current was cut at surface and the cutting could start.

Figure n° 24: American ignition system (107)

Underwater cutting tools history (part 4)

Figure n° 25: English ignition system (108)

Underwater cutting tools history (part 4)

Photo n° 54: Modern ignition system (109)

Underwater cutting tools history (part 4)

As seen through the first three articles, underwater cutting torches helped make huge service and have greatly facilitated the work of divers.

They were intensely used until the fifties then gradually abandoned in favor of new cutting processes easier to use.

Currently, there is only one (real) underwater gas burning torch on the market: The PVL a Dutch manufactured torch that uses MAP gas or other by product. The torch is designed around the mixing nozzle of the P9 Picard torch making it therefore an EXCELLENT tool whose performances are identical to its model of reference.

Photo n° 55: PVL torch (110)

Underwater cutting tools history (part 4)

Photo n° 56: Cutting course with the PVL (111)

Underwater cutting tools history (part 4)

Apart from this Dutch torch some (rare) manufacturers still offer the possibility to use their common torch under water by adapting a special cap on their head.

Photo n° 57: Pyrocopt combustion chambers (112)

Underwater cutting tools history (part 4)

Photo n° 58: Petrogen cutting torch (113)

Underwater cutting tools history (part 4)

Photo n° 59: Harris underwater cutting adapter (114)

Underwater cutting tools history (part 4)

To follow: The other cutting techniques

References :

My special thanks go to David L.Dekker and Lévai Miklós for their information supplied in the references n° 84, 85 (David) and 95,96,104-106 (Lévai).

(83) https://archive.org/stream/literarydigest65newy#page/n671/mode/2up/search/Reliant

(84) « Everything for the diver » « Everything for Submarine Operations » Siebe Gorman and Company,Limited / « Neptune » works, London, S.E.1 page 86-87

(85) « Everything for the diver » « Everything for Submarine Operations » Siebe Gorman and Company,Limited / « Neptune » works, London, S.E.1 page 88

(86) Shipbuilding & Shipping Record 1933 vol 41 page VI

(87) The Electrical Journal volume 120 page 308

(88) https://sites.google.com/site/rexidesilva/history-of-diving-in-sri-lanka

(89) DYKKEHISTORISK TIDSSKRIFT Nr 50-17 Argang 2013 page 4

(90) Deep Diving and Submarine Operation by Robert H.Davis /Siebe,Gorman & Company LTD CWMBRAN, GWENT 175 Anniversary edition / page 221

(91) Deep Diving and Submarine Operation by Robert H.Davis /Siebe,Gorman & Company LTD CWMBRAN, GWENT 175 Anniversary edition / page 222

(92) Marine Salvage by Joseph N. Gores 1972 David & Charles page 288-289

(93) https://www.the-blueprints.com/blueprints-depot-restricted/ships/battleships-uk/hms_valiant_1942_battleship-64634.jpg

(94) Deep Diving and Submarine Operation by Robert H.Davis /Siebe,Gorman & Company LTD CWMBRAN, GWENT 175 Anniversary edition / page 223

(95) Buvarismeretek by Ugray Karoly 1953 page 73

(96) Buvarismeretek by Ugray Karoly 1953 page ??

(97) http://www.mcdoa.org.uk/RN_Diving_Magazine_Vol_15_No_2.pdf page 12

(98) http://d121tcdkpp02p4.cloudfront.net/clim/112031/CIMG1409.JPG

(99) The Professional Diver’s Handbook by John Bevan Submex 2005 page 118

(100) https://pp.vk.me/c619917/v619917217/cdc1/p215pO7s5ws.jpg

(101) http://www.mcdoa.org.uk/RN_Diving_Magazine_Vol_15_No_2.pdf page 12

(102) The Master Diver and the Underwater Sportsman by Capt. T.A.Hampton 1970 David & Charles page 144

(103) http://www.pieds-lourds.com/Pages/pages.htm

(104) Buvarismeretek by Ugray Karoly 1953 page 70

(105) Buvarismeretek by Ugray Karoly 1953 page 72

(106) Buvarismeretek by Ugray Karoly 1953 page 74

(107) Underwater Work by Cayford Cornell Maritime Press 1966 page 112

(108) The Master Diver and the Underwater Sportsman by Capt. T.A.Hampton 1970 David & Charles page 102

(109) http://alahliyah.com/?page_id=7947

(110) http://www.pvlint.com/

(111) https://www.facebook.com/photo.php?fbid=827342850648855&set=o.249684318499419&type=3&theater

(112) http://www.saf-fro.fr/file/otherelement/pj/t%C3%A3%C2%AAtes%20de%20coupe37989.pdf

(113) http://www.petrogen.com/

(114) http://eu.harrisproductsgroup.com/en/Products/Equipment/Torches/Straight-Cutting/model-62-3fw.aspx

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4 avril 2016 1 04 /04 /avril /2016 08:49
Underwater cutting tools history (part 5)

Hi every one,

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

The second method of cutting under water to have emerged uses the principle of arc welding. Here again, this invention is due to the genius of a few great men.

The first is simply the English physicist Sir Humphry David (Edmund’s cousin) who in 1813 managed to create an electrical arc under water.

It will then be necessary to wait until 1890 to see appearing a first patent for a process of arc welding. The problem is that this first method uses bare electrodes without coating and therefore the arc is very unstable and the welds of mediocre qualities.

Fortunately ten years later the first coated electrodes are invented thereby bringing the first welding jobs. Very quickly during these works welders are going to realize that by increasing the current intensity it was then possible to cut or rather melt thin sheets.

Nevertheless, it will again be necessary to wait until the middle of the First World War to see someone use this process under water.

The first under water metal-arc cutting essays with a welding rod seem to have begun simultaneously in France, the United Kingdom and in the United States.

In France tests are performed under water in 1917 by the Soudure Autogène Française Company with two types of electrode: small diameters steel électrodes and large diameters carbon electrodes.

But the generators that are used in those days in France are not powerful enough and the tests are inconclusive. As a result on the French side the electrical cutting trials will not resume before 1924 (115).

The British Admiralty seems to have had more success with this process since the Deep Diving and Submarine Operations book from Siebe-Gorman mentions that its divers used it during World War I (116).

At the American side it is to the firm Merritt-Chapman & Scott that returns the merit to have developed this system that will also be used on the S.S St Paul in addition to the gas burning torch.

Photo n° 60: Diver with cutting torch (117)

Underwater cutting tools history (part 5)

From June 1918 R. E. Chapman and J. W. Kirk applies for a patent for a method of cutting under water by means of the intensity of an electric arc.

For that purpose, the inventors plan 3 manners to cut the steel.

1° by means of the only heat generated by the electric arc of a carbon electrode.

2° by means of a carbon electrode perforated by 3 holes allowing the passage of a flux of oxygen.

3° by means of a carbon electrode provided by two small pipes allowing the passage of a flux of oxygen.

Figure n°26: description of the process (118)

Underwater cutting tools history (part 5)

In practice we will later see that only the use of the hollow electrode will be favoured.

This patent will be followed a little later by another one also filed by Chapman concerning this time the electric cutting torch which is used by its divers.

Figure n°27: Sketch cutting torch (119)

Underwater cutting tools history (part 5)

Photo n° 61: oxy-arc cutting torch (120)

Underwater cutting tools history (part 5)

To train its workers to this new technique a training tank is installed within the company and very quickly the divers will adopt this technique to make some difficult cuttings.

Photo n° 62: Merritt-Chapman & Scott cutting equipment and training tank (121)

Underwater cutting tools history (part 5)

One of the first practical uses will be done in 1919 on the freighter Lord Dufferin. It collided with the steamer AQUITANIA and to prevent it from sinking the ship had been stranded on the island of the Statue of Liberty. About twenty meters from its stern had been partially ripped off and to allow its dry-docking, the divers had to cut by oxy-arc about 8 tons of wrinkled sheets.

Photo n° 63: Lord Dufferin in dry dock (122)

Underwater cutting tools history (part 5)

Another great performance realized by the guys of this company took place in New York in February 1922. At that time a dredge accidentally pierced a 36 inches drinking water pipeline feeding Stade Island one of the New York districts.

Photo n° 64: Cutting training (123)

Underwater cutting tools history (part 5)

The repair planned to remove the damaged section and replace it with a steel spool piece.

Several working days were necessary to clear the damaged part of the pipe which rested under a thick layer of mud and thus enable divers to start cutting. But the job is not simple because despite the mud removal some sections of the pipe must be cut from the inside which one can imagine was far from comfortable with a Mark V helmet on the head.

Furthermore, the main was made of thick (80 mm) cast iron which we know is not readily oxidized. Despite these difficulties the divers finally managed to complete this work within 9 days during which they plunged 24h / 24h and cut not less than 10 linear meters of pipe (124).

Photo n° 65: Removal of the damaged section (125)

Underwater cutting tools history (part 5)

And to end we can still mention the cutting realized by John Tooker in also some difficult conditions of around thirty piles that were protecting one of the Texas bridge piles on the Atchafalaya River, Melville which had been torn away and twisted by a big timber fender pier adrift.

Figure n° 28: Detail of sheet piling (126)

Underwater cutting tools history (part 5)

The work that began November 17, 1922 had required 114 hours of diving among which 67 hours were devoted exclusively to oxy-arc cutting (127).

Becoming aware of the capacities of this electrical cutting tool the US Navy will also develop a first oxy-arc cutting torch. Unlike the Chapman and Kirch torch which we recall is straight, the US Navy one is square and can work with an electrode pointing at 90 °. Among those who participated in the design and the trials we find in particular the Chief Petty Officer John Henry "Dick" Turpin, who was one of the first African American Navy divers.

Photo n° 66: The diver J. H. Turpin (128)

Underwater cutting tools history (part 5)

Thanks to this torch the Navy divers will be able in 1927 to intervene effectively in the refloating work of another submarine the S-4, in which no less than 564 dives of any kinds will be realized (129).

In France in 1924, the Société de la Soudure Autonome Française resumes under the direction of Mr. Lebrun the essays of oxy-electric cutting she had interrupted in 1917 and on June 10, a diver managed using a coated iron tube (4mm inside diameter and 8 mm outer diameter and 80 cm length) to cut a sheet steel section of 20 mm in thickness thanks to a series of contiguous holes (130).

The literature does not specify the type of coating, but it's a safe bet that it was adhesive tape because it (the coating) protected the cutters who worked barehanded from the effects of the alternating current (130). Given the success of the trials it was this technique which was going to be used a few days later to continue the cutting tests on the Tubantia which we remember had been interrupted following the explosion of the flexible hoses (see article 2).

This time a diver managed thanks to 6 iron electrodes to cut a length of 1.2 meters plate in one hour of time. The straightness of the cut had been assured thanks to the implementation of a wooden guide painted in white (130).

As shown, the electrodes used during the French trials were in iron and not in carbon but it is nevertheless this last type of prismatic electrode 30 cm long breakthrough by 2 holes for the arrival of oxygen that will continue to be used by European diving companies into the forties.

By 1932 another cutting method by means of electrode 8 to 10 mm in diameter (without oxygen) will be developed by Mr. Sarrazin but it will be very little applied because its implementation required an operating current of about 1000 amps (131).

In 1935 Siebe-Gorman also describes an oxy-arc torch in its manual. As we can see on the photo 67 it is also a linear shape.

Photo n° 67: Siebe-Gorman oxy-arc torch (132)

Underwater cutting tools history (part 5)

In 1939 the American Swafford applies for a patent for a new torch but it seems that this model was never marketed.

Figure n° 29: Sketch of the Swafford oxy-arc torch (133)

Underwater cutting tools history (part 5)

On the other hand, towards the same time the same Mr. Swafford also manufactures a cutting electrode composed of a brass tube of Ø 9,5 x 350 mm in which are either welded a small square electrode or 3 steel rods. In order to be properly insulated the electrode it is protected by 3-5 wraps of insulating tape.

This electrode that now contains 7 steel rods will be in service for a few years in the US Navy and will still be mentioned in the various Manuals until 1948.

Figure n° 30: Sketch of the Swafford electrode (134)

Underwater cutting tools history (part 5)

It will be necessary to wait until 1940 to see a real evolution in the design of electric cutting.

At that time the department of the United States Navy decided to adapt existing materials in the need for the time. The modernization of this equipment will be realized at the US Naval Engineering Experimental Station located in Annapolis, Maryland and the material will then be tested by the Experimental Diving Unit and Deep Sea Diving School in Washington as well as at the US Naval Training School located at Pier 88 in New York.

It is moreover this number of quay that will give its name to this new oxy-arc torch.

Photo n° 68: The Pier 88 cutting torch (135)

Underwater cutting tools history (part 5)

From that time also the big carbon electrodes are gradually going to disappear in favour of new finer tubular electrodes.

Two new types of hollow electrode will then be available: The ceramic electrodes and the steel tubular electrodes covered with a coating.

Photo n° 69: Models of electrode (136)

Underwater cutting tools history (part 5)

With this new equipment, the American divers are going to be able to work more effectively on the diverse ships which were sunk by Japanese aircraft. At Pearl Harbor, not less than 20,000 hours of diving will be needed to refloat most ships among which numerous hours were dedicated to cutting (137).

What is extremely surprising is that since the advent of electric cutting until the late forties a lot of cutting was also made with alternating current. In spite of the inconveniences and the risks of this type of electric supply the only additional precaution that were taken by the divers with regard to direct current consisted to better insulate the inside of the helmet by covering for example all metal parts which might to touched (139 ).

What is on the other hand to notice is that from the very beginning, it was recommended to turn off the electric current during cutting stops and changes of electrodes (see Chapman and all patent process).

In Europe also the oxy-arc cutting begins to get modernized after the Second World War. If England and to a lesser extent in Italy they continue to favour the use of carbon electrodes until the late sixties.

Photo n° 70: Siebe-Gorman cutting set (140)

Underwater cutting tools history (part 5)

Photo N° 71: Diver using an Italian torch (141)

Underwater cutting tools history (part 5)

In France, Belgium and possibly other countries we begin on the other hand to quickly use the steel tubular electrodes "Oxycuttend" manufactured by the company Arcos and the pink electrodes of Craftsweld. These two cutting rods were covered with a rutile coating which had the advantage to generate an extremely stable arc.

On the other hand this coating degraded rather quickly in the water and it was therefore better to protect the electrodes with insulating tape. To avoid this inconvenience Arcair launches on the market in 1971 the SEA-CUT.1, an electrode composed of a mixture of carbon and graphite which does not contain more than a simple plastic coating.

Photo n° 72: SOGETRAM diver doing some cutting training (142)

Underwater cutting tools history (part 5)

Each type of electrodes available had good cutting performance, but also some disadvantages. The big advantage of the carbon and the ceramic electrodes was their burning time which was generally 10 times higher than that of steel electrodes (143). They were also a little shorter what facilitated the work in confined spaces. On the other hand these electrodes broke very easily and the kerfs were rather narrow. Thereby they become less efficient than the plates became greater than 19 mm.

In the years that followed various oxy-arc cutting torches will be marketed everywhere (ARCOS, BECKMAN, CRAFTSWELD, ARCAIR, BROCO).

All are equal in quality if used and maintained properly.

Figure n° 31: Sketch of the Craftsweld torch (144)

Underwater cutting tools history (part 5)

Photo n° 73: Beckman cutting torch (145)

Underwater cutting tools history (part 5)

Photo n° 74: Russian cutting torch (146)

Underwater cutting tools history (part 5)

Between 1975 and 1978, basing probably on the principle of the thermal lance cutting (see below) as well as on what Swafford had invented in 1939, the Broco Company is developing the first ultra-thermic electrodes.

These are constituted by a fine steel tube 0.7 mm in thickness in which are crimped 7 metal wires of Ø 2.4 mm. Among these one is in a different alloy which allows the maintaining of an exothermic reaction after the cut of the electric current.

Photo n° 75: Electrodes Broco (147)

Underwater cutting tools history (part 5)

This electrode has a number of advantages compared with the steel tubular electrode such as that of requiring only a low intensity current (150 Amps) to work and thus a less heavy generator can be set up on construction sites.

Another undeniable advantage of this type of electrode is due to the fact that thanks to her exothermic reaction it can cut a larger number of materials that are oxidizing or not.

Its implementation is also easier because thanks to the fact that she can burn almost any material the cleaning of the surface to be cut needs no longer be as neat and finally learning how to use it is easier than that of cutting with steel tubular rods.

As a result, this type of ultra-thermic electrodes is fast going to dominate the market and its principle will rapidly be adopted or copied by other manufacturers or even private entrepreneurs who are going to produce in their turn this type of electrodes (Comex pro, Magnumusa, Divex, Arcair, HBS and many others).

Photo n° 76: Cutting with an ultra-thermic electrode (148)

Underwater cutting tools history (part 5)

As mentioned a little earlier, the inventors of this new ultra-thermic electrode were probably inspired by another process of cutting: The thermal lance.

It consists of a steel tube of about 3 meters long with diameters ranging from 13 to 21 mm packed with alloy steel rods. It was invented in the 1930s by the French company Air Liquide, which was itself based on the invention of Ernst Menne German who in 1901 developed an oxygen lance for opening furnace taps in steel blast furnaces (149).

Thanks to its high combustion temperature thermal lance can pierce virtually any type of material. Regarding its use in water, it begins just after the Second World War where it is mainly implemented to create boreholes in the cement or the concrete that filled the holds of some wrecks.

By 1968 the American Marine discovers that this type of oxy-lance is used in Europe and thinks that the process could be used in some salvage operation and therefore asks the Battelle Memorial Institute to conduct an investigation on the risks incurred by the divers (150).

The result of the study was clear: process too dangerous to be used under water because of the high risks of explosion.

Despite these risks, certain diving company will nevertheless use the thermal lance in the end of the 70s for the opening of cavities in the reinforced concrete structures of some offshore platforms (151).

Currently, the thermal lance does not seem to be more used than by small companies not always aware of the risks or for the cutting of big piece when no other cutting mode is possible.

Picture n° 77: Cutting of a pipeline using a thermic lance (152)

Underwater cutting tools history (part 5)

It is then the turn of Reginald Clucas to arrive on the market with a new product.

Probably that this one has in the circle of acquaintances divers who told him about the underwater electric cutting and limitations bound to the electrode burning time. He imagines therefore a system that will allow divers to cut much longer without having to continually change rods and which is also less bulky than long thermal lances.

As a result, in 1968 he launches on the professional diving market a thermic cutting cable for whom he is going to borrow the first name of his daughter Kerie (153).

Photo n° 78: Kerie Cable reel (154)

Underwater cutting tools history (part 5)

The operating principle of the Kerie cable is similar to the thermal lance but contrary to the metallic tubes containing alloy threats, the system consists of an outer sheath of plastic material in which a plurality of multistrand high carbon steel wires forming a hollow core to allow the passage of oxygen are set.

The ignition of the cable is done either by means of a torch flame or electrically with a current of 12 volts. The cables are supplied in lengths of 15 and 30 meters and in three dimensions 6, 9 and 12 mm

Figure n°32: Principle of implementation of the Kerie cable (155)

Underwater cutting tools history (part 5)

Photo N°: 79: Kerie Cable Set (156)

Underwater cutting tools history (part 5)

The burn rate is about 60 cm per minute what gives it a burning time of approximately 50 and 25 minutes by cable.

Although its principle of operation resembles that of the thermal lance, its melting temperature is however much lower (2700 °) what only makes possible that the cutting of ferrous metals.

One big problem with this cable (especially the first generation) was due to the fact that sometimes the plastic sheath was consumed faster than the metal core of the cable which was particularly annoying during cuttings without visibility and more than one diver did burn his hand.

Photo n° 80: Defect of functioning (157)

Underwater cutting tools history (part 5)

This is probably one of the reasons why this system has never really breakthrough and somewhat fell in oblivion for nearly 3 decades. Today, this problem appears to have been solved and the new system seems to be adopted by several navies and companies.

Photo n° 81: Diver using the Kerie cable (158)

Underwater cutting tools history (part 5)

In 2004 we see the arriving of the Swordfish rod from the Speciality Welds society (159).

This new electrode with a high content of iron oxide sold in diameter of 4 mm and 5 resumes the principle of the metal-arc cutting method (without supply of oxygen) used during the early electrical cuttings that is to say that the steel is not oxidized by an oxygen jet but is simply melted by the heat of an arc of about 400 amperes.

Photo N° 82: Result of a Swordfish cutting (160)

Underwater cutting tools history (part 5)

The latest thermal cutting method at disposition of the divers is that of the plasma arc.

Photo n° 83: Plasma arc torch and its control panel (161)

Underwater cutting tools history (part 5)

It was developed in the fifties but at that time it is not yet widely used because of some double arcing phenomena that damaged the electrode and cutting nozzle and it will be necessary to wait from then on until 1963 to see a real start in the surface cutting (162).

Fairly quickly the French company SOGETRAM discovers this process and decides to test it in the dive pool on Garenne sur Eure. The trials will however be quickly stopped because the vibrations and explosions generated by the tool during the cutting sequences were such that the staff feared the breaking of the portholes (163).

It will then be necessary to wait until 1985 to see the underwater arc plasma reappear in the former Soviet Union where this technique will be used together with the oxy-arc on the cutting job of the tanker Ludwig Svoboda that exploded in the port of Ventspils (164).

Photo n° 84: Wreck of the Ludwig Svoboda (165)

Underwater cutting tools history (part 5)

One of the problems of the implementation of the underwater arc plasma is bound to the fact that this process runs at 120-200 V arc voltage and has an open circuit voltage of 250-400 V what exceeds very widely the 30 volts recommended by most regulations (166).

Nevertheless from the beginning of this 21nth century the British company Air Plasma Ltd decides to adapt one of their systems for under water use and managed to eliminate electrical hazards for the divers. Their torch will be used the first time in March 2005 on a project of Mermaid Offshore Services in South Korea on which the divers will cut a series of holes of varied shapes and sizes in a steel sheet 32 mm located at the base of a platform (167).

The same torch will also be used in Canada in 2006 for the underwater cutting of 1500 m of sheet piles (168) and more recently in the United Kingdom to that of a curtain of about 800 m (169). Unfortunately no feedback is available concerning the possible difficulties met during the cutting of the locks and therefore it is a safe bet that only flat parts have been cut by the torch.

One of the advantages of the plasma arc is that the cutting generates relatively little debris and thus this cutting method is also used in nuclear power plants for the dismantling of some submerged structures. In most cases, the torch is remotely manipulated from the surface, but recently the divers of an American company specialized in this type of works cut out all the internal components from four steam generators (170).

Photo n° 85: Cutting trial with the underwater plasma torch (171)

Underwater cutting tools history (part 5)

But apart from these few particular applications there are very little echo’s concerning other types of underwater cutting work using this method.

Conclusions:

As we have seen through these five articles, as well as through the information of Figure n° 33 which represents the cutting speeds achieved during some tests performed in December 1940, the various tools were relatively productive and allowed to perform tasks that without them would have been impossible to make.

Figure n° 33: Length of cut made in 12 minutes using various cutting processes (172)

Underwater cutting tools history (part 5)

Today because of its ease of learning one favourites especially the cutting with ultra-thermic rods. Yet in the point of view of cutting speed per hour, if we except the plasma arc which is currently only used for specific applications and can cut the rate of 3 cm / sec (108 m / h) (173), the undisputed champion for most cutting operations in civil engineering still remains the underwater gas burning torch because used in good conditions and by some competent diver it can reach the speed of 66 m / h (174). It is followed rather far by the oxy-arc cutting (30,5 m / h) (175) and the ultra-thermic cutting (24,5 m / h) (176).

Referring to Figure 33, it is surprising to notice that the cutting speed mentioned for the oxy-hydrogen cutting is so low (7.5 m / h) as it does not correspond to the reality of the time when speeds were rather situated around 36 m / h (177).

It is therefore likely that this test was realized by a diver non-specialized in this type of cutting.

Figure n°34: Extrapolation Figure n° 33 to current performance (174 ,175, 176)

Underwater cutting tools history (part 5)

Despite the efficiency of these tools it is clear that both in civil engineering and offshore, thermal cutting operations have greatly diminished.

This is due to several reasons. On shore where these tools were primarily used for cutting of sheet piling it is partly due to the fact that first the steel prices increased sharply and secondly powerful hydraulic extracting tools were created during these last years which have therefore allowed the removal of the piles in their entirety.

In offshore, this mode of cutting also tends to be replaced by methods less risky for divers. Indeed, regardless of the method that is used it always generates a more or less large quantity of highly explosive gas which if they are confined in an enclosed area near the cutting area may explode violently under pulse of incandescent slag.

Photo n° 86: Diving helmet having suffered the effects of an UW explosion associated with cutting (178)

Underwater cutting tools history (part 5)

This risk is moreover very real because since the invention of the first underwater torch dozen of divers have unfortunately lost their lives by cutting (179).

The problem is that because of this decrease of cutting work the experience is lost and the new divers hardly have the opportunity to practice.

Even in the commercial diving schools this technique is often approached only in a succinct way by teachers who themselves do not always properly master this process. Yet an effort should be made in improving this teaching because even if less used it is almost certain that during still quite some years thermal cutting will remain a valuable tool for the diver.

References:

(115) L’emploi du chalumeau et de l’arc électrique dans les travaux sous-marins 1945 Académie de Marine par Maurice Lebrun page 22

(116) Deep Diving and Submarine Operation by Robert H.Davis /Siebe,Gorman & Company LTD CWMBRAN, GWENT 175 Anniversary edition / page 228

(117) Popular Mechanics Magazine Aug. 1934 page 164

(118) http://www.google.com/patents/US1324337

(119) RALPH E. CHAPMAN, OF MIAMI, FLORIDA. APPARATUS Fon. CUTTING on WELDING METAL. Application ñled October 9, 1925.` Serial No. 61,391.

(120) Popular Science Nov.1932 page 52

(121) Popular Mechanics Magazine May 1922 page 682

(122) Pacific Marine Review 1919 page 598

(123) Pacific Marine Review 1922 page 338

(124) Pacific Marine Review 1922 page 338

(125) Popular Mechanics Magazine May 1922 page 682

(126) Engineering news-record vol 90, n°10 march 8 1923 page 454

(127) Engineering news-record vol 90, n°10 march 8 1923 page 454

(128) http://paris-tx-naacp.blogspot.be/2011_08_01_archive.html

(129) Marine Salvage by Joseph N. Gores 1972 David & Charles page 119-123

(130) L’emploi du chalumeau et de l’arc électrique dans les travaux sous-marins 1945 Académie de Marine par Maurice Lebrun page 23-24

(131) L’emploi du chalumeau et de l’arc électrique dans les travaux sous-marins 1945 Académie de Marine par Maurice Lebrun page 30

(132) The Historical Diving Society Italia hds_48 pdf page 9

(133) http://www.google.com/patents/US2210640

(134) Divers Manual 1948 US Navy Training School (Salvage) Navy Yard Annex Bayonne New Jersey/Reproduction by the Historical Diving Society USA Santa Barbara, California fig.17

(135) Divers Manual 1948 US Navy Training School (Salvage) Navy Yard Annex Bayonne New Jersey/Reproduction by the Historical Diving Society USA Santa Barbara, California fig.10

(136) Underwater Work by Cayford Cornell Maritime Press 1966 page 93

(137) Marine Salvage by Joseph N. Gores 1972 David & Charles page 299-300

(138) L’emploi du chalumeau et de l’arc électrique dans les travaux sous-marins 1945 Académie de Marine par Maurice Lebrun page 30

(139) L’emploi du chalumeau et de l’arc électrique dans les travaux sous-marins 1945 Académie de Marine par Maurice Lebrun page 30

(140) Deep Diving and Submarine Operation by Robert H.Davis /Siebe,Gorman & Company LTD CWMBRAN, GWENT 175 Anniversary edition / page 228

(141) https://www.facebook.com/photo.php?fbid=10201906456641309&set=g.168828609978762&type=1&theater

(142) Brochure Sogetram

(143) Divers Manual 1948 US Navy Training School (Salvage) Navy Yard Annex Bayonne New Jersey/Reproduction by the Historical Diving Society USA Santa Barbara, California section 16

(144) https://www.google.com/patents/US2417650

(145) Commercial Oil-Field Diving by N.B. Zinkowski CMP 1971 page 170

(146) http://shelfspb.ru/upload/structure_1/1/1/6/structure_116/structure_property_image_83.jpg

(147) http://images.marinetechnologynews.com/images/maritime/w400/image-broco-underwater-22265.jpg

(148) https://www.facebook.com/kirby.morgan.apparel/photos/a.312480892127738.68021.288917144484113/1074685842573902/?type=3&theater

(149) http://www.saimm.co.za/Conferences/FurnaceTapping/203-Dienenthal.pdf

(150) Characteristics of Burning Bars Important to Their Being Used for Underwater Salvage Operations G.H. Alexander (Batelle Memorial Institute) Offshore Technology Conference 1969

(151) Anciens de Comex group memories of MCP 01 concrete cutting

(152) https://www.facebook.com/deivis.villalobos.9/videos/10207700185759910/

(153) http://www.google.ch/patents/US3591758

(154) https://www.ohgtech.com/wp-content/uploads/2014/12/IMG_5359-500x500.jpg

(155) U.S.Navy Salvage Manual Volume 1 Strandings, Harbor Clearance and Afloat Salvage Revision 2 2013 Published by Direction of Commander, Naval Sea Systems Command page 301

(156) NAVY EXPERIMENTAL DIVING UNIT REPORT NO. 7-84 EVALUATION OF THE KERIE CABLE THERMAL ARC CUTTING EQUIPMENT SUSAN J. TRUKKEN JULY 1984/ DEPARTMENT OF THE NAVY NAVY EXPERIMENTAL DIVING UNIT PANAMA CITY. FLORIDA 32407 page 9

(157) Experimental Diving Unit Report 24-72 / Evaluation of the Thermo-Jet cutting Torch by LTJ G B. LEBENSON, USNR and HTL.J.SCHLEGEL, USN/ Navy Experimental Diving Unit Washington Navy Yard 1973 page 11

(158) https://commons.wikimedia.org/wiki/File:Underwater_Kerie_cable.jpg

(159) http://www.specialwelds.com/products/swordfish.asp

(160) http://www.specialwelds.com/videos/swordfish-1.htm

(161) F.Hermans personal photo from plasma cutting test at BDC in Sept. 2012

(162) http://www.azom.com/article.aspx?ArticleID=1061#_Conventional_Plasma_Arc

(163) Information anciens de Sogetram (Pierre Graves et Felix Cobos)

(164) http://www.asptr.lv/en/performed-works.html

(165) http://www.asptr.lv/en/performed-works.html

(166) Code of Practice for The Safe Use of Electricity Under Water IMCA 045 page 22

(167) http://www.air-plasma.com/P30u.htm

(168) http://www.air-plasma.com/P30u.htm

(169) http://www.miles-water.com/underwater-plasma-cutting.html

(170) The Use of Divers for the Internal Underwater Segmentation of Steam Generators to Support Decommissioning - 14033 Charles A. Vallance (USA) Underwater Engineering Services, Inc.

(171) F.Hermans personal photo from plasma cutting test at BDC in Sept. 2012

(172) Divers Manual 1948 US Navy Training School (Salvage) Navy Yard Annex Bayonne New Jersey/Reproduction by the Historical Diving Society USA Santa Barbara, California section 17 Plate 2

(173) F.Hermans personal data from plasma cutting test at BDC in Sept. 2012

(174) F. Hermans log book 3 April 1980 Zeebrugge 16,5 m vertical cut in sheetpile in 15 minutes.

(175) F. Hermans log book 17 April 1981 G.O.M cutting of a 20” pipe in 3 minutes.

(176) F. Hermans log book 10 May 1991 Cameroun cutting of a 24” conductor pipe in 5 minutes.

(177) http://www.historicdiving.com/index.php/my-portfolio/videos/item/883-welding-under-water-video

(178) Evaluation Report of Swordfish Iron Oxide Cutting Electrode Shell April 2004 page 16

(179) http://www.thediversassociation.com/index.php/sheets incidents list and news paper achives

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13 septembre 2015 7 13 /09 /septembre /2015 18:01

 

 

Photo : Papy One et son collègue Alain

 

Tout commença un beau matin d’hiver à Berlin

Je travaillais à l’époque sur un énorme chantier de bétonnage où je faisais le poste de nuit.

Je venais à peine de m’endormir quant le téléphone de l’hôtel sonna.

Tout en râlant sur le salaud qui ne respectait pas mon sommeil, je décrochai et dis « Allo Was Wollen Sie ».

A l’autre bout de la ligne, je reconnus immédiatement la voix de Luc mon big boss.

Tiens pourquoi est-ce qu’il m’appelle celui-là ?

Ah salut Francis, j’espère que je ne te réveille pas ?

:O((  Non ça va, qu’est-ce que tu veux ?

Bon il faudrait que tu téléphones le plus vite possible à la Comex car ils ont besoin d’un spécialiste en explosifs pour un chantier en Guyane.

En entendant ces deux mots Explosifs et Guyane mon cœur se mit à battre la chamade.

Bien sur que je vais les appeler, d’ailleurs qu’est-ce que tu attends pour raccrocher.

Tout en faisant le numéro de la grande maison, je me dis que mon patron avait certainement mal compris, car à ma connaissance, il n’y avait pas de pétrole en Guyane donc je me demandais bien ce qu’une boite pour laquelle j’avais travaillé durant de longues années pouvait bien faire là bas.

Je n’allais pas devoir attendre longtemps pour le savoir.

Allo Patricia, oui bonjour c’est Francis, il parait que je dois t’appeler pour un truc spécial?

Ah salut Francis. Tu vas bien?

Oui, en fait on cherche un chef de chantier spécialisé en explosifs et comme cela ne court pas les rues chez nous, on a pensé à toi pour un boulot en Guyane.

Mais il n’y a pas de pétrole en Guyane répondis-je, alors c’est pour quoi?

Non il n’y a pas de pétrole mais il y a des fusées.

Et c’est comme cela que j’appris que la mission qu’on voulait me confier était la récupération en mer des EAP (étage d’accélération à poudre) pour le compte du CNES.

Et comme ces boosters comportaient des charges explosives de destruction, le client exigeait un gars spécialisé dans ce type de joujou.

Il ne me valu pas plus de 2 secondes de réflexion pour accepter la mission et tant pis pour ma moitié qui devait comprendre que je ne pouvais pas laisser passer cela.

D’ailleurs, cela faisait maintenant 2 années que j’avais quitté l’offshore pour elle alors elle pouvait bien me laisser finir ma carrière à l’étranger en beauté.

La mission que Comex devait accomplir, consistait à récupérer en mer au large de Kourou divers boosters provenant de la nouvelle série de propulseur ARIANE 5 afin de pouvoir analyser la structure du métal.

L’ensemble de la procédure de récupération avait été rédigée et mise au point durant de long mois par un bureau d’étude Allemand et maintenant ils étaient arrivés en phase finale d’étude  et me demandait de participer aux dernières réunions préparatoires.



Le vol du premier lanceur Ariane 501 était prévu pour le mois de juin et donc une équipe complète de plongeurs et moi-même plus une tonne de matériel furent mobilisés à bord de l’Amphitrite navire Italien dont l’équipage et le Tonton dénotaient un peu avec le sérieux de la mission.

Quelques jours avant le lancement, le bateau  prit la mer et se mit en attente pour la récupération.

Malheureusement comme chacun s’en souvient, le 4 juin la fusée explosa peu de temps après son  lancement et suite à cela tout le monde rentra à la maison plus vite que prévu.



Idem pour le vol A502 le lancement fut réussi, mais cette fois les parachutes de récupération ne s’ouvrirent pas et les deux boosters s’écrasèrent en mer.

Le vol A503 était programmé pour octobre 98 et à nouveau l’équipe complète mobilisa cette fois le matériel sur le navire Russe Neftegas 66.

Le 19 octobre, le bateau quitta le port de Kourou pour se rendre en plein océan atlantique à quelques 540 km à l’est de la Guyane.



La position d’attente du navire se trouvait dans une zone présumée de chute qui avait une longueur d’environ 25 km pour une largeur de 15 km.

Comme l’endroit exact de l’impact des deux EAP dans cette zone ne pouvait pas être déterminé avec exactitude, le bateau opta de se mettre au centre de celle-ci en se disant que statistiquement c’était là que le risque était le moins élevé de recevoir les boosters sur la tête.

Ariane 503 fut lancée avec succès le 21 octobre et après seulement quelques minutes, la trainée des deux engins nous apparus haut dans le ciel.



Très vite cependant un problème arriva sur l’un d’eux car une sorte d’explosion fit apparaître un panache blanc dans le ciel.



Sa chute à grande vitesse fut suivie et filmée par l’avion de reconnaissance jusqu’à ce que finalement le booster s’écrase violemment dans la mer à quelques kilomètres de l’étrave du bateau.





Le second étage à poudre lui aussi continua sa chute vertigineuse vers la mer, mais tout d’un coup, les divers parachutes de freinage s’ouvrirent comme prévu et permirent ainsi à l’engin d’amerrir plus ou moins en douceur.





Hourrah, Hourrah, cette fois il est pour nous s’esclaffait l’équipe et immédiatement le bateau mis le cap sur le point de chute.

Une fois sur place, on pouvait constater que l’EAP flottait pratiquement à la verticale un peu à la manière d’un bouchon de pêche.



Très rapidement une embarcation fut mise à l’eau et accompagné par notre jolie photographe je pus ainsi aller contrôler l’état des réglettes d’explosifs et vérifier qu’il n’y avait aucun risque pour mes gars.





Comme tout était normal, nous pouvions immédiatement commencer la première partie de la procédure qui consistait à sécuriser le booster à l’aide de quelques immenses ballons remplis d’air et qui avait pour fonction de le maintenir à flot durant la nuit si par malchance un problème apparaissait.

 




Le lendemain matin, grosse surprise, tous les ballons avaient disparus mais l’EAP flottait toujours dans la même position qu’avant !

Comme ici nous étions fort loin des côtes il était exclu que les flotteurs fussent volés.

Donc la seule explication plausible fut que ceux-ci s’étaient détachés seuls à cause des mouvements de houle.

Qu’à cela ne tienne, nous avions maintenant à récupérer les énormes parachutes qui toujours attachés au nez de l’engin traînaient sous eau.

Cette opération était assez délicate car la voile des parachutes était également équipée de charges explosives destinées à en assurer l’ouverture.

En principe, toutes ces charges étaient supposées avoir fonctionner, mais comme rien n’était certain à 100 % il fallait travailler avec précaution.

Si l’on se basait sur la procédure écrite, à l’exception du risque mentionné ci-dessus et du danger de tirer les voiles dans les hélices du bateau, rien d’autre en principe n’étaient à craindre.

Faux sur toute la ligne : à peine avions nous commencé à tirer sur la ligne destinée à remonter les parachutes que le booster se pencha tout d’un coup en avant et se coucha à plat sur la surface de l’eau.



BORDEL, C’EST PAS POSSIBLE ON VA LE PERDRE !

Personne ne savait exactement comment réagir car ceci non plus n’avait été prévu dans le scénario de récupération.

Puis, après une ou deux minutes d’expectative, nous pouvions voir que l’engin restait dans cette même position et aussitôt l’espoir revint.

Aussitôt ordre fut donné de préparer une aussière pour essayer de l’attacher quelque part sur le nez et le sécuriser.

Mais pendant que nous nous préparions à cette manœuvre, le booster se remit lentement de lui-même en position verticale sous les regards ahuris de tous.

Comme tout semblait sous contrôle, l’ingénieur en charge du projet décida de ne plus toucher à rien et convoqua immédiatement les différents responsables pour une réunion de travail afin de déterminer quelle serait maintenant la suite à donner au programme.

Vu le risque de chavirage, il fut décidé de rayer l’enlèvement et la récupération des parachutes de la liste de points à exécuter.

En revanche, il fut décidé de sectionner les sangles des parachutes et  d’ensuite les laisser couler sur le fond qui se trouvait quelques 4000 mètres plus bas.



Ce jour là, la mer était assez rude et une houle de 3 mètres était présente ce qui rendait l’opération de découpage des sangles en kevlar assez compliquée.



Mais finalement, une demi heure plus tard, les parachutes partaient vers le fond.

Ensuite, stand by météo afin de voir l’évolution de l’état de la mer.

Le jour suivant pas de changement, sauf que sur le booster, nous pouvions voir que divers cerclages protégeant les rivets de fixations des divers tronçons (du propulseur) commençaient à se détacher.

Rapidement une plongée était organisée afin de voir ce qui se passait sous eau.

Le résultat de l’inspection ne fut pas très bon car elle démontra que plusieurs rivets manquaient déjà.

Ceux-ci étaient probablement sortis de leur logement suite aux contraintes subies par l’énorme structure.

Immédiatement le mécanicien russe du bord fut mis à contribution pour tourner un tas de nouvelles pièces qui allait ensuite être remise en lieu et place des rivets manquants.

Les rivets manquants furent rapidement remplacés comme prévus, mais, comme il fallait s’y attendre avec les plongeurs, les rivets de rechange restant furent eux aussi utilisés comme pièces de remplacement de rivets encore bien en place, ce qui permit bien sur de se procurer quelques souvenirs de cette campagne.
 


En principe, l’étape suivante de la procédure de travail consistait à introduire de l’air comprimé à l’intérieur de la structure afin d’en chasser l’eau et d’y introduire ensuite un IFD (inflated floating device).



Cet engin qui ressemblait à une espèce d’énorme suppositoire de 5 m de long devait être emmené par plongeurs sous la tuyère immergée à une trentaine de mètres de profondeur, puis être remonté par une série de manipulation assez délicate dans le ventre de l’EAP où il devait finalement être gonflé pour former un bouchon étanche.

 






Cette manœuvre avait bien entendu été testé avec succès par le bureau d’étude, mais les conditions de l’essai n’était pas tout à fait les mêmes qu’ici.

Le test avait lui été réalisé dans un lac où régnait un calme plat ce qui était bien loin des 2 m à 3 m de houle continuelle que nous avions ici.

Le 27 octobre toujours aucune amélioration en vue.

Pire, à cause des courants marins, nous avions déjà dérivé de plus de 500 km et étions maintenant à environ mille kilomètres de la base et quelque chose devait être fait.

L’ingénieur du projet voulait absolument que son bébé (l’IFD) soit mis en place tandis que moi je refusais catégoriquement en lui expliquant que nous étions bien au-delà des hauteurs de vagues autorisées, et que je n’avais nulle envie qu’un de mes plongeurs se fasse écraser entre l’IFD et le booster.

Bien entendu, à bord on commençait à ressentir une certaine tension entre les différentes parties concernées.

Une fois de plus, je proposai comme je l’avais déjà fait quelques jours plus tôt de simplement fixer une aussière autour du booster et de le remorquer ainsi à faible vitesse jusqu’à Kourou.

Mais les responsables du CNES et du bureau d’étude craignaient qu’en opérant ainsi, on mette à feu prématurément les réglettes de destruction.

Faisant preuve de persuasion, je parvins finalement à leur faire comprendre que le risque était négligeable et finalement après une longue discussion tout le monde à bord était maintenant conscient que c’était là l’unique solution restante pour tenter de ramener l’engin à terre.

L’aussière fut mise en place sans problème par l’équipe des plongeurs et finalement le Neftegas 66 mit ses moteurs en route et le remorquage à faible vitesse commença.
 


Les premières heures étaient bien entendu assez stressante car j’avais bien émis l’idée, mais je ne savais pas du tout comment allait réagir le booster au bout de sa ligne de remorquage.

Mais tout se passa bien.

Mes inspections périodiques autour de l’EAP en manœuvre, montraient que les explosifs ne subissaient aucune contrainte dangereuse et le remorquage continua ainsi durant 8 jours.



Durant le voyage, nous avions put observer qu’au cours du remorquage, la structure s’inclinait jusqu’à environ 45°.

Ceci était malheureusement une mauvaise position car elle ne permettrait pas de franchir le détroit peu profond situé en fin de parcours entre les îles du salut et le port de Pariacabo.

Donc, le 4 novembre nous mettions à nouveau le navire à l’arrêt et grâce aux savants calculs de l’ingénieur nous nous entraînâmes pendant 2 jours à faire coucher cet énorme tube sur l’eau puis  de nouveau le redresser.

La position couchée semblait convenir au passage des derniers kilomètres, mais pour assurer le coup, l’ingénieur décidât que le cul de l’engin devait être fermé.

Pour cela, il décidât de démonter l’énorme sac se trouvant dans un des IFD et de l’introduire dans la tuyère.

Ceci était plus facile à dire qu’à faire car son sac était rempli d’une fine pellicule d’air et les plongeurs ne parvenaient pas à le faire couler.
 


Comble de tout nous devions manipuler le sac avec une extrême prudence car il était très fragile.

Bref en fin de journée le sac n’était toujours pas en place et notre ingénieur commençait vraiment à nous taper sur le système à force de vouloir nous faire faire des conneries.

L’ambiance était explosive et je sentais que des coups de poing allaient se perdre.

Résultat, pour la troisième fois dans ma carrière je me décidai à gueuler sur un supérieur et lui criai :

ALEXANDRE TU NOUS FAIS CHIER, ON ARRETE LES CONNERIES POUR AUJOURD’HUI.

Comme il n’avait pas l’habitude de me voir ainsi, il comprit qu’il y avait un problème et acquiesça.

Le sac fut remonté à bord, et l’on arrêta la journée de travail.

Lendemain matin, nouveau briefing où il fut décidé de remplacer le sac de l’IFD par un des ballons gonflables de 10 T que nous avions encore à bord.



Celui-ci fut mis en place le 7 novembre et au  moment ou nous fêtions la réussite de l’opération, le booster  tout d’un coup commença à piquer du nez et à sombrer.



Le nez s’enfonça de plus en plus, puis tout d’un coup l’engin plongea telle en baleine.

OH NON PUTAIN, TOUT CA POUR RIEN.

Puis surprise alors que tout le monde le croyait perdu pour de bon, la descente stoppa alors qu’il ne lui restait plus que 5 mètres à faire avant d’être entièrement immergé.



C’est pas possible, pensais je mon cœur ne va pas tenir le coup.

Mais maintenant j’en étais certain, nous allions ramener la bête à la maison car elle n’avait vraiment pas envie de couler.

Bien entendu comme on pouvait le supposer le grand chef des opérations convoqua son état major afin d’analyser la cause de l’incident.

Après moult discussion, nous étions arrivé à la conclusion que le quasi naufrage était probablement du à un défaut d’étanchéité autour du ballon que nous venions d’installer.

Nous devions maintenant à nouveau faire face à un cas de figure non prévu dans le manuel de récupération.

Comment faire pour retourner un engin spatial  flottant tête en bas dans l’océan Atlantique.

Au bout de plusieurs heures de cogitation durant lesquels nos différents cerveaux  commencèrent à fumer nous arrivâmes à la conclusion qu’il fallait prudemment pomper l’eau qui se trouvait maintenant dans le tube.

Evidemment le risque était grand de voir le booster se remplir à nouveau dès qu’il se recoucherait à plat sur l’eau.

Donc pour éviter cela, pas difficile, on boucherait cette fois l’ouverture de la tuyère avec une tôle métallique percée d’évents assurant le passage des divers câbles et tuyau de pompage.

Pas difficile, c’était vite dit, car il fallait pouvoir monter sur la fusée dont le cul se trouvait tout de même entre 5 et 7 mètres de la surface et ici pas question d’installer une échelle car on se casserait vite la figure à cause de la houle.

Encore une fois, quelqu’un eut une idée géniale : Et si on prenait l’EAP d’assaut avec un grappin et des cordes d’escalade ?

Voilà, l’idée était trouvée, il ne restait plus qu’à faire préparer le matériel nécessaire et l’acheminer depuis Kourou.

Evidemment, la préparation de cette commande spéciale n’allait pas pouvoir se faire en quelques heures.

Aussi, afin de faire baisser le stress et la tension des dernières heures, le chef de projet organisa un petit break sous la forme d’une soirée à terre.

Nous n’étions en effet plus qu’à quelques heures de route de la base et grâce à l’envoi d’une vedette rapide toute l’équipe des plongeurs débarqua pour les Iles du Salut où une navette d’hélico avait été prévue pour nous ramener à Kourou.

Là, des chambres d’hôtel avait été retenues afin que nous puissions passer la nuit au calme.

Malgré le bon repas que nous avions dégusté, nous n’étions pas encore entièrement remis de toutes nos émotions, et donc comme il fallait s’en douter, la seule solution qui s’offrait à nous si nous ne voulions pas sombrer dans la dépression, était de terminer la soirée en boite.

La sortie était mémorable. Une fois de plus mon don innée pour la danse (que je tiens sans doute de ma vieille maman qui aujourd’hui encore à 83 ans va faire la java plusieurs fois par semaine) me permit de me défouler jusqu'aux petites heures au rythme de la musique tropicale.

Le lendemain était plus dur, car pour la première fois, je pouvais maintenant ressentir les premiers inconvénients du à  mon age grandissant.

Heureusement, mon mal au crane ne dura que peu de temps et au  retour à bord, j’étais à nouveau fin prêt à travailler.

Tout le matériel que nous avions demandé était arrivé et il ne nous restait plus qu’à monter à l’assaut du booster.
 




La mise en place de la pompe de vidange et de la plaque d’obturation se déroula sans problème et au bout de quelques heures de pompage, le booster se remis dans sa position normale.

Puis grâce à quelques manipulations complémentaires nous étions fin prêts pour le remorquage final jusqu’aux Iles où nous étions attendus avec impatience.



Une fois sur place avec notre trophée dans une des baies des Iles du Salut, nous attendions la barge locale HENARES car c’était à elle maintenant d’assurer le remorquage final.

Le 14 novembre, tout était prêt il n’y avait plus qu’à recevoir l’autorisation des autorités portuaires pour se mettre en route.
 


Comme celle-ci tardait à venir, nous décidâmes malgré tout de déjà nous mettre en route car le passage de la passe devait se faire à marée haute de manière à être certain d’avoir assez d’eau sous la barge.

Nous étions maintenant à environ mi-chemin dans le chenal lorsque tout d’un coup un ordre incongru parvint à la radio.

Henares ! Henares !  Henares !  ici la capitainerie.

Que faites vous au milieu de la passe?

Je vous donne l’ordre de faire demi tour et de retourner à votre point de départ.

A bord, tout le monde pensait à une blague.

Personne n’aurait pu imaginer qu’un ordre aussi farfelu puisse être donné.

Henares ! confirmez nous que vous avez reçu l’ordre.

Immédiatement le tonton de la drague repris contact.

Capitainerie : ici Henares pour information nous avons l’EAP d’Ariane 503 en remorque et demandons autorisation de poursuivre notre route.

Henares : Vous n’avez pas respectez la procédure d’approche, nous vous intimons l’ordre de faire demi-tour.

Et c’est ainsi, que voyant que nous avions à faire à un fonctionnaire zélé la barge fit un grand demi tour pour retourner au point de départ.

Une fois de plus, la chance nous sourit, car au cours de cette manœuvre, le préposé à la surveillance du tuyau de gonflage que nous avions installé pour maintenir le booster en position horizontale géra mal la longueur du flexible et celui-ci fut arraché du cul de l’engin.

Heureusement, l’équipe des plongeurs veillait et réagit immédiatement à l’incident en replaçant un nouveau flexible.

Finalement, l’autorisation de passage nous parviens et 2 heures plus tard le booster arrivait dans le port de Paracaibo.
 


Quant à nous, il ne nous restait plus maintenant qu’à démobiliser le matériel  avant de pouvoir rentrer en Europe.

Le soir un grand repas de fin de chantier fut organisé par les gens du CNES pour nous remercier.

Quant à moi, je savais qu’il ne me restait plus que quelques jours à rester sur place afin de terminer la paperasserie habituelle.

Ensuite, je n’avais plus qu’à tirer un trait sur cette vie trépidante que j’avais eu durant de longues années et me rabattre maintenant dans une vie professionnelle nettement moins palpitante où les grands voyages étaient terminé.

 

Papy One

 

Conclusion :

D’autres missions de récupération d’EAP furent encore organisées par la suite, mais le marché fut attribué à une compagnie Allemande.

Celle-ci adopta notre technique de remorquage, ce qui enterra définitivement la procédure de mise en place d’IFD qui bien qu’étant une belle solution technique s’avéra être impossible à mettre en œuvre en plein Atlantique.

 

 

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13 septembre 2015 7 13 /09 /septembre /2015 17:44
Ariane 503 or the story of my last offshore project

It all started one fine winter morning in Berlin where I was working at the time on a huge underwater concrete construction where I was doing the night shift. I had just fallen asleep when the hotel phone rang.

While gasping on the bastard who did not respect my sleep, I picked up and said:

- Hello Was Wollen Sie.

At the other end of the line, I immediately recognized the voice of my big boss Luc.

Hey why is he calling me so early?

- Ah hello Francis, I hope I do not wake up?

- No okay, what do you want?

- Well you have to phone Comex as soon as possible because they need a specialist in explosives for a work in French Guiana.

On hearing these words Guiana and Explosives my heart began to beat faster.

- Of course I'll call them; besides what do you wait to hang up.

While I was forming the number of the big house in Marseille, I told myself that my boss was certainly misunderstood because to my knowledge, there was no oil in Guyana so I was wondering what a company for which I had worked for many years could do there.

I would not have to wait long to find out.

- Allo Patricia, yes Francis here, it seems that I have to call you for something special?

- Ah hello Francis. You're okay? Yes, we actually seek a superintendent specialized in explosives and as it does not grow on trees here, we thought of you for a job in Guyana.

- But there is no oil in Guyana I replied, then what is this for?

- No there is no oil but there are rockets.

And that's how I learned that the mission they wanted to give me was the recovery at sea of the new Ariane 5 solid boosters (EAPs) on behalf of CNES and as these boosters contained explosives destruction devices, the customer required a guy specialized with this type of stuff.

It did not cost me more than 2 seconds to accept the mission and sorry for my loved one who had to understand that I could not let this go. Moreover, it was now two years since I had left the offshore for her so she had to let me go and finish my career abroad in beauty.

As I said, the Comex contract consisted to recover at sea off Kourou various boosters from the new series of Ariane 5 in order to analyze the structure of the metal.

The entire recovery procedure had been drafted and developed during long months by a German consulting firm and now they had arrived in the final phase of study and asked me to participate in the final preparatory meetings.

Ariane 503 or the story of my last offshore project

The first Ariane flight 501 was scheduled for June and then a full dive team and I plus a ton of equipment were mobilized aboard the Amphitrite an Italian ship whose crew and her Captain denoted a bit with the seriousness of the mission.

A few days before the launch, the ship sailed and began waiting for recovery. Unfortunately as everyone remembers, on June 4 the rocket exploded shortly after launch and off course everyone went home earlier than expected.

Ariane 503 or the story of my last offshore project

Ditto for the flight A502. The launch was successful, but this time the recovery parachutes did not open and the two boosters crashed at sea.

The A503 flight was scheduled for October 98 and again the whole team mobilized this time on the Neftegas 66 a Russian ship.

On October 19, the ship left the port of Kourou to get in the Atlantic Ocean at some 540 km east of Guyana.

Ariane 503 or the story of my last offshore project

The ship waiting position was in an alleged drop area that had a length of about 25 km and a width of 15 km. As the exact point of impact of the two boosters in this area could not be determined accurately, the ship opted to put herself at the center of the area by saying that statistically speaking this was there that the risk was the lowest to receive the boosters on our heads.

Ariane 503 was successfully launched October 21 and after only a few minutes the drag of the two propellant machines appeared high in the sky.

Ariane 503 or the story of my last offshore project

Very quickly however a problem happened to one of them as a kind of explosion conjured a white plume in the sky.

Ariane 503 or the story of my last offshore project

While the high speed fall was followed and filmed by a reconnaissance plane until the booster crashed violently into the sea at a few kilometers of the boat.

Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

The second booster also continued his vertiginous fall towards the sea, but all of a sudden, the various braking parachutes were opened as planned and thus enabled the craft to land into the water more or less smoothly.

Ariane 503 or the story of my last offshore project

- Hurrah! Hurrah! On board shouts of joy were listened.

This time we could start the mission.

The boat immediately headed to the falling point and once there one could see that the EAP floated almost vertically in the water a bit like a fishing cap.

Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

Very soon a boat was put in the water and I could go and check the status of the explosives strips and look that there was no risk for my guys.

Ariane 503 or the story of my last offshore project

As everything was normal, we could immediately start the first part of the procedure which was to secure the booster with some huge balloons filled with air and which function was to keep it afloat during the night if by chance a problem appeared.

Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

The following morning, big surprise, all the balloons were gone but EAP was still floating in the same position as the previous day.

Like we were very far from the coast it was not possible that the floats were stolen. So the only plausible explanation was that they had come off because of the heavy swell motions.

Never mind, we now had to recover the huge parachutes that were still attached to the nose of the booster but dragged under water.

This was rather difficult because the canopy of the main parachute was also equipped with pyro release charges designed to ensure openness.

In principle, all these charges were supposed to have worked, but as nothing was 100% certain we had to work carefully.

Following the working procedure, if we except for the aforementioned risk and the danger to pull the parachutes in the boat’s propellers nothing else were in principle to fear.

All wrong: we had barely begun to pull on the line to lift the parachutes that the booster leaned suddenly forward and laid down on the surface of the water.

Ariane 503 or the story of my last offshore project

- HELL, IT IS NOT POSSIBLE WE ARE GOING TO LOOSE IT!

No one knew how to react because this had not been foreseen in the recovery scenario.

Then after a minute or two of anxiety we could see that the machine remained in the same position and immediately hope returned. Immediately order was given to prepare a hawser to try to attach it somewhere on the nose to secure it.

But while we were preparing for this maneuver the booster slowly resumed itself vertically under the bewildered eyes of all.

As everything seemed under control, the project engineer decided not to touch anything and immediately called the various officials for a working meeting to determine what would now be the follow-up to the program.

Given the risk of capsizing, it was agreed to scratch the removal and the recovery of the parachutes from the procedure.

Instead, it was decided to cut the straps of the parachute and then let them sink to the bottom, which was about 4000 meters below.

Ariane 503 or the story of my last offshore project

That day, the sea was pretty rough and waves of 3 meters were present which made the cutting operation of the Kevlar straps rather complicated.

Ariane 503 or the story of my last offshore project

But finally, half an hour later, the parachutes went to the bottom.

Then stand-by weather to see the evolution of the sea state.

Ariane 503 or the story of my last offshore project

The next day no change in the sea state but we could see that some of the ring-joints that connected the several segments from the EAP cylinder began to get loose.

A dive was quickly organized in order to see what was happening under water. The result of the inspection was not very good because it showed that several rivets were already missing.

These had probably left their position following the stresses experienced by the huge structure. Immediately the Russian mechanic aboard was enlisted to make a bunch of new pieces that would replace the missing rivets. The missing rivets were quickly replaced in the empty holes but, as was to be expected with the divers, the remaining spare rivets were also used to replace those still in place which allowed us to obtain some memories of this campaign.

Ariane 503 or the story of my last offshore project

In principle, the next step of the working procedure was to introduce compressed air inside the cylinder in order to remove water and then introduce an IFD (inflated floating device) therein.

Ariane 503 or the story of my last offshore project

This piece that looked like a huge suppository 5 m long had to be brought by divers under the submerged nozzle at about thirty meters deep, and then be lift up by a series of rather delicate handling in the belly of the EAP where it would eventually be inflated to form a tight plug.

Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

This maneuver had obviously been successfully tested by the research department, but the conditions of the test were not quite the same as here.

The test had been done in a lake where it was dead calm which was far from the 2 to 3 m continuous swell we had here.

October 27 still no improvement in sight. Worse, because of sea currents, we had already derived more than 500 km and we were now at about one thousand kilometers from the base and something had to be done.

The project engineer insisted to install his baby (IFD) while I categorically refused to do so explaining that we were well beyond the authorized wave heights, and that I had no desire to crush one of my divers between the IFD and booster.

Of course, on board a certain tension began to be felt between the different stakeholders.

Once again, I suggested as I had already done a few days earlier to just set a hawser around the booster and towed it at low speed to Kourou. But the CNES officials and research department feared that doing so would prematurely detonate the destruction strips.

Finally I managed to get them to understand that the risk was negligible and finally after a long discussion everyone on board was now aware that this was the only remaining solution to try to bring this huge cylinder to land.

The hawser was smoothly fixed around the booster by the divers and finally the Neftegas 66 switched his engines on and the low-speed towing began.

Ariane 503 or the story of my last offshore project

The first hours were of course quite stressful because I had raised the suggestion to do so but I did not know at all how the booster would react at the end of its tow line.

But all went well.

My periodic inspections showed that the explosives were free from stress and towing continued for 8 days.

Ariane 503 or the story of my last offshore project

During the trip we could observe that the structure kept an angle varying between 10 and 30 °.

This was unfortunately a bad position because it would not allow to cross the shallow Strait situated between the salute islands and the port of Pariacabo. So on November the fourth we again stopped the ship and thanks to the scientific calculations of the engineer we trained for the next two days to lay this huge tube flat on the water and then straighten it again.

The flat position seemed to suit the passage of the final kilometers, but to ensure the manoeuver the engineer decided that the craft's ass had to be closed.

To do so, he decided to dismantle the huge bag being inside the IFD and introduce it into the booster nozzle.

This was easier said than done because the long bag was filled with a thin film coat of air and divers were unable to make it sink.

Ariane 503 or the story of my last offshore project

Worse yet, we had to handle the bag with extreme caution because it was quite fragile.

In short at the end of the day the membrane was still not in place and our engineer really started to get on our nerves by wanting us to do so shit maneuver.

The atmosphere was explosive and I felt that punches were going to get lost.

Result for the third time in my career I decided to yell at a supervisor and shouted to him:

- ALEXANDRE FUCK-OFF, ENOUGH BULLSHIT FOR TODAY.

As he was not used to see me like that he realized there was a problem and nodded.

The bag was brought back on board and we stopped the working day.

Next morning, new briefing where it was decided to replace the IFD bag by one of the 10 T inflatable balloon we still had on board.

Ariane 503 or the story of my last offshore project

It was put in place on November 7 and by the time we celebrated the success of the operation, the booster suddenly began to nosedive and start to sink.

Ariane 503 or the story of my last offshore project

The nose went deeper and deeper and then suddenly the cylinder plunged like a whale.

- OH NO FUCKING HELL ALL THIS WORK FOR NOTHING - SHIT!

Then suddenly as everyone thought the booster was lost for good, the descent stopped.

- It is not possible my heart will not hold it.

The engine was there floating upside down in a vertical position with only 5 meters to go before being fully submerged.

Ariane 503 or the story of my last offshore project

But now I was certain we were going to bring the beast at home because it really did not feel like sinking.

Of course as you might suppose the big chief summoned his staff to analyze the cause of the incident. After much discussion we concluded that near sinking was probably due to a water leak around the balloon we had to install.

We now had to again face a scenario not foreseen in the recovery manual. How to return a spacecraft floating upside down in the Atlantic Ocean? After several brain storming hours during which our different brains began to smoke we came to the conclusion that it was necessary to cautiously pump the water that was now in the tube.

But the risk was obviously great to see the booster fill up again as soon as he falls flat on the water. So to avoid this, quite simple, we would clog the opening of the nozzle with a metal plate only pierced by a few vents to ensure the passage of some cables and pumping hose.

Not difficult, that was easy to say, because we had to get on the rocket, whose ass was still between 5 and 7 meters above the surface and here no question of installing a ladder in the zodiac as we would break our neck because of the swell.

Again, someone had a brilliant idea:

- Why don’t we storm it with a grapple and climbing ropes?

Here, the idea was found, it remained only to prepare the necessary materials and forward it from Kourou.

Obviously, the preparation of this special order would not be done in a few hours. Thus, to lower the stress and the tension of the last hours, the project manager decided to organize a small break under the form of an evening on land.

We were only a few hours away from the base and thanks to the sending of a speedboat the entire dive crew disembarked for the Salute Islands where a helicopter shuttle was organized to bring us to Kourou.

There, hotel rooms had been retained so that we could spend a quite night.

Despite the excellent meal we had not yet fully recovered from all our emotions, so as it should be expected, the only solution that was offered to us if we did not want to sink into depression was to end the evening in a nightclub.

It was a night to remember. One more time my innate gift for the dance (that I doubtless hold of my old mom) allowed me to let off steam at the rate of the tropical music.

The next day was harder, because for the first time, I could now feel the first disadvantages of my growing age. Fortunately my hangover lasted only a short time and back on board I was again ready to work.

All the requested material had arrived and it only remained us to storm the booster.

Ariane 503 or the story of my last offshore project

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Ariane 503 or the story of my last offshore project

The setting up of the small pump and the blanking of the nozzle passed without problem and after some hours of pumping, the booster slowly returned to its normal position.

Then through some additional manipulations we were ready for the final towing to the Islands where we were eagerly awaited.

Ariane 503 or the story of my last offshore project

Once on-the-spot with our trophy, our boat put herself at anchor while waiting for the arrival of the HENARES. It was indeed this local barge which had to ensure the final towing to the port.

On the 14 November, all was ready, we had installed an air back up hose in the ass of the booster to if necessary blow air in his belly and so keep him in a flat position and we only had to receive permission from the port authorities to get under way.

Ariane 503 or the story of my last offshore project

But as the time passed and no order arrived from shore, we decided nevertheless to already set off for the pass because the passage had to be done at high tide so be sure to have enough water under the barge.

We were now about halfway into the channel when suddenly an incongruous order came on the radio.

- Henares! Henares! Henares! Here the captaincy.

- What are you doing in the middle of the pass?

- I order you to turn back and return to your starting point.

On board, everyone thought it was a joke. Nobody could have imagined that so a silly order could be given.

- Henares! Confirm that you received the order.

The Captain of the barge immediately replied:

- Harbor master: here Henares for your information we have the Ariane 503 booster in tow and request authorization to continue our journey.

- Henares: You did not follow the approach procedure; we summon you to turn back.

And so, seeing that we were dealing with a zealous autocrat the barge made a great loop to return to the starting point.

Once again, we were lucky because during this maneuver, the man in charge of the backup inflation hose didn’t give slack on it and of course the hose was pulled out the nozzle.

Fortunately, the divers responded immediately to the incident by placing the flexible back.

Finally, the authorization was given and two hours later the booster arrived safely in the port of Maracaibo.

Ariane 503 or the story of my last offshore project

Our mission was finished and all there remained to do was to demobilize the equipment.

In the evening a great meal was organized by CNES people to thank us.

Ariane 503 or the story of my last offshore project

My Comex companions left the next day for Europe and I knew I would probably never see them again. I stayed a couple of days more in Kourou to finish the usual paperwork then at my turn said goodbye to Guyana and to this offshore life I had liked so much.

Papy One

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22 août 2015 6 22 /08 /août /2015 15:31
Lost at sea

End 93, I received a phone call from Marseille.

The big House offered me a Mooring Master Supervisor position in Cameroon to replace the old Raymond, who was retiring.

- MMS, this title looks good, I replied, but I do not even know of what it consists.

- BOF you'll see, my interlocutor says, is a super cool job which consists to go on oil tankers and then lead them to an offshore loading buoy (SPM) to refuel them with crude oil.

- To assist you with this job you will have a French and 4 national divers.

- As to help you for the first mooring you don't have to worry, Jean-René the actual supervisor that’s now on board will stay two weeks longer and he will brief you on this particular job.

- Yeah but what about diving l asked him?

- Don't panic, in addition to the tankers, you will also be in charge of the surface and underwater maintenance of the two loading buoys on the Kole terminal.

As there began to be quite a lot of changes within the company and at the same time diving projects seemed to decrease, it didn’t take me long to accept the offer, especially that once again this type of work would allow me to have regular rotations what suited better to my family life.

Result: A few days later I found myself once more in Douala.

Unlike other places in Africa, this town was pretty nice and with the exception of a few places where it was better not to walk alone, insecurity was not too high and during my various stays there I had undergone only a single aggression with theft attempt.

Being arrived at the airport in the early evening, I learned that my departure at sea was planned for the next morning and therefore a room at the IBIS hotel had be reserved for me which I had to recognize was much nicer than being immediately transferred to the barge via one or the other uncomfortable vessel on which we had sometimes to stay during several hours without even receiving any snack.

Here at least I could dine comfortably, take a nightcap at the bar before leaving civilization for the next 8 weeks and enjoy a last good sleep. OK, when I say a good sleep, I am exaggerating a bit because despite being very comfortable, the hotel was quite noisy.

Often during the night we could hear in the corridors a "Toc! Toc! Toc!" on one or the other door which was naturally followed from "what is it? ''

As for the reply it was always the same "it’s love that knocks at your door."

Obviously, the first time that this happened to me, I was somewhat surprised. But now, knowing this type of local custom, I was taking care to always bring with me, my box of … wax earplugs what allowed me to not be too disturbed by the comings and goings of these charming ladies.

The next morning, en route to the port where I embarked with other local workers on a speedboat that take us on the site.

Lost at sea

A few hours later I am on the SEREPCA a buffer tanker on which I found JR the actual MMS, Bruno my second and my new African colleagues.

Lost at sea

After the presentations with the boat commander and the various crew members, direction to my cabin.

- Hey! hey! Not bad at all, a spacious officer cabin with a desk and a small lounge for me alone, this changes me from the crappy cabins of some rotting barges I’ve be on.

Very quickly, JR walked me through a few points:

- Here, we are on a merchant ship and the rules on board are those of the Navy which means a little more discipline than on our diving barges.

- On board, he continued even for dinner, there is a ritual to respect.

- Nobody comes at the table before the Commander and above all, we respect the seats of each other.

At the beginning, I folded myself as everyone to this last rule, but a little later after having been well integrated within this community of sailors, I felt a perverse pleasure to change seats several times a month to the dismay of the concerned persons.

Over the following days, my buddy initiated me to my new mission who as mentioned earlier was among others to fill the tankers arriving lightship on the terminal.

As one might imagine, filling a tanker is not so easy than refueling a car. Our task when a new ship arrived was to first climb on board and while she was still sailing, mobilize all our rigging and towing gear.

Lost at sea

We had about half an hour to prepare all this stuff, then when the tanker was approaching the buoy.

Lost at sea

The role of the MMS, thus mine now was to stand at the bow of the boat and via the walky talky, give my instructions to the Commander to guide him very precisely during its final approach to allow him to stop his ship at a few meters from the loading buoy.

Lost at sea

Then, once the vessel was moored on the buoy, two thick loading hoses had to be hoisted on board and be connected to the loading manifolds, which then permitted to refuel the several tanks in more or less twenty hours.

Lost at sea

As expected, Jean René returned to France after two weeks and one might say that the first time that I was alone for this task, I sweated not from heat, but from fear because I should rather not miss the maneuver.

If so, two scenarios were possible.

First, the tanker passed next to the buoy and stopped a little too far, this then meant that a new approach had to be done with consequence of at least one hour lost

or

secondly and worse case, the tanker hits the buoy and tears it off her position which for me would mean that I would be fired.

Fortunately, during my stays, I rapidly learned how these huge mastodons of 150,000 to 200,000 tons behaved and I managed every time to lead them to good port. The frequencies of the loadings were pretty random, which in the meantime allowed us to work on the buoys of KLB1 and KLB2.

Lost at sea

Each SPM buoy had a complete maintenance program that went both above and below water. Under water, among other things the main task of the divers was to verify the state and configuration of the Chinese lantern under buoy hoses which were connected between the SPM and the pipeline end manifold (PLEM) and the condition and configuration of the six huge chains that maintained the buoy in position.

Lost at sea

The inspection dives on the bottom sometimes reserved a few surprises because the visibility was often very limited and therefore it was quite common to have our fingers nibbled by the few small morays that did not appreciate to be disturbed by our tactile inspections.

Another problem of visibility that we met sometimes on the field, but on the surface this time was due to the harmattan. It was a hot and dusty wind that came from the Sahara and which could darken the atmosphere for several consecutive days.

It was such a situation that we encountered on the 2 February 94. That day we left the SEREPCA in the early morning with our zodiac to do some maintenance on the KLB2 buoy which was at about 20 minutes travel from our storage tanker.

The visibility was not terrible, but was still largely sufficient to localize the buoy at halfway. The morning had passed relatively quickly and as noon approached, I decided to stop work and return to the boat for dinner.

Very quickly however, we realized that the atmosphere was charged with sand dust and visibility was reduced to 50 meters. Never mind, the SEREPCA was large enough and could not be missed.

Lost at sea

Thus, full speed and heading to the North.

About 20 minutes later, everybody was on watch to scrutinize the horizon to detect the mass of the tanker, but nothing was in sight, just this kind of fog that prevented us from seeing anything. Normally, we couldn't be far from her because we had sailed roughly at the same speed and during the same time than the outward journey.

So I asked the diver driver to now slowly head NNE for a minute. Nothing, not any boat.

Same thing for two minutes to the NNW, shit, still nothing.

- Ok guys let us stop here it’s not worth risking to get away more.

- I'm going to call the ship and ask them to operate the fog horn so we will be able to direct us to the sound.

So said, so done:

- SEREPCA, SEREPCA, SEREPCA: Diver’s zodiac!

- SEREPCA, SEREPCA, SEREPCA: Diver’s zodiac!

- SEREPCA, SEREPCA, SEREPCA: Diver’s zodiac!

Nothing! No response from the tanker. I looked my watch. 12 h 10, no point of insisting, they were probably all at table. What could I do? Certainly not wait that they had finished their nap.

I knew that our tender boat the Cristal fish had to be somewhere on the field, and therefore, I decided to call her.

A single call sufficed to get a sailor online.

Immediately, I asked him to call for his Superior and two minutes later he was there on the radio.

- Hello Captain Francis here.

- Say, we have a small problem: We are lost.

- Is your ship close to the SEREPCA?

- No Francis we are next to the BOS.

Ah shit, so it was not necessary to ask her to blow the horn, because even if it was heard, the sound would not lead us in the right direction.

Immediately I asked him:

- Can you try to find us on your radar?

- OK one minute, I’m watching.

- No I see nothing on the screen; do a 360 ° at low speed to see.

- Sorry still nothing.

The situation became annoying, ok we had enough fuel to reach the coast which was at about two-hours sail from where we were but we could land anywhere with all the risks that it carried. While I was thinking how to extricate ourselves from this muck-up an idea came to me.

During my stay at the Clearance Divers Group a few decades earlier, we had on our rubber dive boats a reflector which allowed the radar operator to lead us on the suspicious contacts. Therefore, why not do the same thing here. The problem was that we had no reflector in our canoe.

Ok, but we could perhaps make one?

We already had two paddles that could serve as mast, remained to find what to use for the reflector.

- Do we have smokers on board?

Yes, Hervé and Eke are.

- Well sorry guys, can you empty your packets of cigarettes and give me the packaging.

They complied but looked at me oddly when I took the packages and returned them so as to have the aluminum on the outside.

I now had the reflective material. Remained only to find a support and what better than my small backpack. Very quickly the aluminum was stuck on my bag and then latter mounted on the top of the paddles.

Here it was, we had a semblance of reflector. I recalled the Crystal Fish.

- Captain, we have manufactured a reflector, can you watch if you have a contact?

- Go ahead slowly zodiac.

Slowly, our boat setted out.

- Let’s hope it works.

A few seconds later, new call from the supply:

- Zodiac: Crystal fish.

- I get you! You are half a mile from your destination.

- Follow the 105 heading I will remain in contact and guide you.

10 minutes later, our tanker was in sight.

- Cristal Fish : Zodiac

- Go ahead zodiac.

- OK Captain: Ship in sight thanks’ for your help.

- Ok Francis, see you in a few days

Once on board, I saw that the Commander was moody. He said coldly:

- Gentlemen, next time have the politeness to arrive on time at the table.

Well, that’s very rich coming from him I thought without comment.

During the rest of stays if we except this little incident, nothing special arrived during the four rotations I did on this ship.

Work was interesting but there were not enough dives.

In addition to this, my 'little boy' that I had not seen growing was now 24 years old and had left the family nest. As for my loved one, she was bored of this life and begged me to stop.

Result; on the sad day of the 19 August 94, I decided to give my resignation to this company which had given me the opportunity to live an extraordinary adventure for about 16 years.

The remainder of my career was a bit less exciting but still interesting. It consisted in accordance with the predictions made to me by an Indian sailor in 1983, to spend a part of my time on civil engineering diving projects and for the other part, work at the office preparing these jobs while being nicely pampered by the fairer sex who work there.

Papy One

Photos internet

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