Alexander L. Kielland (platform)
The Alexander L. Kielland was a named after the Norwegian writer Alexander Lange Kielland and used as living accommodation semi-submersible oil rig, which capsized in the North Sea after an accident on March 27, 1980. Here died 123 of the 212 crew members. Cause of the accident was fatigue on the structure of the oil rig. The loss of the Alexander L. Kielland led to a number of significant changes in the design, test and safety equipment on the rigs.
- 7.1 Det Norske Veritas
- 7.2 State Commission of Inquiry
- 7.3 International Maritime Organization
- 7.4 Further consequences
Development
The Institut Français du Petrole was in 1963 a cooperation with the members of the Schlumberger group exploration company Neptune, in a dormant on five floats oil rig should be designed. The first platform, P81, was delivered in 1969. In 1970 the design in collaboration with several other companies has been revised and built P82 in Brownsville (Texas ). This was the basis for a further nine platforms, of which three in Finland and six at the French company Compagnie Française d'Entreprises Métalliques ( CFEM ) were built in Dunkirk. Alexander L. Kielland was the seventh platform of the modified basic type, was built in France and called the Pentagon P 89.
Description of the Alexander L. Kielland
When oil rig it was a semi-submersible type of Pentagon. The platform with the superstructure thus rested on five partially submerged in the sea pillars, which were worn by the submerged buoyancy. The buoyancy bodies had a diameter of 22 m and a height of 7.5 m. The column had a diameter of 8.5 m and merchandise, including the float, 35.6 m high. They were connected to each other and to the platform by a number of struts. The horizontal struts have a diameter of 2.6 m and a wall thickness of 25 mm, the diagonal struts had diameter of 2.2 m. They were made of C -Mn steel structure (according to Lloyds ' steel ship "Grade EH ") with a minimum yield strength of 355 N / mm ² (comparable to mild steel material No. 1.0570 S355J2 N (according to EN 10025-2:2004-10 ) ).
In the columns and buoyancy tanks for ballast water and drinking water, fuel and other supplies were housed. Three of the columns also contained machinery spaces which could be achieved through centrally mounted in the column lifts. Propeller at these three columns could move the oil rig. A total of five diesel generators, one of which is for emergencies, provided the power supply of the Alexander L. Kielland safe. They could be operated up to an inclined position of 20 °. In the columns, were also pump rooms for Lenzen event of flooding.
The actual platform had dimensions of 103 m × 99 m and a mass of 10,105 t. She was in normal operation about 15 m above the water surface. On it there is a 40 m high derrick was located. Since the Alexander L. Kielland should be used in the foreseeable future as a drilling platform, is also found all the equipment necessary for drilling on board. Since commissioning of the Alexander L. Kielland was used as a living platform. For over one another residential containers were set up on the platform in several floors. These containers were set up for four people. Thus, the capacity of 80 persons to 348 persons had been increased.
A system of ten anchors held the Alexander L. Kielland position. The anchor ropes ran it in pairs via arranged on the columns mooring winches. These winches are controlled by three hydrophones were located on horizontal struts of the Alexander L. Kielland. Its signals are received by the hydrophones of a sound wave transmitter is installed on the seabed. This system kept the Alexander L. Kielland always at the same position.
Application and certification
On 5 July 1976, the rig was delivered to Norway to Stavanger Drilling Company. It was then chartered by the U.S. Phillips Petroleum Company. Its field was the oil field located in the geographic center of North Sea Ekofisk. In this area, much of the present in the North Sea at that time about 80 drilling rigs and production platforms in 1980 was settled.
Even at their first deployment in July 1976, the oil rig as a residential property ( so-called Flotel, a contraction of the words "floating hotel", engl. For " floating hotel " ) used for the compressor platform H-7. From 15 July 1976 to August 1, 1979, the Alexander L. Kielland including as residential accommodation for the Henrik Ibsen and the Dyvi Alpha was used. On 1 August 1979, the platform of Albus Kjell 2/4 F to Edda 2/7 C was spent. Here it served as accommodation platform for the workers of the Edda 2/7 C and was most of the time connected by a movable bridge with this platform.
Issuer of the security certificate was Det Norske Veritas, the Norwegian counterpart to Lloyd 's Register of Shipping. When accepting only a few small errors were found. The last annual inspection took place at sea in September 1979. The large 4- year inspection was postponed at the request of the owner from April 1980 to June 1981.
Accident on March 27, 1980
Starting position
The Alexander L. Kielland was next to the platform Edda 2/7 C, based on the position 56 ° 27 ' 53.4 "N, 3 ° 6' 16.1 " O56.4648388888893.10446388888890Koordinaten: 56 ° 27 ' 53.4 "N, 3 ° 6 ' 16.1 " E was. The location corresponded approximately to the height of Edinburgh and was 385 km off the Norwegian coast. The distance to the Dutch coast was about the same distance. The Alexander L. Kielland was for nine months of the production platform Edda 2/7 C assigned as a accommodation platform and connected to it via an approximately 25 -meter-long movable bridge.
On March 27, 1980, the weather had deteriorated during the day. It ruled wind speeds of 16 to 20 m / s with gusts of wind in strength 10 The wave height was 6-8 m. The air temperature was 4-6 degrees and the water temperature was just over 6 degrees. At end of shift Edda 2/7 C, the workers returned after 18 clock back to the Alexander L. Kielland. The connection between the Edda 2/7 C and the Alexander L. Kielland had been removed due to bad weather. About 50 to 80 people were in the two screening rooms, about 50 in the exhibition as well as other in their living quarters. In total, 212 people were on the Alexander L. Kielland.
For the Ekofisk oil field there was a contingency plan, which provided for the presence of three standby vessels so that each platform could be reached in 25 minutes or less. The Motor Ship Silver Pit, a converted trawler, the mitführte next to a fast Rettungsbeiboot also a lifeboat with water jet propulsion for up to three rescuers and twelve to sheltering people, should the platforms Edda 2/7 C, Alexander L. Kielland and Eldfisk Alpha and Eldfisk Bravo secure. To this end, the captain had been instructed to remain in "Area 3" in the middle between Eldfisk Alpha and Edda 2/7 C. The ship remained, however, several months only near Eldfisk on Bravo. In March, a new captain took over the ship. This was insufficient information on the tasks of the Silver Pit. In his testimony before the commission of inquiry, he said that he was assumed to be responsible only for Eldfisk Bravo. At the time of the accident, the Silver Pit was one nautical mile southeast of Eldfisk Bravo, which is about 6 miles from the Alexander L. Kielland away. Thus, the Silver Pit reached the crash site after 19:15 clock and could not save anyone.
Accident sequence
Shortly before 18:30 clock a strong impact was seen on the Alexander L. Kielland, the vibrations followed. Most people need to have these but kept for waves and ignored. After a second shock " shook " the rig and leaned to starboard until it reached an angle of 30 to 35 °. The worker Tony Sylvester described the situation: " Everyone thought it's too late. [ ... ] It crashed horribly, and soon again, and then downed the whole thing by 45 degrees to the side. "
As determined later, broke at this time the horizontal brace D- 6th Thus, the other strut in the lower part of column D were overloaded and also broke. The buoyancy lifted to the column and turned them in so that also broke the remaining struts. The column D dissolved completely from the rig and drove off. As in the column D no more lift was now given the rig heeled after this page. The actual platform was partially flooded by water and the two columns C and E decreased from so deep that it almost completely immersed in the water. In return, the port side lifted sharply.
On the entire rig slipped objects to starboard. In the makeshift cinema on the drilling deck of the drilling equipment parts broke through the wall and injuring several men. In the living accommodation loose cabinets fell and blocked doors. A little later, went from light and alarm signals, since the diesel generators were no longer working at the excessive heeling.
For a short time the rig was stable. During this time, however, had already begun spaces and tanks in the superstructure and the columns C and E to fill with water. This penetrated by otherwise well in excess of the water surface doors, hatches and vents. About 20 minutes took the oblique position to continuously until the oil rig capsized around 19 clock and keel up sponge.
Salvage operation
To the rescue stations of the Alexander L. Kielland were eight motor lifeboats for 50 people, four and six interruptible droppable life rafts for a total of 400 people and eight container together with 125 life jackets available. Overall, 541 life jackets were on the Alexander L. Kielland. The crew of the Alexander L. Kielland also had rescue suits. Of the other persons on board only a part had also rescue suits, as these were not commonly prescribed. Most of these suits also were on Edda 2/7 C, because it was very bulky equipment, which was not always carried by the workers.
Moviegoers were trying to achieve through a hatch on the port side of the theater space the highest point of the platform, the B-pillar. As in the living area, many roads were blocked by loose furniture, there are some people jumped from the windows. According to reports, many people the life-saving equipment but seem not to have reached.
In column B is relatively large number of people had gathered. There the boats were 5 and 7 boat 5 could be climbed only by 14 people. The fully enclosed boat broke free and swam in the sea bottom up until it could be erected by the occupant and float in the water again. It then still 19 people were brought out of the water on board. As leaked on attempts to start the engine smoke was allowed to have an abortion without drive the boat. With Boat 7, an undisclosed number of people could also save.
The lifeboat 1 in the rear of the Alexander L. Kielland could be climbed by 26 people. By heeling it needed to be eased only a maximum of two meters. Since the release gear under load could not be notched, had an ax to be used to get the boat free. In the time required for the boat was thrown and damage to the rig. However, it could be removed with the engine power of the drilling rig.
The lifeboats 2, 3 and 4 were not brought to water and beaten by the waves against pillars and destroyed. Boat 6 was canceled along with column D. Thus, only half of the lifeboats had been used.
The rafts were probably not exposed, but broke away when capsizing and blew himself worked on. Through them and through of the Edda 2/7 C exposed liferafts were rescued another 16 people.
The operator of the Alexander L. Kielland had dropped immediately after the first heeling over VHF a " Mayday" call and then go into lifeboat 5, from where he Edda 2/7 C on the radio the boat on further action informed.
The first Mayday call was received from Baste Fanebust, the ship coordinator for the Ekofisk complex, on a handheld radio. "Charly transport", the radio call, then sent most of the ships in the Ekofisk field to the scene.
There the Rescue Coordination Centre Southern Norway was further notified. Until 18:42 clock ships in the North Sea and rescue stations in Norway, Scotland, Denmark, the Netherlands and Germany were alarmed. The first Norwegian rescue helicopter launched against 19:30 clock. At the same time launched in the UK two helicopters and a reconnaissance machine. Other machines followed, where their use was hampered by fog.
A properties under oil field transport helicopters launched, but did not have rescue equipment on board and could not land on the inclined landing surface.
Lifeboat No. 5 took his Notfunkboje in operation and was at 19:30 Clock of the Normand Skipper, a not equipped for rescue operations catering, located. Twelve inmates could exceed the Normand Skipper over a network, then the action has been canceled as too dangerous. The remaining 21 people were taken between 2:30 to 4:00 clock clock by two helicopters.
Lifeboat No. 1 had radio contact with the Silver Pit and the supply ship Normand Skipper. However, the Silver Pit could not find the boat. The Normand Skipper reached on March 29 against 1:20 clock along with the Normand Vibran the lifeboat, but could not take any people because of the swell. The 26 men were abgeborgen in time to 3:00 clock by two Norwegian helicopter.
The platform Edda 2/7 C rescued with one of their two cranes seven swimmers from the North Sea. More people were rescued by other ships and other helicopters.
Of the 89 people rescued were only wearing a life jacket 59. There were only eight people attracted an immersion suit, of which seven people had the suit not closed properly. Therefore, could only be recovered dead in rescue suits four people. Christian Naess, the captain of the Normand Skipper, reported that they could rescue a person in a suit did not get on board, since the suit was wet and slippery. At that time possessed the suits do not have loops to hold.
To the rescue measures, 71 civilian and military ships and nine 19 rescue helicopters and seven aircraft involved until the cessation of action on March 29 at 19:00 clock. Injured were taken to the Rogaland Hospital. Although the hospital was not prepared for such an emergency, yet could additionally at the airport Sola established an emergency medical station and a response team to the Ekofisk field will be sent.
A nine months later survey carried out by participating in the rescue operation showed that although 67 % had seen exposed himself during the rescue operation significant hazards; many suffered a post -traumatic stress syndrome.
Salvage the oil rig
The wreck of the oil rig was towed to the Gandsfjord before Stavanger. Approximately three and a half years after the accident, she was raised there. This action served both further investigation and especially the recovery of bodies, so that they could be buried by their families ashore. Erecting prepared several months, including a special software for the calculation was made. Furthermore, it was determined by visual inspection and the drilling of the columns, how much water had penetrated into the columns. It floats were welded and secured the living containers with additional steel cables.
The rig was sunk later in Nedstrand fjord at a depth of about 700 m.
Causes of accidents
The accident was caused by the rupture of the strut D-6. In this strut has a drainage hole was cut, which was reinforced by a flange. In addition, a downwardly directed pipe section was welded as a carrier for one of the three required for the positioning of the rig hydrophones.
The pipe section for the hydrophone having a diameter of 325 mm and was 228 mm long. The metal was of low quality, because the manufacturer of the platform did not consider it as a static effective component. To use it, a hole was cut in the strut with a cutting torch. Then it was joined by a fillet weld to the strut. The material of the strut had been heated so twice and was under tension. The weld was among the lowest of the three welding classes used in the construction of the oil rig and was very thin. This place was the starting point of the strut fracture.
" The fillet weld is almost completely drive on the neck side of a crack, which is likely to have come from the root position again, because there he is the fusion line the next. As in the case E is the fusion line runs almost parallel to the rolling plane; the seam takes a little into the joint. Striking was the high inclusion density. It was up to 0.3 percent with a sulfur content of 0.02 percent, that is, there must have been many oxide inclusions. "
Paint residues on cracks indicated out that these cracks must already be created in the construction of the oil rig. More cracks caused by a poor quality of the welds and high voltages on the strut. From high stress points to fatigue cracks extended from the periphery of the strut. After the cracks were extended to two-thirds of the circumference, was carried by storm the breach of the strut. The other struts on column D were now also overloaded and also broke.
The rig would not be so quickly capsized when openings on the columns C and E as well as on the platform would have been proper and appropriate for the weather closed. Thus, the columns could run faster full.
Consequences
Det Norske Veritas
On Easter Sunday, after the accident originating from the same production run as the Alexander L. Kielland and serving as Flotel with 625 beds Henrik Ibsen got a Absenkübung an adverse list of 20 °, the only reason why was not greater, since a leg of the island in shallow water the seabed touched. Det Norske Veritas had then prohibited the use of Henrik Ibsen. Following was scheduled to undergo all about 40 floating drilling rigs and Flotels a four-week inspection on the coast. We went there by production losses in the amount of about 7.5 per million kronor ( 1.5 million euros ), plus inspection costs. In the detailed examination of other semi-submersible, it turned out that several semi-submersible had similar cracks, like the Alexander L. Kielland she had had. If a visual inspection at sea this would not be noticed only at a large 4- year inspection. Platforms with cracks were both certified by Det Norske Veritas and Lloyds.
State commission of inquiry
A commission of inquiry was set up early as the day after the accident that its report submitted in 1981. Until then, especially the steel construction and rescue facilities were studied in detail.
The Commission made a large number of recommendations. So the state should have the overall responsibility for drilling platforms while still. The monitoring of planning, construction and operation, however, should be done by classification societies, since more different specialists would be available. For this purpose, manuals would create.
Platforms have to be built in the future so that errors in the construction and operation would be minimized, inspections would be easy to perform and relatively minor damage can not result in a complete failure of the steel structure.
Around 1970, specialists employed generally more so, to what extent welds may affect fatigue in steel structures. 1976, the year of delivery of the Alexander L. Kielland, released new design guidelines of the British Welding Institute. At this time, no classification society had laid down guidelines regarding fatigue. They got no idea about how the insertion of such a small part, as it was the hydrophone could affect you. It was only after the accident regulations were created here.
Likewise, it was not usual to employ redundant systems. The Alexander L. Kielland was the demolition of the support D no reserve buoyancy on this site more. The investigation Commission requested that future platforms must be so constructed that failure of a support does not cause critical situation and reserve buoyancy is present.
It was found that only a few people had a rescue training aboard the Alexander L. Kielland. 1980 Of the approximately 4000 working on moving platforms persons had only around 1000 and relevant training. For 75 % of the personnel exception permits were applied for and been granted by the State Maritime Directorate. One reason was lack of funds for training. Asked about this, called Ivar Sandvig, the Director of the Directorate, this approach " sense of reality ".
International Maritime Organization
On the 46th Maritime Safety Convention of the International Maritime Organization, the Norwegian delegation proposed a review of the stability requirements of the MODU Code ( Code for the Construction and Equipment of Mobile Offshore Drilling Units). The MSC opted for a periodic review to bring in the progressive development and the experience of the calamities of the Alexander L. Kielland and the Ocean Ranger. At the 28th session of the Sub-Committee on Ship Design and Equipment, it was decided to changes in the general part of the MODU Code and the establishment of ad hoc working groups to regulate the installation of machinery and electrical equipment. They also agreed that the guidelines for rescue equipment are urgently revise.
So lifeboat seats were required for 200% of the persons on board, as had been found again and again that some of the boats in accidents due to fire, shock or damage page could not be used.
It was also required that each person should have a personal survival suit on board in the cabin. On the possible evacuation routes and emergency rescue stations suits for 200% of the people also should be provided on board. In subsequent years, rescue suits were also heavily revised. So they got for example loops on the back, with the aid of which can be a driving person in the water better packed and taken on board.
It should also be assigned in less than one nautical mile distance a willingness ship every platform.
Other consequences
One of the problems with the evacuation was that a lifeboat is not solved, there stood in the back and forth rocking boat one of the triggering devices always under tension. It first came to no decision about a change, since it had previously been some time an accident with a lifeboat, in which the trigger mechanism opened too early and the boat bounced as from a great height on the water. Three people died. Finally, Norway chose an extreme solution in the form of free-fall lifeboats. The people on board, however, need to be trained more intensively for this purpose. Others have resorted to systems where the lifeboat can be achieved by one of the inside to be operated, usually hydraulic, locking of the lifting hooks.