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1 The Alexander L. Kielland accident The Inquiry Commission’s Investigation of the causes of the capsizing and the assessment of evacuation and rescue operations and the associated recommendations & Some comments, especially on what were NOT causes of the capsizing
Torgeir Moan NTNU
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2 Content Mandate and members of the Inquiry Commission Background: - Principles of accident investigations - ALK (P89) lifecycle history vs status of technology & regulations Possible causes of the accident - The Commission’s approach: what causes platform accidents in general (i.e. the risk picture) - «all possible causes» need to be investigated «Media rumors» Facts - the «collapsed structure», environmental conditions at the time of the accident - the life cycle info.: design and analyses (digital twin), fabrication- and operation reports, .. - inspection of sister rig - Henrik Ibsen (P88) & other semi-submersibles - Industry practice : rules & regulations – and their implementation in practice - Examinations after the uprighting of ALK (in 1983) - Personal comments about Expert and Witness statements & Media Brief description of the causes of the capsizing and associated recommendations - technical and physical a well as human and organizational factors for A. structural failure(loss of column D) and B. flooding and capsizing - comments on circumstances that were not «cause of the accident» Brief assessment of evacuation and rescue operations – and assoc. recommendations Final remarks
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3 Mandate for the Inquiry • Investigate the conditions of the accident and, if possible, bring to light the causes of the accident (and recommendations to improve the safety - as agreed with the Ministry of Justice after the appointment)
• Assess the performance of the rescue equipment and how the evacuation and rescue operation were executed and come up with recommendations
Inquiry Commission’s members • Thor Næsheim, Magistrate, Sandnes • Torgeir Moan, Professor, marine technology, NTH (NTNU) • Sivert Øveraas, Director, Shipowners association • Per Bekkvik, Platform manager/ship captain • Aksel Kloster, Personal manager, National Guard and Oil secr. LO - later replaced by Jan B Strømme, «Oljekartellet»
Engagement of Kjell Straume, MSc as a technical secretary and several, independent experts (e.g. from NTH,SINTEF, U.Aachen, Statoil) for special investigations
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Background:4 Principles for accident investigations
Technical/physical event sequence Deficient rules and regulations (and industry practice at large) when it is realized that the industry practice «at large» is not good enough Human errors and omissions Individual by those «errors» must be - doing the job (and their seen in view of Fabrication superiors in the organisation) the management- during the different life cycle and safety culture in the relevant phases organisations and or regulatory bodies - doing the control of integrity management during the lifecycle The The facility’s phases lifecycle based on a «risk management tool»: Mangement Oversight Risk Tree (MORT), (Johnson, 1973) Torgeir Moan, NTNU 4
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5 Background: Principles for accident investigations, cont.d Holistic assessment of all possible causes/factors of influence – in an objective manner, i.e.:
Objectivity
Factuality Impartiality
Neutral Truth Relevance Balance presentation
J. Westerståhl in the book by Hadenius & Weibull (ed.) Massemedier, Aldusserien, Stockholm, 1978.
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6 Background: The development of the offhore O&G industry and the regulatory regime Brief ALK history o ALK was Pentagon-rig no. 9 (denoted P89) o Developed in the late 1960s, the first one, P81, was built in 1969 - The P82-P91 rigs were further developed and built based on «similar analysis and drawings» and delivered in 1973-1977 (CFEM, Rauma Repola, Marathon) . o - ALK (P89) was approved in 1973-74 and delivered from CFEM in 1976.
Pioneering period for the Norwegian O&G activity :1970-1980 • Maritime Dir. regulations for drilling rigs1973, 1975 • DNV: rules for mobile rigs 1973 (ABS 1968) • Petr. Dir. was established in 1973 – Ptil separated as a unit in 2004 • The Petroleum Law 1985 – Petr. Dir. as a coordinating body authority
Milestones: ALK accident in 1980 Research Program «Safety Offshore» 1978-82 - With several implications on safety efforts by the induystry and authorities
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7 Background info. for the Inquiry - assessment of regulations and standards & their use in practice Article published in - experiences from other accidents «Teknisk Ukeblad» (Inquiry reports, risk analyses), e.g. Vol.127. No. 11. T.Moan: “Risk Assessment of Mobile Rig 28.02.1980 Operations”, Report SK/R46, NTH, 1979, (a month before the ALK accident) Safety Offshore (“Sikkerhet på Sokkelen”) research program. Overview of world wide accidents for mobile (1970-1980) platforms, made in connection with the finalizing of the ALK Inquiry Report: NOU 1981:11
organized according to the technical-physical sequence of events
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Possible8 causes of the ALK accident Possible causes (circulating in media and also presented to the Commission in various ways): - open ventilators, watertight doors, (published in 1981) - occurence of cracks (the Commission informed the parties about the D6 fatigue failureene 31.03.80) - ship impact Hovden, Jan; Vinje, Kjell E. A.: Disaster journalism, - «deficient platform structure, struct. materials the newspaper coverage of - «overtensioning of mooring lines» – the "Alexander L. Kielland" especially the first days platform accident, - explosion (sabotage) theory Yrkeslitteratur, Oslo, ca. 1983. The argumentation for and against the theories – were influenced by self interests
(The Commission investigated the various potential causes, but only briefly mention factors that were insignificant to the causes of the accident, in the Commission’s report). Torgeir Moan, NTNU 8
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9 Facts in the Inquiry
- The «collapsed» struct. failure surfaces, material properties, (SINTEF, Statoil) - Inspection of sister rig- Henrik Ibsen (D-column, diver-inspections , - inspection av the ALK platform especially with respect to cracks at i 1980(!) and after uprighting in 1983 other locations – e.g. on brace B5, Material tests , etc) - wave-, wind conditions at the timeof the accident and during operation - design basis (drawings, criteria, analyses,operational manual), - fabrication- (inspection-) - and operational logs - annex: design calc. (stability and strength of hull and mooring system) fatigue analyses (which were not carried out for design) (SINTEF/NTH, U.Aachen) stability- and flooding analyses (NTH) - review of relevant regulatory requirements and their use - interrogation/hearing of designers, fabricators and inspectors during fabrication, class societies, Maritime Dir., Petr.Dir., owners, surviving maritime crew and hotel guests (normally together with the Stavanger Police)
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10Personal comments about Expert & Witness statements & Media Hearing of involved parties: - The French designers and fabricators, class society (DNV, Lloyds Register (LR) , Mar.Dir., Operator (Stavanger Drilling) specialists on strength and stability analysis - Maritime crew - Others (hotel guests)
Opinions expressed by other org. and media
Necessary Many persons – also engineers – have perspective: made statements about the accident Relevant without a holistic perspective of the facility engineering and its life cycle history. competence, familiarity with For instance, media have speculated on accident Fabrication the accident causes based some physical observations during operation by personnel taxonomy The accident took place during on board – without insight about the design operation and fabrication (e.g. the digital twin of the platform) – and often with a certain (hidden) Operation «agenda». Torgeir Moan, NTNU 10
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11 Document delivered to the Ministry of Justice, March 1981: NOU 1981:11 - Main report 216 pages - Technical annexes 143 pages - Documents from different experts
Mandate •Investigate the conditions of the accident and, if possible, bring to light the causes of the accident (and reommendations to improve the safety (as agreed with the Ministry of Justice after the appointment) •Assess the performance of the rescue equipment and how the evacuation and rescue operation were executed and come up with «unauthorized In Norwegian recommendations translation» with a summary in English Torgeir Moan, NTNU 11
12 Uprighting of ALK The main motivation (of the government) for the uprighting was the search for the remains of 36 missing persons In 1980:Inspection of the D-column and the platform: - dry inspection of pieces cut at failure locations - under water inspections by divers on behalf of the Commission In 1983 (after uprighting): - Further investigation of structural damages relating to the accident causes Additional document (hampered by damages caused After uprighting during the uprighting of the platform) Delivered in 1983: - Status of doors, ventilators and NOU 1983:53 valves (associated with flooding, capsizing) Parliament message No. 41, 1983-84 Torgeir Moan, NTNU 12
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13 Accident Causes Accidents can be - Fatalities - Environmental investigated from: damage Technical-physical point of view Critical - Property - Capsizing or total loss of event damage structural integrity commonly develops in a Fault Event tree tree sequence of events
Human and organizational point of view («Root Causes») - All decisions and actions made – or not made during the life cycle are the responsibility of individuals and organizations based on the «tool»: The Management Oversight and Risk Tree – MORT (Johnson,1973; User manual EG&G,Idaho Inc.,1976) Torgeir Moan, NTNU 13
14 The overall accident (technical-physical) sequence (Moan, 1981, 1985) - Column D is lost due to structural failure
- Heeling: 30-35 - Flooding of deck and columns
- Capsizing The scenario for escape, after 20 min evacuation and rescue -123 fatalities Evacuation- and (among 212 persons on board) Rescue operations - total loss of the platform
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15Loss of column D: Technical-physical causes «possible» additional Brace Brace between C and D Based on all physical D-6 not included in the evidence and D design due to considerations of numerical analyses supply ship operations
Column D Fatigue failure in Fatigue failure brace D6
Crack Initiation II Plate thickness not in scale
Crack Hydrophone D6 plate Initiation I support Overload (failure) of the other 5 braces between column D and the platform Loss of column D
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16 Fracture mechanics analysis of the (Moan et al., 1981; Alexander Kielland fatigue crack Moan, 1985, 2006) Brace D-6
D E
Plate thickness not in scale D6 plate 70 mm crack with paint inside Caculated expected Hydrophone time to failure: 3-4 yrs; support ( ca 7 yrs without the gross welding defect) Torgeir Moan, NTNU 16
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Capsizing17 (flooding and capsizing) Background: - The Scenario: Loss of a column - Design of floating platforms to limit the risk of capsizing or progressive flooding (Ch.3.2 in NOU1981:11): Intact and damage stability requirements
Design and operational issues relating damage stability requirements - water filling of 1-2 compartments, typically up to ca 600 m3 in total for columns in ALK. - Doors and valves submerged in the new inclined floating position (typically 22-24 heeling) should be (closed and) designed to tolerate the water pressure to avoid progressive flooding – otherwise it needs to be shown that the capsizing criteria are fulfilled under the revised flooding condition
- Inaccurate stability analyses (in design) implied a payload capacity of 1600-1700 t (not 2100). However, the payload was about 1050 t at the time of the accident - There was also some doubt whether the drainage valves fulfilled IMO’s Load Line convention. - On the other hand, the designers specified in the operational manual some requirements to keeping doors in the deck shut – even if according to the initial stability checks the deck was not going to be submerged into water and hence no requirements to closing of openings in the deck.
NOTE: The main issue is that the scenario with the loss of the column D, was dramatically different from the existing design stability criteria. The discrepancies in the stability analysis and operational follow up, are not significantly contributing to the accident . Torgeir Moan, NTNU 17
18 Capsizing: Technical-physical Causes of the Capsizing given loss of column D – (3.2.5.4 i NOU1981:11) Loss of column D Deck sides resulted in an inclination of 30-35 Flooding of of the trunk and dry tank in column E Lower and trunk in column C deck and 50-75 % of the 9600 m3 deck volume Different - Closing ventilators was openings required at a draft of 20.7 As suggested in Sect. 3.2.5.4 m. Failure to do so, could Note: some extra margin there were also some (small) regarding deck load have contributed to a openings in the deck that should (1050 vs 1600-1700 t) slightly more rapid flooding have been closed according to the (Sect. 3.2.5.4, Annex 1,1.3) operational manual (since the designer tried to make the deck Capsizing after buoyant ) – however, it might be about 20 min unrealistic to expect this to be done in the relevant scenario .
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19 Root (Human & Org. factors) Causes of Structural Failures and Risk Reduction Measures Cause Risk Reduction Measure Quantitative method Less than - Increase characteristic load, Structural adequate safety safety factors/margins in ULS, FLS; reliability margin to cover - Improve inspection of the analysis “normal” inherent structure (FLS) uncertainties. Gross error or - Improve skills, competence, self- Quantitative omission checking (for life cycle phase: d, f, o) risk during life cycle - QA/QC of engineering process (during d) analysis phase: - Direct ALS design (in d)– with - design (d) adequate damage conditions arising - fabrication (f) in f, o (NOT d) - operation (o) - Inspection/repair of the structure (during f, o) Unknown features -Research & Development Indirectly: or phenomena Technology Readiness Level Torgeir Moan, NTNU 19
Basic20 case: Causes of Structural Failure & Capsizing structural failure occurs when the load effect, S > the resistance, R: - S and R are uncertain due to fundamental Tech.-phys. variability (e.g. in loads) and lack of data. Calculated, accepted risk Design : Rc/R > S Sc is based on accepting a certain failure prob. - errors or omissions in design, spec.of fabr. (and oper. ) - too low strength of components …,e.g. not doing fatigue design check; using too low sea state (error by designer or deficiency of industry at large) - errors or omissions during fabrication - use of deficient material Human & - welding faults: excessive defects and geometrical deviations org. factors - errors or omissions during operation: nomally - abnormal loads (payloads, ballast, environmental loads dominating - accidental loads (fires, explosions, ship impact, the actual abnormal ballast distribution...) beyond design risk - abnormal corrosion or crack growth - excessive mooring loads due to maloperation - deficient rules and regulations, (in the industry «at large») - or practicing of them - deficient control of design, fabrication or operation Capsizing occurs due to overturning moment exceeds hydrostatic stabilizing moment – can be treated in a similar manner Torgeir Moan, NTNU 20
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Brief21 Summary of the Alexander L. Kielland Capsizing Technical causes & Human and organizational factors Fillet (Root Causes) weld consequences
• fatigue failure of • fabrication defect due to - deficient weld design Plate of one brace the brace - initiated by a - bad welding Hydrophone gross fabrication - inadequate inspection support defect (crack) and deficient fillet weld • no fatigue design check - low fatigue life carried out
• ultimate progressive • codes did not require structural failure of braces robustness (damage - tolerance)
• loss of column D, • damage stability rules did not cover listing of 30-35, loss of a column (implying a net loss of pump capacity buoyancy loss of 2-3 times the & common “damage”) progressive flooding • failure to shut doors, ventilators etc. “contributed” to the rapid flooding and capsizing • capsizing (after 20 min) Human and organizational errors and omissions as well as deficient Industrial practice Torgeir Moan, NTNU 21
22 Comments Human & Org. Errors and Omissions in view of The state of knowledge/practice at large in the industry, regulatory bodies (Mar. Dir., Class. Societies): - regulations and design codes appearing in 1973 and - control practice – limited semisub. platform years of operation), research community - significant research on fatigue of welded offshore structures in 1970-75 Accident experiences
The state of art in technology design fabrication operation QA/QC - inspection, - inspection
- the accident Example: ALK: -19741) 1976 1976 ……- 27.03.1980 Fatigue 1 P89 - no.8 of 10 sister rigs designed approx. in 1971- 75 analysis and design Torgeir Moan, NTNU 22
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23 Historical notes on fatigue analysis & design (Moan, 2006) - 1840- 50 First fatigue failures - of vehicle and machine shafts - documented in journals - 1847- 70 Wöhler’s scientific investigations ……………………………….. - 1895 Kipling’s description of propeller shaft fatigue failure in ”Bread upon the waters” - 1948 Nevil Shute’s description in ”No Highway” of airplane loss due to fatigue ……………………………….. - 1953 Comet airplanes lost due to fatigue - 1950’s Fatigue failures of welded bridges and ship structures – and R & D - 1960’s Textbooks on fatigue of welded structures
- 1963 (61))Paris-Erdogan’s law ( fracture mechanics) - 1969-73 Offshore Rules with fatigue requirements - 1970-75 Significant fatigue R&D for offshore structures ……………….. - 1979 Ranger I jack-up failure in the Gulf of Mexico ……………….. - 1980 The Alexander L. Kielland accident in the North Sea Torgeir Moan, NTNU 23
24Comments on the report NOU1981:11 & Media Involved parties (except the French designers/fabricators), generally agree on the conclusions (see e.g. Parliament message,No.41,1983-84), even if e.g. the Mar.Dir. and DNV were critized in NOU1981:11. The international offshore engineering community also agrees.
Some media, for various reasons, have, especially in the last few years, made («fake») news based on witness statements especially from survivors, said to be new observations, - however without knowing the existing documentation (facts) or - seeing it in a holistic perspective (lacking the use of the information generated through digital twins of the system and operations). - another issue is what is the trustworthiness of recent statements – 35-40 years after the accident.
The commission based its investigation on all hypotheses. In the following I will comment on frequently mentioned hypotheses regarding the loss of column D: - cracks, ship impacts, explosions and possible effect of mooring system. In the report NOU1981:11 such hyptheses are briefly mentioned - and why they cannot be the causes. Torgeir Moan, NTNU 24
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Cracks25 – rumors and facts Design and inspection plans (no fatigue design) - The platform had been subjected to annual, visual inspections by crew members, with a limited likelihood of detecting e.g. small cracks. - Visual inspection had been carried out on selected joints - The 4-year main inspection should have taken place in june 1980 but was granted a year delay, based on an application. (The critical crack on brace D6 might have been detected during a main inspection if the inspection at this location had been prioritized) - Another matter: statement by platform chief engineer (07.03.1986) that he and the platform manager proposed to PPCoN that the lower braces could be inspected in August 1979 in connection with the the move of ALK in a deballasted condition to Edda - but was not done. Observations/findings during the operation of ALK (before the accident) - the platform manager reported cracks on crane supports, that were repaired in 1979 (p. 53 i NOU1981:11, see also p.237) After the accident there were rumors: «The platform manager knew about cracks». The cracks at the crane support was probably mixed up with the cracks in brace D6 that was reported by the Commission on Mach 31 1980. Observations after the accident - initial cracks at the hydrophone support on D6 - other cracks in ALK and other Pentagone & other platforms,…? (p. 55, 58 in the report). Diver inspections on ALK, without crack findings at the opposite hydrophone holder on brace B5 (p. 55, column 2)
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26 Ship impact hypothesis Ship impact was suggested as a cause or at least a contributing cause of the accident – also by CFEM – Forex Neptune. Extreme char. line tension (in B1-B2) was estimated to be of the order of 2.0 – 2.6 MN and 0.8 - 1.3 MN at the time of the accident (smaller for D1-D2). The tensile capacity of the intact brace D6 was about 70 MN.
For a ship impact to cause failure of an intact brace forces of the order of several MN need to occur – also imposing damage at the impact location The observed damages that could be due to ship impact (contact) are described in NOU1981:11, p. 52-53 - a dent with a depth of 1’’ (25 mm) on brace C-2, between stiffeners at the 3. ringstiffener, 6 m from the lower end of the brace - attributed to a contact with a supply vessel on 21.10.78. - a dent of the same size in column D, 10-12 m from the top of the column, 3-4 m above still water level
These indentations do not correspond to impact forces that can cause failure of an intact brace D6.
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27Explosion hypotheses • Launched early (see Media report of the early stage by J.Hovden og K.Vinje, 1981) a) first as «explosion-»sabotage hypothesis (by Østlund, «Kiellandfondet», book by B.Nilsen «The Ghost in the Nort Sea», 1984) b) later as an «accidental condition», relating to welding station or moving of «gas containers». Scenario a: - material tests (at UiO), said to be from the upper end of the D4 brace, claiming that the microstructure of failure surfaces is due to high pressure and temperature - and hence caused by an explosion. (prof. Gjønnes, UiO, responded «no» to the question whether «explosion could be excluded»). - no footprint due to heat found at failure locations - failure mode at failure locations not compatible with a possible internal/external pressure load. The actual failure of braces other than the D6 show sign of compression and bending of the braces, taking place rapidly, in agreement with the calculations in Ch.5.3 (Table on p.278) and material investigations by SINTEF (annex 8, NOU1981:11) and a later statement e.g. from prof. T.Grong there is no support of the UiO conclusions. - there is no motivation identified for an intended sabotage Typical brace nor any witness statements that can support this hypthesis. failure mode Torgeir Moan, NTNU 27
28 Explosion hypotheses, continued Brace Scenario b: an explosion in the welding station (related D-6 to gas «containers»), causing «rystelser» (shaking) that caused failure at two locations in brace D4 (located some distance away from the welding station). - No quantitative justification has been given regarding explosion pressures and the shaking at D4 (forces in D4). Why should failure occur there and not other places? - no apparent damage at the location of the welding station - where the explosion is said to occur - there is no witness statements about explosion events
Additional note Damages at the node between brace D4 and the lower deck discovered during inspection of the uprighted platform is explained by high forces during the uprighting by the buoyancy bag attached there
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29 Possible influence of mooring system issues on the accident Background The mooring system was initially designed with 10 steel wire lines. At the «Edda 2/7 C» 8 lines were used (C1&C2 lines were not used) The 10-line system was approved by the Maritime Dir., but not the 8-line system (p.53-54 and Annex 5 of NOU1981:11).. DNV was involved in approbation of the mooring system in connection with insurance in 1977. The Commission made alternative mooring anlyses to illustrate the effect of more refined and stringent design analyses (emerging around 1980) due to high line failure rates and «motivation» implied by the ALK accident The 8-line ALK mooring system used at Edda 2/7 C actually did not satisfy ultimate strength design req.(p. 47 in NOU1981:11, and details in Annex 5) The environmental conditions at the time of the accident were moderate («fresh gale – stiv kuling», not storm!: The procedure for relocating - sign. wave height (Hs) 6 m (< 50 % of extreme value) the platform is described on - mean wind speed, about 16-20 m/s, approx. from East p. 222 in NOU1981:11. Line tension : 50 % of the extreme value. The tension in the leeward lines D1 og D2 (and E1/E2), is even lower, about 60-90 t. Torgeir Moan, NTNU 29
30Possible influence of mooring tension on the structural failure? (p.53, 55, 56, 57 and Annex 5 og 7 in NOU1981:11) Line tension measured to 40 t and measurement system found to be ok at 05:00 on 27.03.1980 (p.53, 55 i NOU1981:11) Hs increased from 3 to about 6 m from 09:00 to the time of the accident and the platform was relocated – away from Edda 2/7 C, by reducing the tension in D1/D2/B1/B2, and increasing tension in A1/A2/E1/E2 (p. 55). The relocation took place without any problems and was completed at 17:50 – with a tension level of about 40-60 t. The accident happened at 18:30 Hypothesis 1: High mooring tension ripped off the column D: - assume conservatively that both lines D1 og D2 have a tension at ultimate strength, i.e. each 304 t – 4 times the most likely level. This implies a stress in an undamaged brace D6 approx. 10 % of yield level and about 2-4 % in the actual conditions (Annex 5, p. 261, 275 and Annex 7 in NOU1981:11). Hypothesis 2 : Operational error during relocation causing an abnormal mooring tension that ripped off the column D - The Commission had no reason to believe that there were errors made during the relocation, causing excessive stresses, contributing to the failure of the brace D6. (NOU181:11, p.55) - the normal tension in the lines contribute to the stress level in the brace and hence the fatigue failure and final rupture. Since this effect is very small for an intact brace, even possibly neglecting this effect is a minor «error».
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Recommendations31 (strength & stability) Focus on holistic, unified safety Recommendations management in view of all hazards were weighted to (risks) and measures to limit the risk balance requirements in view of the total risk Improved standards/guidelines picture (accident regarding strength and stability potential) - damage tolerance Rather than to Improved practicing of standards «overreact» on the and quality control (design, inspection features of the during fabr. and operation) particular accident Organization of safety control - Example: conflicting Governmental inst. vs delegation, requirements to the e.g. to class soc. – especially in view of deck structure novel type of platform function or layout regarding possible Limited focus Ensuring competence and (emergency) on R&D creating safety attitude in involved buoyancy, evacuation ways, fire/explosion organizations In general, this accident gave the momentum to a «new deal» in offshore safety in Norway…..
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32The most important recommended new design requirement: A general principle for damage tolerance: - As implemented by NPD in 1984 as ALS and later in international codes
- Extend existing damage stability criteria (based on specified vs risk-based criteria) - Revisit assumption regarding of closing openings in the deck during operation - Introduce damage tolerance criteria for the hull strength and mooring system
a) Capsizing due to flooding/buoyancy loss
c) Mooring system failure after «loss» of one line Important recommendation even if b) Global structural failure due accidental loads mooring system issues cannot be said to or abnormal strength be a contributing cause of the accident. Torgeir Moan, NTNU 32
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33 Assessment of evacuation and rescue operations and equipment The accident scenario Net loss of buoyancy: - 20 min before capsizing 1300 m3 (as opposed to - no el. power typical flooding in - loose equipment damaged condition: 600 m3 , p. 245-247, 357 blocked doors - only 2 of 7 life boats were «successfully» B used - survival suits were not mandatory Status of evacuation means (life boats, life rafts, 212 persons on bord survival suits, means of rescue (stand-by vessel… helicopter….in the field ) 123 fatalities Lifeboat, attempted launched, Total loss of the platform Regulations, rules crushed against the platform Assessment - assisted by NSFI/Marintek, Interrog. of survivors
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34 Lifeboats at the Escape ways B top of the column
Upper deck view, with all life boats (life boats 1, 2 on the lower deck
C
E Intermediate deck – not shown Torgeir Moan, NTNU 34
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35
26
21
7
9
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36 Causes of the ultimate consequence: Fatalities - The role of evacuation and rescue operation
Technical-physical Human and organizational factors causes
• the accident scenario: • the accident scenario was not anticipated - sudden 30-35 heeling, in facility design, and the planning of - capsizing in 20 min. evacuation and rescue operations - low water temp. - hotel platform with 212 persons on board • deficient evacuation • deficient requirements to and rescue operation - lifeboats, survival suits , stand-by vessel (lack of survival suits, etc limited available and - safety training (courses and exercises). “lauchable” lifeboats, (Still, experienced seafarers managed well) stand-by vessel and other • long mobilizing time for rescue (stand-by) rescue fcilities vessel, (helicopters) equipment) Torgeir Moan, NTNU 36
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37Recommendations relating to evacuation and rescue • Holistic view of accident scenarios “Marine events” (heeling platform, flooding, …) Fire and explosions (toxic smoke, heat,….) Important to balance conflicting requirements relating to marine and «industrial» accidents
• Design of the facility - design the platform to avoid accident scenarios such as that of ALK - distance between hazardous areas and living quarters - type and location of lifeboats etc - protection of potential evacuation paths and means of evacuation
evacuation means: number and quality of life boats (free fall rather than launchable life boats) 200 % coverage of lifeboats, survival suits
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38 Recommendations relating to evacuation and rescue
Establishing area emergency system
Stationing of helicopter for rescue operations
Stand-by vessel in the field
Mandatory safety course, training and exercises for all offshore personnel
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39 Concluding remarks
The ALK accident marks the «end» of the pioneering period (1966-1980) of offshore oil and gas activities in Norway • «Errors and omissions» in the design and fabrication were the root causes of the accident, however, to some extent reflecting the «limited» state of knowledge in the industry in the first part of the 1970s. • This accident lead to a focus on safety requiremets and practice (by providing the momentum to introduce long due principles) - providing safety with respect to catastrophic consequences relating to operational errors by requiring damage tolerance with respect to global structural failure, capsizing or total failure of the mooring system - avoiding fatigue failure by proper design, as well as inspection, maintenance and repair during operation - design the platform for efficient escape and evacuation, improved evacuation means and procedures evacuation and rescue – and safety education and training
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40 Significant changes in safety management have been formally implemented in Norway. (NOTE: 105 of 106 safety improvements recommended by the Cullen report following the Piper Alpha disaster had already been implemented in Norway following the earlier accident – Reid, 2020.)
Maintaining safe facilities and operations, requires a safety attitude by all personnel involved in the whole lifecycle.
Such an attitude is supported by motivation e.g. from the lessons learned from previous accidents, focusing on human and organizational factors
THANK YOU!
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41 Selected references beyond NOU1981:11 and NOU 1983:53 and references given in these documents
• Hovden, Jan; Vinje, Kjell E. A.: Disaster journalism, the newspaper coverage of the "Alexander L. Kielland" platform accident, Yrkeslitteratur, Oslo, ca. 1983. • Johnson, W. G. THE MANAGEMENT OVERSIGHT AND RISK TREE – MORT Idaho Operations Office and Aerojet Nuclear Company Grandjean Lowman, Idaho 83637 (4566 River Street Willoughby, Ohio 44094). Prepared for the U.S. Atomic Energy Commission, Division of Operational Safety. 1973. User manual EG&G, Idaho Inc.,1976. • Moan, T.: “Risk Assessment of Mobile Rig Operations”, Report SK/R46, NTH, Trondheim, 1979. • Moan, T.: Kunnskap og holdning vil alltid være viktig for sikkerheten, Teknisk Ukeblad, Vol.127, no.11, 28.02.1980 • Moan, T.: The Alexander L. Kielland accident, First Wallace Lecture, Massachusetts Institute of Technology, Cambridge, 1981. • Moan T., S. Berge and K. Holthe: Analysis of the fatigue failure of the "Alexander L. Kielland", , Americal Society of Mechanical Engineers (ASME) Annual Meeting, Washington DC, November 1981. • Moan, T.:The progressive structural failure of the Alexander L. Kielland platform, Vienna: Springer, 1985. • Moan, T.: Fatigue Reliability of Marine Structures – from the Alexander Kielland Accident to Life Cycle Assessment of Safety", ISOPE Keynote lecture, San Francisco, 2006, J. ISOPE, 2007,17(1), 1-21. • Reid, M. The Piper Alpha Disaster: A Personal Perspective with Transferable Lessons on the Long- Term Moral Impact of Safety Failures. ACS Chem. Health Saf. 2020, 27, 2, 88–95
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