NOU 2003: 5

Pionerdykkerne i Nordsjøen

Til innholdsfortegnelse

7 Summary in English

7.1 The Commission and its mandate

Pursuant to a decision by the Parliament on 13 June 2000 the Norwegian government appointed on 2 March 2001 an independent Commission of Enquiry to investigate all circumstances related to diving in the North Sea in the pioneer period. The Commission was chaired by Petter A. Lossius, Judge, Borgarting Court of Appeals. Members appointed were Per Oskar Andersen, Professor, MD, PhD, University of Oslo; Bård Holand, Senior Engineer, M.Sc., Thelma AS; Alf Petter Høilund, Senior Engineer, M.Sc., Det Norske Veritas; and Gunnar Nicolaysen, Professor, MD, PhD, University of Oslo.

The Commission received the following mandate:

The Commission of Enquiry shall assess all circumstances related to diving in connection with the North Sea oil industry in the pioneer period. This period is defined as 1965 to 1990.

The Commission shall inter alia clarify responsibilities, expertise in the risks entailed by diving, and the harmful effects that diving operations inflicted on the pioneer divers.

Should the Commission find grounds for asserting that injuries have arisen as a result of diving in the pioneer period, the Commission must consider whether any party is to blame for this, including whether any legal liability rests with the authorities or other parties.

The Commission is expected to utilise already ongoing medical examinations of divers at Haukeland Hospital in Bergen. The Commission is also expected to gather information by other means, for example via interviews with the divers, the authorities and other relevant parties on the continental shelf.

The investigations to be undertaken are technically very wide-ranging. The Commission is therefore expected, where necessary, to utilise diving medical and technical diving expertise available both nationally and internationally.

The Commission should ensure a good dialogue with all affected parties, including representatives of the divers. Steps are being taken to establish a contact forum consisting of the social partners. The North Sea Divers’ Alliance will attend the Commission’s meetings in an observer capacity.

The Commission shall start investigations at the earliest opportunity, and complete them without undue delay. The Commission shall prepare a report containing the Commission’s conclusions. The report shall be delivered to the Ministry by the end of December 2001.

Royal Decree of 28 January 2001 empowers the Ministry to amend the mandate, and in the event to appoint new members to the Commission.

7.2 The Commission’s work

The Commission has carried out a thorough investigation of government archives, and has examined archives of the Norwegian Oil and Petrochemical Workers’ Union and of a number of oil companies. It has also interviewed a number of persons in relevant government posts. Moreover, representatives of the labour movement were interviewed, as were several physicians with the speciality in diving medicine.

In order to obtain a good knowledge of the pioneer divers’ health and work environment in the North Sea in the period 1965 to 1990, the Commission conducted a survey of Norwegian pioneer divers, numbering a total of about 350, and interviewed 82 of the 235 who responded to the survey.

7.3 Diving – some technical and medical premises

7.3.1 General comments on diving

To understand what diving entails, the reader needs some background information on various types of diving. Pressure, gas absorption and elimination along with temperature are important diving parameters. Equipment used for diving in the North Sea differs greatly both from the helmet and hose used in traditional diving work, and from diving using lighter equipment. Suits supplied with hot water became the norm from the mid-1970s onwards, and only a mask with a hood – or a helmet – covering the entire head is used. In addition an umbilical is used, often together with a diving bell. Decompression chambers on the surface are often used for air diving operations, and are invariably used for bounce diving and saturation diving. In addition to air, mixed gases – where oxygen is mixed with helium or nitrogen – are used as breathing gas.

The content and pressure of the breathing gas is affecting both respiration and absorption of gas by the body tissues. Temperature regulation, energy turnover, fluid and salt balance, as well as the effects of pressure increase and pressure reduction, also play a part. Altered pressure of some gases such as carbon dioxide, oxygen and inert gases (helium and nitrogen) is significant for nitrogen narcosis («rapture of the deep») and gas bubble formation (micro bubbles in the blood) as well as decompression sickness , osteonecrosis and effects on the central nervous system.

7.3.2 Long-term effects of diving

A key issue is the long-term effects of diving, i.e. whether repeated diving, with or without registered decompression sickness (correctly treated and with no immediate residual symptoms), can entail the development of injuries over time.

The introduction to the first overview article in this field that to the Commission’s knowledge has been published (Bennett & Elliot: The physiology and medicine of diving, 1993, chapter 21, D.H. Elliot & R.E. Moon: Long term health effects of diving) contains the following passage:

For around 100 years, the immediate effects of a diving accident have dominated the preventive, diagnostic and therapeutic aspects of diving medicine. The apparent total recovery on recompression of an unconscious or paraplegic diver was justifiably considered to be a clinical success and any permanent sequelae from less successful treatments were accepted as regrettable but unavoidable risk of diving. The other effects of exposure to raised environmental pressure such as oxygen toxicity and more recently, the high pressure nervous syndrome (HPNS) has been regarded as transient, at least from the exposures usually encountered in conventional sports and professional diving.

Only in recent years has attention been drawn to the possibility of less obvious but potentially serious effects upon an individual who have dived for years but without having experienced any significant diving accident.

Thus far it seems clear that attention has above all focused on possible delayed injury in the lungs and central nervous system.

Injuries can theoretically be attributed or related to:

  • Long-lasting and repeated breathing of gases under high pressure.

  • Divers who have either suffered decompression sickness which was quickly and successfully treated or have never suffered decompression sickness, can none the less be thought to develop a disorder. Gas bubbles that have not produced recognisable symptoms/signs in connection with repeated decompression, could conceivably produce injuries which only become evident later.

  • Repeated life-threatening situations combined with other traumatic experiences may have produced a post-traumatic stress syndrome.

7.3.3 Lungs

There is sound evidence that human lungs can withstand oxygen pressures up to about 50 kPa for many days while higher pressures cause damage. During diving and decompression, the oxygen pressure in the gas breathed by divers will invariably or almost invariably exceed the approx. 20 kPa they are exposed to at sea level, lying in the range 30–40 kPa in the diving phase and at times up to 50–60 during decompression. This direct oxygen burden is accompanied by the likelihood of micro bubble stress during decompression and possible effects of contaminants in the breathing gas.

Up to about 1985 no reports or epidemiological studies appear to have raised the issue of possible negative long-term effects of diving on the lungs, beyond reports that divers show a somewhat higher forced vital capacity 1 than expected (such an increase is not a sign of reduced lung function.) Nor can it be assumed that diving physicians have made systematic findings that should have prompted a response from the authorities. Crosbie et al. (British Journal of Industrial Medicine 1977; 34: 19–25) found no evidence of increased respiratory resistance among a group of 404 divers who had worked an average of seven years in the North Sea. In 1990 Thorsen et al. (British Journal of Industrial Medicine; 47:519–523) published a study of pulmonary function among 152 professional divers and a group of non-diver, but otherwise matching, controls. The divers had an average of 10.5 years of diving experience, and had worked at various depths with and without saturation. Thorsen et al. found a statistically significantly reduced velocity of flow through the air passages. The reduction covaried, albeit not strongly, with diving exposure. This suggests the development of increased respiratory resistance among the divers. The study also showed a reduction in gas transfer velocity among the divers possibly indicating a reduction of alveolar surface area or thickening of the alveolar wall. Changes in pulmonary function were however minimal among the great majority. Thorsen states (in a personal communication) that two divers developed considerable obstruction of the respiratory tract, and that for these two diving was the only possible explanation. Reuter et al. (Scand J Work Environ Health 1999; 25:67–74) found no such changes in respiratory resistance in a group of 27 professional divers with long diving experience, but at moderate depths (70 metres and less).

Summary: The results from studies of negative long-term effects of diving on divers’ lungs are somewhat contradictory. It is possible that a very small number of divers may have incurred lasting and substantial injuries to the lungs in the form of high respiratory resistance, while a number of divers may have incurred a moderate increase in respiratory resistance that has not reduced their quality of life.

7.3.4 Central nervous system

This could involve delayed injury manifested in reduced functions that can be detected by neurological and/or psychiatric examination.

Knowledge in this field is unfortunately limited. No adequate scientific studies are available to provide clear answers. This fact is underscored repeatedly from various quarters (Becker 1983, Bennett 1983, Wright 1989, Wilmhurst et al. 1994, Shields et al. 1996, Dutka 1996, Bennett & Elliott: The physiology and medicine of diving, 2002, chapter 10, Dutka). Several researchers have called for the establishment of supranational databases containing information on divers’ health, their individual diver profiles, gas mixture and any treatment and post-treatment examinations. Such databases could lead to improved knowledge of hazards, and have a major preventative impact. Why are no satisfactory scientific studies available?

There are several reasons for the lack of adequate research into possible late sequelae of a large number of deep dives. A number of conditions must be met in order to draw reliable conclusions from a survey of a group of workers (or patients):

First, the cohort must be large enough to be able to provide a reliable statistical analysis. Second, the cohort must be compared with a control group that must match the examined cohort as closely as possible – apart from in terms of the activity under the spotlight, in our case deep diving. This must be done to find what the exposure in question may be responsible for. The cohort’s exposure should/must be recorded in detail (here: number, frequency and depth of dives, gas mixture, decompression profile, equipment, water temperature, work intensity, pressure of time, communication etc.). The investigation should/must be blinded – i.e. the person examining the diver’s disorders and symptoms should know nothing of the exposure, and those who record the dives should know nothing about the medical findings. This is to prevent preconceived attitudes and opinions from influencing the conclusions.

Although international literature contains no scientific studies that satisfy these requirements, a number of reports have emerged in the past 20 years that suggest more or less convincingly that a large number of deep dives may have negative late effects. Norwegian researchers, especially Johan Aarli and his group, deserve praise for their work on warning of possible neurological late complications after deep dives. An edited selection of international literature in the field follows below, the first part indicating the state of knowledge up to 1983, the second outlining developments since then.

In 1959 Rozsahegyi reported that many caisson workers developed a psychotic condition characterised by impulsiveness and aggressiveness, a condition that could last for many years. Unfortunately, the information is not based on Rozsahegyi’s own clinical investigations, but on the workers’ own information provided in a questionnaire. In an analysis of 10 seriously ill divers, Peters et al. (1977) found that at least 10 of 19 divers had experienced at least one incident of decompression sickness with a cerebral localisation, and eight of them displayed neuropsychological symptoms in the form of a moderate drop in attention span, working memory and emotionality. In a comparison of two groups of divers, one featuring serious accidents involving decompression sickness and one without diving accidents, Værnes and Eidsvik (1982) found that a number of divers in the accident group showed moderate neuropsychological findings involving impaired working memory, reduced sympathetic reflex responses, drop in attention span and some emotional lability. A number of the findings were also observed one month later, but not after four to five months. How far these dysfunctions were related to the decompression sickness, or to the hypoxia accompanying it, is not known. Attempt to reach consensus on possible late effects of diving

Norwegian diving authorities took the initiative for a conference in Stavanger in 1983, whose purpose was to discuss the available evidence for negative effects of deep diving (deeper than 250 metres).

Smith-Sivertsen (1983) writes that after long experience in diving medicine he has come to the conclusion that dives to depths below 250 metres should be seen as a «physiological experiment.»

This view is shared by Aarli (1983) who reported that four out of 23 divers who took part in heliox dives to depths of 300 and 350 metres (most of them in chambers, some in open sea), showed mild to moderate neurological symptoms (reflex changes and EEG changes) when examinations before and after dives were compared. Værnes similarly reported (1983) that after a single 360 metre heliox dive divers showed transient tremors that had normalised one year later.

However, several highly experienced researchers reported that they had not observed long-term neurological injuries. This specifically applied in the case of diving physicians associated with the US Navy, the Royal Navy, the French Navy and Comex, a diving company with considerable research experience in conjunction with outstanding neurophysiologists in Marseilles.

At the conference in Stavanger, Bennett gave an account of deep dives to depths of 300 to 686 metres. Most of the 24 divers experienced no problems after the dives. True enough, one of the three divers taking part in the 686 metre dive complained of loss of concentration, poor attentiveness while diving and difficulties in remembering everyday tasks assigned to him. However, subsequent follow-up revealed nothing of note. Another diver had pathological SEP (somatosensory evoked potentials) probably rooted in spinal decompression sickness. However, there were no further findings of neurophysiological or psychological parameters.

Thalmann, US Navy, told of a series of deep dives involving six divers to each of four depths of 1400, 1500, 1600, and 1800 feet (from 427 to 549 metres). Most of the divers displayed varying signs of HPNS, but none showed pathological conditions three years after the dives.

Török gave an account of a series of experimental dives under Royal Navy auspices involving a total of 10 divers to depths between 300 and 600 metres. With one exception, psychological tests after the dive showed nothing of note. One incident took place during decompression at a depth of 11 metres involving blurred vision, headache, loss of sense of touch and paresthesia in one hand. After the dive a reduced blood flow was detected through the region of the middle cerebral artery, i.e. a case of cerebral decompression sickness. In addition, after the deep dives several divers showed extreme fatigue and loss of initiative over a period of a few days. The author believes this may, at least in some cases, be ascribable to a drop in hemoglobin caused by a long period of inactivity. Despite the small number of cases of late effects of deep dives, the Royal Navy wished to be on the safe side and recommended detailed neuropsychological tests after experimental dives in the future.

Giran gave an account of experiences with deep dives gained by the French Navy and the diving company Comex. Investigation of as many as 190 French divers who had dived deeper than 250 metres in the Navy and with Comex, showed very few morbid after effects. Apart from two cases of light vestibular dysfunction (unsteadiness , nystagmus), his group had not observed any case of long-term neurological sequelae. It emerges from the discussion that the neurological examinations were not carried out by specialists, but by the diving physicians themselves. This clearly limits the value of the checks since light to moderate pathological symptoms (as reported above) could easily have been overlooked.

It is fair to conclude after the Stavanger conference that opinions were divided. Representatives from those with longest experience, namely diving physicians from the US, British and French navies and Comex, considered that diving performed according to prevailing regulations was safe, even though some, short-lived cases of cognitive failure had been seen. A number of other researchers, not least Norwegian physicians, were not convinced inasmuch as they had seen evidence of neurological and psychological changes suggesting a late effect on cerebral functions. However, the late effects described were moderate and often transient. Moreover, the investigations were conducted in ways that do not produce statistically reliable results.

Værnes subsequently (1989) followed 64 saturation divers for three years and found that 20–30 per cent of them showed small changes in visuospatial memory, somewhat more tremor than normal and somewhat increased activity in the sympathetic nervous system (perspiration and skin blood flow). Todnem et al. (1990) examined 156 saturation divers and compared them with 100 control persons of the same age (non-diving oil industry workers and police officers). Thirty-three per cent of the divers reported neurological symptoms in connection with decompression, and as many as 51 per cent had suffered from decompression sickness, 26 per cent with cerebral and 11 per cent with spinal symptoms. Fourteen per cent believed they had lost consciousness during diving. More neurological symptoms, statistically speaking, were found among the divers than in the control group. Most symptoms were of moderate intensity. However, the findings are difficult to assess since the examination was not blind, the control group consisted of two quite different professional groups, and the divers showed a relatively high incidence of loss of consciousness and decompression sickness with symptoms from the central nervous system which may themselves be responsible for some findings. EEGs and auditory and visual evoked potentials were recorded in the same groups. Here too several pathological findings were noted among the divers, but it not possible to establish whether this was due to diving or to the accidents (loss of consciousness and decompression sickness with symptoms from the central nervous system) that had befallen them (Todnem et al. 1991a).

Finally, 40 divers who had carried on saturation diving were compared with 100 non-divers (Todnem et al. 1991b). The divers reported several subjective complaints and also showed several neurological symptoms, albeit moderate, and many were transient. All the same the authors concluded that deep diving may have a late effect on the central nervous system. The study does not provide a basis for distinguishing between effects of saturation diving and of bounce/surface diving since all had previous experience of air diving and some had done a large number of bounce dives. Godøysund conference

In 1993, ten years after the Stavanger conference, Norwegian researchers arranged, in cooperation with international colleagues, a consensus conference at Godøysund near Bergen. Although attitudes were much the same as in 1983, there was some acceptance of the possibility of long-term neurological/psychiatric after-effects of diving performed in accordance with recognised methods. This was reflected in the final declaration which states:

There is evidence that changes in bone, the CNS and the lung can be demonstrated in some divers who have not experienced a diving accident or other established environmental hazard.

The changes are in most cases minor and do not influence the diver’s quality of life. However, the changes are of a nature that may influence the diver’s future health. The scientific evidence is limited, and future research is required to obtain adequate answers to the questions of long term health effects of diving.

The situation changed little up to 2002, although further reports have emerged that support the possibility of late effects. Unfortunately we still lack properly controlled studies of this issue. Later reports of injuries

Sutherland (1990) examined a group of divers over a period of six and 24 months after suffering decompression sickness with symptoms of the skin and joints and found that eight complained of poor concentration and cognition.

The British report, Offshore Technology Report OTO 96 953 (Shields et al. 1996) investigated a group of 31 divers who had reported decompression sickness after diving in the British sector in the North Sea. Together with an equally large group of divers with no history of decompression sickness and a third group comprising voluntary non-divers, they were clinically examined using a comprehensive battery of tests. The DCS group showed more frequent symptoms of cognitive failure than did the other two groups. This was manifested in a reduced ability to reproduce recently learned material, both after a few minutes and after longer intervals (logical memory test), and in a test of concentration and memory based on visual inprints. Divers with DCS showed greater impairment than non-DCS divers who in turn achieved lower scores than the non-divers. In some tests the picture was more complicated since the control group had scores between the two groups of divers.

Based on neurophysiological examinations, Shields et al. found evidence for some damage to sensory paths among the divers.

An examination (HMPAO-SPECT) of blood flow through various regions of the brain was also carried out among the divers. Twenty-eight per cent of the divers showed blood flows outside the expected value compared with 16 per cent of the control group. Shields et al. found no connection between the findings of this study and incidence of decompression sickness; in fact they also found frequent deviations among divers with no DCS history. Nor was there any correlation with the findings of neurophysiological or psychometric examinations.

Shields et al. delivered the best study that the Commission has come across. The authors are very cautious in their conclusions since the material is sparse. After close scrutiny of the uncertainties in the study, they state:

In conclusion, this study has shown decrements in the performance of divers compared with non-diver control subjects. Divers with history of DCS have been found to have significantly poorer performance on neurological investigation than comparable divers with no DCS history. The implications of these findings in terms of the long-term health of the diver, are difficult to assess in the absence of long-term study.

The Commission’s assessment is that even though Shields et al. make many reservations in their conclusions, the study does suggest that some divers may have suffered injury.

A follow-up of 215 scuba divers at the Lake of Geneva showed reduced speed and flexibility in a cognitive test, especially in the case of those who had a large number of cold, deep dives, and who had more than 100 dives per year.

Leplow et al. 2001 (Int Arch Occup Environ Health 2001 April; 74(3) 189–98) assessed 19 construction divers who worked at depths below 60 metres, and found that divers with long professional experience made somewhat more errors in tests of reference memory («where did that happen?») and of their ability to navigate from memory than a control group. The number of magnetic resonance intensities was related to the size and frequency of hyperbaric stress.

Twenty older divers with no history of decompression sickness were compared with 20 control subjects. Sixty per cent of the divers and 45 per cent of the control subjects showed hyper-intensive magnetic resonance (MR) abnormalities (Tetzlaff et al. 1999). The number and size of the abnormalities correlated to the number of hours of deep dives (p<0.05). Tests of divers showed lower mental flexibility (p<0.05) and results of visual tracking compared with the controls (p<0.01).

On the other hand a large number of studies do not show clear-cut late effects of diving. Some recent ones are outlined below.

Murrison et al. (Occup Environ Med. 1994 Nov; 51(11): 730–4) and Murrison et al. (Occup Environ Med. 1995 Jul; 52(7): 451–3) found neither electroencephalographic nor neurophysiological evidence of injuries among divers with a history of decompression sickness, but with an initial complete clinical recovery.

Bast-Pettersen (1999) examined 20 divers with an average age of 40 years. They had an average of 4000 dives and 18 years’ diving experience. None showed signs of cognitive failure, merely a moderate increase in sensomotory response time.

Cordes et al. (2000) examined German military divers with long experience but no history of decompression sickness and found no instances of increased neurological or neurophysiological change among divers compared with a control group. (Compare with Tetzlaff et al. 1999, above). Conclusion of the review of relevant research results

The Commission’s conclusion is that:

  • we still lack reliable data able to answer the question of whether ordinary diving may have negative neuro/cognitive long-term effects

  • opinions are divided on whether correctly executed deep diving can lead to long-lasting or permanent neurological or and/or cognitive damage

  • a number of competent researchers from several countries assert that deep dives do not lead to significant neurological damage provided they are professionally executed

  • another set of equally experienced specialists have reported a long series of individual cases of neurological and cognitive late effects which are best explained as a negative effect of one or more factors linked to diving.

Pending studies that meet all requirements as to scientific tenability, the Commission believes that weight must be given to studies that point to a likely connection between a long diving career and subsequent symptoms signifying damage of a neurological and cognitive nature. It seems clear that such symptoms may be a consequence of decompression sickness, but that they are also seen among divers with no history of serious decompression sickness. It is likely that genetic variability can explain some variation in symptoms from one diver to another. This applies to neurological, cognitive and psychiatric symptoms alike.

7.3.5 Late effects of extreme and long-lasting stress

Post-traumatic stress disorder (PTSD) is described as a consequence of life-threatening situations where the subject has had little or no opportunity to control the course of events. The syndrome resembles that seen among a number of concentration camp inmates (KZ syndrome) and among survivors of shipwrecks (lifeboat situation). The condition has been described in the aftermath of war situations (Vietnam, Gulf War) and after disasters (shipwrecks, Vassdalen avalanche).

In its most dramatic form the subject vividly relives dangerous situations in flashbacks. The subject has the same visual, auditory and olfactory experience as in the original situation, and the feeling of horror is reported to be just as awful as the first time. Many of these hallucinatory experiences are triggered in dreams.

The PTSD syndrome is characterised by:

  1. Reliving the trauma. The subject is afflicted by repeated, irksome memories of the event, by troublesome dreams about it, by a feeling of actual re-experience and is mentally tormented by objects (pointers) that recall the event.

  2. As a rule the subject tries to steer clear of the trauma by avoiding thoughts related to it, by avoiding situations that remind him/her of it. (S)he shows failing recall of important parts of the trauma, less interest in important activities, has a feeling of being estranged from others, has a constrained emotional life, and a sense of a foreshortened or meagre future.

  3. Symptoms of high levels of activation: sleeping problems, irritability, concentration problems, exaggerated alertness, bodily reactions to events that may recall the trauma.

To be diagnosed with PTSD the subject must have been exposed to a psychologically distressing, traumatic event (stress, injury). Situations where the patient’s life is repeatedly in danger, especially if (s)he is unable to intervene in such a way as to influence the outcome, are particularly provocative. The situation worsens in situations where information is scant, if the subject has a feeling of being let down by people (s)he relied on, or experiences a situation involving numerous fatalities or injuries.

Delayed reactions are by no means rare after a symptom-free period of varying duration, probably because the subject – as a coping strategy – suppresses the memory. (S)he does this by actively thinking of something else whenever the difficult memory intrudes.

In time some subjects lose some of their normal ability to stifle the memories – and the PTSD symptoms will come into view. This is particularly the case with subjects who show symptoms of anxiety.

The primary disorder is assumed to be a personality change that began during the original stress, possibly concealed by the adjustment mechanisms that were needed at the time in order to cope.

In order to diagnose someone with lasting change in personality after traumatic events, at least two of the following symptoms must be present:

  • a lasting hostile or suspicious attitude to the surroundings

  • a tendency to social isolation

  • a lasting feeling of emptiness or hopelessness

  • a lasting feeling of being «out of it» or threatened for no obvious reason

  • a lasting feeling of being «altered», different from others, often coupled to the feeling of not reacting emotionally like other people

7.4 Diving in the North Sea

Diving related to activities in the North Sea started on two fronts. Divers contributed to the construction and fitting out of large concrete rigs that took place in the area around Stavanger. And, in the North Sea, divers played a part in exploratory drilling and field development and, once production got under way, at the respective fields. The main features of the work performed by divers are described in brief below.

Developments in diving technology – in the first instance saturation diving – had not made much progress in terms of commercial exploitation when exploratory drilling started in the North Sea. The technology was developed primarily in the United States, and American – and in time French – expertise held sway in the North Sea. In due course Norwegian companies and Norwegian divers entered the picture. Foreign companies trained divers abroad and in Norway. The working language was in the main English. On the Norwegian side there was a gradual build-up of operational and basic expertise. Comprehensive research and test dives were held at NUI (later NUTEC) in Bergen in the early 1980s, and there was considerable exchange and contact between Norwegian and foreign researchers, while diving companies were brought in to conduct test dives ashore.

Later in the 1980s a change also took place in the way oil companies as principals handled diving. Several of them prepared relatively detailed specification documents which the diving companies had to meet in order to win contracts, and which set out required minimum standards.

At the outset diving in the North Sea was done from the stern of supply vessels, rigs and pipeline-laying vessels, and to some extent also from crane barges that had diving systems installed on board. The mid-1970s saw the first specially built diving vessels in operation in the North Sea, and in time these became the main operational diving platforms. An important aid introduced more or less in parallel with these vessels was hot water suits. These meant a lot in terms of divers’ thermal comfort during long work operations that became the norm as saturation diving increasingly took over.

Many divers recruited to the industry received their basic training in the Navy, but there are more cases of sport divers being recruited without additional formal training. In some cases divers were employed by a Norwegian diving company, but were hired out to other companies on a project basis, while in other cases they were employed on an employment contract by the company they dived for. Working hour arrangements for divers varied widely throughout the period, and the Commission has learnt that divers tended to work very long hours. The management was described as hierarchical, and union organisation was unpopular, especially at the start when foreign nationals were in senior positions. Around 1980 a substantial number of Norwegian divers nonetheless organised, and the organisations – above all the Norwegian Oil and Petrochemical Workers’ Union (NOPEF) – marked themselves out during the 1980s.

7.5 Rules in the North Sea and the role of the authorities

Rules governing diving were by and large non-existent right up to 1978, and the Directorate of Labour Inspection lacked resources for supervision. Supervision of diving in the North Sea was ineffectual up to 1978.

After the Petroleum Directorate took over supervision in 1978, the situation gradually improved, but many divers remained critical of the way supervision was performed. It was asserted that the Directorate generally behaved in an employer-friendly manner, although based on the Directorate’s safety effort over time it is difficult to justify this assertion.

The Norwegian State Diving School was only formally established in 1980 in Bergen, and up to then virtually all diver training had been under the auspices of the respective diving companies. Moreover, with the exception of an annual medical certificate, there were there no formal requirements for certification either of divers of diving supervisors on the Norwegian continental shelf prior to 1980.

In the first half of the 1970s the authorities made some unsuccessful attempts to develop decompression tables for general use in the North Sea. This was in response to the fact that decompression tables were employed for competitive purposes by the various diving companies. Not until 1991 did the Petroleum Directorate succeed in establishing common tables for all companies on the Norwegian shelf.

Jurisdictional issues kindled ministerial conflict and in some cases confusion about the rules applying in the Norwegian area of the North Sea. The Commission is critical of the authorities’ inability to unite on a common approach to the issue of jurisdiction in the North Sea.

7.6 Other actors on the shelf

For much of the period 1965–1999 a detrimental work ethos prevailed among diving companies whereby decompression sickness was accepted as part and parcel of the job of diving. The oil companies are not thought to have been unaware of this.

7.7 North Sea divers’ situation today

7.7.1 Introduction

The aim of the Commission’s survey was to obtain information on the pioneer divers’ experience with diving and on their current situation, specifically their family situation, employment or social security status and state of health. The survey questionnaire was prepared after consulting, and utilising the experience of, French, British, Swedish and American colleagues. The form is enclosed with the report. Of 350 divers, 235 completed the questionnaire.

7.7.2 Results Age and diving experience

The average age in 2002 is 50.8 6.3 years (average and standard deviation) (standard deviation shows the spread in the group, normally 68 per cent of the group will be within the average 1 standard deviation) and all are men. Chart 6.1 shows the age breakdown. The average age for starting to dive in the North Sea was 24.0 4.2 years. The oldest subject started at age 36. The average number of years spent diving in the North Sea is 16.3 8.6. There is a large spread in the pioneer divers’ professional experience. For actual respondents the minimum experience is 1 year while one respondent has been diving for 39 years. The breakdown is uneven; many have few years’ experience while a small number have very long experience. Marital status

Of 225 who responded to this question, 14 (7 %) live alone, 149 (61.5 %) are married, 34 (15.1 %) have a live-in partner, and 35 (15.6 %) are divorcees or widowers. Residence

Fifty-five pioneer divers (23 %) live alone, 4 (1.7 %) live with friends, while 150 (64 %) live in a family situation. We lack information on 26 divers (11.1 %). Divers’ educational attainment

Of the 235 divers, 131 had completed upper-secondary schooling (55.7 %), 76 had technical college schooling (32.3 %), while 101 had other types of education (43 %). A total of 184 (78.3 %) had completed diving school, while divers holding a diving certificate in class 1, 2 and 3 totalled, respectively, 122 (51.9 %), 107 (45.5 %) and 116 (49.4 %).

The conclusion is clear: today divers who worked in the North Sea have a high general and technical education. Almost 80 % of them were trained at a diving school. Licences

Ninety-five subjects reported that they were licensed by the Petroleum Directorate, the majority in the period 1979 – 1984.

One hundred and eighty two were licensed by the Directorate of Labour Inspection while 81 report that they hold foreign licences.

Of the 14 respondents reporting that they are not licensed by the Petroleum Directorate, 12 are licensed by the Directorate of Labour Inspection. Seven divers are licensed by foreign schools, but not by the Petroleum Directorate or the Directorate of Labour Inspection.

Only two state that they do not hold a licence from the Petroleum Directorate or the Directorate of Labour Inspection; neither of them holds a foreign licence either.

Not all respondents answer the question on licences. In the case of four divers, information is lacking on licensing from all three sources – the Petroleum Directorate, Directorate of Labour Inspection and foreign certifying bodies. For two of them this is evidently due to illness.

Conclusion: By far the largest portion of the pioneer divers holds a licence from a Norwegian authority – the Petroleum Directorate or Directorate of Labour Inspection. A small number hold a foreign licence only. A very small minority lack a licence, or are too ill to provide this information. Employment/social security situation

Of the 235 divers, 139 (59.1 %) are in permanent employment, the majority in employment other than diving. Eighteen of the 235 pioneer divers (7.7 %) are unemployed.

The Commission has obtained (anonymised) information on the social security status of 335 of those who received the questionnaire. Of the entire group, 63 are on disability pension, including disability pension resulting from injury at work.

Tabell 7.1 Number of divers on disability pension by age

AgeAll diversDisabled divers% disabled divers% disabled men in populationDisabled divers/disabled in population
36-40 21 314,3 3,83,76
41-45 601423,3 5,54,24
46-50 981616,2 7,82,07
51-55 831922,911,51,99
56-60 621016,117,20,94
61-65 9 0 0,031,70,00
66-70 2 150,040,31,24

Almost 19 per cent of all the divers are occupationally disabled today. In some age categories the proportion of occupationally disabled divers is substantially higher than expected based on the average population. Diving disorders and injuries

In the course of an active diving career (13.8 8.6 yrs) as many as 173 of the 227 (76.2 %) who answered this question (Chart 6.2, column 2) report having experienced diving disorders of varying gravity. The most common complaint was pains, usually bends (column 3, 56.2 %). Very few reported injuries to the spinal cord and brain (column 4) and even fewer reported bubbles causing blood congestion, chokes or pulmonary embolism (column 5). An unexpected, and very serious, finding was that as many as 47 (column 6, 20.0 %) had lost consciousness while diving or in the chamber.

Tabell 7.2 Number of incidents of loss of consciousness among Norwegian divers in the North Sea 1970–1999


Loss of consciousness has to be viewed as an extreme situation that could have ended in fatalities. The highest number of cases of loss of consciousness coincided with the period of high fatality rate, and peaked around 1974. During the 1980s occurrences of loss of consciousness fell to a lower level.

No less than 79 divers (33.6 %) experienced contaminated gas in their breathing gas on one or more occasions. Noise is a recurrent problem for divers. Seventy-four of the 235 reported impaired hearing after experiencing noise stress (31.5 %). Presumptive causes of accidents or disorders. Could the disorder (accident) been avoided, and if so how?

Many pioneer divers believed they knew the main cause of the disorder or accident: in fact as many as 121 of the 136 (89 %) who answered this question. The majority of these, 112 of 124 (90 %) who also answered the other question, believed they knew that the accident/disorder could have been avoided and what was needed to avoid it.

These figures reflect the pioneer divers’ considerable knowledge of their profession and insight into their work situation. Extreme stress

The divers were asked whether they had experienced accidents involving fatalities or serious injury to others, and whether they themselves had been in dangerous situations that they were unable to put out of their minds later.

To the first question, 101 of 235 (43 %) replied that they had experienced losing diving friends. Of 211 who answered the question about dangerous situations, as many as 176 (83.4 %) reported having been in dangerous situations that were difficult to put behind them. Assistance received from doctors/social security service

The abiding impression is that the majority were not satisfied with the help they received from the social security service. Forty-four of 111 (39.6 %) were satisfied, while 67 (60.4 %) were dissatisfied. Nine divers (7 %) were satisfied with the medical assistance, but dissatisfied with the assistance given by the social security service. A further two divers (1.6 %) were satisfied with the social security service, but dissatisfied with the medical assistance. A total of 80 divers (65 %) were dissatisfied with the assistance they received. Compensation received

From the employer: Of the 138 who answered the question concerning receipt of compensation from their employer, 5 (3.6 %) replied that they had received compensation.

From the insurance company: One hundred and forty two replied, of whom 29 (20 %) had received compensation.

From the government: Of 145 who replied, 35 (24 %) had received compensation. Employer

A large majority were employed by diving companies or other contractors. A minority worked for oil companies and even fewer were self-employed. Diving methods

Replies from the pioneer divers tell of wide variation in experience in terms of method and number of dives. Moreover, the pattern largely switched from an emphasis on bounce diving in the early years to an emphasis on saturation diving from the mid-1970s onwards. Factors triggering or contributing to diving disorders and injuries

A central point is whether the information provided by the survey can help us to reveal factors that may have triggered or at any rate contributed to subsequent disorders. We have concentrated on two types of diving – bounce diving and saturation diving – for several reasons. First, most pioneer divers regard these two types of diving as the most stressful. This is supported by the admittedly sparse scientific literature in the field. The remaining diving methods – scuba and surface-oriented diving – are largely employed in shallower waters and such dives are of considerably shorter duration.

For the analysis we put the emphasis on a combination of number and depth of dives. In the case of bounce dives there was no correlation (r=0.137, where r denotes degree of covariation; values below 0.5 show low covariation) between the subjective state of health (how the pioneer diver feels today as stated in his answer sheet) and the quantity/depth of his overall professional diving activity.

Examination of the overall material (196 observations) also showed no correlation between assessment of state of health and exposure to bounce dives (r=0.153).

The same value (r=0.138) applies to saturation dives. There was an even wider spread of exposure in this case inasmuch as some subjects had very little experience, while a minority accounted for the truly long-lasting and deep stress factors, a circumstance that could be expected to favour the discovery of a possible link between quantity of saturation diving and subsequent state of health.

Furthermore, we found that the number of air dives did not provide evidence that quantity of air dives influenced the subject’s state of health (r=0.014). The material unexpectedly showed that the more dives done by a diver, the better his self-assessed health!

The conclusion is that it is not possible to predict who will experience long-term disorders on the basis of divers’ information on number of dives or maximum dive depth. This applies to air, bounce and saturation diving alike.

7.7.3 Pioneer divers’ state of health in late autumn 2001 and winter 2002

On a scale of 1 to 5 for subjectively assessed state of health where 1 is Excellent, 2 Good, 3 Satisfactory, 4 Poor and 5 Very Poor, the average for the 209 who answered this question was 3.14 with a standard deviation of 1.25. For a normal population the theoretical average would be 3.0. These figures suggest that the Norwegian pioneer divers as a whole feel that they are by and large in a satisfactory state of health. However, the picture is far from clear-cut, since on the one hand a substantial number feel they are in excellent shape while at the other end of the scale there are unfortunately many whose state of health is poor, in some cases very poor.

Table 7.3 shows disorders reported by the pioneer divers. Among all possible health conditions, we present the most frequently reported complaints. Poor memory, especially in terms of the ability to store new information, often called «short-term memory», appears to be of particular significance. Another common complaint is a reduced ability to tackle mental challenges. This particularly applies to minor everyday challenges, especially situations requiring one’s ability to negotiate and compromise as well as one’s perseverance and concentration. Very many subjects report pains in the joints and many have hearing problems.

Tabell 7.3 Reported frequency of pioneer divers’ disorders

Frequency   Joint painsBack painsMemory problemsMental difficultiesHearing problems
Never0 34 (16%) 28 (13%) 28 (13%)57 (28%)
Occasional1 67 (32%) 68 (33%) 68 (32%) 59 (28%)55 (27%)
Fairly often2 48 (23%) 40 (19%) 29 (14%)22 (11%)
Often3 61 (60%) 75 (36%) 59 (28%)66 (32%)
Total211 (100%)208 (100%)215 (100%)208 (100%)204 (100%)

Two other indicators of the pioneer divers’ state of health are the number undergoing medical treatment and the number taking medication prescribed by a doctor. Of the respondents to this question, 46 of 116 (40 %) reported currently undergoing treatment, while 50 of 203 (25 %) reported taking medication for their condition. These figures are clearly higher than the expected figures for 50-year-old men with a good education.

7.7.4 Assessments and conclusions after the survey

Although the Commission of Enquiry could have hoped for a better basis for their assessments of the pioneer divers’ state of health, it considers that the data obtained permit a qualitatively useful description of the situation. What is most striking is the wide variation: many subjects have managed well, indeed some very well, while a not insignificant share are struggling with serious medical problems.

However, a large number, about three out of four, have experienced diving accidents or diving disorders. More than half have suffered decompression sickness, many of them a number of times. The fact that one in five divers has lost consciousness during dives is very serious. This can trigger post-traumatic stress syndrome in genetically predisposed individuals.

A disturbingly large number of divers are on disability pension. The fact that relatively young people, aged around 40, are affected is especially significant. This, together with the relatively large number with mental disorders, suggests that many divers have had to deal with heavier stress than most people encounter in the ordinary world of work.

In common with findings on the British side, the number of suicides among divers on the Norwegian shelf is disturbingly high. As in the case of other suicides, it is difficult to comment on causes. However, it is not inconceivable that the long-lasting and heavy pressure that divers had to endure may have been a significant factor in the process.

When assessing the state of health of North Sea divers it is important to remember that many of them started out as a specially selected and well-trained group of young men. After an average of about 14 years in the North Sea, the majority are in a satisfactory state of health based on the information they have supplied. However, a relatively high proportion have acquired appreciable health problems, illustrated by the fact that almost one-fifth are disabled, and that a number of divers complain of concentration, memory and hearing impairments. The same symptoms are documented in Norwegian and foreign investigations alike. It seems probable that the extreme stress to which many North Sea divers have been exposed at work has been a significant factor behind the disorders that a number of them have developed.

7.7.5 Fatalities among divers in the North Sea 1965 – 1990 Fatal accidents

Fatal accidents among North Sea divers have been a regular topic of discussion, among the divers themselves as elsewhere. One of the questions raised is whether complete information is available on all fatalities. The Commission has attempted to obtain an overview of names, places and circumstances of fatal accidents among North Sea divers (not confined to the Norwegian sector). In tables enclosed with this document the Commission reproduces information on fatal accidents from five sources: 1) the Petroleum Directorate, 2) Report from Bevan & Gosling, Submex Ltd 1986 (data from UK Department of Energy Diving Inspectorate, AODC and Submex Ltd), 3) Bjørn Kahrs (undergraduate dissertation in History, University of Bergen, 2001), 4) the Norwegian Oil and Petrochemical Workers’ Union (NOPEF, 2001) and 5) Report from Norsk Undervannsinsitutt NUI ( «Norwegian Underwater Institute» ) No.3/1980, author Erik Jacobsen.

The material is presented in two tables (Table 1 and 2), one for the entire North Sea, one for the Norwegian sector alone. The lists are in the main chronological.

The Commission has not independently verified the accuracy of the list. It should, however, be pointed out that the list from the NUI contains quite a number of uncertain cases where neither the diver’s name, nationality nor the site of the accident are known.

Table 1 shows full concord between the respective sources for fatalities when account is taken of the periods they cover, up to and including event no. 53. Events nos. 54 to 56 inclusive took place in the period 1990 to 1999. For events nos. 58 to 99, uncertainty is substantial. Of the latter, 27 stem from E. Jacobsen’s report and, for all but four, information on where the accident took place and on nationality of the person presumed to have died is lacking. In one case listed by E. Jacobsen (1963), the person dived through a hole in the ice, i.e. hardly a North Sea dive.

The deaths of 55 divers during diving missions in the oil industry between 1967 and 1990 can safely be regarded as verified. Five of these are Norwegian. Since 1990 a further three fatalities have occurred (British sector, no Norwegian divers).

In the Norwegian sector reliable information is to hand for 17 fatal accidents for divers, four of which are Norwegian. One Norwegian died in the British sector, although the accident is not regarded as diving-related since it was a fall accident on the deck of a diving vessel (see bottom of the main table).

Table 3 shows that the number of divers (all nationalities included) in the British sector far exceeded the number in the Norwegian sector. The number of divers in the Norwegian sector is estimated on the basis of Bevan & Gosling (those not working in the British sector were assumed to be working in the Norwegian sector). The number of fatalities in relation to the average number of divers was approximately identical for the Norwegian and British sectors in the period 1971 to 1985 inclusive. Another common feature is the marked fall in the number of fatal accidents (and other serious accidents) during the 1980s in both sectors of the North Sea. This is probably ascribable to increasing expertise among divers and diving supervisors, along with clearer rules from the authorities and improved enforcement of the rules. Causes of fatal accidents

Major difficulties are encountered when studying the material to find possible causes of fatal accidents and other serious accidents. The main difficulty lies in the nature of things – the complex technical situation in which the diver is largely left to his own devices, knowledge and assessments. Usually the diver benefits greatly from the presence of his co-diver in the bell (the bellman) and from the dive management team on the surface, but in difficult situations the diver often has to be his own rescuer.

For many fatal accidents only fragmentary information on the accident event itself and prior events is available. The police and commissions of enquiry often have to make do with stating the presumed cause of the accident.

Of the 17 fatal accidents to divers in the Norwegian sector, at any rate eight were due to technical or operative failure. Two men lost their lives when the drop weight beneath the diving bell was released and the bell «flew» up to the surface. The release mechanism had been altered during a stay in dock and the divers had not received the necessary instruction in the new procedure. The Byford Dolphin accident cost the lives of five men, four of whom were divers, when the chamber hatch was inadvertently opened. Here too the chamber operator was not aware of the correct procedure. One diver had his umbilical pulled in and torn by the diving vessel’s side thruster. These three examples show the intimate interplay of technology and people that is required, and that even well-trained personnel can make mistakes in a complex working situation.

Of the remaining fatalities, three were probably due to asphyxia (lack of sufficient breathing gas), one because his umbilical was flattened, one because his gas contained pure helium without oxygen, two from ruptured lungs (too rapid ascent) and from pneumothorax (occurs when air leaks from inside the lung to the space between the lung and the chest wall; probably not induced by decompression). The last-mentioned did not receive correct treatment (wrongly diagnosed by the attending doctor), while the remainder have no known cause.

Looking at the material from the entire North Sea, the reports show that drowning is often stated as the cause of death, with no information given on why the diver drowned. There are many possibilities here: gas cut-off, wrong gas mixture, hypothermia, diving suit failure, to mention a few. Suicide among Norwegian divers

Like their British colleagues (see below), Norwegian divers appear more prone to suicide than their fellow countrymen of the same age. According to the North Sea Divers’ Alliance, 16 Norwegian divers have committed or attempted to commit suicide. According to an article in Vi Menn (no. 23/2001) 11 divers have committed suicide. The magazine cites the North Sea Divers’ Alliance as the source. In the same article Vi Menn states that it failed to obtain facts about a further four divers who had reportedly attempted to commit or succeeded in committing suicide. The Commission, too, failed to obtain this information from the North Sea Divers’ Alliance or to obtain further data from other channels able to throw light on suicide among divers. Most of the cases were familiar to divers who were interviewed. The average age of the 11 for whom we have information was 39.7 when they took their lives. Assuming that the 11 divers who took their lives did so over a 15-year period, the frequency per year is 0.5 per cent. In this age group the suicide rate in the entire male population in 1990 was about 0.025 per cent. There are many uncertainties in this tabulation, but it seems quite clear that suicide has been appreciably higher among divers than in the male population at large. Suicide and accidents among British divers

In 1994 McCallum (Godøysund Report 1994) investigated the life situation of 2,111 British divers. McCallum found that 75 of them (3.6 %) had died in the ten-year period 1972–1981, a disturbingly high figure. Their average age upon death was 37.2, for those who died in accidents 34.4. A comparison with the population of England and Wales showed that divers (considered as a group) died far earlier than the population at large, and that they died in accidents far more often than other people. The differences were statistically certain. He also found unusually high figures for traumatic death and suicide. Twenty-eight per cent of the fatalities were due to drowning (10 persons) or diving accidents (11 persons) while suicide explained as much as 17 per cent of the fatalities.

Similar conclusions were drawn by Welham (Centre for Health and Risk Management, Loughborough University of Technology 1996, Report MaTSU, P3204) who investigated the causes of death of 191 British divers who died in the period 1971 to 1994 (including those included in McCallum’s investigation). He too found that divers died young, at an average age of 38–40. Like McCallum, he found a marked over-representation of drowning, other accidents and suicide as immediate causes of death. His list of the three most important causes of death was identical to that of McCallum: 1) Drowning, 2) Other accidents (incl. diving accidents by choking as the largest individual factor) and 3) Suicide.

Welham calculated the so-called Standard Mortality Ratio (SMR) which is the observed mortality rate divided by the expected mortality rate for the entire population, multiplied by 100. Hence an SMR value of 100 for a group means that this group has the same mortality rate as we expect in the rest of the population. A higher value indicates excess mortality, while a lower value indicates that the group has a mortality rate below that of the standard population. In the case of the 191 divers, Welham found marked excess mortality (SMR=303), particularly from accidents (all types: SMS=866). Fatalities due to drowning accidents (SMR=18666) were overwhelmingly frequent with a clear preponderance of suicides (SMR=431) compared with an age-adjusted portion of the male population. Moreover, an unusually high number died in traffic and other accidents (SMR of 363 and 1090 respectively).

These two British studies show a very high incidence of suicides among divers, and a high incidence of fatal accidents of which a number may in fact involve suicide. Conclusions

A lack of information on the path of events in fatal diving accidents is commonplace and hinders reliable conclusions.

The Commission nonetheless believes it is justified in stating the following:

The most common direct cause of the fatal accidents was drowning. There were numerous underlying causes, possibly the main one being hypoxia/CO2 poisoning, hypothermia and technical failure of diving equipment.

The second most common cause of death was explosive decompression.

In many cases the accidents are due to human error. Such errors appear to have occurred at all levels. A highly complex interplay is involved between people and high-tech equipment.

Inadequate training, either on the part of the individual diver or of diving supervisors, may have contributed in some cases.

The (fortunately) steep decline in serious accidents in the 1980s on both sides of the North Sea can to some extent be ascribed to improved rules and oversight of compliance with the rules. Another important reason was the switch to saturation diving which considerably reduced time pressure on the seafloor.

Furthermore, the Commission finds a disturbing high frequency of suicides among Norwegian divers who have worked in the North Sea, and that the frequency of suicide in general appears to be very high among divers. Divers appear alarmingly often to die in accidents unrelated to the job of diving itself.

Tabell 7.4 Fatal accidents in connection with diving in the North Sea 1965–1990

YearFatal accidentsNo. of divers (from Bevan & Gosling)
Norwegian sectorBritish sectorEntire North SeaNorwegian sectorBritish sector
1965 0 0
1966 0 0
1967 1 0
1968 0 0
1969 0 0
1970 0 0
1971 2 1 200 100 100
1972 0 1 300 100 200
1973 0 2 400 100 300
1974 4 51000 400 600
1975 21500 600 900
1976 0 91700 7001000
1977 0 3240010001400
1978 1 2400010003000
1979 0 33200 6002600
1980 0 0300010002000
1981 0 0320010002200
1982 0 13200 6002600
1983 6 1360010002600
1984 0 1400010003000
1985 0 0400010003000
1986 0 0
1987 1 0
1988 0 0
1989 0 0
1990 0 0
Average2380 6801700

In addition to the fatal accidents in the Norwegian and British sectors of the North Sea, there was one fatal accident in Irish waters and three in Dutch waters in the period 1971 to 1985.

The information in the table is taken from Bevan & Gosling 1986, Clark 1997 and Kahrs 2001.

7.8 Liability issues

7.8.1 Liability for damages under Norwegian law

Under Norwegian law liability for damages may be imposed with a basis in the non-statutory concept of negligence or with a basis in strict liability. The main idea behind strict liability is that the risk entailed by an activity should be borne the party in whose interest the tortious act is committed. Strict liability is grounded in a balancing of interests where the issue is who is closest in terms of bearing the risk. There are no clear-cut dividing lines between negligent and strict liability.

In addition to the basis for liability (negligent or strict), there must be an adequate causal relationship and a financial loss.

7.8.2 Liability for damages on the part of the Norwegian State

When considering the Norwegian State’s liability it is expedient to take a basis in strict liability. Through the State’s declaration of its sovereignty over the Norwegian continental shelf, the State has acquired a limited ownership position over the shelf with proprietary rights to the subsea petroleum deposits and exclusive rights to resource management. By virtue of its ownership the State has overarching responsibility for activities on the Norwegian continental shelf.

The State, as sovereign authority, also has the power to make laws and collect taxes in respect of activities on the shelf.

When the Norwegian State by virtue of owning the Norwegian continental shelf chose to start production of oil and gas resources on the shelf, it did so by issuing licences to private actors who operate the activity for own account, but at the same time undertake to leave a portion of the oil and gas resources free-of-charge to the State. The Commission does not investigate the relatively difficult questions of private and public law that bear on the State’s position on the continental shelf. Suffice it to say that at all events the State earns substantial revenues on the shelf activities. This is the «direct State involvement in the petroleum industry», which is attended to by the State-owned company Petoro.

The State’s substantial revenues must be viewed in light of the substantial risk of damage and injury that shelf activities entail, and that accidents can readily assume large-scale proportions. There are grounds for asserting that since the State has initiated activity on the shelf that entails a constant risk of damage and injury, it is reasonable to expect the State to contribute to bearing the financial liability for damages and injury arising out of the oil activity. As owner of the petroleum resources, the State is usually closer in terms of bearing this liability than is the individual injured party.

Hence the notion of risk distribution that underlies strict liability suggests that to some extent the State has a strict liability for aspects of the activity on the shelf. Any demarcation of the State’s liability in relation to the North Sea divers, who have had central and important tasks in connection with oil production, cannot be deemed necessary.

In the Commission’s view considerable emphasis must, when assessing the State’s liability, be given to the fact that the State’s position as owner means that the State has a certain duty to ensure that activities on the shelf are operated in a proper manner. Moreover, responsibility for basic safety in the field of worker protection rests with the State.

From the foregoing review of the Labour Inspection’s role up to 1978, it is clear that in the view of the Commission the lack of supervision resulted in greater burdens being imposed on divers than on most other categories of employees. The virtual absence of rules and appropriate diver training also contributed. These factors were familiar to the State administration for several years without being remedied.

A further factor is that in the following period, when jurisdictional and ministerial conflicts were in progress, the authorities cannot have focused fully on safety work in the North Sea. The Commission finds it probable that the safety effort was delayed. It is probable that also this too contributed to divers being exposed to greater occupational stress than other categories of employees.

The fact that complete knowledge of the injuries that diving could entail was lacking, and that opinions on the injury situation are divided, cannot be regarded as decisive.

The Commission believes that a link exists between some divers’ workload and their present health situation.

All in all, there is in the Commission’s view much to suggest that the State has a legal liability and should therefore bear the financial liability for injuries sustained by divers as a result of diving in the North Sea and for disorders that may develop (late effects).

7.8.3 Liability for damages on the part of other players

Any liability on the part of the diving companies would seem to be primarily justified in terms of negligence, although, here too, there are arguments in favour of strict liability. The key point when assessing liability is the divers’ workload in the broad sense combined with their fear of being sent ashore, along with the prevailing work ethos according to which decompression sickness with the necessary treatment was acceptable. Reference is also made to the fact that decompression tables were an element in the competition among the companies.

The particular factors associated with the licensee/operator’s controlling position and financial interest in the activity could suggest that they should be held liable on a strict basis irrespective of whether a basis for liability rests with the diving company or not. The observations on risk distribution that justify strict liability for the State also apply in the main in relation to the licensee/operator.

What in the Commission’s view specifically justifies legal liability for the operator/licensee is the divers’ workload coupled with their fear of being sent ashore and the emphasis on speed during diving operations. A further element is the fact that the work ethos prevailing in much of the period investigated by the Commission accepted decompression sickness with ensuing treatment (recompression) as part and parcel of diving. This is assumed to have been familiar to licensees/operators too. All in all there is reason to believe that these factors have contributed to the injuries sustained by a number of divers.

In general the injured parties’ own circumstances carry little weight in employment relationships and in the Commission’s view cannot be assigned importance in light of the health situation of many North Sea divers.

7.8.4 Recommendations

The Commission of Enquiry recommends the establishment of a scheme under the following guidelines in respect of North Sea divers with disorders:

  • Compensation should be granted for financial loss

  • The scheme should be established and funded by the State

  • Licensees/operators should be invited to participate in such funding



Forced vital capacity: The total volume of air voluntarily expelled in one breath of maximum effort from full inspiration to maximum expiration.

Til forsiden