Departments
of Engineering and Psychology
University of Aberdeen
Modeling & Managing Human Factors in Industrial
Safety Using Virtual Reality Techniques
Work-package 7
Report D 7.2
Michael Baker, Kathryn Mearns & Emma Noble
Departments of Psychology & Engineering
University of Aberdeen
Executive Summary
The overall objective of this study is to carry out a series of investigative studies that will
lead to a new methodological approach to identify and control for potential failures
associated with human factors using state-of-the-art virtual reality as an integrated tool.
The main aim of this work-package is to select a methodology for identifying and
controlling potential failures associated with human factors. The methodology was
selected in relation to the process industry. BP Exploration, Oil, and Gas at the
Grangemouth site provided access to their extensive database relating to accident and
incidents. By accessing the ‘Total Loss Control’ (TLC) database currently operating at
the site, a number of accidents/incidents were selected and reviewed according to the
selected methodology. Analysis of the selected accidents and incidents reviewed the
physical hazards present and the human factor issues contributing to the
accidents/incidents. Subsequent analysis considered the feasibility of simulating these
accidents/incidents using immersive virtual reality.
2
Executive Summary ............................................................................................................ 2
1. Introduction ................................................................................................................. 1
1.1
Objectives of Work package 7 ............................................................................ 1
2. BP Grangemouth ......................................................................................................... 1
3. What is an accident or incident? ................................................................................. 1
4. Criterion for selection ................................................................................................. 1
4.1
Human Error ....................................................................................................... 1
4.2
Physical Hazards ................................................................................................. 2
4.3
Person Injury ....................................................................................................... 4
4.4
Location .............................................................................................................. 4
4.5
Accident/Incident Type ....................................................................................... 4
4.6
Severity ............................................................................................................... 4
4.7
Person Involvement ............................................................................................ 5
4.8
Injury sustained whilst working alone ................................................................ 5
4.9
Injury sustained whilst working in groups (two persons or more) ..................... 5
4.10 Incidents without loss ......................................................................................... 5
4.11 Accidents/incidents occurring during maintenance activities............................. 5
4.12 Accident/Incidents involving procedural tasks ................................................... 6
5. Feasibility of accident/incident simulation ................................................................. 1
Table 1 – Physical Hazards, Human Factors Causes and Consequences of Fires ...... 3
6 Conclusions ...................................................................................................................... 1
References ........................................................................................................................... 1
APPENDIX 1 ...................................................................................................................... 2
‘SLIPS, TRIPS & FALLS’ INCIDENTS ........................................................................... 2
‘Slips, Trips & Falls’ Incident 1 ................................................................................. 2
Plater fall incident ....................................................................................................... 2
Summary ..................................................................................................................... 2
Physical Factors .......................................................................................................... 2
Human Factors ............................................................................................................ 2
Human Factors Investigation Tool (HFIT) ................................................................. 3
Capability to model ..................................................................................................... 3
CRUSHING INCIDENTS .................................................................................................. 1
Crushing Incident 1 ..................................................................................................... 1
Inshore Marine Accident............................................................................................. 1
Time 09:30 hrs ............................................................................................................ 1
Summary ..................................................................................................................... 1
Physical Factors .......................................................................................................... 1
Human Factors ............................................................................................................ 1
HFIT ............................................................................................................................ 1
Capability to model ..................................................................................................... 2
Crushing Incident 2 ..................................................................................................... 2
Serious Hand Injury .................................................................................................... 2
Summary ..................................................................................................................... 2
Physical Hazards ......................................................................................................... 3
Human Factors ............................................................................................................ 3
HFIT ............................................................................................................................ 3
3
Capability to Model .................................................................................................... 3
Crushing Incident 3 ..................................................................................................... 4
Injury to workshop employee ..................................................................................... 4
Time 14:40 .................................................................................................................. 4
Physical Hazards ......................................................................................................... 4
Human Factors ............................................................................................................ 4
HFIT:........................................................................................................................... 4
Capability to Model .................................................................................................... 5
FIRE INCIDENTS .............................................................................................................. 1
Fire Incident 1 ............................................................................................................. 1
Lab Technician Splashed with Concentrated Acid ..................................................... 1
Time: 11:45am ............................................................................................................ 1
Summary ..................................................................................................................... 1
Physical Hazards ......................................................................................................... 1
Human Factors ............................................................................................................ 1
HFIT ............................................................................................................................ 2
Capability to model ..................................................................................................... 2
Fire Incident 2 ............................................................................................................. 3
Fire during recatalysation ........................................................................................... 3
Summary ..................................................................................................................... 3
Physical Hazards: ........................................................................................................ 3
Human Factors: ........................................................................................................... 4
HFIT ............................................................................................................................ 4
Capability to Model .................................................................................................... 5
Fire Incident 3 ............................................................................................................. 5
Investigation into fire on Catalyst Filter ..................................................................... 5
Summary ..................................................................................................................... 5
Physical Hazards ......................................................................................................... 6
Human Factors ............................................................................................................ 6
HFIT ............................................................................................................................ 6
Capability to Model .................................................................................................... 6
CRUSHING INCIDENTS .................................................................................................. 1
Crushing Incident 1 ..................................................................................................... 1
Inshore Marine Accident............................................................................................. 1
Time 09:30 hrs ............................................................................................................ 1
Summary ..................................................................................................................... 1
Physical Factors .......................................................................................................... 1
Human Factors ............................................................................................................ 1
HFIT ............................................................................................................................ 1
Capability to model ..................................................................................................... 2
Crushing Incident 2 ..................................................................................................... 2
Serious Hand Injury .................................................................................................... 2
Summary ..................................................................................................................... 2
Physical Hazards ......................................................................................................... 3
Human Factors ............................................................................................................ 3
HFIT ............................................................................................................................ 3
4
Capability to Model .................................................................................................... 3
Crushing Incident 3 ..................................................................................................... 4
Injury to workshop employee ..................................................................................... 4
Time 14:40 .................................................................................................................. 4
Physical Hazards ......................................................................................................... 4
Human Factors ............................................................................................................ 4
HFIT:........................................................................................................................... 4
Capability to Model .................................................................................................... 5
FIRE INCIDENTS .............................................................................................................. 1
Fire Incident 1 ............................................................................................................. 1
Lab Technician Splashed with Concentrated Acid ..................................................... 1
Time: 11:45am ............................................................................................................ 1
Summary ..................................................................................................................... 1
Physical Hazards ......................................................................................................... 1
Human Factors ............................................................................................................ 1
HFIT ............................................................................................................................ 2
Capability to model ..................................................................................................... 2
Fire Incident 2 ............................................................................................................. 3
Fire during recatalysation ........................................................................................... 3
Summary ..................................................................................................................... 3
Physical Hazards: ........................................................................................................ 3
Human Factors: ........................................................................................................... 4
HFIT ............................................................................................................................ 4
Capability to Model .................................................................................................... 5
Fire Incident 3 ............................................................................................................. 5
Investigation into fire on Catalyst Filter ..................................................................... 5
Summary ..................................................................................................................... 5
Physical Hazards ......................................................................................................... 5
Human Factors ............................................................................................................ 6
HFIT ............................................................................................................................ 6
Capability to Model .................................................................................................... 6
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1.
Introduction
The proposed project aims to define a new methodological approach to identify and
control for potential failures associated with human factors. Using virtual reality as an
integrated tool, the participating chemical process industries would be able to analyze the
human factor aspects of accident causation, as well as model physical hazards and the
consequences arising from them. The chemical processing industries were selected on
the basis of the high potential hazards and risks that they impose. These industries are
considered as ‘high-risk’ due to the social and environmental implications that they
impose potentially transferring risks and hazards to society through raw products.
Therefore, it is widely recognized that there is a need for improvement in safe working
practices and accident prevention measures within the industry.
The proposed project has been divided into a number of work packages in order to
achieve the desired objective. The first work package reviews the existing methodologies
for identifying and controlling failure associated with human factors. The second work
package, which this report details, consists of defining criteria for selecting
accidents/incidents and consequent identification of a selected number accident/incident
scenarios for detailed study. Subsequent work packages involve the analysis of
contributing factors associated with the selected accident/incident scenarios, evaluation of
current methodologies, reviewing of the state-of-the-art virtual reality modeling,
investigating the potential contribution of VR to improve the selected method, and
preliminary evaluation of the revised methodology.
1.1
Objectives of Work package 7
The primary objective of this work package is to define criteria for selecting accidents
and incidents, consequently identifying a number of scenarios to be simulated using stateof-the-art virtual reality. The aim is to produce a reasonable amount of data, selected
from accidents/incidents to enable the evaluation process to be carried out.
The participating company specific to this work package is BP Grangemouth (UK). This
site was selected on the basis of its unique location and infrastructure, integrating three
business units on one site, exploration, oil and gas, and chemical processes. Further
details of the site and its accident/incident history and databases are given below.
2.
BP Grangemouth
BP Exploration, Oil, and Chemical processes make up 27 operations and 8 functions in
Grangemouth, employing over 2000 people to ensure continuous production 24 hours a
day. Central to the success of BP Grangemouth is the Forties Pipeline System (FPS).
The FPS provides Grangemouth with direct access to oil and gas from the North Sea,
carrying around one million barrels of oil a day, which is stabilized by removal of the gas
content. The Refinery processes a proportion of the crude oil, producing a range of fuels
and other products. The gas separated from the oil and refinery streams is subsequently
used at the petrochemical plants where ethylene and other derivative products such as
ethanol and polyethylene are produced. It is therefore essential that the products meet the
qualitative and environmental requirements of the customer.
BP Grangemouth has shown a variable performance in health, safety and the
environment, having experienced a number of accidents and incidents in recent years.
The early summer 2000 saw three major incidents at the site, a power failure on 29th
May, a medium pressure steam line rupture on 7th June and a fire on the Catalytic
Cracker. No personal injuries occurred during these incidents. However, they were all
potentially major incidents. Following these incidents a comprehensive safety review
was carried out across the site whereby a total of 850 recommendations were made on
improving the health, safety and environment of the workplace. Most of these
recommendations are to be completed by the end of the year 2001. The site therefore
offers an extensive and valuable amount of data with regard to accidents and incidents.
Currently operating at Grangemouth is an accident and incident database termed the TLC
system. The TLC (Total Loss Control) system stores all reported accidents and near miss
incidents on the site. The database holds information regarding the events and conditions
leading up to the accident/incident, and the attributed causal factors. Entry of accidents
and incidents into the TLC database is the responsibility if the line manager, supervisor
or person responsible for safe working practices within the area at the time of the
accident/incident. Entry of accidents/incidents requires a number of mandatory questions
to be answered in order to determine if further investigation is required. The severity of
the accident/incident is determined using a Boston Square, which has definitions for
Minor, Serious and Major injuries, environmental or financial loss. During investigation
of reported accidents and incidents all critical factors, immediate causes and root cause
should be identified. Immediate causes are the conditions or actions occurring
immediately prior to the event. Root causes are the underlying preconditions and can be
categorised into personal factors and job factors. Full investigation reports should
identify all immediate and root causes and further detail a list of recommendations for
corrective action.
The aims of this work package were to review accident and incident reports recorded on
the TLC database at the BP Grangemouth site. By identifying common human factors
and physical hazards that give rise to accidents/incidents criteria can be made for
selecting accidents to simulate using immersive virtual reality. The TLC database was
accessed over the duration of a three-day visit to the site and a number of more detailed
accidents and incident reports were selected according to a variety of criteria. The
feasibility of modeling the selected accidents and incidents was subsequently reviewed.
In an effort to select a number of accidents and incidents for virtual reality simulation,
five years of retrospective accident/incident data from the BP Grangemouth database was
studied. In attempting to establish an understanding of the underlying human errors that
result in accidents and incidents, it was decided to study the most frequently occurring
accident and incident types at the site.
During the study of the database in order to gain an overall feel for types of accidents and
incidents occurring on site, it became apparent that there were three distinct accident
types. These were slips/trips and falls, crushing incidents, and fires. Furthermore, it was
evident that these accident types were occurring most frequently during periods of
‘turnaround’ whereby maintenance activities and numbers in the workforce increase.
Thus, these three accident/incident types were considered as a starting point for the
selection of accidents and incidents. Using virtual reality and its limitations as the
driving force for selection, the feasibility of modeling accidents/incidents was then
determined.
After considering possible accidents and incidents according to the above criteria
selection was determined by the limitations of the virtual reality system. Whilst the most
frequent accidents and incidents in the petro-chemical process industry are caused by
‘slips, trips and falls’, and the most serious and potentially major accidents result in
crushing incidents, the most feasible scenario within the limits of the virtual reality
system is fire.
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3.
What is an accident or incident?
‘Accidents’ can be defined as being unplanned and undesirable deviations in systems
operations. The consequences of accidents can take the form of personal injury, loss of
life, property damage, environmental damage, or the loss of the system itself. The term
‘Incident’ tends to adopt the definitive meaning of a near-miss accident or an event
without injury (Kontogiannis etal, 2000). Near-miss incidents are significant to the
process of organisational learning because they result from the same pre-conditions that
underlie many accidents, typically caused by the combination of latent failures and
erroneous human interventions.
Analysing near-miss incidents therefore enables
recovery processes to be assessed. Subsequently any weaknesses in the system can be
identified and eliminated, preventing future accidents of its form occurring (Reason,
1997). It was therefore important that as an initial criterion for selecting appropriate
scenarios for simulation that both accident and incident reports were reviewed.
There are a variety of factors that significantly impact on safety performance. These
factors can directly cause accidents and incidents or be contributory factors in the
causation of accidents. Direct and indirect influences on safety performance include
personal characteristics of the employee performing the task, aspects of the task itself,
and the equipment used directly or indirectly in the task (Wickens, Gordon & Liu, 1998).
When considering factors for the simulation of accident and incident scenarios both
human components and physical properties of the environment and task have to be
considered. Human factor representations and physical system representations of
accident causation should be complementary to one another. This project aims to achieve
this and in doing so will gain a holistic view of accident causation. Physical system
representations alone neglect cognitively derived human behaviour, thus failing to
accurately represent the real world. Human perceptions and cognitive capacities enable
the extraction and interpretation of information from the environment, determining
actions and behavioural responses in given situations (Groner, 2001). Fundamentally,
human behaviour is governed by an information processing system, by which information
is extracted, given meaning, used to consider responses and applied behaviourally. Thus,
by assessing human behaviour within given virtual reality situations, an understanding of
the cognitive capabilities and perceptions will be achieved. Subsequently, an insight will
be gained as to how individuals use information to make decisions and of the physical
properties of the working environment that lead to human error.
4.
Criterion for selection
4.1 Human Error
Human factor assessment in accident analysis is becoming more widely recognised
within process industries. ‘Human error’ is a term often found in root cause statements,
implying that underlying the causes of all accidents and incidents human actions have
played a contributory role. Human error is characterised by a combination of overload,
decision to ‘err’, and poor work designs/conditions (DeJoy, 1990) and incorporates
individuals, group and organisational failings. It is needless to say that the safety
behaviour, attitudes and beliefs of individual(s) significantly influence the safety
performance of organisations and collectively define the safety culture of an organisation
at a given time. Often defined as ‘the way we do things around here’, the prevailing
safety culture has serious implications on how health, safety and environment issues are
managed within the organisation.
Underlying human factor issues contributing to accidents and incidents have been
identified as job factors, personal factors and substandard practices. Job factors include
inadequate engineering and maintenance, inadequate purchasing and inadequate
supervision. Personal factors include motivational issues, lack of knowledge and skill,
physical or cognitive incapability, physical stress and psychological stress. Substandard
practices include the following issues, abuse/misuse of tools and equipment, failure to
assess risks, failure to communicate risks, failure to adhere to rule, procedures and
regulations, operating without authority, improper positioning for task, improper
placement of equipment, and failure to use appropriate protective equipment.
There are five human components that influence job factors, personal factors and
substandard practices giving rise to accidents. These human components are visibility,
sensation, perception, cognition (communication) and motor control (Wickens, Gordon,
E & Liu, 1998). Failure within any of these components significantly impacts on human
performance and in turn, safety. Thus, simulation of accident and incident scenarios
should manipulate physical and contextual properties that influence one or more of the
five human components.
For example, presenting information and hazards visually to the user, or through the
creation of sensation, observers/management will be able to assess the capabilities of the
individual to perceive and interpret their environment, the risks and hazards present
within the environment and their ability to respond. Auditory sensation, touch and smell
are important for the early detection of hazards and assessment of associated risks. When
sensory functions fail there is less time to be aware and assess risks. In addition,
communicative and cognitive skills of the user are equally important (Shappell &
Wiegmann, 1999). The ability to communicate and warn others of hazards and risks
present will be demonstrated through immersive virtual reality environments.
Although the human information system largely implies that human behaviour is
mediated by intentional decision making processes, human error resulting in accidents do
not typically result from the intention to create error. Instead it is unintentional human
error that gives rise to the majority of accidents and incidents. Intentional human error is
where the individual actively chooses to deviate and violate systems (Groner, 2001).
Predicting intentional human error is extremely difficult and unreliable and it is for this
reason that this work package will focus primarily on accidents and incidents caused by
unintentional human error.
Additionally, in the event of accidents and incidents resulting from mechanical or
technological failure, human error is not immediately observable. Thus, it is proposed
that the selection of accidents and incidents for virtual reality modeling should focus on
human error as the immediate cause of accidents and incidents. Human factors will be
the immediate observable cause of accidents throughout simulation. These observable
errors, or action errors, take the form of omission and co-mission of acts, lack of situation
awareness, procedural error, work preparation, person factors, competence,
communication, and supervision. Action errors tend to be the results of other human
errors (or management failings) further back in the system. In other words, operators at
the ‘sharp end’ are quite often ‘set up to fail’.
4.2
Physical Hazards
Of central importance to the safe operation of any work task is the work environment.
The work environment features numerous physical conditions that are potentially
hazardous. Hazards present within the working environment include fire and explosion
hazards, reactive materials and substances, controls and displays, electrical and
mechanical hazards. Radioactive materials, potential pressure and kinetic sources,
carcinogens and toxic materials are additional physical hazards often referred to as
‘hidden hazards’. These are odorless or colorless substances not immediately detectable
by the human sensory system (www.lehigh.edu/~kaf3/background/odors.html).
The presence of ‘hidden hazards’ in the working environment has serious implications on
safety. However, difficulties may arise over the capability to model such hazards. The
capability of the proposed virtual reality system will allow modeling of substance release
via the simulation of atmospheric movement, vapor, and pool evaporation. Thus, making
the release of hazardous material visually identifiable. ‘Hidden hazards’ often have
distinctive odors that are detectable by the human sensory system; simulation of these
odors may present some difficulty. The ability to simulate odors, at this stage, is an
ethical uncertainty. Many chemicals have a permissible exposure level due to risks that
may be imposed on the wellbeing of the participant. Other difficulties with regard to odor
simulation include the participant’s sensitivity to smell. It is estimated that 96 percent of
the population have a normal sensitivity to smell. However, the small percentage
remaining is insensitive to smell (Friedman, 1994 – see website address above). This is
particularly characteristic of populations of workers who have been exposed to and are
accustomed to certain smells. It is for this reason that the simulation of synthetic odors
may not be desirable. Additionally, participants may have highly tuned sense of smell
being able to distinguish even the most discrete difference between actual chemical odor
and synthetic odor. Thus, simulated odors may not be effective at producing the desired
response from the participating V.R user in part due to the consequence of exposure, and
2
in part due to the uncertain ability of creating odors with a high degree of likeness to
hazardous chemical odors. Furthermore, even when chemical odors are detectable it does
not necessarily follow that they are hazardous. Some chemicals, for example carbon
monoxide, are deadly and do not have an odor detectable by the human sensory system.
In such cases the simulation of chemical release using atmospheric movement and vapor
would be recommended.
Auditory simulation of chemical release would be
recommended in cases whereby release of chemicals is ‘invisible’ to the participant.
Additional physical hazards within the working environment are conditions that lead to
‘slips, trips, and fall’ hazards. These are typically present due to poor housekeeping,
confined or restricted areas, inadequate safeguards and barriers, or inadequate protective
equipment. Over a third of all major injuries reported each year are caused as a result of
a slip or trip (HSE, 1999). Thus, it would be beneficial to raise awareness of factors and
conditions that give rise to accidents in the form of slips, trips and falls. However, the
ability to simulate ‘slip, trip, and fall’ accidents is limited requiring an advance in the
proposed virtual reality system capability. In order to simulate slips, trips or falls using
the virtual reality system, monitoring of foot movement and force sensors would be
required. The capability of the proposed VR system at the present time only allows for
body orientation and hand movements to be monitored and modeled.
Further physical hazards within the working environment leading to accidents and
incidents occur from excessive light and illumination, noise exposures, inadequate
ventilation, high or low temperature exposures and inadequate warning systems. With
the exception of ventilation and temperature exposure, all of these can be manipulated
within the simulated environment to create conditions likely to give rise to accidents.
Many features of the physical work environment influence safety behaviours. Evidence
from previous studies highlights the effects of noise, lighting, congestion, workload and
physical overload on the propensity to behave safely. Particular to the process industries
is the increase in accidents/incidents during plant shutdowns or ‘turnarounds’. During
these times there is an increase in the amount of ongoing maintenance work, with a
subsequent increase in workers and materials, such as scaffolding and machinery. It is
not surprising then that accident and incident rates increase. Congested areas present the
hazard of limiting the movements and actions of workers resulting in a higher potential
for accidents. With an increased potential for spillage and the presence of hazardous and
flammable materials fires, slips/trips and falls, particularly from ladders and scaffolding
increase during ‘turnarounds’. Thus, consequences of accidents can be manipulated and
anticipated from the physical hazards present in the virtual environment.
Consequences of physical hazards can occur through contact with a single isolated hazard
or from a combination of physical hazards. Consequences of physical hazards include
personal injury, property damage and environmental damage. For the benefit of the
individual user accident and incident scenarios will incorporate many of these physical
hazards with the consequence of personal injury and property damage. Some
environmental consequences can be ‘invisible’ in the sense that damage is not directly
observable, occurring over a period of time. On the other hand, environmental damage
can also be very visible, e.g. spills and large emissions. Although, it may be feasible fo
3
model such environmental incidents using VR techniques, this work package focuses on
personal injury and damage to property as consequences of accidents and incidents
suitable for modeling. Direct observation of the consequences of unsafe acts will enable
the user to understand the full implications of their behaviour.
4.3
Person Injury
Personal injuries and fatalities are very effective at highlighting hazards and the
consequences of unsafe acts. They bring home the costs of unsafe behaviour. Injuries
can be sustained through contact with a single isolated hazard or a combination of
physical hazards within the environment. Hazards within the working environment can
impact on work performance in addition to imposing physical health hazards.
Personal injury as a consequence of unsafe acts varies depending on the type of
interaction that occurs between the individual and the physical hazard. The consequences
on individuals who are exposed to fire, explosions and carcinogens include burns and
scalding to the skin and possible death. Individuals exposed to hazards of the electrical,
mechanical, kinetic energy and pressure types may suffer the following forms of injury;
cutting or tearing of the skin, shearing resulting in loss of limbs, crushing, breaking of
bones, and physical strain injuries. Additionally, individual injuries resulting from ‘slips,
trips, and falls’ may vary from minor injuries such as bone breakage and head injury to
death. It is estimated that 50 percent of individuals impacting against a surface at a
velocity of 18 mph will die (Wickens, Gordon & Liu, 1998). Injuries sustained through
excessive exposure to noise, illumination, vibration and temperature can also have an
adverse impact on health. However, injury types are usually progressive in nature and
occur over a prolonged period of exposure to the hazard. Examples of injury include
impaired hearing ability, vision loss, and decreased work performance (Wickens, Gordon
& Lui, 1998).
4.4
Location
From the point of view of simulating an environment using Virtual Reality (VR)
techniques, finding a location in the plant where there had been a high proportion of
accidents and incidents may facilitate the process since only one location would need to
be modeled. The Total Loss Control (TLC) database at BP Grangemouth was studied in
an attempt to identify a specific location within the site with the greatest percentage of
accident and incidents. However, no specific location was found to have a significantly
greater amount of accidents and incidents than other parts of the plant.
4.5
Accident/Incident Type
Despite the lack of location on site with a high frequency of accidents and incidents, the
most frequently occurring accident and incident types were identified. It was evident
from the database that three categories could be formed. These were ‘slips, trips and
falls’, ‘crushing’, and ‘fires/burns’.
4.6
Severity
The severity rating of the accidents and incidents should span the whole spectrum from
minor incidents with the potential to be major, to serious/major accidents with the
4
potential to be major. The analysis of minor accidents with the potential to be major is
particularly important to establish the weaknesses in the system and also to highlight the
strengths in the system that the accident/incident from escalating into something major.
4.7
Person Involvement
Selected accidents and incidents require some form of individual involvement such as an
eyewitness. Eyewitness accounts, whilst being subjective in nature, provide essential
information relating to the conditions prior to, during and after an accident. Irrespective
of the ‘objectivity’ of eyewitness accounts they still represent an individual’s physical,
emotional and cognitive experience of the incident, providing a source of ‘human factors’
information that can be used in the modelling process.
4.8
Injury sustained whilst working alone
Working alone on job tasks is a common occurrence within the chemical process
industry. Accidents and near-miss incidents resulting from individual work tasks
provides a means of monitoring and assessing the safety behaviours and risks individual
workers are willing to take. Working alone forces the individual to take their own
initiative and make their own decisions. In turn, decision-making and reasoning
processes of the individual are more observable, easier to measure and predict.
4.9
Injury sustained whilst working in groups (two persons or more)
Additionally, it is worthwhile modeling accidents and incidents occurring from group
work (comprising two or more persons).
This would enable assessment of
communicative behaviours between the individuals, conveying potential hazards and
sharing situation awareness. Group tasks effectively demonstrate the influence workmates can have on communication, safety behaviours, and performance. Additionally,
the simulation of group accidents/incidents will allow individuals to experience the
consequences of another person’s actions and or the consequences of poor group decision
making.
4.10 Incidents without loss
Near-miss incidents are significant to the process of organisational learning because they
result from the same pre-conditions that underlie many accidents, typically caused by a
combination of latent failures and erroneous human interventions. Analysing near-miss
incidents therefore enables recovery processes to be assessed. Subsequently any
weaknesses in the system can be identified and eliminated, preventing future accidents
from occurring (Reason, 1997).
4.11 Accidents/incidents occurring during maintenance activities.
Accidents relating to maintenance present a problem in the chemical process industry.
An estimated 40 percent of all reported accidents are related to maintenance (Hale et al,
1998). Eighty per cent of these accidents occur during execution of the maintenance
procedure itself. These are caused by rule-based errors or skill-based errors. Skill-based
errors include the conduct of the maintenance such as the technique adopted, inattention,
or memory failure. The remaining 20% occur as a result of deficiencies in maintenance
5
management such as management preparation and the scheduling of the work plan
(DeJoy, 1990).
Periods of ‘turnaround’ involve a vast increase in the level of maintenance work. Thus,
there are subsequent increases in the number of workers on site. With an increase in
work activities and workforce, there is the inevitable increase in materials and equipment
on the site, which in turn can lead to accidents and unsafe events. Maintenance activities
provide an opportunity to assess housekeeping, work preparation and other issues relating
to human factors during periods when safety behaviour is paramount. The simulation of
maintenance procedures will prove insightful as they give the opportunity to present new
unfamiliar task requirements to an otherwise familiar routine task. In doing so this will
enable the assessment of work planning procedures, scheduling and risk assessments. It
will also enable monitoring of hazard perception and the user’s ability to make decisions
to avoid any presented hazards or risks.
Simulation of maintenance activities will be beneficial to the improvement of
maintenance management systems, safety policies, maintenance concepts, designs,
planning and procedures.
4.12 Accident/Incidents involving procedural tasks
It was evident through examination of the TLC database that a higher percentage of
accidents and incidents occurring at the Grangemouth site were in part caused by an
inadequate or lack of formal procedure for the task. Human error relating to procedures
take the following forms, deviations from or non-compliance to the existing procedure,
omissions, sequence errors, and a lack of formal procedure. Accidents occurring during
procedural tasks will enable any weaknesses or inadequacies of procedures to be
identified.
6
5.
Feasibility of accident/incident simulation
Slips, trips and falls are one of the most common causes of injuries at work (HSE, 1999).
There are many measures that can be taken to prevent the frequency of this accident type.
Prevention relies on the ability to identify and eliminate hazards. Adequate lighting,
congestion-free workspaces, removed obstructions, clearly marked barriers and
appropriate protective equipment can effectively reduce accidents of the ‘slip, trip and
fall’ type. However, in selection of scenarios for virtual reality modeling the needs of the
end user must be considered. Notwithstanding the limitations of the virtual reality system
on the modeling of ‘slip, trip and fall’ accidents, simulation of this accident type would
provide users with a limited amount of new knowledge and information regarding the
underlying causes of slips, trips and falls.
Reportedly, the most common human failing or ‘error’ found within the process industry
is ‘slips’ (Hoffman, et al., 1995). ‘Slips’ are characteristic of process industries because
they usually result from highly automatised and familiar tasks, tasks that can be
completed ‘without even thinking about it’. Such slips are typically physical in nature,
i.e, slipping on an oily surface. However, ‘slips’ in the cognitive sense takes the form of
omissions in procedural tasks and lapses in memory or conscious thought. It would seem
plausible that an environment could be created and simulated to give rise to accidents of
this type. The creation of a ‘busy’ and congested working environment with many
distractions could lead to the occurrence of unintentional human error. The second
category of consequence resulting from human error is crushing incidents. The nature of
crushing and its severity depend largely on the interaction between the physical hazards
and the individual.
The simulation of conditions giving rise to accidents of the ‘crushing’ type would provide
an effective means of enabling users to directly observe the consequences of their actions.
It would also enable management to identify weaknesses in existing ‘hard’ and ‘soft’
systems. It is out with the capabilities of the proposed virtual reality system to simulate
force and kinetic energy. Thus, human error with crushing as a consequence to the
individual user is not feasible within the domains of the virtual reality system and
additionally, would have ethical implications. However, the virtual reality system has the
capability to simulate a virtual agent (a virtual reality individual occupying the virtual
world). Therefore, accidents resulting in crushing type incidents can be demonstrated on
the virtual agent. Individual users would be enabled to observe the consequences of their
own actions on other individuals.
The use of a virtual reality agent to demonstrate consequences of unsafe acts can also be
applied to the third category of accidents, fires. Fires can occur anywhere. This category
of accident type is particularly useful for simulation in that it is not industry specific.
Fires are common both in the home and in the place of work. Thus, simulation of fire
scenarios would provide industries, particularly the chemical and processing industries
with a greater knowledge and understanding of the behaviours and hazards present within
the working environment that give rise to a fires. Not only would accident scenarios
provide a means of understanding the human factors relating to fire hazards, it would
provide an means of training and improvement of existing emergency management
systems.
An integrated perspective of both the physical representations of fire hazards and the
representation of human behaviours will allow for a greater understanding of the
cognitive capabilities and perceptions of the user. Simulation of hazardous working
environments will enable management to observe user’s behaviours and responses to
presented hazards, subsequently gaining an understanding of the information processing
systems used to make decisions (Groner, 2001). Fire accident scenarios appear to be the
most feasible accident type for modeling using virtual reality. Fires occur from a number
of unpredictable ways. It is therefore important that workers are effectively trained in the
identification, prevention and control of fire hazards.
There are a variety of work activities that can be manipulated to consist of fire and
explosion hazards. The presence of flammable substances and an ignition source within
the environment during task execution are the preconditions to fire accidents. It would be
useful to create a number of scenarios requiring a number of different task executions.
These can be job specific or generic in nature. Thus, providing training methods or
raising general awareness of hazardous working environments. In particular, it would
appear that procedural tasks and maintenance procedures would be most beneficial to the
chemical process industries.
The majority of serious accidents within the chemical industry are caused by
maintenance. Eighty percent of accidents occur during execution of the maintenance
procedure itself. These may be caused by rule-based errors or skill-based errors. Skillbased errors include the conduct of the maintenance such as the technique adopted,
inattention, or memory failure (Rasmussen, 1983). The remaining 20% occur as a result
of deficiencies in maintenance management such as management preparation and the
scheduling of the work plan (DeJoy, 1990). The simulation of maintenance procedures
will prove insightful as they give the opportunity to present new unfamiliar task
requirements in to an otherwise familiar routine task. In doing so this will enable the
assessment of work planning procedures, scheduling and risk assessments. It will also
enable monitoring of hazard perception, the decision to avoid and the user’s ability to
avoid any presented hazards or risks. Maintenance tasks executed could possibly take
any of the following forms; physical (manual handling, climbing), operating machinery,
and working with chemicals. However, there are limitations to the extent to which
physical tasks can be simulated. The virtual reality system as it stands today offers the
ability to operated machinery within the virtual world, however, it is out with the
capabilities to perform climbing act or acts of physical movement unless the object being
enacted upon features as part of the user’s interface. Thus, accidents involving slips, trips
and falls with regard to ladders and scaffolding are not feasible. Similarly, operating or
maneuvering heavy objects and equipment can not be simulated ruling out the feasibility
of crushing incidents. Operating machinery and working with chemicals may be more
feasible. Operating machinery could present crushing injuries and other personal injury
when the user is accompanied in the virtual world with an agent. However, the extent to
2
which this can be modeled is uncertain. The plausibility of modeling accidents and
incident resulting from and in fires, on the other hand, seems to be possible.
The physical hazards, human factors causes and consequences of fires are outlined in
Table 1 below.
Table 1 – Physical Hazards, Human Factors Causes and Consequences of Fires
Human Factors
Procedures
Work prep
Person Factors e.g. physical
capability & condition
Supervision
Competence
Communication
Physical Hazards
Presence of Hydrocarbons
Uncontrolled release
Accumulation of explosive
atmospheres
Leaks of flammable liquids
Ignition
Consequences
To self: burns, death
To others: burns, death
Property damage
From our knowledge and understanding of the limitations of Virtual Reality techniques, it
should be possible to model all of the above in a scenario.
3
6 Conclusions
Appendix 1 outlines a series of accidents/incidents from the Grangemouth TLC database,
for which detailed reports were available. The accidents/incidents are of 3 different types
– ‘slips, trips & falls’, ‘crushing’ and ‘fires’. For each incident, a summary of the report
is made followed by an outline of the physical factors and the human factors associated
with it. The Human Factors Investigation Toolkit (HFIT), which is under development at
the University of Aberdeen, was used to investigate the immediate action error of the
individual(s) that occurred prior to the accident, followed by analysis of the situation
awareness failings of the individual(s) involved in the incident. In addition, a number of
potential threats that could have led to the individual losing ‘situation awareness’ are
identified. The capability of each accident for scenario modeling using VR techniques is
discussed.
The systematic consideration of each incident type through in depth analysis of accident
reports, indicates that fires are the only types of incident that could be successfully
simulated, due to the limitations of VR at the current time.
From the accidents analysed and detailed in the appendix it should be quite evident how
the power of VR tools and techniques does not reach everything. This means that there
are some privileged type of accidental situations that could be more effectively
reproduced using VR than others.
The simulations of safety-critical situations which involve manual handling of heavy
components is a clear example of how limited VR tools can be. But for all cognitiverelated hazardous situations, like the control rooms, for instance, VR can respond
effectively enabling analysts to get useful insights.
References
Groner, N. E (2001) Intentional Systems representations are useful alternatives to
physical systems representation of fire-related human behaviour, Safety Science, 38, pp
85-94
Hale, A. R etal (1998) Evaluating safety in the management of maintenance activities in
the chemical process industry. Safety Science, 28 (1) pp 21-44
HSE (1999) Preventing slips, trips and falls at work. HSE Books, Suffolk
http://www.lehigh.edu/~kaf3/background/odors.html
Kontogiannis, T et al (2000) A comparison of accident analysis techniques for safety
critical man-machine systems. Industrial Ergonomics, 25, pp 327-347
Rasmussen, J (1983) Skills, Rules, and Knowledge: Signals, Signs, and Symbols, and
Other Distinctions in Human Performance Models. IEEE Transactions on Systems, Man,
and Cybernetics, 13 (3) pp257-267
Reason, J (1997) Managing the risks of organisational accidents. Aldershot. Ashgate
Shappell, S & Weigmann, D (1999) Human Factors Analysis of Aviation Accident Data:
Developing a Needs-Based, Data Driven, Safety Program. Paper presented at Human
Error, Safety & System Development, June 199, Leige, B .E
Wickens, C. Gordon, S & Liu,Y (1998) An Introduction to Human Factors Engineering.
New York. Longman.
APPENDIX 1
‘SLIPS, TRIPS & FALLS’ INCIDENTS
‘Slips, Trips & Falls’ Incident 1
Plater fall incident
Summary
A plater sustained broken ribs as a result of a fall whilst working on scaffold in the
Cracked Gas Compressor House area. The individual was working on a split-level
scaffold. He was required to modify a pre-fabricated ‘T’ section structural pipe support.
The work involved reducing the length of the beam assembly. The risk severity was
given a ‘medium’ rating. Control measure includes adopting a sensible lifting technique
according to the Contractor’s safety handbook. The manual handling work assessment
states that heavy, large, or awkward load should not be lifted alone. The ‘T’ section was
lifted into an upright vertical position to enable him to move it along to the lower scaffold
to cut. He was wearing appropriate PPE. Dragging the north end of the ‘T’ support
eastwards to enable him to cut the side of the beam, he lost grip. Rapidly staggering back
into a protruding scaffold tube he subsequently landed with his upper body on the lower
scaffold and his feet resting on the upper scaffold (a gap of 400mm). The individual
concerned sustained a broken right rear rib. There were no eyewitnesses at the accident.
Physical Factors
The work involved maneuvering a heavy and awkward prefabricated ‘T’ section support
assembly. The hazards included the possibility of muscle strain and back injury, slipping
and loosing grip whilst pulling. Despite housekeeping being satisfactory the presence of
scaffold pole ends presented a hazard. The split level scaffolding imposed a further
hazard increasing the potential for falls. In addition, the ‘T’ section itself presented
physical hazards with the potential for high kinetic energy and the presence of sharp
edges.
Human Factors
An inadequate assessment of the risks during work planning stages resulted in the use of
insufficient manual handling techniques to maneuver the ‘T’ section. The noncompliance of manual handling procedure may have been the result of the organisational
safety climate in general or due to the lack of supervision and reinforcement of
procedures. The task was typical of an everyday activity therefore over-familiarity
coupled with too focused attention on completing the task may also have contributed to
this incident.
2
Human Factors Investigation Tool (HFIT)
Action error
Quality; wrong action on right equipment (dragging equip)
Rule Violation: non-compliance to manual handling procedure
Situation Awareness
Attention: too focused
Memory: Failure to consider all factors and risks associated with manual handling
Threats
Procedures: manual handling not complied too
Supervision: lack of reinforcement of safety procedures
Capability to model
The capability to model is out with the limitations of the Virtual Reality system. There
are two main constraints that restrict the ability to simulate this type of incident. Firstly,
the virtual reality system has no means of measuring or sensing user’s force. Therefore,
the ‘dragging’ technique used to maneuver the ‘T’ sections could not be simulated unless
the ‘T’ section was a feature of the control interface. Secondly, in order to simulate the
fall from the split-level scaffold, sensors on the feet would be required. The simulation
of an incident such as this would only be beneficial for the assessment of manual
handling techniques. It is inappropriate to the present study, which requires the
simulation of a selection of accidents/incidents that are common to the chemical process
industry and highlight the underlying human factors that give rise to human error. The
above accident would not provide the insight sought after for training purposes and
management improvement. Additionally, the consequences of the accident would be
difficult to present.
3
CRUSHING INCIDENTS
Crushing Incident 1
Inshore Marine Accident
Time 09:30 hrs
Summary
Gary and his colleague Robin secure the line boat, ‘Ross point’ and await pick up by the
passenger boat, ‘Drumsand’. The two men wait outside the safety rail on the starboard
side of the ‘Ross Point’. The ‘Drumsand’ arrives and the men board. Two webbing
strops on the ‘Drumsand’ are to be transferred on to the ‘Ross point’ for the next
morning. As the ‘Drumsand’ maneuvers away from the ‘Ross point’ one of the
passangers on the ‘Drumsand’ notices that the webbing strops are still on the
‘Drumsand’. The passenger throws the strops on to the ‘Ross point’, however, they land
on the safety rail. Gary decides to jump across on to the ‘Ross point’ to properly stow the
strops. The ’Drumsand’ maneuvers 360 degrees to pick up Gary from the ‘Rosspoint’ for
the second time. Gary again stands outside the safety rail, but this time he moves further
up the bow of the ‘Ross point’ and attempts to jump on to the ‘Drumsand’. Gary is at this
time in line with the break of the ‘Ross point’s’ deckhouse and appears to have been
crushed by the flare of the ‘Drumsand’s’ bow against the deckhouse of the ‘Ross point’.
Physical Factors
Several physical factors largely contributed to this incident. The presence of westerly
winds at 25knots and a sea state of 1 – 1.5 meters with a short period of 2-3 seconds,
presented the physical hazard of the lively movement of the line boats. The relative
motion of the prevailing sea gave a vertical differential between the decks of the two
vessels up to four feet. A further hazard included the lack of non-slip paint on the deck
of the line boats and passenger boat.
Human Factors
An immediate cause of the above accident can be attributed to the perceived time
pressure on the employee. The perceived lack of time led the employee to position
himself at a dangerous part of the boat. A focused attention on boarding the passenger
boat caused the employee to fail to consider all the risks, resulting in poor decision
making and judgement. A channeled attention on properly stowing the strops was the
initiating cause leading the employee to re-board the ‘Ross point’. Several human factor
issues underlie this focused attention. These include the lack of communication between
the passengers and crew of the ‘Drumsand’ in relation to the rules and procedures of
passenger conduct, a poorly defined procedure relating to the roles and responsibilities of
the crew and passengers, a lack of supervision, and the overall organisational safety
culture.
HFIT
Action Error 1: Leaving boat whilst boat is maneuvering away from ‘Ross point’
Rule Violation: Exceptional violation
Situation Awareness 1
Attention: too focused
Memory: failure to consider all factors
Judgement/decision making: Apply inappropriate solution
Threats 1
Organisational safety culture
Lack of supervision
Action Error 2
Quality: Action in wrong direction
Situation Awareness 2
Attention: too focused
Threats 2:
Work environment: weather conditions
Procedures: inadequate/not followed
Job factors: Time pressure
Capability to model
This incident presents physical hazards whereby the Sea State and relative motion of the
boats could be simulated. However, within the limitations of the virtual reality system as
it stands today, the capability to simulate an individual jumping between two boats during
extreme wind conditions appear to be infeasible. The VR system would require sensors
to record and monitor foot movement. Furthermore, it would be out of the VR systems
capabilities to simulate the crushing affect of the individual between the two boats. As an
alternative, it would seem possible to simulate the effect of an agent (person) within the
virtual world and model the crushing effect occurring to this virtual agent.
Crushing Incident 2
Serious Hand Injury
Summary
An employee, sustained a serious hand injury during the task of cleaning float heads.
Three days prior to the accident risk assessments and work permits had been completed
allowing Robert to power jet wash the float heads. Power jet washing whilst the float
heads were hanging was considered to be the safest option in the risk assessment.
However the decision was made to clean the float heads by hand rather than by power jet
because the float heads were stacked together. The float heads were then lowered the
following day. One float head remained dome side up. A work permit was re-issued for
the hand cleaning of the float heads the following day. The employee and a work
colleague rig the float head and turn it bowl up, stablising it with scaffold boards. During
cleaning of the float heads the employee finds difficulty accessing the area closest to the
kick plate. The employee pushes the float head to allow access, slipping he lands face
forward in to the float head simultaneously trapping his fingers.
2
Physical Hazards
The float heads present a physical hazard type of high kinetic energy. This hazard is also
present due to the insecure support of the float head using scaffold boards. The heavy
and awkward size and weight of the float heads meant that according to manual handling
procedures, Robert should not have attempted to manoeuvre the object alone.
Furthermore, the working area consisted of badly worn floor plates and presented slip
hazards. Poor housekeeping presented trip hazards in the form of congested and
restricted workspace and uneven floor plating.
Human Factors
The human factor issues that gave rise to this accident can be attributed to the failure to
reassess the risks associated with the change of job task. This can be accounted for by
the lack of supervision, not only at the planning stage of the work task, but also during
the work preparation and execution stages. The failure to comply with the COSHH
assessment regulations regarding appropriate protective clothing was in part due to the
inadequate assignment of workers to the task. The injured party failed to wear
appropriate PPE because he had not seen the COSHH assessment for pronature despite
this being available to him. The lack of training and competence to carry out the task is
also reflected in that employee had no previous experience of cleaning the float heads.
The lack of compliance to manual handling procedures reflects the organisational safety
culture.
HFIT
Action Error 1
Quality: Wrong action on equipment. I.e. pushing the float head
General violation: Employee aware of the manual handling procedures however
chose to disregard them
Situation Awareness 1
Memory: Failure to consider all factors of the action
Main Threats 1
Supervision: only at planning stage
Procedure: manual handling not complied to.
Capability to Model
The ability to model this incident is not feasible within the domain of this project. The
virtual reality simulator has the ability to monitor movement and orientation, however
does not currently have the capability to register force. Thus, an incident such as the one
detailed above, would require the object (in this case the float head) to exist as a control
future on the simulator interface. Whilst this is possible to build and create, it would
prove expensive to build and is therefore out with the capabilities of this project.
3
Crushing Incident 3
Injury to workshop employee
Time 14:40
Two workshop employees were operating a press brake in the fabrication workshop,
pressing lengths of stainless steel sheets (0.7mm thick). During operating of the press
brake, Robert was helping John lift the steel into the press brake. Robert verbally
communicated to John that the steel was in the brake and all was clear for operating the
press. However, Robert had failed to remove his hand from the press brake and
subsequently trapped his fourth finger of his left hand in the spare blades of the press
brake. It is thought that failure to remove the ‘spare’ blades from the equipment and the
shut down of the light guard system contributed to the incident. The crush effect lead to
the amputation of his finger.
Prior to the incident the machinery had been out of operation due to the possibility of
faulty ‘light guard’ protection system. This system shuts off the press brake when the
light beam is broken. However, because the sheets of steel required manual lifting into
and out of the press brake the setting of the beam had been altered to 60mm whereby the
light beam becomes inoperative. Thus, if this had been set lower the press brake would
not have operated with the position of Robert’s hand.
Physical Hazards
The presence of sharp objects, such as the ‘spare’ blades were a key factor in the
accident. Furthermore, the non-operating light guard was particularly hazardous,
allowing objects to enter the press brake whilst in operation.
Human Factors
No formal risk assessment had been carried out for the task, so there was a failure to
consider all possible hazards. Although the men involved were experienced, there was
no formal training on the operating of the press brake. Furthermore, there was no formal
written procedure, thus, the workmen did not adhere to the PPE requirements of hearing
protection.. The workmen followed and informal procedure that had been presented to
the workforce five years prior. There were also no formal maintenance records for the
machine.
HFIT:
Action Error (1)
Communication: Incorrect information communicated
Situation Awareness
Detection & perception; Tactile misperception
Attention:
Distracted: in-between jobs, waiting for a welder
Main Threats
Job Factors: Inadequate assignment of people to tasks
Action error (2)
Omission: Task not performed (failure to remove spare blades)
Situation Awareness:
4
Memory: Failure to consider all factors
Main threat
Procedure: No formal procedure
Work preparation; No risk assessment
Supervision: Failure to reinforce safety procedures/ lack of supervision
Competence & Training: No formal training given
Capability to Model
It would certainly be feasible to model an accident such as the one detailed above.
However, similar to crushing incidents 1 and 2 modelling of this accident is out with the
immediate limitations of the virtual reality simulator. It would be feasible to simulate the
consequences of a user’s actions, crushing another a virtual reality agent occupying the
same virtual world. However, it would not be feasible to simulate crushing accidents to
the user themselves. The Virtual reality system can not simulate and has no means of
measuring force.
5
FIRE INCIDENTS
Fire Incident 1
Lab Technician Splashed with Concentrated Acid
Time: 11:45am
Summary
Following analysis of Innovex catalyst sample, it is common practice to clean all
glassware to remove any traces of catalyst residue before the equipment can be used
again. As part of this procedure a solution of 50:50 concentrated nitric acid and water is
used. This incident occurred when a fresh solution of acid and water was being prepared.
The agency technician was about to add the required volume of water to a screw top
bottle marked “50:50 nitric acid/water” when he noticed that the wash bottle of water was
empty. He walked to the UHQ water purifier and picked up an adjacent wash bottle. He
used this to make up the volume of “water”. He then added concentrated nitric acid from
a Winchester to the screw top bottle and mixed. He then placed the screw top bottle in
the cupboard under the fume cupboard and began to tidy up. He then noticed that the
wash bottle he had been using was “IPA” and not UHQ water and realised that a mistake
had been made. As he recovered the screw top bottle from the cupboard, he noticed a
brown colour and evidence of bubbling. When he picked up the bottle the cap blew off.
He “started” back, but noticed no movement from the liquid in the bottle. He then lifted
the bottle in order to put it in the fume cupboard to segregate it from the other chemicals.
At this point the liquid released from the bottle, showering his face and body.
Physical Hazards
The labels were small and unclear on the bottles, presenting a potential hazard of mixing
the wrong chemical solutions. In addition, the screw cap bottles were unsuitable for the
preparation of the acid solution. A flask with cooling should have been used. A potential
energy hazard was present as pressure from the incorrect mixing of concentrated nitric
acid and IPA solution caused the cap to blow off. The presence of other hazardous
substances and chemicals within the laboratory present flammable and toxic hazards.
Human Factors
Particular care and attention was required due to the smallness of the bottle labels. In this
incident the technician had too focused attention on completing the job. Additional to
these factors was that there was no official procedure for cleaning the equipment and
COSHH assessment did not exist for the equipment. Additionally no training had been
given specifically on the preparation of acid solution. There was an assumption that all
agents would beware of the necessary precautions for this procedure. Poor work
standards and housekeeping of the chemicals, i.e. no segregation of wash bottles, is
thought to have contributed to this incident. As there were no official procedures for the
preparation of the acid solution, then it would seem that a review of the appropriate PPE
would be required. Similarly it was recommended that roles and responsibilities of the
agents should be defined more clearly.
HFIT
Action Error
QUALITY: correct act on wrong equipment. Mixing wrong chemicals
Situation Awareness
ATTENTION: Lack of attention to the labeling of bottles
Too focused on getting job done
VISUAL MISPERCEPTION: Mistaken label of solution bottle
Main Threat
WORK ENVIRONMENT: poor housekeeping/untidiness. Chemicals not
stored properly. Solutions not stored separately/to order
SUPERVISION: lack of supervision during task/inadequate assessment of
risk
PROCEDURES: No formal procedure for task
Capability to model
This incident involves an individual technician working alone in a potentially hazardous
environment. The incident would be particularly useful to model in that the environment
lends itself well to the virtual reality system. Through the creation of this environment
whereby information is ambiguous, labelling of chemicals are unclear, poor
housekeeping standards and inadequate supervision, the simulation of accidents would be
feasible.
It would appear feasible to simulate this environment and to manipulate the job task of
the user to obtain the desired outcome. Simulation of this environment type offers
managers and industries to observe and assess how effectively workers undertake a series
of job specific or task generic activities. The information available to the user for
completing the task successfully, i.e. without injury, loss or damage, could be
manipulated. The modelling of a task such as the mixing of solutions would allow the
end user to assess how the individual prepares the working environment for the task.
Assessing how the individual evaluates risks and potential hazards and how successfully
hazards are eliminated. Furthermore, a scenario as described above would enable
manipulation of the accessibility of this information to the participating individual. Thus,
providing greater insight into the relationship between physical hazards and human
factors.
Through the manipulation of physical hazards human factor issues can be assessed and
addressed. Not only would an understanding be gained in relation to the properties
underlying physical hazards, but also an understanding of how humans make use and
process incoming information. Various distracters and irrelevant information can be
simulated to create pressure on the participant’s cognitive capabilities, thus providing a
greater accuracy in responses during high-pressure situations. Chemical reactions can
also be simulated to varying degrees enabling the participant to interact ‘feeling’ the
2
consequences of their actions. Simultaneously allowing any attempts of recovery to be
assessed.
The above incident offers the opportunity to assess individual and group interactions with
physical hazards, monitoring and assessing the relationship between the two. Therefore,
the effectiveness of both individual and group decision processes and communication
skills can be measured. Furthermore, it enables the assessment of existing procedures
and instructions on both job specific generic tasks. The clarity of procedural information
given to the participating individual(s) can be manipulated in order to identify any
weaknesses in existing procedures.
Fire Incident 2
Fire during recatalysation
Summary
A fire was caused during the operation of reinstating pipe-work in the closing stages of a
reactor recatalysation. Following a release of process material while a blank was being
removed the process material caused a fire in a skip lying under the reactor. John
McIntosh was in a kneeling position below the reactor as he was removing the hydrogen
nozzle on the reactor. The skip below him was nearly full of paraffin. As the blank was
removed black wet sludge was present on it. He turned away from it, and on hearing a
gurgling noise he turned back. Liquid was ejecting from the nozzle under pressure. On
turning away again, some liquid caught him on the shoulder. The liquid contained
sodium fines. Pouring down into the skip containing paraffin beneath the sodium fines
acted as a source of ignition causing the skip to catch fire.
The technician involved suffered a burn to his arm but there was obvious potential for
more serious consequences.
Physical Hazards:
Several Flammable hazards were present during this job task. A source of ignition was
present due to sodium fines from catalyst being released into atmosphere. A hydrogen
trailer next to the area of the incident was also a physical hazard. During recatalysation
the Reactor was105c which is greatly above its flash point of 69c. Furthermore, the
storage of drums meant that some drums might have had dry catalyst present due to
insufficient paraffin, thus presenting a hazard if opened to the atmosphere.
In addition to the presence of flammable hazards there was also the potential for energy
release. This is evident from the potassium and sodium fines ejecting from the nozzle.
Additional energy hazards were reduced by the technician draining to the skip instead of
draining to a lower pressure class pipe-work. There was also the possibility of back-flow
occurring when blank was removed had the drain-line to the tank not been shut off.
Further hazards included poor housekeeping and congested areas with sharp and
protruding objects. Scaffold poles and congestion around overhead piping, the build up
3
of lagging/cladding against pipe-work presented tripping hazards and kinetic energy
hazards. Explosive materials such as the skip containing paraffin under the reactor also
presented a hazard.
Human Factors:
Several human factor issues gave rise to the occurrence of this accident. No formal risk
assessment had been carried out prior to commencing work. Therefore there was a lack
of understanding and an underestimation of the risks involved in the work. The lack of
risk assessment can partially be attributed to the lack of supervision at both the work planning stages and the execution of the task.
Additionally, poor work standards and inadequate checking caused failure of the purge
and a lack of knowledge resulted in the failure to repeat the purge process. A
combination of job factors and improper motivation to move on to next stage also
contributed to the technician’s failure to re-purge effectively. The technician’s failure to
identify and evaluate the risks associated with the grey specs of catalyst and sodium fines
is due to the lack of experience and knowledge of the hazards.
HFIT
Action Error (1)
No risk assessment of task
Main Situation Awareness
Assumption relating to task
Memory failure of formal procedures
Main Threats
Organisational safety culture
Supervision
Action Error (2)
Task Omission Failure to re-purge correctly from top to bottom
Main Situation Awareness
Assumption of Procedures: assumed correct action was being carried out
Main Threats
Procedures: procedure unknown
Training: need for emergency training not recognised, training Inadequate
for job task
Supervision: Only at planning stage/failed to assess risks effectively
Action Error (3)
Quality, Wrong action: Drained paraffin to skip instead of to class 150
pipe-work
Main Situation Awareness
Judgement/Decision making: Choose wrong/incorrect solution
Main Threats
Competence and Training: Inadequate
Supervision: Lack of supervision
4
Capability to Model
This incident scenario has a great potential for virtual reality simulation. Despite the job
task executed being job specific, the underlying principles and structure provide a solid
foundation to model accidents. The accident occurred during normal operations and
resulted through various human factors such as lack of knowledge and situation
awareness. The hazards within the individual’s surrounding working environment had
not been effectively identified and therefore no attempts had been made to reduce or
eliminate them. A number of the physical hazards identified can be manipulated within
the virtual reality simulation in order to achieve the desired preconditions of an accident.
The accident detailed above occurred during normal operations whereby the presence
flammable substances and an ignition source lead to a fire. Again, as with fire incident 1,
this accident involved an individual executing a work task. The consequences of this
accident had the potential to be major and affect more persons other than the operator.
Simulation of this accident can be manipulated to include more than one working person.
Through modeling of this accident a number of issues can be assessed. Namely, the
individual user’s situational awareness skills, assessment and identification of potential
risks and hazards within the surrounding work environment, and the effectiveness by
which these hazards and risks are reduced or eliminated. Furthermore, the simulation of
the fire will enable monitoring of the individual’s emergency and crisis management
skills. The effectiveness of existing emergency procedures can also be measured and
weaknesses in the procedures can be identified.
The environment in which this accident took place is manageable to simulate. The
environment consists primarily of fixed structures with only the main equipment being
used or operated and the chosen physical hazards requiring changing properties.
Additionally, the ability to simulate a fire in virtual reality is certainly within the
capabilities of the virtual reality system proposed.
Fire Incident 3
Investigation into fire on Catalyst Filter
Summary
The following incident took place on Saturday 8th August 2000 at 0130 hrs. Two
manufacturing technicians were in the process of opening the vent on the Loop 5
Dollinger filter when the hydrocarbon from the event released and caught fire, resulting
in a localized fire. It is thought that the source of ignition was static electricity caused by
using a polythene bag over the end of the drain connection whilst opening the drain valve
and by the friction created by different phases of the material passing out. In the course
of evacuating the scene one technician fell and badly caught his leg, as well as receiving
several less severe injuries. Both technicians suffered superficial burns.
5
Physical Hazards
The pipe-work around the Dollinger filter was congested, requiring the technicians to be
unnecessarily close to the filter during maintenance. The technicians were not wearing
the appropriate PPE for the filter cleaning operation. Furthermore, a fire and explosion
hazard existed. Venting hydrocarbon to atmosphere will produce a flammable
atmosphere as dispersion proceeds. Additionally, venting a mixture of hydrocarbon and
catalyst from the filter created a hazardous environment. Pressure release from valve and
the presence of catalyst were additional hazards. The filter/vent drain size, location and
orientation made the operation difficult. This was due to inadequate engineering and
maintenance. There was no means for raising the alarm thus one of the men would have
had to run to the control room, leaving the other alone to fight the fire.
Human Factors
The technicians thought that it would be best to fight the fire rather than raise the alarm,
as this would leave one technician alone fighting the fire thus making him more
vulnerable. This presented a physical hazard as well as a human factor issue of
inadequate emergency response procedures. Furthermore, the decision to stay and fight
the fire may have been based on inadequate or a lack of emergency training.
Additionally, it was indicated that poor working practices had become accepted on the
dollinger filters, reflecting the overall safety culture of this work area. The cleaning
procedure the technician was undertaking did not meet the company’s safety standards,
thus the tools and equipment used for the cleaning operation were inadequate. It is
thought that the polythene bag the technicians used to contain the vented catalyst created
a static discharge, which may have been a source of ignition for the fire. Moreover, it
was also highlighted that a lack of maintenance and regular cleaning of the filter may
have prevented the accident from occurring.
HFIT
Action Error
Task omission; Risk assessment not performed
Situation Awareness
Assumption: relating to procedures & equipment
Main Threats
Procedures: inadequate, cleaning procedures did not consider all factors of
risks or meet safety standards, Not properly defined in operating
instructions
Supervision: Inadequate reinforcement of standards.
Capability to Model
The above accident is feasible to model using the virtual reality system proposed.
Identification of hazardous chemical release is important within the chemical process
industries. Thereby, modeling situations and working environments where the release of
reactive chemicals and flammable substances is a likely occurrence will facilitate in the
training and improvement of identification and prevention of fire/explosive hazards.
Simulation of fire incidents occurring in this working environment give the opportunity
to observe participating workers and situational awareness.
6
7
CRUSHING INCIDENTS
Crushing Incident 1
Inshore Marine Accident
Time 09:30 hrs
Summary
On January 28th 2000, Gary and his colleague Robin secure the line boat, ‘Ross point’
and await pick up by the passenger boat, ‘Drumsand’. The two men wait outside the
safety rail on the starboard side of the ‘Ross Point’. The ‘Drumsand’ arrives and the men
board. Two webbing strops on the ‘Drumsand’ are to be transferred on to the ‘Ross
point’ for the next morning. As the ‘Drumsand’ maneuvers away from the ‘Ross point’
one of the passangers on the ‘Drumsand’ notices that the webbing strops are still on the
‘Drumsand’. The passenger throws the strops on to the ‘Ross point’, however, they land
on the safety rail. Gary decides to jump across on to the ‘Ross point’ to properly stow the
strops. The ’Drumsand’ maneuvers 360 degrees to pick up Gary from the ‘Rosspoint’ for
the second time. Gary again stands outside the safety rail, but this time he moves further
up the bow of the ‘Ross point’ and attempts to jump on to the ‘Drumsand’. Gary is at this
time in line with the break of the ‘Ross point’s’ deckhouse and appears to have been
crushed by the flare of the ‘Drumsand’s’ bow against the deckhouse of the ‘Ross point’.
Physical Factors
Several physical factors largely contributed to this incident. The presence of westerly
winds at 25knots and a sea state of 1 – 1.5 meters with a short period of 2-3 seconds,
presented the physical hazard of the lively movement of the line boats. The relative
motion of the prevailing sea gave a vertical differential between the decks of the two
vessels up to four feet. A further hazard included the lack of non-slip paint on the deck
of the line boats and passenger boat.
Human Factors
An immediate cause of the above accident can be attributed to the perceived time
pressure on the employee. The perceived lack of time led the employee to position
himself at a dangerous part of the boat. A focused attention on boarding the passenger
boat caused the employee to fail to consider all the risks, resulting in poor decision
making and judgement. A channeled attention on properly stowing the strops was the
initiating cause leading the employee to re-board the ‘Ross point’. Several human factor
issues underlie this focused attention. These include the lack of communication between
the passengers and crew of the ‘Drumsand’ in relation to the rules and procedures of
passenger conduct, a poorly defined procedure relating to the roles and responsibilities of
the crew and passengers, a lack of supervision, and the overall organisational safety
culture.
HFIT
Action Error 1: Leaving boat whilst boat is maneuvering away from the shore
Rule Violation: Exceptional violation
Situation Awareness 1
Attention: too focused
Memory: failure to consider all factors
Judgement/decision making: Apply inappropriate solution
Threats 1
Organisational safety culture
Lack of supervision
Action Error 2
Quality: Action in wrong direction
Situation Awareness 2
Attention: too focused
Threats 2:
Work environment: weather conditions
Procedures: inadequate/not followed
Job factors: Time pressure
Capability to model
This incident presents physical hazards whereby the Sea State and relative motion of the
boats could be simulated. However, within the limitations of the virtual reality system as
it stands today, the capability to simulate an individual jumping between two boats during
extreme wind conditions appear to be infeasible. The VR system would require sensors
to record and monitor foot movement. Furthermore, it would be out of the VR systems
capabilities to simulate the crushing affect of the individual between the two boats. As an
alternative, it would seem possible to simulate the effect of an agent (person) within the
virtual world and model the crushing effect occurring to this virtual agent.
Crushing Incident 2
Serious Hand Injury
Summary
An employee, sustained a serious hand injury during the task of cleaning heat exchanger
floating heads. Three days prior to the accident risk assessments and work permits had
been completed allowing Robert to power jet wash the floating heads. Power jet washing
whilst the floating heads were hanging on a block and tackle was considered to be the
safest option in the risk assessment. However the decision was made to clean the floating
heads by hand rather than by power jet because they float heads were stacked together.
The floating heads were then lowered to the working platform the following day. One
floating head remained dome side up. A work permit was re-issued for the hand cleaning
of the floating heads the following day. The employee and a work colleague rig the
floating head and turn it bowl up, stablising it with scaffold boards. During cleaning of
the floating head the employee finds difficulty accessing the area closest to the kick plate.
The employee pushes the floating head to allow access, slipping he lands face forward in
to the floating head simultaneously trapping his fingers.
2
Physical Hazards
The floating heads present a physical hazard type of high kinetic energy. This hazard is
also present due to the insecure support of the floating head using scaffold boards. The
heavy and awkward size and weight of the floating heads meant that according to manual
handling procedures, Robert should not have attempted to manoeuvre the object alone.
Furthermore, the working area consisted of badly worn floor plates and presented slip
hazards. Poor housekeeping presented trip hazards in the form of congested and
restricted workspace and uneven floor plating.
Human Factors
The human factor issues that gave rise to this accident can be attributed to the failure to
reassess the risks associated with the change of job task. This can be accounted for by
the lack of supervision, not only at the planning stage of the work task, but also during
the work preparation and execution stages. The failure to comply with the COSHH
assessment regulations regarding appropriate protective clothing was in part due to the
inadequate assignment of workers to the task. The injured party failed to wear
appropriate ppe because he had not seen the COSHH assessment for pronature despite
this being available to him. The lack of training and competence to carry out the task is
also reflected in that employee had no previous experience of cleaning the floating heads.
The lack of compliance to manual handling procedures reflects the organisational safety
culture.
HFIT
Action Error 1
Quality: Wrong action on equipment. I.e. pushing the floating head
General violation: Employee aware of the manual handling procedures however
chose to disregard them
Situation Awareness 1
Memory: Failure to consider all factors of the action
Main Threats 1
Supervision: only at planning stage
Procedure: manual handling not complied to.
Capability to Model
The ability to model this incident is not feasible within the domain of this project. The
virtual reality simulator has the ability to monitor movement and orientation, however
does not currently have the capability to register force. Thus, an incident such as the one
detailed above, would require the object (in this case the floating head) to exist as a
control future on the simulator interface. Whilst this is possible to build and create, it
would prove expensive to build and is therefore out with the capabilities of this project.
3
Crushing Incident 3
Injury to workshop employee
Time 14:40
Two workshop employees were operating a press brake in the fabrication workshop,
pressing lengths of stainless steel sheets (0.7mm thick). During operating of the press
brake, Robert was helping John lift the steel into the press brake. Robert verbally
communicated to John that the steel was in the brake and all was clear for operating the
press. However, Robert had failed to remove his hand from the press brake and
subsequently trapped his fourth finger of his left hand in the spare blades of the press
brake. It is thought that failure to remove the ‘spare’ blades from the equipment and the
shut down of the light guard system contributed to the incident. The crush effect lead to
the amputation of his finger.
Prior to the incident the machinery had been out of operation due to the possibility of
faulty ‘light guard’ protection system. This system shuts off the press brake when the
light beam is broken. However, because the sheets of steel required manual lifting into
and out of the press brake the setting of the beam had been altered to 60mm whereby the
light beam becomes inoperative. Thus, if this had been set lower the press brake would
not have operated with the position of Robert’s hand.
Physical Hazards
The presence of sharp objects, such as the ‘spare’ blades were a key factor in the
accident. Furthermore, the non-operating light guard was particularly hazardous,
allowing objects to enter the press brake whilst in operation.
Human Factors
No formal risk assessment had been carried out for the task, so there was a failure to
consider all possible hazards. Although the men involved were experienced, there was
no formal training on the operating of the press brake. Furthermore, there was no formal
written procedure, thus, the workmen did not adhere to the PPE requirements of hearing
protection.. The workmen followed and informal procedure that had been presented to
the workforce five years prior. There were also no formal maintenance records for the
machine.
HFIT:
Action Error (1)
Communication: Incorrect information communicated
Situation Awareness
Detection & perception; Tactile misperception
Attention:
Distracted: in-between jobs, waiting for a welder
Main Threats
Job Factors: Inadequate assignment of people to tasks
Action error (2)
Omission: Task not performed (failure to remove spare blades)
4
Situation Awareness:
Memory: Failure to consider all factors
Main threat
Procedure: No formal procedure
Work preparation; No risk assessment
Supervision: Failure to reinforce safety procedures/ lack of supervision
Competence & Training: No formal training given
Capability to Model
It would certainly be feasible to model an accident such as the one detailed above.
However, similar to crushing incidents 1 and 2 modelling of this accident is out with the
immediate limitations of the virtual reality simulator. It would be feasible to simulate the
consequences of a user’s actions, crushing another a virtual reality agent occupying the
same virtual world. However, it would not be feasible to simulate crushing accidents to
the user themselves. The Virtual reality system can not simulate and has no means of
measuring force.
5
FIRE INCIDENTS
Fire Incident 1
Lab Technician Splashed with Concentrated Acid
Time: 11:45am
Summary
Following analysis of Polyethylene Production catalyst sample, it is common practice to
clean all glassware to remove any traces of catalyst residue before the equipment can be
used again. As part of this procedure a solution of 50:50 concentrated nitric acid and
water is used. This incident occurred when a fresh solution of acid and water was being
prepared. The agency technician was about to add the required volume of water to a
screw top bottle marked “50:50 nitric acid/water” when he noticed that the wash bottle of
water was empty. He walked to the UHQ water purifier and picked up an adjacent wash
bottle. He used this to make up the volume of “water”. He then added concentrated
nitric acid from a Winchester to the screw top bottle and mixed. He then placed the
screw top bottle in the cupboard under the fume cupboard and began to tidy up. He then
noticed that the wash bottle he had been using was “IPA” and not UHQ water and
realised that a mistake had been made. As he recovered the screw top bottle from the
cupboard, he noticed a brown colour and evidence of bubbling. When he picked up the
bottle the cap blew off. He “started” back, but noticed no movement from the liquid in
the bottle. He then lifted the bottle in order to put it in the fume cupboard to segregate it
from the other chemicals. At this point the liquid released from the bottle, showering his
face and body.
Physical Hazards
The labels were small and unclear on the bottles, presenting a potential hazard of mixing
the wrong chemical solutions. In addition, the screw cap bottles were unsuitable for the
preparation of the acid solution. A flask with cooling should have been used. A potential
energy hazard was present as pressure from the incorrect mixing of concentrated nitric
acid and IPA solution caused the cap to blow off. The presence of other hazardous
substances and chemicals within the laboratory present flammable and toxic hazards.
Human Factors
Particular care and attention was required due to the smallness of the bottle labels. In this
incident the technician had too focused attention on completing the job. Additional to
these factors was that there was no official procedure for cleaning the equipment and
COSHH assessment did not exist for the equipment. Additionally no training had been
given specifically on the preparation of acid solution. There was an assumption that all
agents would beware of the necessary precautions for this procedure. Poor work
standards and housekeeping of the chemicals, i.e. no segregation of wash bottles, is
thought to have contributed to this incident. As there were no official procedures for the
preparation of the acid solution, then it would seem that a review of the appropriate PPE
would be required. Similarly it was recommended that roles and responsibilities of the
agents should be defined more clearly.
HFIT
Action Error
QUALITY: correct act on wrong equipment. Mixing wrong chemicals
Situation Awareness
ATTENTION: Lack of attention to the labeling of bottles
Too focused on getting job done
VISUAL MISPERCEPTION: Mistaken label of solution bottle
Main Threat
WORK ENVIRONMENT: poor housekeeping/untidiness. Chemicals not
stored properly. Solutions not stored separately/to order
SUPERVISION: lack of supervision during task/inadequate assessment of
risk
PROCEDURES: No formal procedure for task
Capability to model
This incident involves an individual technician working alone in a potentially hazardous
environment. The incident would be particularly useful to model in that the environment
lends itself well to the virtual reality system. Through the creation of this environment
whereby information is ambiguous, labelling of chemicals are unclear, poor
housekeeping standards and inadequate supervision, the simulation of accidents would be
feasible.
It would appear feasible to simulate this environment and to manipulate the job task of
the user to obtain the desired outcome. Simulation of this environment type offers
managers and industries to observe and assess how effectively workers undertake a series
of job specific or task generic activities. The information available to the user for
completing the task successfully, i.e. without injury, loss or damage, could be
manipulated. The modelling of a task such as the mixing of solutions would allow the
end user to assess how the individual prepares the working environment for the task.
Assessing how the individual evaluates risks and potential hazards and how successfully
hazards are eliminated. Furthermore, a scenario as described above would enable
manipulation of the accessibility of this information to the participating individual. Thus,
providing greater insight into the relationship between physical hazards and human
factors.
Through the manipulation of physical hazards human factor issues can be assessed and
addressed. Not only would an understanding be gained in relation to the properties
underlying physical hazards, but also an understanding of how humans make use and
process incoming information. Various distracters and irrelevant information can be
simulated to create pressure on the participant’s cognitive capabilities, thus providing a
greater accuracy in responses during high-pressure situations. Chemical reactions can
also be simulated to varying degrees enabling the participant to interact ‘feeling’ the
2
consequences of their actions. Simultaneously allowing any attempts of recovery to be
assessed.
The above incident offers the opportunity to assess individual and group interactions with
physical hazards, monitoring and assessing the relationship between the two. Therefore,
the effectiveness of both individual and group decision processes and communication
skills can be measured. Furthermore, it enables the assessment of existing procedures
and instructions on both job specific generic tasks. The clarity of procedural information
given to the participating individual(s) can be manipulated in order to identify any
weaknesses in existing procedures.
Fire Incident 2
Fire during recatalysation
Summary
A fire was caused during the operation of reinstating pipe-work in the closing stages of a
reactor recatalysation. Following a release of process material while a blank was being
removed the process material caused a fire in a skip lying under the reactor. John
McIntosh was in a kneeling position below the reactor as he was removing the hydrogen
nozzle on the reactor. The skip below him was nearly full of paraffin. As the blank was
removed black wet sludge was present on it. He turned away from it, and on hearing a
gurgling noise he turned back. Liquid was ejecting from the nozzle under pressure. On
turning away again, some liquid caught him on the shoulder. The liquid contained
sodium fines. Pouring down into the skip containing paraffin beneath the sodium fines
acted as a source of ignition causing the skip to catch fire.
The technician involved suffered a burn to his arm but there was obvious potential for
more serious consequences.
Physical Hazards:
Several Flammable hazards were present during this job task. A source of ignition was
present due to sodium fines from catalyst being released into atmosphere. A hydrogen
trailer next to the area of the incident was also a physical hazard. During recatalysation
the Reactor was at 105°C which is greatly above its flash point of 69°C. Furthermore,
the storage of drums meant that some drums might have had dry catalyst present due to
insufficient paraffin, thus presenting a hazard if opened to the atmosphere.
In addition to the presence of flammable hazards there was also the potential for energy
release. This is evident from the potassium and sodium fines ejecting from the nozzle.
Additional energy hazards were reduced by the technician draining to the skip instead of
draining to a lower pressure class pipe-work. There was also the possibility of back-flow
occurring when blank was removed had the drain-line to the tank not been shut off.
Further hazards included poor housekeeping and congested areas with sharp and
protruding objects. Scaffold poles and congestion around overhead piping, the build up
3
of lagging/cladding against pipe-work presented tripping hazards and kinetic energy
hazards. Flammable materials such as the paraffin contained in the skip under the reactor
also presented a hazard.
Human Factors:
Several human factor issues gave rise to the occurrence of this accident. No formal risk
assessment had been carried out prior to commencing work. Therefore there was a lack
of understanding and an underestimation of the risks involved in the work. The lack of
risk assessment can partially be attributed to the lack of supervision at both the work planning stages and the execution of the task.
Additionally, poor work standards and inadequate checking caused failure of the purge
and a lack of knowledge resulted in the failure to repeat the purge process. A
combination of job factors and improper motivation to move on to next stage also
contributed to the technician’s failure to re-purge effectively. The technician’s failure to
identify and evaluate the risks associated with the grey specks of catalyst and sodium
fines is due to the lack of experience and knowledge of the hazards.
HFIT
Action Error (1)
No risk assessment of task
Main Situation Awareness
Assumption relating to task
Memory failure of formal procedures
Main Threats
Organisational safety culture
Supervision
Action Error (2)
Task Omission Failure to re-purge correctly from top to bottom
Main Situation Awareness
Assumption of Procedures: assumed correct action was being carried out
Main Threats
Procedures: procedure unknown
Training: need for emergency training not recognised, training Inadequate
for job task
Supervision: Only at planning stage/failed to assess risks effectively
Action Error (3)
Quality, Wrong action: Drained paraffin to skip instead of to class 150
pipe-work
Main Situation Awareness
Judgement/Decision making: Choose wrong/incorrect solution
Main Threats
Competence and Training: Inadequate
Supervision: Lack of supervision
4
Capability to Model
This incident scenario has a great potential for virtual reality simulation. Despite the job
task executed being job specific, the underlying principles and structure provide a solid
foundation to model accidents. The accident occurred during normal operations and
resulted through various human factors such as lack of knowledge and situation
awareness. The hazards within the individual’s surrounding working environment had
not been effectively identified and therefore no attempts had been made to reduce or
eliminate them. A number of the physical hazards identified can be manipulated within
the virtual reality simulation in order to achieve the desired preconditions of an accident.
The accident detailed above occurred during normal operations whereby the presence
flammable substances and an ignition source lead to a fire. Again, as with fire incident 1,
this accident involved an individual executing a work task. The consequences of this
accident had the potential to be major and affect more persons other than the operator.
Simulation of this accident can be manipulated to include more than one working person.
Through modeling of this accident a number of issues can be assessed. Namely, the
individual user’s situational awareness skills, assessment and identification of potential
risks and hazards within the surrounding work environment, and the effectiveness by
which these hazards and risks are reduced or eliminated. Furthermore, the simulation of
the fire will enable monitoring of the individual’s emergency and crisis management
skills. The effectiveness of existing emergency procedures can also be measured and
weaknesses in the procedures can be identified.
The environment in which this accident took place is manageable to simulate. The
environment consists primarily of fixed structures with only the main equipment being
used or operated and the chosen physical hazards requiring changing properties.
Additionally, the ability to simulate a fire in virtual reality is certainly within the
capabilities of the virtual reality system proposed.
Fire Incident 3
Investigation into fire on Catalyst Filter
Summary
Two manufacturing technicians were in the process of opening the vent on the Loop 5
Dollinger filter when the hydrocarbon from the event released and caught fire, resulting
in a localized fire. It is thought that the source of ignition was static electricity caused by
using a polythene bag over the end of the drain connection whilst opening the drain valve
and by the friction created by different phases of the material passing out. In the course
of evacuating the scene one technician fell and badly caught his leg, as well as receiving
several less severe injuries. Both technicians suffered superficial burns.
Physical Hazards
The pipe-work around the Dollinger filter was congested, requiring the technicians to be
unnecessarily close to the filter during maintenance. The technicians were not wearing
the appropriate PPE for the filter cleaning operation. Furthermore, a fire and explosion
5
hazard existed. Venting hydrocarbon to atmosphere will produce a flammable
atmosphere as dispersion proceeds. Additionally, venting a mixture of hydrocarbon and
catalyst from the filter created a hazardous environment. Pressure release from valve and
the presence of catalyst were additional hazards. The filter/vent drain size, location and
orientation made the operation difficult. This was due to inadequate engineering and
maintenance. There was no means for raising the alarm thus one of the men would have
had to run to the control room, leaving the other alone to fight the fire.
Human Factors
The technicians thought that it would be best to fight the fire rather than raise the alarm,
as this would leave one technician alone fighting the fire thus making him more
vulnerable. This presented a physical hazard as well as a human factor issue of
inadequate emergency response procedures. Furthermore, the decision to stay and fight
the fire may have been based on inadequate or a lack of emergency training.
Additionally, it was indicated that poor working practices had become accepted on the
dollinger filters, reflecting the overall safety culture of this work area. The cleaning
procedure the technician was undertaking did not meet the company’s safety standards,
thus the tools and equipment used for the cleaning operation were inadequate. It is
thought that the polythene bag the technicians used to contain the vented catalyst created
a static discharge, which may have been a source of ignition for the fire. Moreover, it
was also highlighted that a lack of maintenance and regular cleaning of the filter may
have prevented the accident from occurring.
HFIT
Action Error
Task omission; Risk assessment not performed
Situation Awareness
Assumption: relating to procedures & equipment
Main Threats
Procedures: inadequate, cleaning procedures did not consider all factors of
risks or meet safety standards, Not properly defined in operating
instructions
Supervision: Inadequate reinforcement of standards.
Capability to Model
The above accident is feasible to model using the virtual reality system proposed.
Identification of hazardous chemical release is important within the chemical process
industries. Thereby, modeling situations and working environments where the release of
reactive chemicals and flammable substances is a likely occurrence will facilitate in the
training and improvement of identification and prevention of fire/explosive hazards.
Simulation of fire incidents occurring in this working environment give the opportunity
to observe participating workers and situational awareness.
6