an inherent safety based incident investigation methodology … · auxiliary ventilation system:...

AN INHERENT SAFETY BASED AN INHERENT SAFETY BASED INCIDENT INVESTIGATION INCIDENT INVESTIGATION

METHODOLOGYMETHODOLOGY

Attiq Goraya, Dalhousie UniversityAttiq Goraya, Dalhousie UniversityPaul Amyotte, Dalhousie UniversityPaul Amyotte, Dalhousie UniversityFaisal Khan, Memorial UniversityFaisal Khan, Memorial University

2005 Canadian Chemical 2005 Canadian Chemical Engineering ConferenceEngineering Conference

OUTLINEOUTLINE

Introduction Introduction Incident InvestigationIncident InvestigationInherent SafetyInherent SafetyPrinciples of Inherent Safety Principles of Inherent Safety Incident Investigation MethodologyIncident Investigation MethodologyCase Study: Westray Mine ExplosionCase Study: Westray Mine ExplosionConcluding RemarksConcluding Remarks

INTRODUCTIONINTRODUCTION

Scope: Development of a methodology or Scope: Development of a methodology or protocolprotocol–– For incident investigationFor incident investigation–– Explicitly incorporating principles of inherent safety Explicitly incorporating principles of inherent safety

via guidewords and checklistvia guidewords and checklist

Motivation:Motivation:–– Inherent safety focus within research groupInherent safety focus within research group–– Also emphasis on use of case studies for validationAlso emphasis on use of case studies for validation–– In case of Westray, due to its extreme nature, use of In case of Westray, due to its extreme nature, use of

case study for methodology developmentcase study for methodology development

INCIDENT INVESTIGATIONINCIDENT INVESTIGATION

The process by which underlying (root) The process by which underlying (root) causes of an incident are uncovered and causes of an incident are uncovered and steps are taken to prevent recurrencesteps are taken to prevent recurrence

A wellA well--recognized and vital part of Process recognized and vital part of Process Safety Management (PSM)Safety Management (PSM)

Element 9 in CSChE PSM Guide (based Element 9 in CSChE PSM Guide (based on CCPS approach)on CCPS approach)

INHERENT SAFETYINHERENT SAFETY

Inherent, Engineered, Procedural SafetyInherent, Engineered, Procedural Safety

Elimination, Minimization, Substitution, Elimination, Minimization, Substitution, Moderation, SimplificationModeration, Simplification

INCIDENT INVESTIGATION INCIDENT INVESTIGATION METHODOLOGYMETHODOLOGY

Combination ofCombination of–– Syncrude Canada protocolSyncrude Canada protocol–– CCPS guidelinesCCPS guidelines–– Bird and Germain domino loss causation modelBird and Germain domino loss causation model–– Kletz’s layered modelKletz’s layered model

StagesStages–– Preparation and initial responsePreparation and initial response–– Data gatheringData gathering–– Data analysisData analysis–– Recommendation reporting, implementation and Recommendation reporting, implementation and

followfollow--up up


Integrated approach to loss managementIntegrated approach to loss management–– PeoplePeople–– Property (assets)Property (assets)–– Production (business interruption)Production (business interruption)–– EnvironmentEnvironmentIncorporation of inherent safetyIncorporation of inherent safety–– GuidewordsGuidewords–– ChecklistChecklist


..

Team Planning

Incident

Loss

Notification to Activate Team

On-Site Investigation

Identification of Immediate Causes

Identification of Basic Causes

Lack of Management Control Factors

Recommendations

Implement Recommendations

Follow-Up

Inherent SafetyGuidewords

Inherent Safety Checklist

Inherent SafetyGuidewords

• People• Property• Production• Environment

• Position• People• Parts• Paper

• Immediate/Technical

• Avoid Hazards• Improve

Management System

CASE STUDY:CASE STUDY:WESTRAY MINE EXPLOSIONWESTRAY MINE EXPLOSION

WESTRAYWESTRAYCoal mining has been an integral part of Coal mining has been an integral part of Pictou County (Nova Scotia) history since Pictou County (Nova Scotia) history since the first commercial mine opened in the first commercial mine opened in Stellarton in 1807, to the closing of the Stellarton in 1807, to the closing of the Drummond mine in Westville in 1974. On Drummond mine in Westville in 1974. On September 11, 1991 Westray opened a September 11, 1991 Westray opened a new mine in Plymouth.new mine in Plymouth.At 5:20 am on May 9, 1992 after only eight At 5:20 am on May 9, 1992 after only eight months of operation, an explosion ripped months of operation, an explosion ripped through the mine killing 26 men who were through the mine killing 26 men who were underground at the time.underground at the time.

INCIDENTINCIDENT

There was an explosion in There was an explosion in the Westray mine on the the Westray mine on the morning of May 9, 1992.morning of May 9, 1992.

FuelFuelOxidant Oxidant Ignition SourceIgnition Source

..

Fire Triangle

Ignition Source

Fuel

Oxidant

LOSSLOSS

Losses resulting from Westray explosion Losses resulting from Westray explosion include:include:Deaths of 26 minersDeaths of 26 minersDestruction of mining equipment and the Destruction of mining equipment and the mine itselfmine itselfBankruptcy of the parent companyBankruptcy of the parent companyDefault of millions of dollars in government Default of millions of dollars in government loansloans

ONON--SITE INVESTIGATIONSITE INVESTIGATION

The objectives of onThe objectives of on--site activities are to gather site activities are to gather information used for determining root causes.information used for determining root causes.Position, People, Parts, Paper Position, People, Parts, Paper –– IS GuidewordsIS Guidewords

MethaneMethane: Methane layering provided a rich : Methane layering provided a rich source of fuel for the explosion in the presence source of fuel for the explosion in the presence of an ignition source. of an ignition source. Coal DustCoal Dust: According to Richard (1997) coal : According to Richard (1997) coal dust at least ankledust at least ankle--deep accumulated on many deep accumulated on many of the underground roadways, making foot travel of the underground roadways, making foot travel difficult.difficult.

ONON--SITE INVESTIGATIONSITE INVESTIGATION

NonNon--Flameproof vehiclesFlameproof vehicles: According to Richard : According to Richard (1997) there were instances in which workers, (1997) there were instances in which workers, supervisors and management employed nonsupervisors and management employed non--flameproof vehicles underground.flameproof vehicles underground.Fuel StorageFuel Storage: Fuel for mining machinery was : Fuel for mining machinery was improperly stored underground (Richard, 1997).improperly stored underground (Richard, 1997).Auxiliary Ventilation SystemAuxiliary Ventilation System: Westray used : Westray used auxiliary fans in the exhaust mode (Richard, auxiliary fans in the exhaust mode (Richard, 1997).1997).

IMMEDIATE CAUSESIMMEDIATE CAUSES

Immediate causes are divided into two broad categories:Immediate causes are divided into two broad categories:Substandard PracticesSubstandard Practices

Continuation of mining in spite of inoperable Continuation of mining in spite of inoperable methane detection devicesmethane detection devices

SimplifySimplifyInadequate rock dustingInadequate rock dustingModerateModerate

Improper use of ventilation system; e.g., reImproper use of ventilation system; e.g., re--routing routing without provision for minerswithout provision for miners

SubstituteSubstitute

Poor housekeeping with respect to cleanPoor housekeeping with respect to clean--up and up and removal of coal dustremoval of coal dust

Storing fuel and reStoring fuel and re--fuelling vehicles in nonfuelling vehicles in non--flameflame--proof areas undergroundproof areas underground

MinimizeMinimize

Substandard PracticeSubstandard PracticeGuideword/Guideword/ChecklistChecklist

IMMEDIATE CAUSESIMMEDIATE CAUSES

Substandard ConditionsSubstandard Conditions

Inadequate system to warn of high methane Inadequate system to warn of high methane concentration in the mine atmosphereconcentration in the mine atmosphere

SimplifySimplify

High concentration of airborne coal dustHigh concentration of airborne coal dustModerateModerate

Inadequate ventilation design and capacityInadequate ventilation design and capacitySubstituteSubstitute

High methane concentrationsHigh methane concentrationsThick layers of coal dust on the mine floor, having Thick layers of coal dust on the mine floor, having

an unacceptably high level of combustible matteran unacceptably high level of combustible matter

MinimizeMinimize

Substandard ConditionSubstandard ConditionGuideword/Guideword/ChecklistChecklist

BASIC CAUSESBASIC CAUSES

Basic causes are divided into two broad categories:Basic causes are divided into two broad categories:Personal FactorsPersonal Factors

Improper motivation by which production Improper motivation by which production proceeded at the expense of safetyproceeded at the expense of safety

Psychological stress caused by fear of reprisal for Psychological stress caused by fear of reprisal for reporting safety concernsreporting safety concerns

SimplifySimplify

Lack of knowledge of safe underground work Lack of knowledge of safe underground work practicespractices

ModerateModerate

Lack of mining experience of personnel working in Lack of mining experience of personnel working in the minethe mine


Physiological stress caused by methane Physiological stress caused by methane overexposure and fatigue due to 12overexposure and fatigue due to 12--hour shifthour shift

MinimizeMinimize

Personal FactorPersonal FactorGuideword/Guideword/ChecklistChecklist

BASIC CAUSESBASIC CAUSES

Job FactorsJob Factors

Inadequate leadership in terms of assignment of Inadequate leadership in terms of assignment of responsibilityresponsibility

SimplifySimplify

Lack of safe work practices and proceduresLack of safe work practices and proceduresInadequate purchasing and maintenance of rock Inadequate purchasing and maintenance of rock

dust inventorydust inventory

ModerateModerate

Inadequate engineering during mine ventilation Inadequate engineering during mine ventilation design and planningdesign and planning


Inadequate followInadequate follow--through on recommendations through on recommendations from mine inspectorate personnelfrom mine inspectorate personnel

MinimizeMinimize

Job FactorJob FactorGuideword/Guideword/ChecklistChecklist

LACK OF MANAGEMENT LACK OF MANAGEMENT CONTROL FACTORSCONTROL FACTORS

Inadequate Program Elements:Inadequate Program Elements:(adopted from Amyotte and Oehmen, 2002)(adopted from Amyotte and Oehmen, 2002)

–– Management commitment and accountability to safety Management commitment and accountability to safety matters matters

–– Incident investigationIncident investigation–– Training (orientation, taskTraining (orientation, task--related, etc.)related, etc.)–– Task definitions and safe work practices and Task definitions and safe work practices and

proceduresprocedures–– Workplace inspections and more detailed hazard Workplace inspections and more detailed hazard

identification methodologiesidentification methodologies–– Program evaluation and auditProgram evaluation and audit


Inadequate Program Standards:Inadequate Program Standards:(adopted from Amyotte and Oehmen, 2002)(adopted from Amyotte and Oehmen, 2002)

–– Management’s concern toward safety mattersManagement’s concern toward safety matters–– FollowFollow--through on inspections for substandard through on inspections for substandard

practices and conditionspractices and conditions–– Action on hazard reports submitted by employeesAction on hazard reports submitted by employees–– Job instructions for employeesJob instructions for employees–– Equipment maintenanceEquipment maintenance–– Scheduling of management/employee meetings to Scheduling of management/employee meetings to

discuss safety concernsdiscuss safety concerns


Inadequate Compliance with Standards:Inadequate Compliance with Standards:(adopted from Amyotte and Oehmen, 2002)(adopted from Amyotte and Oehmen, 2002)

–– Poor correlation between management actions and Poor correlation between management actions and official company policy concerning the relationship official company policy concerning the relationship between safety and productionbetween safety and production

–– Compliance to industry practice and legislated Compliance to industry practice and legislated standards concerning numerous aspects of coal standards concerning numerous aspects of coal mining: methane concentrations, rock dusting, control mining: methane concentrations, rock dusting, control of ignition sources underground, etc.of ignition sources underground, etc.

RECOMMENDATIONSRECOMMENDATIONS

Immediate Technical Recommendations:Immediate Technical Recommendations:Use of IS GuidewordsUse of IS Guidewords

–– Removal of coal dust accumulations would Removal of coal dust accumulations would have immediate benefits.have immediate benefits.

–– Relocation of the fuel and the vehicles to the Relocation of the fuel and the vehicles to the surface would have an immediate positive surface would have an immediate positive effect.effect.


Recommendations to Avoid the Hazard:Recommendations to Avoid the Hazard:Use of Principle MinimizeUse of Principle Minimize–– MethaneMethane

DegasificationDegasificationAdequate ventilation design and systemAdequate ventilation design and system

–– Coal DustCoal Dust–– Length of shiftLength of shift–– NonNon--flameproof equipment (ignition sources)flameproof equipment (ignition sources)–– Storing fuel undergroundStoring fuel underground


Use of Principle SubstituteUse of Principle Substitute

–– Auxiliary ventilation system:Auxiliary ventilation system:forcing, rather than exhaust, system for adequate forcing, rather than exhaust, system for adequate airflow to clear methane from the working face of the airflow to clear methane from the working face of the minemine

–– Main ventilation fan:Main ventilation fan:alternate design and location so as not to pick up dust alternate design and location so as not to pick up dust and other debris from the coal return conveyor beltand other debris from the coal return conveyor belt


Use of Principle ModerateUse of Principle Moderate

–– Purchase of adequate rock dust inventoryPurchase of adequate rock dust inventory–– Implementation of rock dusting programImplementation of rock dusting program–– Roadway consolidationRoadway consolidation


Use of Principle SimplifyUse of Principle Simplify–– Installation of a reliable, robust mine air Installation of a reliable, robust mine air

monitoring systemmonitoring system


Recommendations to Improve the Recommendations to Improve the Management System:Management System:SYSTEM + ATTITUDESYSTEM + ATTITUDE–– Program elements such as hiring procedures, Program elements such as hiring procedures,

training, safe work procedures, and hazard training, safe work procedures, and hazard identificationidentification

–– Program standards such as appropriate Program standards such as appropriate followfollow--through on inspection resultsthrough on inspection results

–– Compliance issues relating to both internal Compliance issues relating to both internal and external standards.and external standards.

CONCLUDING REMARKSCONCLUDING REMARKSA methodology has been developed to enable the A methodology has been developed to enable the explicit use of inherent safety principles (minimize, explicit use of inherent safety principles (minimize, substitute, moderate and simplify) in an incident substitute, moderate and simplify) in an incident investigation protocol. investigation protocol.

Application of the methodology to the Westray coal Application of the methodology to the Westray coal mine explosion has demonstrated how a lack of mine explosion has demonstrated how a lack of inherent safety considerations played a key role in the inherent safety considerations played a key role in the incident occurrence and severity.incident occurrence and severity.

What can the CPI learn from a What can the CPI learn from a coal mine explosion?coal mine explosion?

Westray was a process safety incident, not simply OH&S.Westray was a process safety incident, not simply OH&S.“Worker safety not my responsibility, says ex“Worker safety not my responsibility, says ex--Westray engineer” Westray engineer” (newspaper headline) is not an acceptable attitude.(newspaper headline) is not an acceptable attitude.Management system deficiencies were at the core.Management system deficiencies were at the core.“Lessons from Longford” by Andrew Hopkins (CCH Australia “Lessons from Longford” by Andrew Hopkins (CCH Australia Limited, 2000) relates essentially the same story by drawing Limited, 2000) relates essentially the same story by drawing parallels between a coal mine explosion and a gas plant parallels between a coal mine explosion and a gas plant explosion in Australia.explosion in Australia.In Nova Scotia, the lessons learned have led to a new OH&S Act In Nova Scotia, the lessons learned have led to a new OH&S Act which is underpinned by the Internal Responsibility System.which is underpinned by the Internal Responsibility System.In Canada, the lessons learned have led to changes in the In Canada, the lessons learned have led to changes in the Criminal Code of Canada (Bill CCriminal Code of Canada (Bill C--45) regarding criminal 45) regarding criminal negligence charges for inappropriate corporate level behaviour.negligence charges for inappropriate corporate level behaviour.When educating ChE students at Dalhousie University, it is When educating ChE students at Dalhousie University, it is important to consider Westray as well as Flixborough, Bhopal,…important to consider Westray as well as Flixborough, Bhopal,…

an inherent safety based incident investigation methodology … · auxiliary ventilation system:...

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