1 Development and Application of Hazard Analysis & Risk Assessment Models for the Korea Railway International Railway Safety Conference 2008 Denver, Colorado October 5-10, 2008 Chan-Woo Park, Jong-Bae Wang, Sang-Log Kwak, Don-Bum Choi

2 About KRRI : Korea Railroad Research Institute

3 Founded in 1996, financed by Korean government 254 individuals works for railway R&D division and national project division Key research area - Rolling stock, track & civil engineering, signaling & electrical engineering, railway policy & operation National projects High speed train development, upgrading conventional railway, design urban rail transit system, transportation technology, trans-Korean railway construction National safety R&D program from 2004 Homepage : About KRRI : Korea Railroad Research Institute

4 IIntroduction Contents II Risk Assessment Procedure III Hazard Identification IVRisk Assessment Model Development VConclusion

5 Background 1. Introduction Cyclic occurrence of major train accidents Cyclic occurrence of major train accidents : Daegu, subway train fire accident, 191 fatalities : Daegu, subway train fire accident, 191 fatalities : Gupo, train derailment accident, 78 fatalities : Gupo, train derailment accident, 78 fatalities : Kyongsan, train collisions, 54 fatalities : Kyongsan, train collisions, 54 fatalities Environmental changes in Korea - KTX (Korea Train eXpress) operation at Structural reform of railroad industries - Electrification of conventional lines - Preparation of TCR & TSR “Railway Safety Act” announced in Focused on the risk-based safety management - Focused on the risk-based safety management - Nation-wide railroad safety program & safety regulations - Hazard analysis, risk assessment & control

6 1. Introduction Research Objective Since Oct. 2005, KRRI has developed the common hazard analysis & risk assessment models for the Korea Railway. - Developing procedure of the risk models - Application of the developed model to the Korea railway. Research Objective is to introduce

7 Construction 2. Risk Assessment Procedure Common Approach Risk Management Railway System Techniques/ Technology Context Organization Operation Concept Design Exploitation Demolition SystemDefinition RiskManagement RiskAnalysis RiskDefinition RiskEvaluation RiskReduction Modification Maintenance System Life Cycle Risk Management Process

8 2. Risk Assessment Procedure National Railway Risk Management System Architecture

9 2. Risk Assessment Procedure Railway Risk Assessment Procedure Railway Accident Appearance Scenarios Railway Accident Appearance Scenarios FTA Model Railway Accident Progress Scenarios Railway Accident Progress Scenarios ETA Model Casual Analysis Consequence Analysis Hazard Identification Defining the Initiating Hazardous Events Development of Accident Scenarios Risk Evaluation & Reduction HazardousEvents

10 3. Hazard Identification using Railway Accident Scenarios Hazard Identification Procedure System definition and boundary setting Identifying hazardous events/ hazards/ barriers Developing accident appearance scenarios Developing accident progress scenarios Accident scenario management Setting up objective of hazard identification & its boundary Including the definition of measures which stops the increases of accident Defining relationships among hazardous events, hazards and barriers. Considering the relevant key influential factors. Drawing up hazard log.

11 3. Hazard Identification using Railway Accident Scenarios System & Boundary Definition Typical railway system configuration proposed in SAMRAIL project According to the accident classification of “Railway Accident Report Regulation”, The scenarios were divided into the five main areas 1) Train collision accident, 2) Train derailment accident, 3) Train fire accident, 4) Level crossing accident, 5) Railway (traffic/safety) casualty accident.

12 3. Hazard Identification using Railway Accident Scenarios Hazardous Event Identification Railway CategoryHazardous Events Train Collision Misrouted train Mistaking in dealing points, point faults, mistaking in dealing blockage, interlocking system faults Faults in driving Signal/direction violation, signal fault, mistaking in dealing braking system, braking system fault, over speeding Abnormal train Train separation, car rolling, train stop, backward moving Obstacles on the track External obstacles, parts from train/freight falling, infrastructure collapsing/obstruction Level Crossing Accident Being trapped in level crossing -Engine stop -Deviation of pathway -Gangway blocking -Lack of propulsion/braking -Violation entry -Limit interference -Breaking or detour Crossing during warning signal Breaking through or detour the barrier Railway Traffic Casualty Accident People struck/crushed Striking with train, Striking with objects Trip/Slip Trip/slip during train boarding/alighting, Trip/slip by train emergency braking/emergency start Falling Falling from train, Falling from platform during train boarding/alighting Caught/Dragged Caught in a train door, Caught between platform and train Others Electric Shock, Burn, Suffocation

13 3. Hazard Identification using Railway Accident Scenarios Railway Accident Appearance Scenario Built up by classifying properly the immediate causes and underlying causes. Immediate Causes: conditions which immediately cause hazardous events - Substandard Act: Substandard acts/behavior of who can cause hazardous events - Substandard Conditions: Physical conditions which can cause hazardous events Underlying Causes: reason or source of substandard acts and conditions - Human Management Factors - Technological Factors - External Factors

14 3. Hazard Identification using Railway Accident Scenarios Immediate Causes Underlying Causes Hazardous Event Railway Accident Appearance Scenario

15 3. Hazard Identification using Railway Accident Scenarios Railway Accident Scenario Critical factors influencing accident severity were identified in the accident progress scenarios” Example of the Accident Progress Scenarios

16 4. Risk Assessment Model Development Risk Measure Method Collective Risk (Average Number of FWI/year) =Frequency (Average frequency at which the scenario sequence occurs) XConsequences (the number of FWI/scenario sequence) 1 FWI = 1 fatality = 10 major injuries = 200 minor injuries Risk assessment model : the form of a cause and consequence analysis : using fault trees and event trees.

17 4. Risk Assessment Model Development Data Population Industry safety data: safety related incidents within industry database. Incidents recorded range from train collisions to passenger burns from coffee spills Many thousands of records are reviewed and classified Where data was not available, Use was made of: - Human error probability assessments : using a revised Human Error Assessment and Reduction Technique (HEART) - Safety expert judgment from in-house expertise within Korea railway. - Statistical methods including Monte Carlo simulation and Bayesian uncertainty distributions.

18 4. Risk Assessment Model Development Railway Risk Assessment & Information Management System (RAIMS) RAIMS Accident Analysis Accident Search Environment Analysis Hazard Analysis Damage Analysis Options Analysis Risk Analysis Event Tree Analysis Fault Tree Analysis Risk Evaluation Human Factor Analysis Safety Requirement Verification Management Safety Requirement Management Railway System Management Safety Requirement Change Management Requirement Traceability Management System Management User Management Code Management Classification Management

19 4. Risk Assessment Model Development Web-Based Accident Analysis Subsystem One purpose is to provide - Fundamental information for an in-depth risk assessment of railway accidents - Information on railway safety performance levels to both assessors and the public This system is composed of three modules 1) Accident input module. 2) Accident analysis & statistics module 3) Hazard management module. Environment AnalysisAccident AnalysisAccident Statistic Analysis Application running on the web

20 4. Risk Assessment Model Development Risk Analysis Subsystem Dedicated railway risk assessment software package - Event Tree Analysis, Fault Tree Analysis, Risk Evaluation, Human Factor Analysis The risk of the railway systems can be assessed by the ET/FT linking approach - Accident progress scenarios: defined as event trees, using an event tree editor. - Each branch of the accident progress sequences requires one or more supplementary fault trees, which can be developed by a fault tree editor. - Sum of the frequency of each sequence becomes the total frequency of the accident of concern. Windows-based application Event Tree Editor ViewET/FT Linking approachFault Tree Editor View

21 4. Risk Assessment Model Development Railway Human Reliability Analysis (R-HRA) Module Supporting the analysts in analyzing potential human errors Used under the railway risk assessment framework Computer software developed for aiding the R-HRA process. Revised R-HRA method supplementing the original R-HRA method developed by RSSB Providing a specific task analysis guideline and a classification of performance shaping factors (PSFs) General Information InputError Analysis & QuantificationReporting Results

22 4. Risk Assessment Model Development Railway Accident Risk Assessment Results Railway accident data until 2005 year on the main line of South Korea Train operation on the main line fully carried out by Korea Railroad Corp.. The total risk: 217 FWI per year The overall risk made up from different profiles of frequency and consequences. Railway casualty accident : Tend to consist of high frequency low consequence type events (slips, trips and falls) Train accidents : Tend to have a risk contribution from the low frequency high consequence type events : Increase the risk contribution for the hazardous events above the level seen in practice. Accident CategoryRisk (FWI) Train collision accident Train derailment accident Train fire accident14.1 Level crossing accident16.94 Railway traffic casualty accident Railway safety casualty accident Total

23 4. Risk Assessment Model Development Future Development of the Risk Model The model is being prepared currently and will include: Feasibility and uncertainty test in the results of the developed model Improved level of human factors modeling Use of more sophisticated statistical analysis techniques

24 5. Conclusion This study has proposed Developing procedure of the risk models for the Korea railway Application of their application to the Korea railway The developed model will provide a generic model of the safety risk on the Korea railway Which will Increase the industry’s knowledge of the risk from the operation and maintenance Allow the identification of areas of railway operation that need further risk controls Allow sensitivity analyses to be carried out to determine the risk reduction Allow cost benefit analysis of proposed changes

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