safety risk model: risk profile bulletin, version 8 - …€¦ · safety risk model: risk profile...

Issue 1.1 – published December 2014

Safety Risk Model: Risk Profile Bulletin, version 8.1

This report is issued by RSSB.

If you would like to give feedback on any of the material contained in this report,

please contact:

Marcus Dacre RSSB Block 2, Angel Square 1 Torrens Street London EC1V 1NY 020 3142 5476

[email protected]

© RAIL SAFETY AND STANDARDS BOARD LTD. 2014 ALL RIGHTS RESERVED This publication may be reproduced free of charge for research, private study or for internal circulation within an organisation. This is subject to it being reproduced and referenced accurately and not being used in a misleading context. The material must be acknowledged as the copyright of RSSB and the title of the publication specified accordingly. For any other use of the material please apply to RSSB for permission. This publication can be accessed via the RSSB Rail Risk Portal at www.safetyriskmodel.co.uk.

This is Issue 1.1 of the report. It details SRM version 8.1 and contains corrections to hours

worked by workforce groups and associated results.

mailto:[email protected]

http://www.safetyriskmodel.co.uk/

Version 8.1 - Issue 1.1 - December 2014 ii

This page has been intentionally left blank

Executive summary

Version 8.1 - Issue 1.1 - December 2014 iii

Executive summary

The Safety Risk Model (SRM) consists of a series of fault tree and event tree models

representing 131 hazardous events (HEs) that collectively define the overall level of risk on

the railway. It provides a structured representation of the causes and consequences of

potential accidents arising from railway operations and maintenance. The reported risk

estimates relate to the network-wide risk and they indicate the current level of residual risk (ie

the level of risk remaining with the current risk control measures in place and with their current

degree of effectiveness).

Version 8 of the safety risk model has an extended scope to previous versions as it merges

mainline railway risk (as previously modelled in SRMv7.5) and risk on yards, depots and

sidings (previously modelled in the YDS-SRM). The version 8 SRM update also included a

number of modelling changes, precursor additions/restructurings and a refresh of data up to

the data cut-off date of 30th September 2013.

Following the completion of SRM v8 changes were made to the classification of a number of

suicide and trespass events. This resulted from improved liaison and data sharing between

RSSB and British Transport Police, which allowed for more accurate distinctions between

suicide and non-suicide events. Due to the magnitude of these data changes the risk

associated with affected hazardous events was recalculated to create a further version of the

SRM, version 8.1, using the same model structures and data cut-off date as version 8.

It is the results of version 8.1 that are reported on in this document. The risk results are

presented as a measure of the absolute risk on the railway. As with any quantified risk

assessment, the results are estimates and are dependent on modelling assumptions and

limitations of the available data. Quantified risk estimates can be a useful input to the decision

making process, but should not be the only input, and their inherent uncertainty must be taken

into account.

Overall risk

SRMv8.1 estimates that the overall level of risk on the railway is 139.6 FWI/year1. This

represents a decrease of 4.8% from the figure of 146.6 FWI/year estimated by SRMv7.5 and

the YDS-SRM

Risk by person type

The overall figures for SRMv8.1 broken down by each exposed group are given in Table 1.

Table 1: SRMv8.1 results by person group

Person category Passenger Workforce Public Total

SRMv8.1 (FWI/yr) 58.4 33.4 47.8 139.6

Passenger risk is 58.4 FWI/year. The main contributors to this risk are slips trips and falls and

assaults.

1 Unless otherwise specified all risk figures quoted exclude the direct risk from suicide events. That is, injuries to the suicidal person are excluded whilst secondary injuries, eg, train driver and crew shock/trauma injuries are included.

Executive summary

Version 8.1 - Issue 1.1 - December 2014 iv

Workforce risk is 33.4 FWI/year. The main causes of workforce risk are slips, trips and falls

and contact with objects.

Risk to members of the public is 47.8 FWI/year. The majority of this risk is due to trespass.

Risk by accident type

Alternatively, the overall risk figure of 139.6 FWI/year can be broken down by accident type

as shown in Table 2.

Table 2: SRMv8.1 results by accident category

Accident category HET HEM HEN Total

SRMv8.1 (FWI/yr) 8.0 49.6 82.0 139.6

Where:

HET: Train accidents

HEM: Movement accidents

HEN: Non-movement accidents

Further information is available on the Rail Risk Portal: www.safetyriskmodel.co.uk.

Contents

Version 8.1 - Issue 1.1 - December 2014 v

Table of contents

Executive summary .................................................................................................... iii

Table of contents ........................................................................................................ v

List of tables ........................................................................................................... vii

List of figures .......................................................................................................... viii

1 Introduction ......................................................................................................... 1

2 SRM objectives and overview ............................................................................. 3

2.1 Objectives ..................................................................................................... 3

2.2 Overview ....................................................................................................... 4

2.3 Key assumptions and exclusions .................................................................. 5

3 SRM update strategy .......................................................................................... 6

3.1 Overview of the SRMv8 update ..................................................................... 6

3.2 Update to SRM version 8.1 ........................................................................... 7

4 Total risk on the railway ...................................................................................... 9

4.1 Overall profile ................................................................................................ 9

4.1.1 Mainline profile ..................................................................................... 12

4.1.2 Yards, depots and sidings .................................................................... 16

4.1.3 Estimation of YDS underreporting ........................................................ 19

4.2 Risk by ASPR hazard categorisation .......................................................... 20

4.2.1 Risk by annual FWI .............................................................................. 20

4.2.2 Risk by annual fatalities ........................................................................ 20

4.2.3 Detailed risk profiles ............................................................................. 20

5 Key risk areas ................................................................................................... 23

5.1 Other risk groupings .................................................................................... 25

6 SRM risk vs observed risk ................................................................................. 26

7 Uncertainty in the SRM risk estimates .............................................................. 28

7.1 Introduction ................................................................................................. 28

7.2 Uncertainty methodology ............................................................................ 28

7.3 SRM uncertainty results .............................................................................. 29

7.4 Uncertainty analysis next steps ................................................................... 32

8 Individual fatality risk ......................................................................................... 33

8.1 Introduction ................................................................................................. 33

8.2 Fatality risk .................................................................................................. 33

8.3 Passengers ................................................................................................. 34

8.4 Workforce .................................................................................................... 35

8.5 Members of the public ................................................................................. 37

9 Multiple fatality risk: the F-N Curve ................................................................... 39

9.1 F-N results................................................................................................... 39

9.2 F-N modelling approach .............................................................................. 43

Contents

Version 8.1 - Issue 1.1 - December 2014 vi

10 Remodelling risk at the platform-train interface ................................................. 44

10.1 Background and objectives ......................................................................... 44

10.2 The remodelling process ............................................................................. 44

10.2.1 Scope of changes ................................................................................. 44

10.2.2 Remodelling steps ................................................................................ 45

10.2.3 PTI structural changes .......................................................................... 45

10.3 Impact on the risk profile ............................................................................. 46

11 SRM governance and RPB updates ................................................................. 48

11.1 Data and Risk Strategy Group .................................................................... 48

11.1.1 SRM Practitioners Working Group ........................................................ 48

11.2 Update history ............................................................................................. 48

11.3 Updates to the SRM during CP4 ................................................................. 50

11.4 Future updates during CP5 ......................................................................... 50

12 Contributors ...................................................................................................... 51

13 Acronyms and glossary ..................................................................................... 52

13.1 Acronyms .................................................................................................... 52

13.2 Glossary ...................................................................................................... 53

14 References ........................................................................................................ 61

Appendix A. SRM outputs...................................................................................... 62

Appendix B. ASPR hazardous event groupings .................................................... 63

Appendix C. Individual fatality risk summary .......................................................... 65

Appendix D. Modelling approach ........................................................................... 66

D.1. Key assumptions .................................................................................. 66

D.2. Hazardous event definitions ................................................................. 67

D.3. Normalisation data ................................................................................ 67

D.4. Significant modelling changes for SRMv8 ............................................ 67

D.4.1. Inclusion of YDS-SRM risk ................................................................... 67

D.4.2. Remodelling of risk at the PTI ............................................................... 67

D.4.3. Inclusion of MCB+OD and AOCL+B crossing types ............................. 67

D.4.4. New approach to assault data analysis ................................................ 67

Appendix E. Railway lines in SRM scope .............................................................. 68

List of tables

Version 8.1 - Issue 1.1 - December 2014 vii

List of tables

Table 1: SRMv8.1 results by person group ........................................................................... iii Table 2: SRMv8.1 results by accident category ..................................................................... iv Table 3: Scope of the railway infrastructure .......................................................................... 4 Table 4: Exceptions to the physical boundary of the SRM ..................................................... 4 Table 5: Risk changes from SRMv8 to SRMv8.1 ................................................................... 8 Table 6: Total risk by accident category ................................................................................ 9 Table 7: Total risk by person category ................................................................................ 10 Table 8: Total risk to each person category from each accident category ........................... 10 Table 9: Total risk by accident category .............................................................................. 12 Table 10: Total risk by person category............................................................................... 13 Table 11: Total risk to each person category from each accident category ......................... 14 Table 12: Total risk by accident category ............................................................................ 16 Table 13: Total risk by person category............................................................................... 17 Table 14: Total risk to each person category from each accident category ......................... 17 Table 15: Grouped risk figures for SRMv8.1, not including YDS risk ................................... 23 Table 16: Selected SRMv8.1 risk groupings ........................................................................ 25 Table 17: Comparison of SRM and uncertainty model risk estimates .................................. 29 Table 18: Total passenger individual fatality risk ................................................................. 35 Table 19: Workforce individual fatality risk breakdown ........................................................ 37 Table 20: Frequency of train-related incidents leading toRI multiple fatalities ...................... 39 Table 21: Return periods of train-related incidents leading to multiple fatalities ................... 39 Table 22: Remodelled PTI HE descriptions ......................................................................... 45 Table 23: Remodelled PTIHEs. Summary of changes......................................................... 46 Table 24: Summary of the changes in risk for PTI hazardous events .................................. 47 Table 25: SRM update history ............................................................................................. 49 Table 26: Accident groups used within the ASPR ............................................................... 63 Table 27: Workforce group individual fatality risk by cause classification. ........................... 65 Table 28: Key modelling assumptions in the SRM .............................................................. 66 Table 29: Railway lines in and out of scope of the SRM ...................................................... 68

List of figures

Version 8.1 - Issue 1.1 - December 2014 viii

List of figures

Figure 1: Summary of the SRM remodelling and data updates. ............................................ 7 Figure 2: Total risk profile by person type (% of total FWI/year) .......................................... 11 Figure 3: Mainline railway risk profile by person type (% of total mainline FWI/year) ........... 15 Figure 4: YDS risk profile for workforce (% of total workforce FWI/year) ............................. 18 Figure 5: Risk profile in FWI/year (with % change from SRMv7.5+YDS) ............................. 21 Figure 6: Risk profile in fatalities/year (with % change from SRMv7.5+YDS ........................ 22 Figure 7: Breakdown of SRMv8.1 (excluding YDS risk) by risk area ................................... 24 Figure 8: Passenger observed FWI vs SRM FWI approximation ......................................... 27 Figure 9: Risk distribution for the total SRMv8.1 HEM/HEN risk .......................................... 29 Figure 10: Risk distribution for the SRMv8.1 risk for HEM and HEN separately .................. 30 Figure 11: Risk distribution for the SRMv8.1 risk by person type ......................................... 31 Figure 12: Fatality risk for each person category per year (SRMv8.1) ................................. 34 Figure 13: Causal breakdown of passenger fatality risk ...................................................... 34 Figure 14: Expected annual fatalities by workforce role ....................................................... 36 Figure 15: Individual fatality risk by workforce role .............................................................. 36 Figure 16: Causal breakdown of MOP fatality risk ............................................................... 38 Figure 17: The F-N Curve – all person and train accident types. ......................................... 40 Figure 18: Estimated frequency of train accident-related fatality events .............................. 41 Figure 19: F-N curve – plotted separately for three categories of train accidents ................ 42 Figure 20: Contribution of key hazardous events to the F-N curve ...................................... 43 Figure 21: Timeline of updates of the SRM and RPB that occurred in CP4 ......................... 50

Introduction

Version 8.1 - Issue 1.1 - December 2014 1

1 Introduction

RSSB works with its members to support the development of safety strategies, develop

standards and monitor and report on the safety performance of the industry. An understanding

of the overall risk level and risk profile of the railway is a key foundation for this role. RSSB

supports its members — who comprise the railway industry — by providing risk information to

help them understand their own risk profile and benchmark their performance. This in turn

helps them formulate their own safety policies, plans and measures. The Safety Risk Model

(SRM) provides the network-wide risk profile and this information is communicated to the

industry in a range of ways, the primary one being the SRM Risk Profile Bulletin (SRM-RPB).

The SRM consists of a series of fault tree and event tree models representing 131 hazardous

events (HEs), which collectively define the overall level of risk on the mainline railway. It

provides a structured representation of the causes and consequences of potential accidents

arising from railway operations and maintenance on railway infrastructure as well as other

areas where the industry has a commitment to record and report accidents.

The SRM has been designed to take account of both high-frequency, low-consequence events

(occurring routinely, and for which there is a significant quantity of recorded data) and low-

frequency, high-consequence events (occurring rarely, and for which there is little recorded

data). The results for each HE are presented in terms of the frequency of occurrence (number

of events per year) and the risk (number of fatalities and weighted injuries (FWI) per year).

The FWI weightings equate injuries of differing degree with a fatality, which allows all of the

risk on the railway to be totalled and contrasted in comparable units. These FWI weightings

are shown in Section 13.2.

The risk estimates presented can be used to support risk assessments and for judging how

the risk relating to particular operations compares with and contributes to the network-wide

risk.

The information contained in this document relates to the network-wide risk on railway

infrastructure covering all running lines, rolling stock types, stations, yards, depots and sidings

currently in use. The system boundaries are detailed in Section 2.2. The risk estimates are for

the current level of residual risk on the railway, which is the level of risk remaining with the

current risk control measures in place and with their current degree of effectiveness.

Because of the network-wide nature of the SRM, it is necessary to make average assumptions

that represent the general characteristics of the network. The model also hinges on the

definitions of the HEs and precursors by which risk estimates are reported. These definitions

are available on the RSSB Rail Risk Portal at www.safetyriskmodel.co.uk, and a thorough

understanding of them is essential to the correct interpretation and use of the risk information

reported here. The SRM does not provide risk profiles for specific lines of route and train

operating companies (TOCs), although a Risk Profile Tool is also available from the Rail Risk

Portal to help scale the results for this purpose. The information in this report should not be

considered to be representative of the risk for any particular line of route or TOC, without

further localised analysis.

This risk profile bulletin details the risk estimates made for version 8.1 of the SRM. Version

8.1 is a partial update from SRM version 8 that came about as the result of significant changes

being made to the classification of suicide and trespass events (detailed in section 3.2). The


Introduction


cut-off date for incident data used to inform SRMv8.12 was 30 September 2013.3 Comparisons

are made against the combined SRMv7.5 and the Yards, Depots and Sidings SRM, referred

to throughout this document as SRMv7.5+YDS.

The main part of this report sets out:

An overview of the SRM and its objectives (Section 2.1)

The SRM update strategy (Section 3)

Total risk on the railway (Section 4)

Breakdown of risk by the Strategic Safety Plan (SSP) risk areas (Section 5)

A comparison of observed FWI with SRM risk estimates (Section 6)

Detail of the uncertainty involved in the SRM risk estimates (Section 7)

A summary of individual risk (Section 8)

A summary of multi-fatality risk (Section 9)

Modelling changes made for SRMv8.1 (Section 10)

SRM governance arrangements (Section 11)

The SRM Practitioners Working Group (SRM-PWG) was the industry governance body for the

SRM throughout Control Period 4 (CP4). It was formed under the authority of the Safety Policy

Group (SPG) to engage stakeholders in the development and control of future versions of the

SRM and its related outputs. The modelling changes implemented as part of the update of the

SRM to version 8 have been endorsed by the SRM-PWG. The revised version 6 figures

(SRMv6.7) and the version 8 figures (SRMv8) were presented to the group and approved in

March 2014. As part of the modernisation of safety co-operation (MOSC) initiative, SPG and

SRM-PWG have been wound up and oversight for future SRM updates and developments will

be provided by the Data and Risk Strategy Group (DRSG) which is a subgroup of the System

Safety Risk Group (SSRG).

The Department for Transport (DfT) has been using the outputs from the SRM as the primary

means of measuring the performance of the industry against the High Level Output

Specification (HLOS) safety metrics. The risk estimates derived from SRMv6 provided the

initial baseline against which to compare safety performance through CP4 (April 2009 to March

2014). This is achieved by comparing the risk metrics derived from SRMv8 against the

baseline safety metrics determined from SRMv6 (and subsequently updated to SRMv6.7). A

full report of the HLOS metric calculation is given in the report HLOS Safety Metrics – baseline

and progress metrics following completion of the update of the SRM to version 8 [Ref. 1] which

was delivered to SRM-PWG on the 27 March 2013.

Additional appendices for this document may be downloaded from the RSSB Rail Risk Portal

at http://www.safetyriskmodel.co.uk.

2 The term SRMv8.1 is used to refer to the full SRM scope of events including those events which did not need to be recalculated in the partial update. 3 There are four hazardous event models that are exceptions to this data cut-off: HEM-12, HEM-25, HEM-31 and HEN-77. The mapping of incidents to these HEs is influenced by coroners’ reports, which may not be available until a considerable time after the event. Therefore, to ensure there is confidence in the data used to analyse them, an earlier cut-off date (30 September 2012) was used.


SRM objectives and overview


2 SRM objectives and overview

2.1 Objectives

The SRM has been developed and published to support RSSB members. The primary

objectives of the SRM are:

To provide an estimate of the extent of the current risk on the railway.

To provide risk information and risk profiles relating to the railway.

This information is used for risk assessments, appraisals and to inform decision making

throughout the railway industry.

Taking Safe Decisions, [Ref. 2] sets out the rail industry’s consensus view on how safety is

taken into account when making decisions. The guidance was updated in 2014 to reflect

changes to the legal environment and evolving industry practice. In the Great Britain (GB) rail

industry, almost every policy, investment or operational decision has an impact on safety. In

order to make these decisions and to ensure that risk is acceptable, the rail industry needs to

understand safety risk, its causes and consequences. The SRM is one of the key tools used

to help support this decision making through:

Monitoring: are operations safe or might changes be required?

Analysing and selecting options: what (if anything) should I change and can it be done

safely?

Making a change: how do I make sure a change is safe?

This includes:

Enabling risk-informed assessments and cost-benefit analyses (CBAs) to be carried

out to support decisions taken about:

Whether changes to the railway can be made safely.

Which risk control measures should be applied or can be relaxed or changed.

Technical modifications and upgrades such as new infrastructure investment.

Revision of Railway Group Standards (RGS), in terms of their contribution to

risk mitigation (including development of impact assessments for proposed

changes to the RGS).

Providing risk information to support:

The development of priorities for the Industry Strategic Business Plans 2014–

2019 [Ref. 3].

Transport operator risk assessments, as required by The Railways and Other

Guided Transport Systems (Safety) Regulations 2006.

Identification and prioritisation of issues for audit and/or research.

RSSB’s contributions and comments on the development of Technical

Standards for Interoperability (TSIs), National Technical Rules and National

Safety Rules.



Providing an understanding about the contribution of a particular item of equipment or

failure mode to the overall risk.

2.2 Overview

The SRM includes the safety risk from incidents which could occur during the operation and

maintenance of the railway. For SRMv8.1 the scope has been extended to include risk within

yards, depots and sidings, previously covered by the separate Yards, Depots and Sidings

(YDS) Risk Profile Report [Ref. 4].

For SRMv8.1 the extent of the railway infrastructure in question is defined below in Table 3.

Table 3: Scope of the railway infrastructure

Inclusions Exclusions

The sections of the operational railway4 which are managed or operated by Network Rail.

Any assets, structures, stations, yards, depots and sidings associated with the above.

Any yard, depot or siding that is connected to but away from the running lines on railway infrastructure, where train maintenance, stabling, marshalling and/or servicing (including refuelling) takes place under the management of other infrastructure managers.

Station car parks.

Offices (except areas normally accessible by MOP).

Mess rooms.

Training centres.

IECCs/SCCs.

Outside of the entrance to stations.

Station and site toilets.

Retail units and concessions in stations.

Construction sites which are completely segregated from the public areas.

Track sections closed for long term construction, maintenance, renewal or upgrade.

This defines the physical boundary of the SRM. Any incidents which occur inside this

boundary, and are listed in GE/RT8047, are included in the SRM. Conversely, any incidents

outside this boundary are excluded from the SRM.

The exceptions to this rule are listed below in Table 4.

4 The operational railway includes all lines for which the infrastructure manager & railway undertaking have been granted a safety authorisation & certificate respectively by the ORR (under European Safety Directive 2004/49/EC [Ref 5]). This provides evidence that there is a suitable SMS in place, and that operations are being conducted in accordance with that SMS. 5 For instance, this would include delivery of goods to a trackside location, but exclude travel to a training centre.

Table 4: Exceptions to the physical boundary of the SRM

Inclusions outside the SRM boundary Exclusions inside the SRM boundary

Injuries to people which are directly caused by operations or maintenance inside the boundary.

Injuries to railway staff who are on duty and travelling between sites, except if their destination is one of the excluded areas in Table 3 (eg an office).5

Long-term occupational health issues.

Terrorist activity.



Appendix G of the YDS Risk Profile Report contains a more detailed discussion of the SRM-

YDS scope and the boundaries of yards, depots and sidings. It also gives specific guidance

as to what aspects of the operation and maintenance of the railway are within scope of the

SRM.

2.3 Key assumptions and exclusions

Appendix D.1 lists key assumptions that are applicable to the SRM. Further clarity on the

definitions and assumptions applicable to individual HEs can be provided on request.

SRM update strategy


3 SRM update strategy

3.1 Overview of the SRMv8 update

The SRM was used by the DfT as the primary means of measuring the performance of the

industry against the HLOS safety metrics throughout control period 4 (CP4). It was therefore

necessary to be able to distinguish between changes in estimated risk arising from genuine

changes in safety performance and changes due to modelling refinements (for SRM versions

6 through 8).

To incorporate YDS risk modelling and to enable the HLOS comparison to be meaningful, the

update of the SRM to version 8 has been split into three distinct stages.

1. Bring the YDS risk model into the main risk model framework.

2. Produce risk estimates for SRMv8 incorporating:

a. Changes to the model structure. This included:

i. Restructuring of the various platform-train interface (PTI) hazardous

events following industry requirements for greater understanding of

risk at the PTI (explanation of this remodelling is covered in detail in

Chapter 10).

ii. Extension of the seven level crossing hazardous events to include the

recently introduced crossing types: MCB with obstacle detection

(MCB+OD) and AOCL with half barriers (AOCL+B).

b. Changes to the calculation methods. This included:

i. Improved estimates of the risk from passenger and public assaults

utilising a refined matching of records between SMIS and the BTP

CRIME database.

ii. Correcting minor errors from previous SRM versions.

c. Changes to historical data (incidents which occurred prior to the data cut-off

for previous versions). This included:

i. Inclusion, exclusion or reclassification of incidents in the light of new

information.

ii. Inclusion of late reported incidents.

d. Inclusion of new data for incidents which occurred since the data cut-off for

the previous version and the SRMv8 data cut-off of 30 September 2013.

3. Apply step 2a) to 2c) above to SRMv6 to create SRMv6.7. This updated version

represents the risk as would have been calculated for SRMv6 had the modelling

changes for the mainline railway risk implemented in SRMv8 been implemented at

the time SRMv6 was first created.

The required comparisons between risk estimates can then be meaningfully made:

1. SRMv6.7 and SRMv8 can be compared to provide the estimated change in risk over

CP4 as required for HLOS.

SRM update strategy


2. SRMv7.5 and SRMv8 (without YDS) can be compared to give the estimated change

in risk due to remodelling and the refresh of the data up to 30 September 2013

(compared to 30 June 2012 for SRMv7.5).

3. The YDS-SRM and the YDS subsection of SRMv8 can be compared to give the

estimated change in YDS risk.

This is the third time the SRM update has required previous models to be simultaneously

updated. The other occasions being for SRMv7 and SRMv7.5. This has been necessary in

order to provide a framework that is compatible with the requirements for monitoring the HLOS

metrics and to provide risk estimates for different points in time that are calculated on a like-

for-like basis.

Figure 1 summarises the different SRM versions and how they have been derived. For HLOS

comparative purposes, the light grey boxes show valid comparisons based solely on changes

in data between different versions of the model.

Figure 1: Summary of the SRM remodelling and data updates.

3.2 Update to SRM version 8.1

In 2013/14, BTP made more information about railway fatalities available to the rail industry

as a result of the enhanced co-operation effected by the National Suicide Prevention Strategy

Group. BTP provided additional information dating back to 2009/10, which has enabled the

industry to update the classification of a number of fatalities6.

6 Further information on the suicide/trespass data reclassification is available in the Annual Safety Performance

Report 2013/14.

Date of version release

Data

cut-

off

date SRM v6 SRMv6.5 SRMv6.6 SRMv6.7

SRMv7 SRMv7.1

SRMv7.5

YDS-SRM

SRMv8

Remodelling

Data refresh

Extension of scope

KEY

Final HLOS comparison

1st HLOScomparison

2nd HLOS comparison

Partial Update

SRM update strategy


The reclassified data only became available after the SRMv8 update had been completed.

However, due to the expected scale of the impact RSSB decided to update risk estimates for

the relatively small number of affected hazardous events and incorporate them in a partial

update to SRMv8 to create SRMv8.1.

The hazardous events for which data was recoded and the risk recalculated are:

HEM-31-Suicide (or attempted suicide) involving rolling stock in motion.

HEN-77-Suicide (or attempted suicide) not involving rolling stock in motion.

HEM-12-MOP (trespasser) struck/crushed by train while on tracks at station.

HEM-25-MOP (trespasser) struck/crushed by train while on railway infrastructure not

at station.

HEN-38-MOP (adult trespasser) electric shock (conductor rail).

HEN-71-MOP (adult trespasser) fall/jump onto railway infrastructure.

Other hazardous events were indirectly affected due to dependencies on the above, these

were:

HEM-31-YDS-Suicide or attempted suicide involving rolling stock in motion.

HEN-45-MOP (non-trespasser) fall onto railway infrastructure.

HEN-72-MOP (child trespasser) fall/jump onto railway infrastructure.

HEN-77-YDS-Suicide (or attempted suicide) not involving rolling stock in motion.

The overall effects of these changes are given in Table 5.

Table 5: Risk changes from SRMv8 to SRMv8.1

Change in FWI from v8 to v8.1

Absolute Percentage

Suicide risk 7.97 3.4%

Other risk -11.59 -27.1%

These changes only had a negligible impact on passenger and workforce risk so did not affect

the HLOS calculations.

Throughout this report all values, charts and tables reflect the SRMv8.1 results.

Total risk on the railway


4 Total risk on the railway

4.1 Overall profile

This section presents the overall risk on the railway for the 131 HEs which make up the SRM.

Risk is presented as:

Injury severity by accident category (Table 6)

Injury severity by person category (Table 7)

Person type injured by accident category ( Table 8)

The total risk from the 131 HEs is estimated to be 139.6 FWI/year7. This is made up of

approximately:

55 fatalities per year8

567 major injuries per year

2494 class 1 minor injuries per year


1887 shock/trauma events per year

This compares to the 146.6 FWI/year calculated in SRMv7.5 and SRM-YDS9. These total risk

estimates are broken down by accident category and injury type in Table 6.

7 The values presented exclude direct risk due to suicide and attempted suicide. Indirect suicide risk (eg the shock/trauma of witnesses) associated with these events is included. 8 Note that, due to rounding, values in tables and the text throughout this document may not match. 9 This version of the SRM is the first version that has included both mainline and yards, depots and sidings. Consequentially comparisons have been made to the combined results from SRMv7.5 and the SRM-YDS.

Table 6: Total risk by accident category

Accident category FWI / year

Fata

liti

es/y

ea

r

Majo

r in

juri

es

/

year

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma

/

year

Cla

ss

2

sh

ock/t

rau

ma

/

year

Train accidents 8.0 6.1 14 79 39 4 38

Movement accidents (excl. trespass)

25.2 12.4 76 372 1822 253 217

Non-movement accidents (excl. trespass)

72.8 5.6 457 2024 9964 9 1340

Trespass 33.6 31.3 21 19 9 26 0.4

Total 139.6 55 567 2494 11833 292 1595



Table 7 shows the risk to each person category on the railway, broken down by person category and accident category. Reasons for the changes in risk are explored in more detail in section 4.1.1 (which focuses on the changes in mainline risk from SRMv7.5) and section 4.1.2 (which focuses on the changes in risk on YDS sites from the YDS-SRM).

Table 7: Total risk by person category

Person category

SRMv8.1 SRMv7.5+YDS

FW

I/y

ear

Fata

liti

es/y

ea

r

Majo

r in

juri

es/

year

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma/

year

Cla

ss

2

sh

ock/t

rau

ma/

year

FW

I/y

ear

% C

han

ge f

rom

SR

Mv7.5

+Y

DS

to

SR

Mv8.1

Passenger 58.4 8.3 352 1616 6001 1.6 801 54.7 +6.9%

Workforce 33.4 4.2 173 798 5683 289 763 34.0 -2.0%

MOP 47.8 43 42 80 150 1.1 31 57.9 -17.5%

Total 139.6 55 567 2494 11833 292 1595 146.6 -4.8%

The reclassification of suicide/trespass events has only been applied to this latest version of

the SRM. This means that those hazardous events that were reanalysed for SRM version 8.1

are no longer directly comparable to their SRMv7.5+YDS counterparts due to the significant

differences in the data. A significant proportion of the reduction in risk to both members of the

public and HEM events can be attributed to this.

Figure 2 presents the total risk profile for passengers, the workforce and members of the

public. It shows that the bulk of the risk is split between passengers and members of the public,

with 42% and 34% respectively — the remaining proportion (24%) is attributed to the

workforce. Fatalities still dominate the risk to the public, comprising 90% of the total risk to

members of the public (equivalent to 43 fatalities per year). Fatalities due to trespass make

up 73% of member of public fatalities (equivalent to 31 fatalities per year).

Table 8: Total risk to each person category from each accident category

Accident category

SRMv8.1 SRMv7.5+YDS

Total FWI/year

Passenger FWI/year

Workforce FWI/year

MOP FWI/year

Total FWI/year

% change from SRMv7.5+ YDS to SRMv8.1

HET 8.0 2.8 1.1 4.0 8.3 -4.4%

HEM 49.6 11.7 6.6 31.4 56.4 -12.0%

HEN 82.0 43.9 25.6 12.4 81.9 +0.1%

Total 139.6 58.4 33.4 47.8 146.6 -4.8%



Figure 2: Total risk profile by person type (% of total FWI/year)

To

tal ri

sk

= 1

39.6

FW

I/year

Ma

jor

inju

rie

s(5

1.7

%)

Cla

ss

2 m

ino

r in

juri

es

(0.3

%)

Cla

ss

2 s

ho

ck/t

rau

ma

(0

.1%

)

Fa

tali

tie

s(1

4.2

%)

Ma

jor

inju

rie

s(6

0.3

%)

Cla

ss

1 m

ino

r in

juri

es

(13.8

%)

Cla

ss

2 m

ino

r in

juri

es

(10.3

%)

Cla

ss

1 s

ho

ck/t

rau

ma

(0

.01

%)

Fa

tali

tie

s (

12.7

%)

Cla

ss

1 m

ino

r in

juri

es (

12.0

%)

Cla

ss

2 m

ino

r in

juri

es

(17.0

%)

Cla

ss

2 s

ho

ck/t

rau

ma

(1

.4%

)

Cla

ss

1 s

ho

ck/t

rau

ma

(4

.3%

)

Cla

ss

2 s

ho

ck/t

rau

ma

(2

.3%

)

Fa

tali

tie

s(8

9.9

%)

Majo

r in

juri

es (

8.9

%)

Cla

ss

1 m

ino

r in

juri

es (

0.8

%)

Passen

ger

(42%

)

Mem

bers

of

the p

ub

lic

(34%

) Wo

rkfo

rce

(24%

)

Cla

ss

1 s

ho

ck/t

rau

ma

(0

.01

%)



4.1.1 Mainline profile

This section presents the overall risk for the 122 hazardous events on the mainline railway

(that is, excluding all hazardous and sub-hazardous events referring to YDS risk), which are

considered within the SRM. Risk is presented as:



Person type injured by accident category (Table 11)

The total risk from the 122 HEs for the mainline railway is assessed to be 132.0 FWI/year.

This is made up of approximately:

55 fatalities per year

520 major injuries per year



1874 shock/trauma events per year

These total risk estimates are broken down by accident category and injury type in Table 9.

Table 10 shows the risk to each person category on the railway. Risk to passengers forms the

greatest proportion of the total risk, at 58.4 FWI/year (an increase of 6.9% from SRMv7.5).

However, over the same period passenger journeys have increased by 2% and passenger

kilometres have increased by 3% (from 57.7 billion to 59.2 billion passenger km).


Accident category FWI/ year

Fata

liti

es/y

ea

r

Majo

r in

juri

es/y

ear

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma/

year

Cla

ss

2

sh

ock/t

rau

ma/

year

Train accidents 7.8 6.0 13 76 37 0.8 38


24.6 12.3 72 357 1760 253 216


66.2 5.3 414 1863 8803 9.2 1331

Trespass 33.4 31.1 20 19 9.1 26 0.4

Total 132.0 54.8 520 2314 10609 289 1585



The increase in passenger risk is due to increases in several hazardous events, the top

contributors of which are HEN-14: Passenger slip, trip or fall and HEN-64: Passenger physical

assault. The rise in risk from HEN-14 is mainly driven by an increase in estimated frequency

due to a larger number of observed slips, trip or falls on stairs and escalators.

Absolute MOP risk decreased by 17.7% since SRMv7.5. This is due to a number of trespass

events being reclassified as suicides following further information from BTP. Trespass events

are still the largest contributor to MOP risk but following this reclassification, the trespass risk

has decreased by 10.9 FWI/year.

The risk to the workforce is now 26.1 FWI/year which represents a 2.9% reduction from

SRMv7.5. The decrease in workforce risk is due to a decrease in the risk from several

hazardous events, of which the top contributors are HEM-19: Infrastructure worker

struck/crushed by train in motion and HEN-65: Workforce physical assault.


Person category

SRMv8.1 SRMv7.5

FW

I/y

ear

Fata

liti

es/y

ea

r

Majo

r in

juri

es/

year

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma/

year

Cla

ss

2

sh

ock/t

rau

ma/

year

FW

I/y

ear

% c

han

ge f

rom

SR

Mv7.5

to

SR

Mv8.1

Passenger 58.4 8.3 352 1616 6000 1.6 800 54.7 +6.9%

Workforce 26.1 3.8 126 620 4463 286 754 26.9 -2.9%

MOP 47.5 42.7 42 78 146 0.9 30 57.7 -17.7%

Total 132.0 54.8 520 2314 10609 289 1585 139.2 -5.2%

Table 11 presents the risk on the mainline railway broken down by person and accident

category. As in the previous section, the table shows that overall risk due to train accidents

(HETs) has decreased by 4.6%, largely due to the decrease in estimated frequency of

derailments. Movement accidents (HEMs) have seen a 12.4% reduction in risk, whereas non-

movement accidents (HENs) have remained relatively constant. Overall, the total decrease in

risk from SRMv7.5 to SRMv8.1 is 5.2%.




Accident category

SRMv8.1 SRMv7.5

Total FWI/year

Passenger FWI/year

Workforce FWI/year

MOP FWI/year

Total FWI/year

% change from SRMv7.5 to SRMv8.1

HET 7.8 2.8 1.0 4.0 8.2 -4.6%

HEM 49.0 11.7 6.0 31.3 55.9 -12.4%

HEN 75.2 43.9 19.1 12.2 75.1 +0.1%

Total 132.0 58.4 26.1 47.5 139.2 -5.2%

Figure 3 presents the total risk profile for passengers, workforce and public. It shows that the

bulk of the risk is split between passengers and public, with 44% and 36% respectively — the

remaining proportion (20%) is attributed to workforce incidents. Fatalities still dominate risk to

public, comprising 90.0%. This is due to public trespass events, contributing 31.3 fatalities per

year.


Version 7.1 — August 2011 15

Figure 3: Mainline railway risk profile by person type (% of total mainline FWI/year)

Cla

ss 2

min

or

inju

ries

(0.3

%)

To

tal ri

sk

= 1

32.0

FW

I/year

Cla

ss 2

sh

oc

k/t

rau

ma (

0.1

%)

Fa

tali

tie

s(1

4.2

%)

Ma

jor

inju

rie

s(6

0.3

%)

Cla

ss

1 m

ino

r in

juri

es

(13.8

%)

Cla

ss

2 m

ino

r in

juri

es

(10.3

%)

Cla

ss 1

sh

ock/t

rau

ma (

0.0

1%

)

Fata

liti

es (

14.5

%)

Ma

jor

inju

ries

(48.1

%)

Cla

ss

1 m

ino

r in

juri

es (

11.9

%)

Cla

ss

2 m

ino

r in

juri

es

(17.1

%)

Cla

ss

2 s

ho

ck/t

rau

ma

(1

.4%

)

Cla

ss

1 s

ho

ck/t

rau

ma (

5.5

%)

Cla

ss 2

sh

ock/t

rau

ma (

2.9

%)

Fata

liti

es

(90.0

%)

Ma

jor

inju

rie

s (

8.8

%)

Cla

ss 1

min

or

inju

rie

s

(0.8

%)

Passen

ger

(44%

)

Mem

bers

of

the p

ub

lic

(36%

)

Wo

rkfo

rce

(2

0%

)

Cla

ss 1

sh

oc

k/t

rau

ma

(0

.01

%)



4.1.2 Yards, depots and sidings

This section presents the overall risk for the nine hazardous events and 40 sub-hazardous

events related to YDS, which are considered within the SRM. Risk is presented as:



Person type injured by accident category (Table 14)

The total risk from the 49 HEs for YDS is assessed to be 7.6 FWI/year. This is made up of

approximately:

0.7 fatalities per year

47.6 major injuries per year



13.4 shock/trauma events per year

These total risk estimates are broken down by accident category and injury type in Table 12.


Accident category FWI/ year

Fata

liti

es/y

ea

r

Majo

r in

juri

es/

year

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma/

year

Cla

ss

2

sh

ock/t

rau

ma/

year

Train accidents 0.17 <0.1 0.72 3.2 2.4 3.3 <0.1


0.64 <0.1 4.0 15 61 <0.1 1.0


6.59 0.35 43 161 1160 <0.1 8.8

Trespass 0.21 0.19 0.20 0.21 <0.1 0.12 <0.1

Total 7.61 0.70 47.6 180 1224 3.58 9.80

Table 13 shows the risk to each person category on YDS. The majority of the risk on YDS can

be attributed to the workforce (96%). The remaining 4% of risk is allocated to members of the

public and over-carried passengers. The risk to workforce is now 7.3 FWI/year in comparison

to the 7.2 FWI/year in SRM-YDS.

The absolute risk to members of the public and over-carried passengers is small and therefore

susceptible to large percentage changes in risk from year to year as it is based on relatively

few events, as can be seen in Table 13 and Table 14.




Person category

SRMv8.1 YDS SRM-YDS

FW

I/y

ear

Fata

liti

es/y

ea

r

Majo

r in

juri

es/

year

Cla

ss

1 m

ino

r

inju

ries

/ye

ar

Cla

ss

2 m

ino

r

inju

ries

/ye

ar

Cla

ss

1

sh

ock/t

rau

ma/

year

Cla

ss

2

sh

ock/t

rau

ma/

year

FW

I/y

ear

% c

han

ge f

rom

SR

M-Y

DS

to

SR

Mv8.1

Passenger <0.1 - <0.1 <0.1 0.27 - <0.1 <0.1 -19.1%

Workforce 7.28 0.44 47 178 1220 3.3 8.8 7.2 +1.4%

MOP 0.33 0.26 0.57 1.4 3.9 0.25 1.0 0.29 +14.9%

Total 7.61 0.70 47.6 180 1224 3.58 9.80 7.47 +1.9%

Table 14 presents the risk broken down into person category and accident categories. The

table shows that overall risk due to train accidents (HETs) has increased by 6% but is still a

relatively small absolute risk at 0.2 FWI/year. Movement accidents (HEMs) have seen an

increase of 0.14 FWI/year which amounts to a 27.9% increase in risk (this is largely a

consequence of having a larger pool of data to analyse for SRMv8). Non-movement accidents

(HENs) have remained relatively constant. Overall, the total increase in risk from SRM-YDS

to SRMv8.1 is 1.9%.


Accident category

SRMv8.1 YDS SRM-YDS

Total FWI/year

Passenger FWI/year

Workforce FWI/year

MOP FWI/year

Total FWI/year

% change from SRM-YDS to SRMv8.1

HET 0.17 - 0.13 <0.1 0.16 +6.0%

HEM 0.64 - 0.60 <0.1 0.50 +27.9%

HEN 6.80 <0.1 6.5 0.26 6.8 -0.1%

Total 7.61 <0.1 7.27 0.33 7.47 +1.9%

Figure 4 presents the total risk profile for the different workforce types on YDS sites10. Risk to

engineering staff is the highest of all workforce types at 36% of the total YDS risk. Across all

workforce types, major injuries are the highest contributors to workforce risk on YDS.

10 Workforce type groups are detailed in the glossary (section 13.2).



Figure 4: YDS risk profile for workforce (% of total workforce FWI/year)

To

tal w

ork

forc

eri

sk =

7.2

8 F

WI/

year

Cla

ss

1 m

ino

r in

juri

es (

12.8

%)

Cla

ss

2 m

ino

r in

juri

es (

21.1

%)

Cla

ss

1 s

ho

ck/

tra

um

a (

0.0

%)

Fa

tali

tie

s (

5.9

%)

Ma

jor

inju

rie

s(6

0.1

%)

En

gin

eeri

ng

Sta

ff (

36%

) Dri

ver/

sh

un

ter

(30%

)

Cle

an

er/

ad

min

(14%

)

Infr

astr

uctu

rew

ork

er

(21%

)

Ma

jor

inju

rie

s(6

5.0

%)

Ma

jor

inju

rie

s(6

7.4

%)

Ma

jor

inju

rie

s(6

8.6

%)

Fa

tali

tie

s (

8.1

%)

Cla

ss 1

min

or

inju

ries (

11.3

%)

Cla

ss

2 m

ino

r in

juri

es (

15.3

%)

Cla

ss

1 s

ho

ck/

tra

um

a (

0.0

%)

Fa

tali

tie

s (

3.2

%)

Cla

ss

1 m

ino

r in

juri

es (

12.3

%)

Cla

ss

2 m

ino

r in

juri

es (

17.0

%)

Cla

ss

1 s

ho

ck/

tra

um

a (

0.0

%)

Fa

tali

tie

s (

6.0

%)

CC

lass

2 m

ino

r in

juri

es (

12.4

%)

Cla

ss

1 s

ho

ck/t

rau

ma

(0

.7%

)

Cla

ss

1 s

ho

ck/

tra

um

a (

0.2

%)

Cla

ss 1

min

or

inju

ries (

12.2

%)

Cla

ss

2

sh

oc

k/t

rau

ma

(0

.1%

)

Cla

ss

2 s

ho

ck/t

rau

ma

(0

.1%

)

Cla

ss

2 s

ho

ck/

tra

um

a (

0.2

%)



4.1.3 Estimation of YDS underreporting

There is some evidence for underreporting of incidents across the whole of the railway11. For

most areas of risk on the mainline railway this is not currently thought to be a significant issue

as:

Reporting into SMIS is mandatory.

RSSB operates a data quality programme for mainline data reporting.

Underreported events tend to be less severe and due to the way in which minor injuries

are weighted limits their effect on overall FWI risk.

However there are specific problems relating to the quality of YDS data. The reporting of

events that occur on YDS into SMIS is not mandatory, and some companies do not report any

incidents into SMIS at all. Consequentially there are gaps in the data for events on YDS sites.

To attempt to address this issue of underreported YDS events, the scale of underreporting

has been estimated based on reporting from all freight companies and train maintenance

companies, taking into account the size of each company.

Of the freight operators who have agreed to provide event data, there is evidence that up until

2008/09 reporting was not complete. However, incident reporting from April 2009 is considered

fairly complete and by looking at the level of reporting since then it is possible to estimate what

level of reporting would have occurred pre-April 2009 if there had been no underreporting. In

doing so, an increased freight-based rate of reporting was estimated, which in turn increased

the freight proportion of the overall risk figure. Using this same method, the gaps for other

freight reporting have been filled in and scaled accordingly.

Estimates can also be made for train maintenance companies. Discussions were held with

three of the four train maintenance companies regarding; the scale of their operations, their

injury rates and the types and locations of those injuries. One company has also provided

some injury data, which has been used to aid the estimates. Based on these discussions and

data an estimate was made of the number of injuries that would have been reported had the

companies been doing so.

An extrapolation from the data that is available can be made to estimate a figure for the risk

associated with the missing data. This gives an increase of around 24% in the overall level of

risk on YDS sites. If we assume a similar profile of injury types for this missing data we can

extrapolate the total risk by this proportion. This gives an overall risk on YDS sites:

Estimated total risk = 9.4 FWI/year

This provides an estimate of the overall risk on YDS sites (the equivalent figure calculated for

the YDS-SRM was 9.2 FWI/year). Note that there is more uncertainty in this estimate than the

base figure of 7.6 FWI/year based on the known dataset. The portion of the extrapolated figure

that relates to workforce is 9.0 FWI/year (based on the existing ratio of workforce risk to overall

risk).

11 Further information on data quality is given in Chapter 10 of the ASPR 2013-14



4.2 Risk by ASPR hazard categorisation

The 131 HEs which make up the SRM have been grouped into the 22 accident groups used

in the ASPR [Ref. 6] in Table 26 (Appendix B). Combining the HEs in this manner allows

identification of the types of accidents that contribute the greatest proportion of risk.

4.2.1 Risk by annual FWI

Figure 5 presents the risk profile in FWI/year and indicates the percentage change in risk

between SRMv7.5 and SRMv8.1 for each of the 22 HE categories listed above. The greatest

overall risk contribution results from Slips, trips and falls with 39.0 FWI/year, an increase of

6% compared with SRMv7.5+YDS. The next-highest risk contribution results from Trespass

with 33.6 FWI/year, which is dominated by fatality risk.

The majority of risk from Slips, trips and falls occurs to passengers, contributing 27.2 FWI/year,

which represents 47% of the overall risk to passengers. After Slips, trips and falls, the category

which contributes most to the overall risk to passengers is Assault and abuse, representing

9.6 FWI/year, followed by Platform edge incidents (both boarding/alighting and non-

boarding/alighting). Considered together, these four categories account for over 80% of the

risk to passengers.

The greatest workforce risk also comes from the Slips, trips and falls category (10.2 FWI/year),

with the second-highest contribution coming from Contact with object (5.4 FWI/year). Together

these categories represent 47% of the risk to the workforce.

A large proportion of the risk to the public results from Trespass (33.5 FWI/year), followed by

Struck/crushed by train (not trespass) with 6.5 FWI/year. Together they represent 84% of the

risk to MOP.

For both Figure 5 and Figure 6 the large percentage change in road traffic accident risk is due

to significantly improved reporting of this type of event. The large percentage change in

trespass event is mainly due to the reclassification of suicide and trespass events as a result

of the SRMv8.1 update.

4.2.2 Risk by annual fatalities

Figure 6 shows the combined risk by event type in fatalities per year (excluding the contribution

from injuries, shock and trauma). Fatality risk is dominated by Trespass accidents, accounting

for more than half, with 31.3 fatalities per year down 25% on the SRMv7.5+YDS figure due to

the reclassification of a number of suicide/trespass events. The accident type contributing the

second-highest number of fatalities is Struck/crushed by train with 8.5 fatalities per year,

suggesting these events have remained relatively constant since SRMv7.5+YDS. Together,

these two categories account for 72% of all fatalities.

The highest contribution to passenger fatalities is Platform edge incidents (not

boarding/alighting), which accounts for 3.8 fatalities per year (representing 46% of passenger

fatality risk).

The most significant contributor to workforce fatalities is Struck/crushed by train, accounting

for 1.6 fatalities per year (39% of the workforce fatality risk total). The 31.3 fatalities per year

due to MOP Trespass represents 73% of public fatality risk.

4.2.3 Detailed risk profiles

More detailed risk profiles for each accident type and person category can be found in the

Annual Safety Performance Report 2013/14.



Figure 5: Risk profile in FWI/year (with % change from SRMv7.5+YDS)

THe

01

02

03

04

0

Tra

in a

ccid

ents

: o

the

r

Lea

n o

r fa

ll fr

om

tra

in in

run

nin

g

Fire

s a

nd

explo

sio

ns (

no

t in

volv

ing

tra

ins)

Con

tact w

ith

pe

rso

n

Wo

rkfo

rce

ele

ctr

ic s

ho

ck

Tra

in a

ccid

ents

: str

ikes w

ith

obje

cts

Ma

chin

ery

/too

l op

era

tio

n

Fa

lls f

rom

heig

ht

Indir

ect

risk d

ue t

o s

uic

ide

Oth

er

Roa

d t

raffic

accid

en

t

Ma

nu

al h

an

dlin

g/a

wkw

ard

mo

vem

ent

Tra

in a

ccid

ents

: colli

sio

ns a

nd d

era

ilme

nts

Tra

in a

ccid

ents

: str

ikes w

ith

ro

ad

ve

hic

les a

t le

ve

l…

Pla

tfo

rm e

dg

e in

cid

ents

(no

t bo

ard

ing/a

ligh

tin

g)

Con

tact w

ith

ob

ject

On

-boa

rd in

juri

es

Pla

tfo

rm e

dg

e in

cid

ents

(bo

ard

ing/a

ligh

tin

g)

Str

uck/c

rush

ed

by t

rain

Assa

ult a

nd

ab

use

Tre

sp

ass

Slip

s, tr

ips,

an

d fa

lls

Passen

ger

Wo

rkfo

rce

Pu

blic

39.0

(+

6%

)

33.6

(-2

5%

)

11.8

(+

2%

)

9.0

(+

1%

)

9.0

(+

16%

)

6.9

(-4

%)

6.7

(-4

%)

6.2

(+

9%

)

3.6

(+

5%

)

3.5

(-1

2%

)

1.7

(-8

%)

1.3

(+

62%

)

1.2

(+

4%

)

1.2

(+

16%

)

1.1

(+

10%

)

1.1

(+

7%

)

0.5

4 (

-8%

)

0.5

3 (

-19%

)

0.4

2 (

-9%

)

0.4

0 (

-27%

)

0.3

9 (

-10%

)

0.3

1 (

-9%

)



Figure 6: Risk profile in fatalities/year (with % change from SRMv7.5+YDS

02

46

83

03

2

Indir

ect

risk d

ue t

o s

uic

ide

Co

nta

ct w

ith

pe

rso

n

Ma

nu

al h

an

dlin

g/a

wkw

ard

mo

vem

ent

On

-boa

rd in

juri

es

Ma

chin

ery

/too

l op

era

tio

n

Pla

tfo

rm e

dg

e in

cid

ents

(bo

ard

ing/a

ligh

tin

g)

Co

nta

ct w

ith

ob

ject

Tra

in a

ccid

ents

: o

the

r

Fire

s a

nd

explo

sio

ns (

no

t in

volv

ing

tra

ins)

Wo

rkfo

rce

ele

ctr

ic s

ho

ck

Lea

n o

r fa

ll fr

om

tra

in in

run

nin

g

Tra

in a

ccid

ents

: str

ikes w

ith

obje

cts

Oth

er

Fa

lls f

rom

heig

ht

Assa

ult a

nd

ab

use

Ro

ad t

raffic

accid

en

t

Slip

s, tr

ips,

an

d fa

lls

Tra

in a

ccid

ents

: colli

sio

ns a

nd d

era

ilme

nts

Tra

in a

ccid

ents

: str

ikes w

ith

ro

ad

ve

hic

les a

t le

ve

l…

Pla

tfo

rm e

dg

e in

cid

ents

(no

t bo

ard

ing/a

ligh

tin

g)

Str

uck/c

rush

ed

by t

rain

Tre

sp

ass

Pa

ss

en

ge

r

Wo

rkfo

rce

Pu

blic

31.3

(-2

5%

)8.5

(+

1%

)

4.3

(+

7%

)

3.2

(+

6%

)

2.4

(-1

3%

)

1.4

(-2

7%

)

0.8

7 (

+293%

)

0.6

6 (

-67%

)

0.6

2 (

+23%

)

0.3

4 (

-3%

)

0.3

2 (

-3%

)

0.3

2 (

-10%

)

0.3

2 (

-21%

)

0.2

9 (

-30%

)

0.2

1 (

-5%

)

0.1

7 (

-47%

)

0.1

6 (

-25%

)

0.0

6 (

-1%

)

0.0

3 (

+10%

)

0 0 0

Key risk areas


5 Key risk areas

Effective safety planning requires a detailed understanding of risk areas – the activities or circumstances where the safety risk profile for passengers, the workforce, and the public is the greatest. This allows resources and effort to be concentrated where they will have the greatest impact.

Though it is no longer produced, the SSP [Ref. 7] considered nine key risk areas (KRAs) that have been selected from the original breakdown of the SRM into 15 risk areas. These nine KRAs represent the top 98% of the overall SRM risk (and the percentage has remained the same since SRMv7.5) and are thus considered to be the key to understanding the causes of risk in the rail industry.

A complete breakdown of the SRMv8.1 figures into the 15 risk areas is shown in Table 15 and diagrammatically in Figure 7 (the KRAs are indicated in both). These figures do not include YDS risk.

Table 15: Grouped risk figures for SRMv8.1, not including YDS risk

Risk area group

Risk in FWI/year (% of SRMv8.1)

Risk areas (key risk areas in bold)

SRMv8.1 risk (excluding YDS) (FWI/yr)

% of SRMv8.1 risk (excluding YDS) (FWI/yr)

SRM v7.5 risk (FWI/ yr)

Change from SRMv7.5 to SRMv8.1

Engineering 4.48

(3.4%)

Infrastructure 2.47 1.87% 3.04 -19%

Level crossing 0.20 0.15% 0.23 -11%

Rolling stock 1.81 1.37% 2.09 -13%

Environment 0.23

(0.2%)

Adjacent property/land 0.04 0.03% 0.03 +14%

Weather 0.19 0.14% 0.18 +5%

Passengers 28.0

(21%)

In stations 24.7 18.7% 23.1 +7%

On trains 3.32 2.52% 3.02 +10%

Public behaviour

59.3 (44.9%)

Crime 46.3 35.1% 57.3 -19%

General 2.02 1.53% 1.44 +14%

Level crossings

Pedestrian user

7.26 5.51% 6.80 +7%

Road vehicle user

3.63 2.75% 3.58 +1%

Workforce 40.0

(30%)

Shunter 0.12 0.09% 0.06 +108%

Signaller 0.68 0.52% 0.78 -13%

Station staff 17.8 13.5% 16.6 +7%

Track worker 14.0 10.6% 13.6 +3%

Train crew 7.43 5.63% 7.38 +1%

Total 132.0 132.0 139.2

Key risk areas


Figure 7: Breakdown of SRMv8.1 (excluding YDS risk) by risk area

*Indicates that the risk area was one of the nine KRAs reported in the SSP 2009-2014.

The 15 risk areas relate to the sources of risk. For example the Infrastructure worker risk area relates to the risk that arises from infrastructure workers carrying out their activities and their behaviour in doing so, rather than the risk to infrastructure workers in their role. This means that the risk areas relate to the causes of the SRM precursors.

In some cases, where a precursor has more than one cause, it has been necessary to assign proportions of the precursor risk between two or more risk areas. Appendix C gives full details of how the figures in Table 15 have been derived – it lists all of the precursors making up each of the risk areas and gives the proportions that have been applied for any precursor split between two or more risk areas.

The 15 risk areas can be further grouped into five higher level risk area groups – namely engineering, environment, passenger behaviour, public behaviour and workforce behaviour. These groupings can also be seen in Table 15.

Table 15 provides information to the industry regarding the significant causes of HEs. Precursors, by definition, are the main contributors to the HEs that ultimately lead to harm. Targeting the precursors through effective management actions will lead to a reduction in risk for all associated HEs.

Engineering3.4% Environment

0.2%

Passengers21.2%

Public behaviour44.9%

Workforce30.3%

Infrastructure1.9%

Level crossing0.2%

Rolling stock*1.4% Adjacent property/land

0.03%

Weather0.14%

In stations*18.7%

On trains*2.5%

Crime*35.1%

General1.5%

Pedestrian user5.5%

RV user2.8%

Shunter0.1%

Signaller0.5%

Station staff*13.5%

Track worker*10.6%

Train crew*5.6%

Total Risk = 131.95 FWI/year

Level crossing*RV user +

Pedestrian user8.2%

Key risk areas


5.1 Other risk groupings

It is also useful to group the HE and precursor into high level groups that relate to specific causes or areas of risk on the railway. Significant risk groupings include track faults, rolling stock, signals passed at danger (SPADS) and level crossings. Table 16 provides a summary of the top level figures for a variety of groupings concerning these four broad categories. It should be noted that these groupings are not mutually exclusive and the same precursor risk contribution may be counted in more than one group.

Table 16: Selected SRMv8.1 risk groupings

Group description Passenger train risk (FWI/year)

Non-passenger train risk (FWI/year)

Total Risk (FWI/year)

Track faults - grouped for both passenger and non-passenger trains (outside possession)

- - 1.75

Track faults (including incidents inside possession)

1.67 0.11 1.77

Rolling stock faults 3.32 0.50 3.82

SPADs resulting in collision 0.36 0.24 0.60

SPADs resulting in derailment or level crossing collision

0.06 0.03 0.09

Other SPADs and runaways 0.01 0.27 0.28

All level crossings - - 11.21

Road vehicles at level crossings 3.19 0.42 3.61

Footpath crossings - - 3.30

Non-footpath level crossings - - 7.60

To accompany this chapter a detailed breakdown of risk by key risk areas is provided in

Table C1, C2 and C3 which are available via the via the RSSB Rail Risk Portal

www.safetyriskmodel.co.uk

SRM risk vs observed risk


6 SRM risk vs observed risk

The level of safety risk estimated by the SRM is often higher than the observed rate of harm.

This is because the SRM accounts for rare events and the small contributions from many

different types of rare events add up to make an annual average modelled risk that is usually

higher than that which is observed. This holds despite the volatility in observed FWI and the

multi-year risk smoothing used in the SRM to reduce this volatility.

This is particularly the case for passenger risk as shown in Figure 8. This chart is an attempt

to show how the total observed passenger risk has changed over the last nine years and over

CP4.

The blue line represents an annual moving average of all observed FWI normalised by

passenger train km. This is calculated using all of the FWI data reported in the ASPR excluding

passenger assaults. Risk from passenger assaults has been estimated using BTP data

because such events are not well reported in SMIS. This includes all reported injuries in train

accidents as well as movement and non-movement related accidents.

The green line shows a risk metric that attempts to mimic the modelling of the SRM. This is

done by selecting different periods to average the different injury types over. The chart shows

fatalities averaged over ten years, major injuries over 2.5 years, class 1 and class 2 minor

injuries over four years. This is mostly based on data except, unlike the blue line, the FWI

contributions for HETs and passenger assaults are determined from the SRM modelling. This

is a significant simplification of the SRM and should be seen as a rough approximation.

Figure 8 shows the change in different measures of risk over the past nine years and illustrates

the volatility of taking a one-year average of observed risk compared to the relatively less

volatile SRM risk.

Some key observations are:

SRM risk estimation is nearly always higher than that of observed risk.

The occurrence of a major accident may temporarily push the rate of observed risk

higher than the SRM risk estimation (Grayrigg) or closer to the SRM risk estimation

(Ufton Nervet).

There has been a long term trend of decreasing risk, which is becoming less

pronounced and may now have started to plateau.

Because of the difficulty, without hindsight, of differentiating between genuine

trends/turning points and short-term statistical variation, and with the requirement for

a data sample large enough to produce robust risk estimates yet relevant to current

operations, the SRM estimates will lag during periods when the risk profile is changing.

The extent to which they lag is dependent on the time period used in the modelling and

this will vary from HE to HE.

SRM risk vs observed risk


Figure 8: Passenger observed FWI vs SRM FWI approximation

SR

Mv6.7

SR

Mv8

.1

10

14

710

14

710

14

710

14

710

14

710

14

710

14

710

14

710

14

7

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

Normalised passenger risk

SR

M a

ppro

xim

ation

Observ

ed F

WI (m

ovin

g 1

2-m

onth

avera

ge)

SR

M r

esults

Uft

on N

erv

et

Gra

yrig

g

Uncertainty in the SRM risk estimates


7 Uncertainty in the SRM risk estimates

7.1 Introduction

The SRM risk estimates represent the underlying level of risk on the GB rail network. They

are based on an analysis of data reported to SMIS, which is classified according to the HE

and precursor structure of the SRM. The amount of data for each precursor in the SRM can

vary quite considerably. In some cases, there is a lot of data to base a precursor estimate on,

in other cases there is little or very little, and in some cases there is none.

The SRM precursor/HE estimates represent the best estimate of risk based on the available

data for that precursor/HE. For cases where there is a lot of data available, there is a high

level of confidence in the estimations, however, where there is little data, there is less

confidence in the estimate. It has been a long standing aim to quantify this level of uncertainty

and to develop a framework that can determine selected confidence intervals around the SRM

estimates.

This section gives some background to the work that has been undertaken in this area, outline

the methodology that is currently being developed and presents some results based on the

version 8.1 update.

7.2 Uncertainty methodology

In 2003, RSSB commissioned research to investigate quantification of the uncertainty in a risk

assessment model, using the SRM as an example. This research formed R&D project T306

[Ref. 8]. While methods investigated apply primarily to the train accident (HET) models (as

they are built using fault and event tree models), the principles can be equally applied to the

other models of the SRM.

The main difference between the HET models and the HEM/HEN models is that in general

the HEM/HEN models are based on significant amounts of actual injury-related data, while the

HET models are not. This means that the HET uncertainty methodology is mainly aimed at

quantifying model uncertainty in conjunction with statistical uncertainty due to the lack of data.

The HEM/HEN methodology focus, however, can be aimed more at quantifying statistical

uncertainty, as there is ample data.

The occurrence of a hazardous event and the consequences associated with it can be regarded as random. This means that there is inherent uncertainty in the SRM estimates, and year to year it could be expected that different event counts and consequences would be observed for a given hazardous event even if the ‘underlying risk’ did not change. The aim of the uncertainty methodology is to quantify this uncertainty and determine relevant confidence intervals within which we would expect the true value of the SRM estimates to lie given a specified level of confidence.

The main part of the methodology consists of quantifying the uncertainty in the frequency and in the average consequence estimates for each precursor. This involves constructing distributions (either from data or expert judgement, or a mixture of the two) for each of these factors. Once these have been set, a simulation can be run, where frequency and consequence estimates are sampled from the distributions many thousands of times and combined to give a distribution of the risk estimates for each precursor. Subsequently, these can be sampled to give distributions of the risk at HE level, HEM/HEN level or at the overall SRM system risk level which can be used to determine confidence intervals.



7.3 SRM uncertainty results

The uncertainty methodology currently in development has been applied to the version 8.1

HEM/HEN risk estimates. YDS risk has been included, while HET risk has been excluded from

this analysis. Excluding the HET contribution gives an overall SRM combined HEM/HEN risk

of 131.6 FWI per year. Comparison between the uncertainty model and the SRM risk

estimates are given in Table 17 (values in this table exclude all HET risk).

It should be noted that the uncertainty and confidence intervals in this section are based on

statistical uncertainty and do not take into account other potential sources of error such as

modelling assumptions (many models implicitly assume that the risk has been relatively stable

for the past few years) and data quality, particularly the underreporting of events.

Figure 9: Risk distribution for the total SRMv8.1 HEM/HEN risk

SRM

LL 125.8 -7.1 Mean 132.9 UL 140.6 7.7

Figure 9 shows the 95% confidence interval12 around the overall HEM/HEN risk of 131.6

FWI/year. The boxes above the chart show some properties of the distribution of the risk that

12 A confidence interval indicates the range of values an estimate is likely to lie in given a specified level of confidence. In this case a 95% confidence interval means that if we were to rerun (if this was possible) the whole operation of the railway again, as it was over the SRMv8.1 data period, collect the data and calculate a 95%

121 123 125 127 129 131 133 135 137 139 141 143 145

Pro

bab

ilit

y d

en

sit

y

Risk (FWI/year)

95%

Table 17: Comparison of SRM and uncertainty model risk estimates

SRM risk group SRM estimate (FWI/yr) Uncertainty model

distribution mean (FWI/yr)

Overall 131.6 132.9

HET Not shown Not calculated

HEM 49.6 50.0

HEN 82.0 82.8

Passengers 55.6 55.8

Workforce 32.2 32.5

MOPs 43.8 44.5



has been constructed. The central white box gives the mean (average) value of the distribution

and it can be seen that this corresponds well with the overall SRM HEM/HEN risk estimate of

131.6 FWI/year13 (see Table 2). The other two white boxes either side show the extent of the

95% confidence interval, with a lower limit (LL) of 125.8 FWI/year and an upper limit (UL) of

140.6 FWI/year. The blue boxes show the absolute risk difference between the LL/UL and the

distribution mean. In this case it can be seen that the UL is 7.7 FWI/year above the mean risk,

while the LL is 7.1 FWI/year below the mean risk. Note that all charts are drawn to the same

scale on the x axis to allow comparisons between them.

Figure 10 shows the 95% confidence interval for HEM risk and HEN risk considered separately, while Figure 11 shows the 95% confidence interval for passenger, workforce and public risk considered separately. Figures for the mean risk of each of these distributions along with the LL and UL of the 95% confidence interval can be read from the white and blue boxes as before.

Figure 10: Risk distribution for the SRMv8.1 risk for HEM and HEN separately

HEM

LL 44.1 -6.0 Mean 50.0 UL 56.8 6.8

HEN

LL 79.5 -3.3 Mean 82.8 UL 86.2 3.4

confidence interval for the overall HEM/HEN risk, we would expect in 19 out of 20 occasions (ie 95% of the time) the confidence interval would contain the true underlying level of risk. 13 This is to be expected from the way the HEM/HEN uncertainty model has been constructed. There is a slight overestimate due to the use of lognormal distributions to model the uncertainty in low event counts.

38 40 42 44 46 48 50 52 54 56 58 60 62

Pro

ba

bil

ity d

en

sit

y

Risk (FWI/year)

95%

70 72 74 76 78 80 82 84 86 88 90 92 94

Pro

bab

ilit

y d

en

sit

y

Risk (FWI/year)

95%



Figure 11: Risk distribution for the SRMv8.1 risk by person type

Passenger

LL 53.6 -2.1 Mean 55.8 UL 57.9 2.1

Workforce

LL 31.4 -1.1 Mean 32.5 UL 33.6 1.1

Member of Public

LL 38.1 -6.4 Mean 44.5 UL 51.9 7.4

44 46 48 50 52 54 56 58 60 62 64 66 68

Pro

bab

ilit

y d

en

sit

y

Risk (FWI/year)

95%

20 22 24 26 28 30 32 34 36 38 40 42 44

Pro

bab

ilit

y d

en

sit

y

Risk (FWI/year)

95%

33 35 37 39 41 43 45 47 49 51 53 55 57

Pro

bab

ilit

y d

en

sit

y

Risk (FWI/year)

95%



Note that proportionally, there is more uncertainty in the estimate of HEM risk. This is because HEM risk tends to be dominated by a relatively small number of fatalities, whereas HEN risk tends to be dominated by a greater number of lower consequence events. The same reasoning explains why there is more uncertainty in the estimate of public risk than in the estimates of risk to passengers or members of the workforce.

7.4 Uncertainty analysis next steps

The work presented in this chapter is on-going and the results should be treated as preliminary

findings, however they do illustrate how the results can be presented. The next steps are to

finalise the HEN/HEM uncertainty methodology and to continue to develop the HET

methodology.

The eventual aim of this work is to construct a framework that can be used to assess the

uncertainty in the SRM risk estimates at any level that is required and to present the

information in a format that is accessible and understandable. This can help inform decisions.

For example, when interpreting benefit-cost ratios to determine whether a measure is needed

to ensure safety so far as is reasonably practicable, the judgement as to whether the cost is

grossly disproportionate to the benefit is informed by an understanding of the level of

uncertainty in the estimates of both.

Individual fatality risk


8 Individual fatality risk

8.1 Introduction

Individual fatality risk is defined as the probability of a fatality to which a category of individual

is exposed. Fatality risk is distinct from FWI risk, because it excludes the component of risk

relating to injuries and shock/trauma.

The industry document Taking Safe Decisions [Ref. 2] clarifies that collective risk (rather than

individual fatality risk) is used in the formulation of arguments about whether a particular

measure is needed to ensure risk is acceptable. However, individual risk can help a company

understand its risk profile and prioritise safety management effort.

Note that the comparisons made in the following sections are between the figures reported in

the SRM-RPB version 7 (based on SRMv7), the YDS report (based on the SRM-YDS) and

the latest figures for SRMv8.1. Changes between versions shown here are due to both

modelling changes and the updating of data to 30 September 2013.

8.2 Fatality risk

The predicted individual fatality risk from SRMv8.1 was analysed for each of the person

categories listed below:

Passengers

Workforce, including:

Train drivers (eg passenger train (PT) drivers, freight train drivers,

driver/shunters)

Other train crew

Infrastructure workers

Other workforce (eg train dispatch and ticket line staff)

YDS based staff members (engineering staff and YDS cleaner/admin)

Members of the public

Fatalities on the railway are dominated by suicide and trespass, together amounting to 56.5%

of the total fatality risk. Excluding these types of event, Figure 12 shows the fatality risk for

each person category.

In the following sections, the individual fatality risk to each person category is discussed and

compared with its equivalent value in SRMv7+YDS.

To accompany this chapter a detailed breakdown of individual fatality risk by person group

and hazardous event is provided in Table D1 which is available from the RSSB Rail Risk

Portal www.safetyriskmodel.co.uk.




Figure 12: Fatality risk for each person category per year (SRMv8.1)

8.3 Passengers

Of the population of train passengers, regular commuters have the greatest exposure to risk

from the railway environment. The individual fatality risk to a commuter is therefore assumed

to be indicative of the worst-case for the whole population of train passengers14.

Figure 13: Causal breakdown of passenger fatality risk

It is assumed that, on average, each commuter makes 450 journeys per year (two journeys

per day, five days per week for 45 weeks per year). SRMv8.1 predicts a probability of fatality

of 1 in 403,976 per year for the average passenger (Table 18), which is a reduction of 33.6%

compared with the corresponding risk in SRMv7+YDS. This large reduction in individual

fatality risk is due in part to the increase in passenger journeys and partially due to a reduction

in observed and modelled fatality risk resulting from assaults and passenger train derailments.

As assault risk was not recalculated using the SRMv7 data cut-off the reduction in observed

fatalities is not directly comparable.

14 Whilst it is logical to do this, analysis has shown that per journey, regular commuters have a lower level of risk than other travellers. This worst case should be seen as a best guess approximation.

8.30 Fatalities per year



0

2

4

6

8

10

12

14

Passenger Workforce Public

An

nu

al

fata

liti

es

45.8%

20.6%

11.5%

7.3%

6.4%

8.4%

0 1 2 3 4

Platform edge incidents (notboarding/alighting)

Train accidents: collisions andderailments

Slips, trips, and falls

Assault and abuse

Struck/crushed by train

All other risk categories

Annual fatalities



The most significant contributions to passenger individual fatality risk are broken down in

Figure 13.

Table 18: Total passenger individual fatality risk

SRMv8.1 SRMv7+YDS % change v7+YDS to v8.1

Fatality risk per year 8.30 10.44 -20.49%

Annual passenger journeys 1,508,403,942 1,259,400,000

19.77% Population size (assuming each person undertakes 450 journeys per year)

3,352,009 2,798,667

Individual fatality risk (probability of a fatality per year per passenger)

2.48E-06 3.73E-06

-33.62% 1 in 403,976 1 in 268,169

8.4 Workforce

The total workforce fatality risk calculated in SRMv8.1 was distributed into specific workforce

types in order to estimate their individual fatality risk.15 Individual and absolute fatality risks are

summarised in Figure 14 and Figure 15.

Population numbers for each of these workforce types; estimated from Network Rail (NR)

timesheet data (infrastructure workers and OTP drivers), and RSSB surveys of NR and each

TOC/FOC (all other workforce groups), are presented in Table 19 along with their individual

fatality risk.

Comparison of Table 18 with Table 19 shows that individual fatality risk to the workforce is an

order of magnitude greater than for passengers. This is in line with the workforce’s increased

exposure to the railway environment and the hazardous nature of the work carried out in the

rail industry.

Note that for SRMv7 ‘OTP driver’ risk was grouped with the ‘Other workforce’ risk. This has

been separated out here as the OTP driver risk is observed to be significantly higher than risk

for the ‘Other workforce’ group. Therefore there are no comparisons between SRMv7 and

SRMv8.1 for these workforce groups.

A summary of expected annual fatalities by workforce group is given in Table 27 in Appendix

C.

15 During this process a number of assumptions were made, which are detailed in Appendix D.1.



Figure 14: Expected annual fatalities by workforce role

Figure 15: Individual fatality risk by workforce role

0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

2.4

2.7

3D

rive

r(s

hun

ter)

OT

P d

rive

r

Infr

astr

uctu

rew

ork

er

Fre

ight tr

ain

driver

Oth

er

wo

rkfo

rce

Pa

ssen

ge

rtr

ain

drive

r

YD

Se

ng

inee

ring

sta

ff

Oth

er

tra

incre

w

YD

Scle

an

er/

adm

in

Exp

ecte

d a

nn

ua

l fa

talit

ies

Expected annualfatalities

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Driver

(shunte

r)

OT

P d

river

Infr

astr

uctu

rew

ork

er

Fre

ight tr

ain

driver

Oth

er

wo

rkfo

rce

Pa

ssen

ge

r tr

ain

driver

YD

S e

ngin

eering

sta

ff

Oth

er

train

cre

w

YD

Scle

an

er/

adm

in

Indiv

idual fa

talit

y r

isk p

er

10,0

00 y

ears

Individual fatalityrisk per 10,000years



Table 19: Workforce individual fatality risk breakdown

Person Type Expected annual fatalities

Population v8

Individual fatality risk (probability of a fatality per year)

SRMv8 SRMv7 or YDS-SRM

% change

Infrastructure workers

2.399 30,500 7.86E-05 9.22E-05

-15% 1 in 12,716 1 in 10,847

OTP drivers 0.129 1,525 8.48E-05

- - 1 in 11,799

Passenger train drivers

0.473 13,145 3.60E-05 4.22E-05

-15% 1 in 27,805 1 in 23,670

Freight train drivers

0.136 2,378 5.74E-05 5.43E-05

6% 1 in 17,432 1 in 18,410

Other PT crew members

0.204 13,284 1.54E-05 2.34E-05

-34% 1 in 65,117 1 in 42,818

Other workforce 0.594 16,019 3.71E-05

- - 1 in 26,960

Driver/shunter 0.120 1,338 8.96E-05 1.30E-04

-31% 1 in 11,161 1 in 7,721

YDS engineering staff

0.146 6,379 2.29E-05 2.43E-05

-6% 1 in 43,652 1 in 41,226

YDS cleaner/admin

0.022 2,123 1.04E-05 1.01E-05

4% 1 in 95,757 1 in 99,455

8.5 Members of the public

In hazardous industries where all operations occur within a discrete, clearly-defined,

geographical location, the numbers of exposed members of the public, and therefore individual

fatality risk to the public, can be determined. For the GB railway, however, it is only possible

to discuss fatality risk to the public population as a whole. The individual fatality risk to

members of the public (excluding suicides and trespass) is equivalent to 11.6 fatalities per

year. The most significant contributions to MOP individual fatality risk are broken down in

Figure 16.



Figure 16: Causal breakdown of MOP fatality risk

The dominant fatality risk to members of the public (non-trespasser) occurs at level crossings,

including all events in the struck/crushed by train category. Individual fatality risk to members

of the public (non-trespasser) at levels crossings is equivalent to 9.3 fatalities per year, or

80.2% of the non-trespass total fatality risk.

Individual fatality risk estimates for regular crossing users have not been given as it has not

been possible to calculate reliable values given the uncertainty in usage data and the large

variations in crossing types.

54.7%

25.5%

4.3%

3.9%

3.3%

8.4%

0 2 4 6 8


Train accidents: strikes withroad vehicles at level crossings

Platform edge incidents (notboarding/alighting)


Falls from height

All other risk categories

Annual fatalities

The F-N curve


9 Multiple fatality risk: the F-N Curve

While there are no specific criteria associated with the acceptability of the frequency of train

accidents that could potentially lead to multiple fatalities, it is important to understand the

vulnerability of the railway to such accidents. Guidance on taking multiple fatality events into

account in the decision making process is given in Taking Safe Decisions.

9.1 F-N results

Using the event tree structures within SRMv8.1, for all the train accident hazardous events

with the potential to lead to multiple fatalities, an overall F-N curve (frequency versus number

of fatalities) for train accidents has been produced. This curve is shown in Figure 17.

The curve shows that as the number of potential fatalities associated with an event increases,

the frequency of occurrence of the event reduces rapidly. Key points on the curve and

information on how the rest has changed between SRM versions are given in Table 20 and

Table 21.

Table 20: Frequency of train-related incidents leading to multiple fatalities

Incidents (events/year) affecting passengers, staff and MOP

SRMv2 (Jul-99)

SRMv3 (Mar-01)

SRMv4 (Dec-03)

SRMv5 (Dec-05)

SRMv6 (Sep-08)

SRMv7 (Sep-10)

SRMv8.1 (Sep-13)

>=5 fatalities 0.700 0.416 0.265 0.189 0.186 0.173 0.144

>=10 fatalities 0.320 0.180 0.127 0.110 0.065 0.055 0.047

>=25 fatalities [not

included] [not

included] [not

included] 0.021 0.020 0.016 0.011

Table 21: Return periods of train-related incidents leading to multiple fatalities

Years between incidents affecting passengers, staff and MOP

SRMv2 (Jul-99)

SRMv3 (Mar-01)

SRMv4 (Dec-03)

SRMv5 (Dec-05)

SRMv6 (Sep-08)

SRMv7 (Sep-10)

SRMv8.1 (Sep-13)

>=5 fatalities 1.4 2.4 3.8 5.3 5.4 5.8 6.9

>=10 fatalities 3.1 5.6 7.9 9.1 15.3 18.3 21.2

>=25 fatalities [not

included] [not

included] [not

included] 48 50 62 87.0

The F-N curve


Figure 17: The F-N Curve – all person and train accident types.

1.0

0E

-07

1.0

0E

-06

1.0

0E

-05

1.0

0E

-04

1.0

0E

-03

1.0

0E

-02

1.0

0E

-01

1.0

0E

+0

0

2 2

0 2

00

Cumulative frequency (events/year)

Nu

mb

er

of p

asse

ng

er,

sta

ff a

nd

me

mb

er

of p

ub

lic f

ata

litie

s

The F-N curve


The continued increase in expected time between train-related incidents that lead to multiple

fatalities can be seen from SRMv2 to SRMv8.1 (Figure 18). The more recent reductions are

due to a generally improving safety performance trend, as reflected in the SRMv8.1 train

accident model results. The reasons for these reductions include many steps that the industry

has taken to reduce the likelihood of accidents occurring (eg the introduction of TPWS) and to

reduce the consequences if accidents do happen (eg the overall improvement in train vehicle

crash-worthiness due to the removal of Mark 1 slam-door rolling stock). There is also likely to

be some effect from enhancements to the train accident models over successive SRM

versions.

Figure 18: Estimated frequency of train accident-related fatality events

Figure 19 shows the F-N curve for the three main categories of train accident: collisions,

derailments and level crossing accidents. This chart shows that multi-fatality derailment events

generally occur more frequently for all severity levels and level crossing events least

frequently. Note that these three categories do not cover the entirety of the train accident HEs

in the SRM.

Figure 20 shows the contribution of key hazardous events to the F-N curve. It is apparent that

the majority of events with fewer than 100 fatalities are HET-12 (passenger train derailments)

events, whilst the majority of events with 100 or more fatalities (which are estimated to occur

very infrequently at a rate of less than 1 per 7500 years) result from HET-13 (non-passenger

train derailments) events as a result of train accidents involving trains carrying hazardous

materials.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Fre

qu

en

cy (

eve

nts

/ye

ar)

>=5 fatalities >=10 fatalities

v4, Dec-03

v5, Dec-05 v6, Sep-08

v3, Mar-01

v2, Jul-99

v7, Sep-10

v8, Sep-13

The F-N curve


Figure 19: F-N curve – plotted separately for three categories of train accidents

1.0

0E

-09

1.0

0E

-08

1.0

0E

-07

1.0

0E

-06

1.0

0E

-05

1.0

0E

-04

1.0

0E

-03

1.0

0E

-02

1.0

0E

-01

1.0

0E

+0

0

2 2

0 2

00

Cumulative frequency (events/year)

Nu

mb

er

of p

asse

ng

er,

sta

ff a

nd

me

mb

er

of

pu

blic

fa

talit

ies

Co

llisio

ns

De

railm

en

tsL

eve

l cro

ssin

g R

V s

trik

es

The F-N curve


Figure 20: Contribution of key hazardous events to the F-N curve

9.2 F-N modelling approach

Only the train accident models have been considered in the F-N curve calculation as these

are the main contributors to multiple fatality events. Previous F-N figures have included all

HEs, however the contribution for non-train accidents with two or more fatalities to these

figures is minimal.

SRMv3 F-N results were presented in two versions — with and without the effects of TPWS.

For comparison in this section the without TPWS figures have been used, as SRMv3 was

produced during the transition period before TPWS had been fully implemented.

As in previous SRM versions, the basic F-N analysis suggests that the frequency of accidents

leading to 25 fatalities has reduced. However, even though the event trees within the SRM

break down the HEs into a large number of different potential outcomes, each consequence

estimate still only represents a single average consequence for that outcome. In reality a

greater spread of consequences might actually be possible. This is the case, for example, with

public fatalities in models involving the spillage of hazardous goods, where the possibility for

very high consequence events exists, albeit with a very low frequency.

Consequently, while the average risk associated with such outcomes is accurately modelled

within the SRM, the full range of higher and lower consequence outcomes that make up this

average is not always explicitly modelled. The F-N analysis has been adjusted for high-fatality

public events. The adjusted results have been calculated by redistributing the high-fatality

portion of public fatality events whilst maintaining the overall level of risk. As a result of the

correction, the frequencies of higher fatality events are now considered to be more realistically

represented on the F-N curve in SRMv6, SRMv7 and SRMv8.1.

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2 5 10 30 100 300

HET-01

HET-02

HET-10

HET-12

HET-13

HET-17

Fatalities per event

Pe

rce

nta

ge

co

ntr

ibutio

n t

o F

-N C

urv

e

Risk at the PTI


10 Remodelling risk at the platform-train interface

The update process to SRMv8 has involved the remodelling of several hazardous events that

together cover hazards at the platform-train-interface (PTI). The new structure provides more

granular information to improve understanding of PTI risk and the assessment of PTI hazards.

The following five passenger hazardous events and one member of public (non-trespasser)

hazardous event have been remodelled. These are:

HEM-05 and HEM-43 (train door closes on passenger/MOP incidents), remodelled to

single out ‘trap and drag’ incidents and train movement.

HEM-09 and part of HEM-06 (boarding and alighting incidents), restructured and new

precursors defined to detail train motion at the time of the event.

HEM-06, HEM-08, and HEM-10 (fall from platform and/or struck by train incidents),

restructured and new precursors defined to detail train motion at the time of the event.

The following sections describe the changes in more detail and explain further some of the

motivating factors behind the remodelling.

10.1 Background and objectives

High-profile accidents, including at James St in 2011, have focused attention on accidents at

the PTI involving train dispatch. Consequently there has been considerable interest in

improving the management of the PTI with discussions being held at an Industry Safety

Meeting in February 2013 and the ORR/RSSB industry workshop in April 2013.

The rail industry has established a PTI Strategy Group which is developing a PTI Strategy

focused on optimising safety, capacity and performance issues. To support the work of this

group and industry efforts to manage the risk there is a need to better understand risk at the

PTI, which this remodelling aims to facilitate.

Changes to the PTI model permit more detailed, immediate insight into PTI hazards than has

been the case for past SRM versions.

10.2 The remodelling process

10.2.1 Scope of changes

The hazardous events considered in this remodelling are all hazardous events which relate

specifically to passenger and member of public PTI risk. These hazardous events are given

in Table 22.

Risk at the PTI


Table 22: Remodelled PTI HE descriptions

HE Code Description

HEM-05 Train door closes on passenger

HEM-06 Passenger falls between stationary train and platform

HEM-08 Passenger fall from platform and struck by train

HEM-09 Passenger injury while boarding/alighting a train (platform side)

HEM-10 Passenger struck by/contact with moving train while on platform

HEM-43 Train door closes on MOP (non-trespasser)

10.2.2 Remodelling steps

The remodelling process can be seen as a compromise between creating a highly detailed

model and being able to reliably quantify it using the available accident and incident data. In

order to create the new PTI accident models the available accident dataset was analysed with

an emphasis on finding what useful information could be reliably extracted from incident

narratives. The conclusions of this investigation were then used to decide on a consistent and

quantifiable way to restructure the models that would benefit the PTI strategy.

The datasets have all been recoded to the new structure and the model was analysed in this

new format for SRM v8.

10.2.3 PTI structural changes

Table 23 summarises the new model structure for each affected hazardous event.

Risk at the PTI


Table 23: Remodelled PTIHEs. Summary of changes

HE code Description Summary of changes

HEM-05 Train door

closes on

passenger

Remodelled to isolate 'trap and drag’ incidents. Now

distinguishes between events where the train door has

closed on a passenger, and where the train has or has not

subsequently moved with the passenger remaining trapped.

HEM-06 Passenger fall

between train

and platform

Expanded to segregate three train movement scenarios

that are connected to a passenger fall between a train and

platform.

There are now three sub-hazardous events covering

passenger falls involving a stationary train, a moving train

and a stationary train which subsequently moves.

HEM-08 Passenger fall

from platform

and struck by

train

Remodelled so that events are grouped according to the

motion of the train (arriving at, departing from, or travelling

through the station) at the time of accident.

HEM-09 Passenger

injury while

boarding and

alighting

Existing boarding and alighting sub-hazardous events have

been duplicated to distinguish between events involving

stationary and moving trains.

A new sub-hazardous event for passenger alighting not at

platform has been added.

HEM-10 Passenger

struck

by/contact with

moving train

while on

platform

This event has been more rigorously defined so it is

restricted to events where a passenger has made contact

with a moving train while on the platform and has remained

entirely on the platform. Events that no longer fit this

definition were moved to newly created sub-hazardous

events for the other PTI HEMs.

Precursors restructured to separate events according to

train motion (arriving at, departing from, or travelling

through the station) at the time of accident.

HEM-43 Train door

closes on MOP

(non-trespasser)

This hazardous event is the MOP (non-trespasser)

equivalent of HEM-05. Similarly it has been remodelled to

isolate 'trap and drag’ incidents.

10.3 Impact on the risk profile

These changes led to some events being re-categorised (for example, moving from HEM-08

or HEM-10 to HEM-06). Table 24 summarizes the hazardous events affected along with the

overall change in the modelled risk for version 6.6 to version 6.7 (an equivalent comparison

between SRMv7 and SRMv8.1 cannot be provided as results were not computed using the

new PTI structure for SRMv7). This table shows that overall risk at the PTI has remained

relatively the same but it has shifted between HEs significantly as a result of the remodelling.

Risk at the PTI


Table 24: Summary of the changes in risk for PTI hazardous events

HE HE description Risk (FWI/year)

v6.6 v6.7

HEM-05 Train door closes on passenger 0.57 0.66

HEM-06 Passenger fall between stationary train and platform

1.55 2.80

HEM-08 Passenger fall from platform and struck by train

2.19 1.50

HEM-09 Passenger injury while boarding/alighting a train (platform side)

3.35 3.14

HEM-10 Passenger struck by/contact with moving train while on platform

1.32 0.68

HEM-43 Train door closes on MOP (non-trespasser)

0.0021 0.0044

Total 8.99 8.79

SRM governance and RPB updates


11 SRM governance and RPB updates

11.1 Data and Risk Strategy Group

The Safety Risk Model (SRM) and related tools such as the SRM Risk Profile Tool are now

under the remit of the DRSG. This group is a subgroup of the SSRG. Full details of the scope

and remit of DRSG can be found on the RSSB website16.

11.1.1 SRM Practitioners Working Group

Throughout control period 4, including the production of SRMv8, SRM-PWG was the industry

governance body of the SRM. It was set up to facilitate a structured process for eliciting the

industry’s views on the development and use of the SRM. The SRM-PWG provided

governance for changes to the SRM.

The SRM-PWG was formed under the authority of the industry’s Safety Policy Group (SPG) -

the predecessor to the current System Safety Review Group (SSRG). SRM-PWG’s remit was

to engage stakeholders in the development and control of future versions of the SRM and its

related outputs. These outputs include the SRM-RPB and SRM-RPT.

The modelling changes implemented as part of the update of the SRM to version 8 have been

endorsed by SRM-PWG. The re-revised version 6 figures (SRMv6.7) and the SRMv8 figures

were presented to the group in March 2014 and recommended for approval by SSRG, which

took on responsibility after SPG was disbanded and before DRSG was formed. Following this

meeting the results were then presented to SSRG and approved in March 2014.

11.2 Update history

Since version 1 in 2001, the SRM-RPB has been updated regularly so that the risk profile

remains as current as is reasonably practicable. Since version 2, the SRM-RPB has been

issued approximately every 18–24 months. The last SRM-RPB update was for version 7

which was issued August 2011. Since then there have been two shorter versions of the Risk

Profile Bulletin, Risk Profile Reports (RPRs) which were:

Version 7.5, detailing the SRM v7.5 partial update,

The Yards, Depots and Siding Risk Profile Report detailing the development and

calculation of the YDS-SRM

This RPB version 8.1 is the ninth Bulletin (eleventh including Risk Profile Reports) release

and covers SRMv6.7, SRM-YDS and SRMv8.1. The update history up to and including this

version is shown in Table 25 below.

16http://www.rssb.co.uk/groups-and-committees/rssb-board/safety/system-safety-risk-group/data-and-risk-strategy-group

http://www.rssb.co.uk/groups-and-committees/rssb-board/safety/system-safety-risk-group/data-and-risk-strategy-group

http://www.rssb.co.uk/groups-and-committees/rssb-board/safety/system-safety-risk-group/data-and-risk-strategy-group



Table 25: SRM update history

Version Issue date Data cut-off Major change (from previous version)

1 January 2001 July 1999 First version

2 July 2001 July 1999 Re-release of SRMv1

3 February 2003 March 2001 Full data update and model enhancements

Inclusion of TPWS

4 January 2005 December 2003 Full data update and model enhancements

5 August 2006 December 2005

Full data update and model enhancements

Removal of Mk1 slam-door rolling stock from models

Inclusion of OTP risk model

5.5 May 2008 October 2007 Interim partial data update

Change in FWI weightings

6 June 2009 September 2008 Full data update and model enhancements CP4 HLOS benchmark version

6.5 January 2011 September 2008 Enhanced version 6

7 June 2011 September 2010 Full data update

YDS November 2012

September 2011 Introduction and calculation of yards, depots and sidings risk profile

6.6 March 2013 September 2008 Enhanced version 6.5 (required for HLOS comparisons)

7.1 March 2013 September 2010 Enhanced version 7 (required for HLOS comparisons)

7.5 March 2013 June 2012 Interim partial data update

6.7 March 2014 September 2008

Enhanced version 6.6 (required for HLOS comparisons).

Model enhancements to allow like for like comparisons with v8.

8 March 2014 September 2013

Full data update and model enhancements.

Full incorporation of YDS–SRM into main SRM model.

Final CP4 HLOS benchmarking.

8.1 May 2014 September 2013 Update of suicide and trespass risk models due to improved data accuracy resulting from improved data sharing with BTP.



11.3 Updates to the SRM during CP4

Version 8 is the final full update of the SRM required for HLOS metric comparisons across

CP4 using SRMv6 figures as benchmarks. Figure 21 illustrates the timeline of SRM updates

during CP4.

Figure 21: Timeline of updates of the SRM and RPB that occurred in CP4

11.4 Future updates during CP5

Moving into CP5 there is no longer the requirement to use the SRM to track industry

progress against HLOS targets. SRM-PWG has been disbanded with DRSG taking its place.

As a result of this, future plans for the development of the SRM are being discussed and a

strategy is currently being developed.

2009 2010 2011 2012 2013 2014

Version 6Mar 2009

(risk figures)

Jun 2009(RPB)

CP4

2015

CP5

Version 7Mar 2011

(risk figures)

Jun 2011(RPB)

Version 7.5Dec 2012

(risk figures)Mar 2013

(RPR)

Version 8Mar 2014

(risk figures)Aug 2014

(RPB)

Contributors


12 Contributors

Details of the preparation and approval of the SRM and SRM-RPB are given below:

Prepared by: Carol Bloxsome

Steven Burke

Stuart Carpenter

Marcus Dacre

Joanna Evans

Alex Gilchrist

Ben Gilmartin

Jonathan Gregory

Chris Harrison

Alex Healy

Jay Heavisides

Matthew Hunt

Rachael Johnson

Albert Law

Reuben McDonald

Paul Murray

Kevin Thompson

Reviewed by: George Bearfield

Marcus Dacre

Chris Harrison

SRMv8 and SRMv6.7 scope and update changes were endorsed by the SRM Practitioners

Working Group on behalf of the SSRG.

Approved by: George Bearfield

Release date: August 2014

Correspondence may be sent to: RSSB

Block 2, Angel Square 1 Torrens St London EC1V 1NY UK

Or: [email protected]

mailto:[email protected]

Acronyms and glossary


13 Acronyms and glossary

13.1 Acronyms

ABCL Automatic barrier level crossing, locally-monitored

AHB Automatic half-barrier (level crossing)

ALCRM All Level Crossing Risk Model

AOCL+B Automatic open level crossing, locally-monitored (with half barrier)

ASPR Annual Safety Performance Report

BTP British Transport Police

CP4/CP5 Control period 4/5

CSM RA Common Safety Method on Risk Evaluation and Assessment

DfT Department for Transport

DRSG Data and Risk Strategy Group

FP Footpath level crossing

FWI Fatalities and weighted injuries

GB Great Britain

HE Hazardous event

HLOS High-level output specification

HSE Health and Safety Executive

KRA Key risk area

LC Level crossing

LUL London Underground Ltd

MCB Manually-controlled barrier level crossing

MCB+OD Manually-controlled barrier level crossing with obstacle detector

MCG Manually-controlled gate level crossing

MOP Members of the public

NR Network Rail

OC Open level crossing

ORR Office of Rail Regulation

POS Inside possession

PTI Platform-train interface

RGS Railway Group Standards

RIDDOR The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations

1995

RMF Risk Management Forum



RSSB Rail Safety and Standards Board

SMIS Safety Management Information System

SPAD Signal passed at danger

SPG Safety Policy Group

SRM Safety Risk Model

SRM-PWG Safety Risk Model Practitioners Working Group

SRM-RPB Safety Risk Model: Risk Profile Bulletin

SRM-RPT Safety Risk Model: Risk Profile Tool

SSP Strategic Safety Plan

SSRG System Safety Risk Group

TABS Track Access Billing System

TfL Transport for London

TPWS Train Protection and Warning System

UWC(+T) User-worked level crossing (+telephone)

VPF Value of preventing a fatality

YDS Yards, depots and sidings

13.2 Glossary

The following list describes terms as they are used in the SRM.

acceptable level of risk The CSM RA defines risk acceptance principle to mean: “the

rules used in order to arrive at the conclusion whether or not the

risk related to one or more specific hazards is acceptable”. It

also defines safety measures to mean: “a set of actions either

reducing the frequency of occurrence of a hazard or mitigating

its consequences in order to achieve and/or maintain an

acceptable level of risk”.

The risk acceptance principles are explained in detail in Taking

Safe Decisions [Ref. 2]

ACTRAFF A database for recording actual traffic movement across the

network.

assault SMIS records incidents in which ‘in circumstances related to

their work, a member of staff is assaulted, threatened or

abused, thereby affecting their safety or welfare’.

BTP records and categorises criminal assaults in accordance

with Home Office rules. For the majority of RSSB’s work, BTP

crime codes have been grouped into higher level categories to

facilitate analyses and comparisons with SMIS records.



awkward movement An injury caused by an unusual body movement, eg twisting or

stretching, which is received in the course of carrying out

normal everyday activities. It excludes any injuries received

from lifting or carrying objects which are classified under

manual handling.

child A person aged 15 years or below.

cleaner/admin staff All those workers who are not engineering and maintenance

staff, and who are not involved in shunting/driving activities.

It is specifically directed at those engaged in cleaning and train

servicing activities that do not actually involve any physical

maintenance work, plus those supervisors and administration

staff who are occasionally on the shop floor or in the yard.

collective risk The aggregate risk, possibly for a range of different groups,

associated with their exposure to a particular scenario or

hazardous event. The SRM calculates collective risk as the

average number of fatalities, or FWI/year that would be

expected to occur from a hazardous event, or group of

hazardous events. When undertaking an assessment of

whether or not a measure is necessary to reduce risk to a

level that is acceptable, the change in risk associated with the

measure is a collective risk estimate.

consequence The amount of safety harm directly caused by a hazardous

event. This is quantified in terms of fatalities, injuries and

occurrences of shock and trauma.

control measure Any means to reduce the frequency of a hazardous event

and/or minimise the consequence following its occurrence.

Control measures may be physical devices, procedures, or a

system of both.

driver/shunter Drivers of trains undertaking shunting manoeuvres (and

entering/exiting the site) on YDS sites, and the shunters that

assist in those manoeuvres on the ground.

engineering staff All workers who are undertaking engineering and maintenance

work (including maintenance during train servicing) on trains

and train-related components on a YDS site. This also includes

fitters and machine operators, loading workers (freight) and

other workers on the site involved in operational rail activities

that do not fit into other categories.



escalation factor Any failure which significantly increases, or ‘escalates’, the

consequence of a hazardous event. For instance, a train

derailment (the hazardous event) could escalate into a bridge

collapse onto the train, a fire or release of hazardous goods.

An escalation factor may be a system failure, sub-system

failure, component failure, human error, physical effect or

operational condition. It may occur individually, or in

combination with other escalation factors.

fatalities and weighted

injuries (FWI)

The aggregate amount of safety harm.

One FWI is equivalent to:

one fatality, or

10 major injuries, or

200 Class 1 minor injuries, or

200 Class 1 shock/trauma events, or

1,000 Class 2 minor injuries, or

1,000 Class 2 shock/trauma events.

fatality Death occurs within one year of the accident.

frequency The rate of occurrence (eg the number of events per year).

hazardous event (HE) An incident that has the potential to be the direct cause of

safety harm.

HLOS A key feature of the access charges review. Under Schedule 4

of the 2005 Railways Act, the Secretary of State for Transport

(for England and Wales) and Scottish Ministers (for Scotland)

are obliged to send to ORR a high level output specification

(HLOS) and a statement of funds available, to ensure the

railway industry has clear and timely information about the

strategic outputs that Governments want the railway to deliver

for the public funds they are prepared to make available. ORR

must then determine the outputs that Network Rail must

deliver to achieve the HLOS, the cost of delivering them in the

most efficient way, and the implications for the charges

payable by train operators to Network Rail for using the

railway network.

individual fatality risk The probability of fatality per year to which an individual is

exposed from the operation of the railway. Individual risk is a

useful notion when organisations are seeking to benchmark

their risk profile and to prioritise safety management effort.

The ORR categorises individual risk as ‘unacceptable’,

‘tolerable’ and ‘broadly acceptable’ for the purposes of

prioritising its enforcement activity.



infrastructure worker A member of the workforce whose responsibilities include

engineering or technical activities on or about the track. This

includes track maintenance, civil structure inspection,

signalling and telecommunications renewal/upgrade,

engineering supervision, acting as a controller of site safety,

hand signaller or lookout and machine operation.

level crossing A junction between a road, footpath, bridleway etc and the

railway, where both are at ground-level.

mainline railway Any location that is connected to the running lines but is not a

YDS site

major injury Injuries to passengers, staff or MOP as defined in Schedule 1

of RIDDOR. This includes losing consciousness, most

fractures, major dislocations, loss of sight (temporary or

permanent) and other injuries that resulted in hospital

attendance for more than 24 hours.

1 FWI is equivalent to 10 major injuries.

minor injury Class 1: Injuries to passengers, staff or MOP, which are neither a fatality nor a major injury, and:

For passengers or MOPs, result in the injured person being taken to hospital from the scene of the accident (as defined as reportable in RIDDOR 1995 amended April 2012).

For workforce, result in the injured person being incapacitated for their normal duties for more than three consecutive calendar days, not including the day of the injury.

Class 2: All other physical injuries that are not Class 1, but must still be reported in SMIS for compliance with GE/RT8047 [Ref. 9]

1 FWI is equivalent to 200 Class 1 minor injuries, or 1000 Class 2 minor injuries.

movement accident

(HEM)

An accident causing injury to people, involving trains (in

motion or stationary) but excluding injuries sustained in train

accidents, which occurs within the scope of the SRM.

non-movement

accident (HEN)

An accident causing injury to people, unconnected with the

movement of trains, which occurs within the scope of the

SRM.

operational incident An irregularity affecting, or with the potential to affect, the safe operation of trains or the safety and health of persons.

The term operational incident applies to a disparate set of human actions involving an infringement of relevant rules, regulations or instructions.



operational railway All railway lines for which the infrastructure manager has been

granted a safety authorisation, and the railway undertaking

has been granted a safety certificate by the ORR (under

European Safety Directive 2004/49/EC [Ref. 5]). This provides

evidence that there is a suitable safety management system

(SMS) in place, and that operations are being conducted in

accordance with that SMS.

Ovenstone criteria An explicit set of criteria, adapted for the railway, which

provides an objective assessment of suicide if a coroner’s

verdict is not available. The criteria are based on the findings

of a 1970 research project into rail suicides and cover

aspects such as the presence (or not) of a suicide note, the

clear intent to commit suicide, behavioural patterns, previous

suicide attempts, prolonged bouts of depression and

instability levels [Ref. 10].

outcomes The range of scenarios that could arise following the

occurrence of a hazardous event.

passenger A person on railway infrastructure, who either intends to travel

on a train, is travelling on a train or has travelled on a train or

has been over carried to a YDS site after a train has been

taken out of service. This does not include passengers who

are trespassing or who commit suicide — they are included

in the SRM as MOP.

possession (POS) The complete stoppage of all normal train movements on a

running line or siding for engineering purposes. This includes

protection as defined by the Rule Book (GE/RT8000) [Ref. 9].

precursor A system failure, sub-system failure, component failure,

human error or operational condition which could, individually

or in combination with other precursors, result in the

occurrence of a hazardous event.

probability The likelihood of an event occurring on demand.

public, members of

(MOP) Persons other than passengers or workforce members. This

includes passengers who are trespassing (eg when crossing

tracks between platforms), or attempting to commit suicide.

Any authorised visitors to a YDS site, except those who work

for, or are under contract to, the company who manages the

site, are considered to be MOP.



railway infrastructure All structures within the boundaries of Network Rail’s

operational railway, including the permanent way, land within

the lineside fence and plant used for signalling or exclusively

for supplying electricity for railway operations. It does not

include stations or YDS that are owned by, or leased to, other

parties. It does, however, include the permanent way at

stations and plant within these locations.

residual risk The level of risk remaining with the current risk control

measures in place and with their current degree of

effectiveness.

RIDDOR

(The Reporting of

Injuries, Diseases and

Dangerous

Occurrences

Regulations)

The Reporting of Injuries, Diseases and Dangerous

Occurrences Regulations 1995 is a set of health and safety

regulations that require any major injuries, illnesses or

accidents occurring in the workplace to be formally reported to

the enforcing authority. It defines major injuries and lists

notifiable diseases — many of which can be occupational in

origin. It also defines notifiable dangerous occurrences, such

as collisions and derailments.

risk Risk is the potential for a known hazard or incident to cause

loss or harm; it is a combination of the probability and the

consequence for that event.

Safety Management

Information System

(SMIS)

A national database used by railway undertakings and

infrastructure managers to record any safety-related events

that occur on the railway. SMIS data is accessible to all of the

companies who use the system, so that it may be used to

analyse risk, predict trends and focus action on major areas of

safety concern.

Safety Risk Model

(SRM)

A quantitative representation of the safety risk that can result

from the operation and maintenance of the GB rail network. It

comprises 131 individual models, each representing a type of

hazardous event.

shock/trauma Class 1: Shock or trauma results from being involved in, or

witnessing, events that have serious potential of a fatal

outcome, eg train accidents such as collisions and

derailments, or personal accidents such as being struck by a

train.

Class 2: Shock or trauma results from other causes, such as

verbal abuse, near misses, or personal accidents of a typically

non-fatal outcome.

1 FWI is equivalent to 200 Class 1 S/T injuries, or 1000

Class 2 S/T injuries.



signal passed at

danger (SPAD)

An incident when any part of a train has passed a stop signal

at danger without authority or where an in-cab signalled

movement authority has been exceeded without authority.

Full definitions are available from GO/RT3119 [Ref. 9].

Strategic Safety Plan

(SSP)

This is a joint statement by the companies responsible for

Britain’s mainline rail network setting out and agreed industry

approach to managing safety.

The 2009-2014 plan was developed by bringing together

commitments made by individual companies in their own

individual safety plans, thus creating a link with the duty holder

planning process.

In the plan, trajectories have been developed which describe

the industry’s ambitions in nine key risk areas and identify

actions that are being undertaken to achieve them [Ref. 7].

suicide and suspected

suicide

A fatality is classified as a suicide according to a coroner’s

verdict. It is classified as a suspected suicide where the

coroner has yet to return a verdict or returns an open verdict,

but where objective evidence of suicide exists based on the

application of the Ovenstone criteria.

The consequences of suicide events are split into direct risk

(injuries to the suicidal person) and indirect risk (injuries to

persons who observe the event or are injured in any

associated accident).

train Any self-powered vehicle, or vehicles hauled by a self-

powered vehicle, with flanged wheels on guided rails.

train accident (HET) Reportable train accidents as defined in RIDDOR. The main

criterion is that the accident must be on or affect the running

line. There are additional criteria for different types of

accident, and these may depend on whether the accident

involves a passenger train.

Train Protection and

Warning System

(TPWS)

A safety system that automatically applies the brakes on a train which either passes a signal at danger, or exceeds a given speed when approaching a signal at danger, a permissible speed reduction or the buffer stops in a terminal platform.

trespass An occurrence of a person entering a location where they are never authorised to be. This is distinct from a person behaving inappropriately at a place where they are allowed to be under certain conditions (eg level crossing violations/errors).

workforce Persons working for the industry on railway operations, either as direct employees or under contract.



YDS site Any location that is connected to but away from the running lines, where train maintenance, stabling, marshalling and/or servicing (including refuelling) takes place.

References


14 References

[Ref. 1] HLOS Safety Metrics – baseline and progress metrics following completion of the update of the SRM to version 8. Report delivered to SRM-PWG 27th March 2013.

[Ref. 2] RSSB (2014) Taking Safe Decisions — How Britain’s railways take decisions that affect safety. http://www.rssb.co.uk/Library/risk-analysis-and-safety-reporting/2014-guidance-taking-safe-decisions.pdf

[Ref. 3] Network Rail (2012) Strategic Business Plans 2014-2019. http://www.networkrail.co.uk/publications/strategic-business-plan-for-cp5/

[Ref. 4] RSSB (2012) Yards, Depots & Sidings Risk Profile Report, version 1. www.safetyriskmodel.co.uk

[Ref. 5] European Railway Safety Directive 2004/49/EC. http://www.dft.gov.uk/pgr/rail/Safety/ersd

[Ref. 6] RSSB (2014) Annual Safety Performance Report 2013/14.

[Ref. 7] RSSB (2009) The Railway Strategic Safety Plan 2009–2014. http://www.rssb.co.uk/safety/Pages/default.aspx

[Ref. 8] Cheng D., 2009, Uncertainty Analysis of Large Risk Assessment Models with Applications to the Rail Safety & Standards Board Safety Risk Model. Glasgow: Strathclyde University. http://strathprints.strath.ac.uk/13400/

[Ref. 9] Information on railway group standards, guidance notes and similar is available at: http://www.rgsonline.co.uk

[Ref. 10] Ovenstone, I.M. (1973) A psychiatric approach to the diagnosis on suicide. British Journal of Psychiatry, 123 (572), pp15–21.

http://www.rssb.co.uk/Library/risk-analysis-and-safety-reporting/2014-guidance-taking-safe-decisions.pdf

http://www.rssb.co.uk/Library/risk-analysis-and-safety-reporting/2014-guidance-taking-safe-decisions.pdf

http://www.networkrail.co.uk/publications/strategic-business-plan-for-cp5/


http://www.dft.gov.uk/pgr/rail/Safety/ersd

http://www.rssb.co.uk/safety/Pages/default.aspx

http://strathprints.strath.ac.uk/13400/

http://www.rgsonline.co.uk/

Appendices


Appendix A. SRM outputs

The outputs from the Safety Risk Model are available via the RSSB Rail Risk Portal

www.safetyriskmodel.co.uk.

The following tables of results are available:

Table A1 which gives a breakdown of risk at the sub-hazardous event level.

Table B1 which provides the most detailed breakdown of risk to the precursor level.

Table A2 which gives reasons for the changes in risk from version 7 to version 8/8.1.

Table C1 which contains the full breakdown of the SRM at precursor level into the Key

Risk Areas as summarised in Table 15.

Tables C2 and C3 which contain the breakdown of the SRM by Key Risk Grouping as

summarised in Table 16.

Table D1 which details individual fatality risk by person group and hazardous event

summarised in Chapter 8.

Table E1 details the normalisation data used in the calculation of SRMv8.1, the

sources of that data and an explanation of changes from v7 normalisers.

Tables are provided as .xls files, other formats are available on request.


Appendices


Appendix B. ASPR hazardous event groupings

Table 26: Accident groups used within the ASPR

Accident grouping

Description of the types of event contained within grouping

Hazardous events

Assault and abuse All types of assault, verbal abuse and threat. Also includes unlawful killing.

HEN-64, HEN-65, HEN-66

Contact with object Any injury involving contact with objects, not covered by another category.

HEM-20, HEM-32, HEM-42, HEM-45, HEN-21, HEN-23, HEN-26, HEN-44, HEN-55, HEN-56, HEN-59, HEN-76, HEN-79, HEN-80

Contact with person

Injuries due to bumping into, or being bumped into by, other people. Excludes assaults.

HEN-55, HEN-56

Falls from height Generally speaking, falls of more than 2m. Excludes falls down stairs and escalators.

HEN-15, HEN-25, HEN-45, HEN-78

Fires and explosions (not involving trains)

Fires or explosions in stations, lineside or other in scope locations.

HEN-01, HEN-02, HEN-03, HEN-04, HEN-05, HEN-48, HEN-49

Indirect risk due to suicide

Second party injuries arising from suicide, suspected suicide and attempted suicide.

HEM-31, HEN-77

Lean or fall from train in running

Injuries resulting from accidental falls from trains, or from leaning from trains.

HEM-03, HEM-07, HEM-15, HEM-17

Machinery/tool operation

Injuries from power tools, being trapped in machinery, or track maintenance equipment. Does not include injuries due to arcing. Does not include injuries due to being struck by things thrown up by tools or from carrying tools/equipment.

HEN-22, HEN-27, HEN-56

Manual handling/awkward movement

Strains and sprains due to lifting or moving objects, or awkward movement. Excludes injuries due to dropping items being carried, which are classed under contact with objects.


On-board injuries

All injuries on trains, excluding train accidents, assaults, and those occurring during boarding or alighting, or whilst leaning from trains.

HEM-38, HEM-39, HEM-48, HEN-62, HEN-63

Platform edge incidents (not boarding/alighting)

Accidents that involve falls from the platform (with or without trains being present) or contact with trains or traction supplies at the platform edge. Excludes accidents that take place during boarding or alighting.

HEM-05, HEM-06, HEM-09, HEM-16, HEM-21, HEM-22, HEM-23, HEM-43, HEN-84

Platform-train interface (boarding/alighting)

Accidents occurring whilst getting on or off trains. Includes falls between train and platform where it is not known if the person is boarding or alighting.

HEM-06, HEM-08, HEM-10, HEM-21, HEM-40, HEM-41, HEM-49, HEN-09, HEN-10, HEN-13, HEN-52, HEN-67

Appendices


Accident grouping

Description of the types of event contained within grouping

Hazardous events

Road traffic accident

All accidents directly resulting from road traffic accidents, apart from road vehicle incursions not at LC.

HEN-35


Generally speaking, falls of less than 2m at any in scope location (except on trains), and falls of any height down stairs and escalators.

HEN-14, HEN-16, HEN-24, HEN-25, HEN-46, HEN-68, HEN-78, HEN-80


All incidents involving pedestrians struck/crushed by trains, excluding trespass, platform edge and boarding and alighting accidents.

HEM-11, HEM-14, HEM-19, HEM-27, HEM-45

Train accidents: collisions and derailments

Collisions between trains, buffer stop strikes and derailments (excluding those caused by striking road vehicles at level crossings).

HET-01, HET-02NP, HET-02P, HET-03, HET-06, HET-09, HET-12, HET-13, HET-26, HET-27

Train accidents: other

Train divisions, train fires, train explosions, structural damage affecting trains.

HET-17, HET-20, HET-21, HET-22, HET-23, HET-24, HET-25

Train accidents: striking objects

Train striking an object, including road vehicles not at level crossings and trains hit by missiles. Excludes derailments.

HET-04

Train accidents: striking road vehicles at level crossings

Includes derailments. HET-10, HET-11

Trespass

First-party injuries resulting from people engaging in behaviour involving access of prohibited areas of the railway, where that access was the result of deliberate or risk-taking behaviour. Errors and violations at level crossings are not included in this category.

HEM-12, HEM-25, HEM-30, HEM-44, HEM-46, HEN-36, HEN-37, HEN-38, HEN-39, HEN-40, HEN-41, HEN-42, HEN-43, HEN-71, HEN-72, HEN-81

Workforce electric shock

Electric shock involving third rail, OLE, or non-traction supply. Includes burns from electrical short circuits. Does not include injuries due to arcing, which are classed under ‘other’.


Other Any other event not covered by the categories above.

HEM-01, HEM-50, HEN-07, HEN-08, HEN-11, HEN-27, HEN-28, HEN-29, HEN-33, HEN-50, HEN-51, HEN-53, HEN-54, HEN-57, HEN-58, HEN-60, HEN-61, HEN-70, HEN-75, HEN-79

Note that the risk from some HEs has been split across two or more accident types based on

precursor level risk estimates.

Appendices


Appendix C. Individual fatality risk summary

Table 27: Workforce group individual fatality risk by cause classification.

NB – the shading in this table indicates the relative magnitude of the figures. The more green the box is the higher the risk figure.

Assa

ult a

nd

ab

use

Co

nta

ct w

ith

ob

ject

Falls

fro

m h

eig

ht

Fire

s a

nd

exp

losio

ns (

not

involv

ing t

rain

s)

Lea

n o

r fa

ll fr

om

tra

in in r

unn

ing

Ma

chin

ery

/to

ol o

pera

tion

Oth

er

Pla

tfo

rm e

dg

e in

cid

en

ts

(boa

rdin

g/a

lightin

g)

Ro

ad

tra

ffic

accid

en

t

Slip

s,

trip

s,

an

d f

alls

Str

uck/c

rush

ed

by tra

in

Tra

in a

ccid

en

ts: co

llisio

ns a

nd

dera

ilme

nts

Tra

in a

ccid

en

ts:

str

ikin

g r

oad

ve

hic

les a

t le

vel cro

ssin

gs

Tra

in a

ccid

en

ts:

oth

er

Wo

rkfo

rce e

lectr

ic s

hock

Tota

l an

nu

al fa

talit

ies

PT driver

9.3

E-0

4

6.3

E-0

4

0.0

04

-

0.0

02

-

0.0

11

9.2

E-0

4

0.0

71

-

0.1

05

0.2

05

0.0

44

0.0

04

0.0

25

0.4

73

FT driver

8.6

E-0

5

5.7

E-0

5

4.1

E-0

4

-

0.0

02

-

9.8

E-0

4

8.6

E-0

5

0.0

07

-

0.0

10

0.0

60

0.0

06

0.0

49

0.0

02

0.1

36

Other train crew 0

.00

8

0.0

02

- -

0.0

72

-

0.0

07

0.0

02

0.0

25

0.0

02

0.0

25

0.0

47

0.0

11

0.0

01

-

0.2

04

Infrastructure worker

1.8

E-0

4

0.1

02

0.1

33

0.0

03

0.0

34

0.0

21

0.0

51

5.1

E-0

4

0.5

11

0.0

10

1.2

95

- - -

0.2

40

2.3

99

OTP driver -

0.0

01

- -

0.0

32

- - - - -

0.0

09

0.0

83

5.1

E-0

4

0.0

04

-

0.1

29

Other workforce 0

.01

1

0.0

47

0.0

47

0.0

42

- -

0.0

60

5.1

E-0

4

0.2

11

0.0

22

0.1

35

- - -

0.0

20

0.5

94

Driver (shunter)

6.6

E-0

5

0.0

02

-

0.0

03

0.0

01

0.0

07

0.0

29

-

0.0

27

0.0

07

0.0

43

- - -

0.0

02

0.1

20

YDS engineering staff 2

.6E

-05

0.0

09

-

0.0

11

-

0.0

29

0.0

37

-

0.0

15

0.0

12

0.0

05

- - -

0.0

27

0.1

46

YDS cleaner/ admin

4.4

E-0

5

4.1

E-0

4

-

0.0

02

-

0.0

02

0.0

06

-

0.0

08

0.0

02

6.3

E-0

4

- - -

0.0

02

0.0

22

Total annual fatalities 0

.02

1

0.1

64

0.1

85

0.0

59

0.1

44

0.0

59

0.2

00

0.0

04

0.8

74

0.0

56

1.6

28

0.3

95

0.0

61

0.0

57

0.3

17

4.2

23

Appendices


Appendix D. Modelling approach

D.1. Key assumptions

Table 28 describes the main assumptions used in the analysis for SRMv8. Assumptions for

individual models are available on request.

Table 28: Key modelling assumptions in the SRM

Assumptions

1. Train accident (HET) event frequencies are calculated based on all recorded incidents, irrespective of injury, whereas movement and non-movement (HEM and HEN) event frequencies are only based on incidents that resulted in an injury to a person.

2. An average day has been divided into:

Night: 0000–0600 hrs

Peak: 0700–1000 and 1600–1900 hrs

Off-peak: 0600–0700, 1000–1600 and 1900–0000 hrs

25% of peak trains are assumed to be crush loaded.

3. Average train distributions:

Night: 0.6 PTs and 0.4 NPTs per hour

Peak: 5 PTs and 0.05 NPTs per hour

Off-peak: 2 PTs and 0.38 NPTs per hour

4. Consequences are based on a five car train with average passenger loadings per train:

Night-loaded train: 2 passengers per carriage: 10 passengers per train

Peak-loaded train: 50 passengers per carriage: 250 passengers per train

Off-peak-loaded train: 10 passengers per carriage: 50 passengers per train

Crush-loaded train: 90 passengers per carriage: 450 passengers per train

5. Average passenger train loadings are calculated using assumptions 2 and 3, as well as an assumed proportion of passenger loadings at each time of day:

11% of all PTs are night loaded

63% of all PTs are off-peak loaded

19.5% of all PTs are peak loaded

6.5% of all PTs are crush loaded

6. Average train crew:

Passenger trains: 1 driver and 1 guard

Freight, ECS & parcels trains: 1 driver

OTMs/RRVs: 2 operators

Shunting manoeuvres: 1 driver (shunter)

7. The frequency of train accidents at stations and in tunnels is based upon their respective proportions of overall length compared with total track kilometres. The length of each platform is assumed to be 200m.

8. It is assumed that there is complete and correct reporting of injury events.

Appendices


D.2. Hazardous event definitions

Full descriptions of all HEs and precursors used in the SRM are available via the RSSB Rail

Risk Portal www.safetyriskmodel.co.uk.

D.3. Normalisation data

The values used to normalise data in SRMv8.1 along with equivalent values from past

versions of the SRM are provided in Table E1 available via the RSSB Rail Risk Portal

www.safetyriskmodel.co.uk

D.4. Significant modelling changes for SRMv8

D.4.1. Inclusion of YDS-SRM risk

Risk previously modelled in the YDS-SRM has been fully incorporated into this version of the

SRM.

D.4.2. Remodelling of risk at the PTI

The platform-train interface risk models and precursor structure have be remodelled in order

to better understand risk at the PTI. Full details are given in Chapter 10.

D.4.3. Inclusion of MCB+OD and AOCL+B crossing types

Two new crossing types, MCBs with obstacle detection and AOCL with half barriers, have

been introduced. All level crossing models (HET-10, HET-11, HEM-11, HEM-27, HEN-44,

HEN-46 and HEN-75) have been extended to explicitly calculate the risk at these crossing

types.

D.4.4. New approach to assault data analysis

For this version a change has been made to the assault modelling. Algorithms have been

written and automated to match BTP recorded assault data with SMIS recorded assault data

in order to provide a larger, richer dataset. In previous updates this was done manually and

so only a subset of the data was analysed then scaled up. This has resulted in more reliable

assault risk modelling.



Appendices


Appendix E. Railway lines in SRM scope

The SRM only includes railway lines which are managed and/or operated by Network Rail.

Table 29 contains examples of some commonly-queried lines (and sections of lines), along

with the reason for their inclusion or exclusion.

Table 29: Railway lines in and out of scope of the SRM

Line / Section Notes

Criteria In/Out of Scope

NR

Man

ag

ed

?

NR

op

era

ted

sig

nallin

g?

In

Sta

tio

ns

ab

ou

t th

e

track/a

t

PT

I

High Speed 117 The entire line, including St Pancras, is managed, operated and maintained by NR.

In In

The Cambrian line18 Owned and managed by NR. In In

Heathrow Express: Paddington to Heathrow Central

NR-owned infrastructure. In In

Heathrow Express: Heathrow Central to Terminals 4 and 5

Owned by BAA but maintained on their behalf by NR. In In

Nexus — Tyne and Wear Metro: Fellgate to South Hylton

Owned and managed by NR. Out In

Nexus — Tyne and Wear Metro: All sections apart from Fellgate to South Hylton

Neither managed by NR, nor is the signalling controlled by NR. Out Out

LUL Metropolitan Line: Chiltern services between Harrow-on-the-Hill and Amersham

This section is owned and operated by LUL and its subsidiaries / operators.

Out Out19

LUL District Line: Gunnersbury to Richmond

This section was a joint operation with Silverlink Metro, for which NR is now responsible.

Out In

LUL District Line: East Putney to Southfields

LUL owns the infrastructure. NR owns the signals, but the signalling is operated by LUL.

Out Out

LUL Bakerloo Line: Services north of Queens Park

Track managed by NR, who also operates the signalling. Out In

Island Line on the Isle of Wight The service is wholly operated and managed under a franchise to South West Trains.

Out Out

East London Line TfL owns and maintains the track, but NR operates the signalling.

In In

17 The risk from High Speed 1 train operations is modelled in the same way as all other lines, ie as an average railway, rather than explicit modelling of High Speed 1 characteristics. The contribution of Eurostar services to HEM/HEN risk is included. 18 The risk from the Cambrian line is modelled in the same way as all other lines, ie, as an average railway rather than modelling explicit ERTMS characteristics. This is under investigation for future versions of the SRM. 19 PTI and on-board injuries on these Chiltern services are in scope, injuries on or about the track are out of scope.

safety risk model: risk profile bulletin, version 8 - …€¦ · safety risk model: risk profile...

Documents