Rail Accident Report
Collision between a road-rail vehicle and a
trolley near Brading, Isle of Wight
22 November 2023
Report 12/2024
                                       October 2024
This investigation was carried out in accordance with:
• the Railway Safety Directive 2004/49/E C
• the Railways and Transport Safety Act 2003
• the Railways (Accident Investigation and Reporting) Regulations 2005.
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Preface
Preface
The purpose of a Rail Accident Investigation Branch (RAIB) investigation is to
improve railway safety by preventing future railway accidents or by mitigating their
consequences. It is not the purpose of such an investigation to establish blame or
liability. Accordingly, it is inappropriate that RAIB reports should be used to assign
fault or blame, or determine liability, since neither the investigation nor the reporting
process has been undertaken for that purpose.
RAIB’s findings are based on its own evaluation of the evidence that was available at
the time of the investigation and are intended to explain what happened, and why, in a
fair and unbiased manner.
Where RAIB has described a factor as being linked to cause and the term is
unqualified, this means that RAIB has satisfied itself that the evidence supports both
the presence of the factor and its direct relevance to the causation of the accident or
incident that is being investigated. However, where RAIB is less confident about the
existence of a factor, or its role in the causation of the accident or incident, RAIB will
qualify its findings by use of words such as ‘probable’ or ‘possible’, as appropriate.
Where there is more than one potential explanation RAIB may describe one factor as
being ‘more’ or ‘less’ likely than the other.
In some cases factors are described as ‘underlying’. Such factors are also relevant
to the causation of the accident or incident but are associated with the underlying
management arrangements or organisational issues (such as working culture).
Where necessary, words such as ‘probable’ or ‘possible’ can also be used to qualify
‘underlying factor’.
Use of the word ‘probable’ means that, although it is considered highly likely that the
factor applied, some small element of uncertainty remains. Use of the word ‘possible’
means that, although there is some evidence that supports this factor, there remains a
more significant degree of uncertainty.
An ‘observation’ is a safety issue discovered as part of the investigation that is not
considered to be causal or underlying to the accident or incident being investigated,
but does deserve scrutiny because of a perceived potential for safety learning.
The above terms are intended to assist readers’ interpretation of the report, and to
provide suitable explanations where uncertainty remains. The report should therefore
be interpreted as the view of RAIB, expressed with the sole purpose of improving
railway safety.
Any information about casualties is based on figures provided to RAIB from various
sources. Considerations of personal privacy may mean that not all of the actual effects
of the event are recorded in the report. RAIB recognises that sudden unexpected
events can have both short- and long-term consequences for the physical and/ or
mental health of people who were involved, both directly and indirectly, in what
happened.
RAIB’s investigation (including its scope, methods, conclusions and recommendations)
is independent of any inquest or fatal accident inquiry, and all other investigations,
including those carried out by the safety authority, police or railway industry.
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Collision between a road-rail vehicle and a
trolley near Brading, Isle of Wight, 22 November
2023
Contents
Preface3
Summary7
Introduction8
     Definitions                                                                 8
The accident9
     Summary of the accident                                                     9
     Context10
Background information16
The sequence of events17
     Events preceding the accident                                              17
     Events during the accident                                                 21
     Events following the accident                                              23
Analysis25
     Identification of the immediate cause                                      25
     Identification of causal factors                                           25
     Identification of underlying factors                                       30
     Observations31
Summary of conclusions 34
     Immediate cause                                                            34
     Causal factors                                                             34
     Underlying factors                                                         34
     Additional observations                                                    35
Actions reported as already taken or in progress relevant to this report36
     Actions reported that address factors which otherwise would have resulted
     in an RAIB recommendation                                                 36
Recommendations and learning points37
     Recommendations37
     Learning points                                                            38
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Appendices39
     Appendix A - Glossary of abbreviations and acronyms            39
     Appendix B - Investigation details                             40
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Summary
Summary
At around 01:50 on Wednesday 22 November 2023, a road-rail vehicle, travelling
in a work site, collided with a hand trolley being used by a work group on the Isle of
Wight’s Island Line. The road-rail vehicle was being used to clear vegetation and was
travelling between its work locations when the collision occurred.
The road-rail vehicle was approaching the work group, who were repairing the track,
on a descending gradient and was unable to stop before their site of work. When
members of the work group realised that the road-rail vehicle was not stopping, they
removed tools and equipment from the trolley and lifted it off the track. However, once
removed, the trolley was inadvertently left too close to the track and remained foul of
the road-rail vehicle’s path. The road-rail vehicle then collided with the hand trolley.
As a result of the collision, the trolley struck two members of the track repair work
group on the legs, pushing them into bushes beside the track. Both received minor
injuries, attended hospital independently later that day and were then discharged.
The collision was caused because the controller of site safety responsible for the
track work group had not been informed of the road-rail vehicle’s movement before
it approached, and because the road-rail vehicle was unable to stop in the expected
distance once the machine operator realised the work group was ahead.
Two underlying factors were that South Western Railway, the infrastructure manager
for the track on the Island Line, did not have an effective process for planning and
managing the risk of on-track plant movements, or for managing low adhesion
risk for maintenance activities. A third underlying factor was that South Western
Railway’s assurance processes had not identified informal working arrangements in
possessions.
Since the accident, South Western Railway has updated its risk assessment for
machine movements and introduced new control measures to specifically manage
the risks of conflicting sites of work within work sites and possessions. It has also
addressed the deficiencies found within its assurance process for monitoring how
possessions are managed.
As a result of the investigation, RAIB has made three recommendations, all
addressed to South Western Railway. The first is to review how it manages safety
during infrastructure work on the Island Line. The second is to review its assurance
processes and the third is to provide its infrastructure maintenance staff and
contractors with accurate information about its infrastructure.
Additionally, three learning points have been identified. The first reinforces the
importance of transport undertakings and on-track plant operators applying industry
codes of practice in the event of an accident or incident involving on-track plant. The
second concerns the importance of promptly reporting notifiable accidents to RAIB,
and the third the importance of well-established process and procedure for dealing
with post‑accident or incident evidence collection and testing.
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               Introduction
Introduction
Definitions
               1    Metric units are used in this report, except when it is normal railway practice to
                    give speeds and locations in imperial units. Where appropriate the equivalent
                    metric value is also given.
               2    The report contains abbreviations and acronyms, which are explained in appendix
                    A. Sources of evidence used in the investigation are listed in appendix B.
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The accident
The accident
Summary of the accident
3    At around 01:50 on Wednesday 22 November 2023, a road-rail vehicle
     (RRV) weighing approximately 30 tonnes collided with a hand trolley between
     Smallbrook Junction and Brading on the Isle of Wight’s Island Line (figure 1).
4    At the time of the accident, the Island Line was under possession and closed to
     normal rail services. The possession occurred during the 5th week of a 6-week
     major maintenance programme which saw overnight working involving additional
     track maintenance staff contracted in as well as the normally employed workforce,
     and equipment brought over from the mainland. The hand trolley was being used
     by a track repair work group to transport tools and equipment.
5    The collision occurred on a descending gradient. The RRV’s machine operator
     (MO) saw the stationary hand trolley and intended to stop their vehicle a short
     distance from it to allow members of a track repair work group to lift the trolley
     off the track. However, when the MO attempted to slow the RRV, its rail wheels
     stopped rotating and started to slide. The RRV’s speed did not immediately
     reduce so the MO sounded the horn to give a warning. The MO and machine
     controller (MC), who was travelling in the rear of the RRV cab, repeatedly shouted
     a warning to the work group ahead of them.
6    When the members of the work group realised that the RRV was not stopping,
     they quickly removed tools and equipment from the trolley and lifted it off the
     track. They then put the trolley down close to the track.
7    As the RRV passed at low speed, its leading right-hand rubber tyre struck a
     corner of the trolley, causing it to spin round. The trolley struck two members of
     the track repair work group on the legs. They were pushed into adjacent bushes,
     either after being directly struck or struck by the other person, with the trolley
     then landing on one person’s legs. An ambulance was not required, but both staff
     members involved independently attended hospital later on 22 November after
     returning to the mainland. One person was diagnosed with a muscle injury to
     the upper back and soft tissue injury to the legs. The other was diagnosed with a
     minor head injury. Both were discharged the same day.
8    Neither the RRV nor the hand trolley were damaged in the accident. Witness
     evidence indicates that the RRV eventually stopped around 100 metres beyond
     the point of collision.
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The accident
Location of accident
Contains Ordnance Survey data: @Crown Copyright and database right 2024.
                                                                                 OS license number: AC0000833184. Source: Department for Transport, RAIB 2024
Figure 1: Extract from Ordnance Survey map showing location of accident near Brading.
Context
               Location
               9    The Island Line is a standard gauge railway that runs for 8 miles 31 chains
                    (13.5 km) between Ryde Pier Head and Shanklin on the eastern side of the Isle of
                    Wight. There are six intermediate stations (figure 2).
               10 The accident occurred at 3 miles 37 chains (from a reference point at Ryde
                  Pier Head station), on the line between Smallbrook Junction and Brading. On
                  the Island Line, small metal plates are attached to some sleepers showing the
                  location in miles and chains. There are 80 chains in a mile; each chain is 22
                  yards (20 metres). The single‑track approach to this location, when travelling in
                  the down direction towards Shanklin, is a left-hand curve with a falling gradient of
                  1 in 78.
               Organisations involved
               11 Network Rail is the owner of the Island Line’s infrastructure and maintains its
                  structures (such as bridges) and signalling. It is not responsible for maintaining
                  the track or stations which are leased to South Western Railway (SWR).
               12 SWR is a train operating company which operates rail services between London
                  and the South/South-West of England. It is also the train operating company for
                  the Island Line and infrastructure manager for its stations and track. It holds a
                  lease to operate, maintain and renew Island Line infrastructure from Network
                  Rail. It was the employer of the person in charge of possession (PICOP), the
                  engineering supervisor (ES) in charge of the work site, and the controller of site
                  safety (COSS) involved in the accident.
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                                                                                          The accident
                                Ryde Pier Head
                                                                          N
Ryde Esplanade
Ryde St Johns Road
                   depot
1 mile (0.6 km)
       Smallbrook Junction
Accident location
           3 miles 37 chains
Brading
Sandown
         Sandown yard
Lake
                                                  Milepost
                                                  Station
Shanklin
Figure 2: Simplified diagram showing Island Line route.
13 Sonic Rail Services (SRS) was the contracted supplier of the RRV and employer
   of the MO and MC.
14 SGC Rail Solutions Ltd (SGC) was the contracted agency supplying track
   maintenance staff, including those who were struck by the trolley. The Companies
   House website states that SGC Rail Solutions is now in liquidation.
15 These organisations freely co-operated with the investigation.
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               Rail vehicles involved
The accident
16 The RRV is equipped with rubber tyres and rail wheels and has a gross vehicle
                  weight of 30.16 tonnes (figure 3). It is a Type 9A machine with its rail wheels
                  powered by a hydrostatic drive, with three forward gears and a hydrostatic brake.
                  It has a 20 mph (32 km/h) maximum permitted travelling speed on plain line track
                  with an audible in-cab alarm if the maximum speed is exceeded. The machine is
                  also fitted with a passive speed restrictor which removes drive power when this
                  audible alarm sounds until the speed reduces. The machine is fitted with a data
                  logger, although this does not record the speed of the vehicle. At the time of the
                  accident, the machine was not fitted with a global positioning system (GPS) to
                  record its location or a closed-circuit television (CCTV) system.
Figure 3: Road‑rail vehicle used on 21 to 22 November (courtesy of Sonic Rail Services).
17 At the time of the accident, the RRV had no recorded defects. It subsequently
                  passed a static brake test in the hours following the accident and passed a
                  post- accident dynamic brake test on a later date (see paragraph 96). It was one
                  of two similar machines which had been in use on the Island Line for 5 weeks
                  preceding the accident as part of the major maintenance programme. The RRV
                  was being operated with an on‑track plant Engineering Conformance Certificate
                  issued in 2018 and valid for 7 years. This certificate was issued in accordance
                  with RIS-1530-PLT, ‘Rail Industry Standard for Technical Requirements of
                  On- Track Plant and Associated Equipment’, issue 6 dated December 2015, which
                  was in force when the certificate was issued.
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18 The hand trolley, which was struck by the RRV, weighs 50 kg unloaded and has a
The accident
   carrying capacity of 1000 kg (figure 4). It had red lights affixed front and back as
   required by GERT8000 (the Rule Book) HB10, ‘Duties of the COSS or SWL [safe
   work leader] and person in charge when using a hand trolley’, issue 4.1, dated
   November 2022.
19 Before the accident, the hand trolley was being used to carry hand-tools, jacks,
   petrol-driven hand-tamping machines and fuel cans.
Figure 4: Hand trolley used on 21 to 22 November 2023.
Rail systems involved
20 The Island Line is a single-track railway, except for a 1.6 mile (2.5 km) section
   of double-track between Ryde Esplanade and Smallbrook Junction. Passing
   loops are provided at Brading and Sandown stations. The line is electrified via
   a 750 V DC third rail system, controlled from Eastleigh electrical control room.
   The line is signalled using colour light signalling which is controlled from Ryde St
   Johns signal box.
21 The accident occurred on the Brading single line which has a permanent speed
   limit for trains of 45 mph (72 km/h), reducing to 40 mph (65 km/h) just south of the
   point of collision. In this area, the track is curved and constructed from flat-bottom
   rail on timber sleepers (figure 5).
Staff involved
22 SWR employs a core team of seven infrastructure maintenance staff on the Island
   Line. Most members of this team are trained to undertake ES and COSS duties
   and had worked only, or mainly, on the Island Line infrastructure.
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The accident
Figure 5: Location of accident looking north. The RRV approached from this direction.
23 The safe work pack (SWP) for the track repair work on 21 to 22 November 2023
                  was prepared and signed by the SWR route section manager who had overall
                  responsibility for Island Line maintenance activities.
               24 The ES for the work site had over 10 years’ experience on the Island Line.
                  They had taken over from a different ES part-way through the maintenance
                  programme.
               25 The track repair work group was led by a COSS who had 4 years’ experience and
                  was also qualified as an ES, regularly undertaking these duties. The track repair
                  being undertaken comprised two tasks. These consisted of a group of two staff
                  measuring and identifying where track needed to be lifted, and another larger
                  group following in close proximity making the remedial repairs.
               26 The track repair work group included a site supervisor, who had over 30 years’
                  experience on the mainland and on the Island Line as a track worker and
                  supervisor. The site supervisor had signed the SWP as the planner and was
                  working with another member of infrastructure maintenance staff to measure
                  the track geometry. Both were employed by SWR. The track repair work group
                  also included four experienced track workers, based on the mainland, and were
                  employed under contract by SGC.
               27 The MO was employed by SRS and had over 10 years’ experience in operating
                  RRVs. The MC was also employed by SRS, was acting as COSS for the
                  RRV and had 4 years’ experience as a machine controller. Both had worked
                  within numerous possessions on infrastructure managed by Network Rail on
                  the mainland and had been working in possessions on the Island Line for the
                  previous 5 weeks. The MC and MO were in the RRV undertaking lineside
                  vegetation cutting during the possession. The MC travelled between sites of work
                  in the rear of the RRV’s cab which was provided for this purpose (figure 6).
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               Brading
                                                                                                             The accident
Figure 6: RRV’s double cab. The MC sat in the rear part of the cab with limited forward visibility
(courtesy of Sonic Rail Services).
28 The MO is responsible for the RRV’s safe operation. The MC, with permission
   from the ES, authorises safe movements of the RRV in a work site.
External circumstances
29 At the time of the accident, the weather was clear, cold (6°C) and damp with a
   light wind. There was no external lighting.
30 SWR had issued warnings of expected poor rail adhesion conditions (red
   adhesion status notices) covering their mainland network and the Island Line on
   19 November and 20 November 2023. There was no equivalent warning issued
   for 21 or 22 November as this was not warranted by the prevailing weather
   conditions.
31 The accident occurred in a rural area with lineside trees and vegetation. There
   are also areas on the railway between Ryde and Brading known to have a poor
   mobile telephone signal.
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                         Background information
Background information
32 SWR holds a lease from Network Rail to operate, maintain and renew the Island
                            Line’s railway infrastructure. As a condition of its safety certificate, SWR is
                            required to comply with all relevant Network Rail and other standards applying
                            to the mainline railway on the mainland (such as Railway Group Standards).
                            However, these may be adapted to local circumstances on the Island Line if
                            supported by a risk assessment.
                         33 SWR adopted the use of GERT8000 for its activities on the Island Line
                            infrastructure. The possession on the night of the accident was set up in
                            accordance with Rule Book Module T3, ‘Possession of a running line for
                            engineering work’, issue 11 dated September 2022. Rule Book HB9, ‘IWA,
                            COSS or PC blocking a line’, issue 8 dated September 2022, states that a work
                            site is the portion of line within a possession of a running line where work will be
                            undertaken. Each work site is under the control of an ES. The ES is responsible
                            for authorising the entry of on-track plant (OTP) such as RRVs to the work site
                            and for any OTP movements within it.
                         34 A possession with an isolation of the electrical traction supply is taken on the
                            Island Line each Monday to Thursday night. Once the possession has been taken
                            by the PICOP, it is then handed over to the ES who manages it as a single work
                            site, extending the full length of the Island Line from the buffer stops at Ryde Pier
                            Head to the buffer stops at Shanklin. This differs from many possessions taken on
                            the mainland, which may be composed of several work sites.
                         35 Rule Book HB12, ‘Duties of the engineering supervisor (ES) or safe work leader
                            (SWL) in a possession’, issue 9 dated September 2022, requires work site marker
                            boards to be placed 100 m from each end of a work site. These are provided to
                            control the movement of on-track machines and OTP entering or leaving a work
                            site. These boards were not placed at the buffer stops during possessions on the
                            Island Line, as it was considered that there would be no purpose in doing so in
                            the circumstances.
                         36 Sites of work, each controlled by a COSS, are established within the work site.
                            The limits of sites of work were not required to be marked on site as part of the
                            agreed SWP.
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                         Brading
The sequence of events
The sequence of events
Events preceding the accident
37 During the week before the accident, the MC informed the ES that the RRV had
   had trouble ascending the gradient where the accident later occurred due to
   slippery rail conditions. On that occasion the RRV was towing a large trailer, and
   the MO had found it necessary to increase the RRV’s speed at the bottom of the
   slope to keep it moving all the way up. The ES did not take any action in response
   to that report as there was no established process for doing so.
38 The ES arrived at Ryde St Johns depot at around 21:00 on Tuesday 21
   November and was briefed by the site supervisor. The ES was informed that they
   would be responsible for 3 sites of work within the work site during the overnight
   possession, each with its own COSS. These consisted of the track repair work
   group, a group working on Ryde Pier and another working between Brading
   and Sandown. The ES was also responsible for two RRVs, one cutting back
   vegetation along the railway and the other working in Sandown yard, each with
   an MO and an MC also acting as a COSS. The ES did not make a written note of
   the plan but believed that the track repair work group was going to start work at
   Brading. The ES stated they briefed the COSSs for the three sites of work. The
   ES told them not to go onto the track until the RRV had gone past, and that it
   would be coming back during the possession.
39 The track repair work group assembled at Ryde St Johns depot before the
   possession to be briefed by their COSS and to sign the safe work pack covering
   the track repair task (referred to in this report as the SWP (track)). The SWP
   (track) stated that the site of work for the work group would extend from 3 miles
   33 chains to 4 miles 40 chains. Brading station is outside this area at 4 miles 55
   chains (figure 9). The SWP (track) had been prepared by the section manager for
   the repair of ‘level 2 twists’. This involved measuring the track and using jacks to
   lift the track and repack the ballast to improve track geometry. The SWP (track)
   identified that the site of work would be safeguarded, meaning that all lines would
   be blocked to normal trains, and that engineering train or OTP movements would
   be ‘made at no greater than 5 mph (10 km/h)’ in accordance with Rule Book HB9
   (paragraph 33).
40 At around 22:00, the MC for the RRV involved in the accident attended Ryde
   St Johns depot to sign in and receive a briefing from the ES, as they had done
   before possessions during the previous 5 weeks. The MO was not required to
   attend as their certificates had been checked previously by the ES. The MC (as
   COSS) was responsible for briefing the MO when they arrived at Sandown yard,
   where the RRV was stabled.
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                         41 The MO and MC were required to work in accordance with their own safe
The sequence of events
work pack (referred to in this report as the SWP (RRV)) which covered RRV
                            operations. This SWP (RRV) covered a series of possessions and had been
                            signed by the MC on 15 November 2023 and authorised by an SRS manager
                            the following day. A copy was signed again by the MC on 21 November 2023 to
                            cover the possession that night. The SWP (RRV) showed all lines as being under
                            possession with a speed limit of 5 mph (8 km/h), but the document was generic
                            and did not contain any information about other work groups present during
                            this possession. The MC then travelled to Sandown yard, where the RRV was
                            stabled, to meet and brief the MO.
                         42 At 23:50, the COSS received a phone call from the ES informing them that the
                            possession had been taken, but that the RRV would be passing through their site
                            of work in 10 to 15 minutes’ time. Members of the track repair work group were
                            loading equipment onto a vehicle at Ryde St Johns Road depot at this time.
                         43 The COSS and the track repair work group then travelled by road to a track
                            access gate at Rowborough Lane bridge (3 miles 60 chains) near the middle of
                            their planned site of work (figure 7). The COSS phoned the ES at 00:25 to confirm
                            they had arrived at the access gate, then briefed the work group that there would
                            be an RRV in the area.
Location of
                                                                       accident
Figure 7: View from Rowborough Lane bridge looking north up the gradient towards location of
                         accident.
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                         Brading
44 During the briefing at Sandown yard, the ES gave the MC a handwritten list of
The sequence of events
   six locations where lineside vegetation was to be cut back (figure 8). As the SWP
   (RRV) did not include details of any tasks or sites of work for the RRV, the ES
   instructed the MC to start cutting vegetation at 1 mile 42 chains, towards the
   north end of the line near Ryde St Johns station, and then travel back to the next
   location at Rowborough Lane bridge (3 miles 60 chains). The MC stated that the
   ES had told them that the track repair work group would be at Brading station.
   The first two RRV sites of work were both located north of Brading (figure 9).
Shanklin
Brading
                                                                           Rowborough Lane
                                                                           bridge and access
Ryde St Johns
Figure 8: Handwritten list of sites of work which the ES gave to the MC.
45 At about 00:30 on Wednesday 22 November, the MO and MC travelled north in
   the RRV. After passing Brading station, they encountered members of the track
   repair work group by the track near the Rowborough Lane bridge access point.
   They stopped the RRV and waited until members of the work group were in a
   position of safety before passing them. The MO and MC acknowledged the work
   group and the RRV continued its journey.
46 As the RRV ascended the gradient in the area where the accident later occurred,
   the MO stated they heard a “crunching noise”. Although the wheels did not
   slip, they mentioned this to the MC. The MO believed the noise was caused by
   leaf mulch on the railhead. This was the first occasion within the maintenance
   programme where the RRV had climbed the gradient without towing a trailer.
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The sequence of events
Ryde Pier Head
N
                              Ryde Esplanade
Ryde St Johns Road
                                       depot
1 mile (0.6 km)
                            Smallbrook Junction
3 m 33 ch
Accident location
                                Rowborough Lane
                           access gate (3 m 60 ch)                            4 m 40 ch
Brading (4 m 55 ch)
Sandown
                              Sandown yard                                           RRV sites of work (x6)
Track repair work group site of work
                                          Lake
                                                                                     Other sites of work
Milepost
Station
                         Shanklin
Figure 9: Sites of work on 21 to 22 November.
47 After the RRV had passed the work group, the trolley was put onto the line by
                            members of the work group and loaded with equipment. The work group then
                            pushed it north up the gradient, following the direction of travel of the RRV. They
                            stopped at around 3 miles 37 chains, 463 metres from the access point.
                         48 The work group started to measure and correct track faults. The work was
                            undertaken using head torches which were considered adequate for this task.
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                         Brading
49 Aware that the RRV would need to pass again at some point on its return journey,
The sequence of events
   the COSS did not participate directly in the track repair work and they were
   anticipating a phone call from the ES notifying them that the RRV was travelling
   back towards their site of work. The COSS believed that the RRV would not
   approach the site of work without them receiving a call from the ES.
50 After completing vegetation trimming at the RRV’s first site of work near Ryde
   St Johns, it started its return journey travelling south towards its second site of
   work next to Rowborough Lane bridge (figure 9). This required the RRV to pass
   through the track repair work group’s site of work.
51 From Ryde St Johns, the line south climbs towards a summit at 3 miles 20 chains.
   The MO was aware of the incline and stated that they drove slightly faster than
   5 mph (8 km/h) in second gear which allows a maximum speed of 15 mph
   (24 km/h) to make it up the incline. Although it was not discussed, both the ES
   and the MC believed that the RRV already had approval from the ES to travel
   at more than 5 mph (8 km/h) within the work site while moving to, or between,
   its sites of work as it had been doing so earlier in the major maintenance
   programme. An ES may permit movements at a speed above 5 mph (10 km/h)
   under certain conditions (see paragraph 71).
Events during the accident
52 Members of the track repair work group were correcting a track fault at 3 miles
   37 chains when the COSS noticed a bright light approaching from the north. The
   COSS had not been contacted by the ES about the RRV’s return journey, but
   recognised the lights as being those on the RRV. The COSS instructed the work
   group to remove all tools and the trolley from the track and move to a position of
   safety.
53 The RRV, on passing over the summit of the hill, started to descend. Analysis
   undertaken by RAIB has concluded that the MO would have been able to see the
   work group from the RRV cab from a maximum of 240 metres away, as sighting
   was obstructed by trees on the inside of the left-hand curve before this point
   (figure 10). As they came into view, the MO could see the reflective strips on the
   work group’s protective clothing. The usual procedure when the RRV encountered
   work groups on the track during possessions was to stop close enough to the
   work group to allow the MC and COSS to communicate and arrange the safe
   passage of the RRV. The MO anticipated, therefore, that they would need to stop
   and wait until the track was clear and they could be waved through.
54 As the RRV approached the work group, witness evidence indicates that the MO
   lifted their foot off the RRV’s accelerator pedal intending to slow the vehicle down
   using the hydrostatic drive. The MO stated that they had never had a reason
   to brake going down this gradient before. Instead of the vehicle quickly slowing
   down as expected, the MO could see that the front rail wheels had stopped
   rotating and, along with the MC, could feel that the RRV was sliding. Both the MO
   and MC stated that they had not experienced this before.
Report 12/2024                             21                                 October 2024
Brading
The sequence of events
Track repair
                                                                            work group’s
                                                                              location
Figure 10: View looking south from 3 miles 25 chains, with first sighting of the accident location around
                         240m ahead.
55 The MO applied the brake which had no effect because the wheels were sliding.
                            They tried briefly accelerating to restore grip to then stop the vehicle. The MO
                            realised the RRV was not stopping and sounded the horn. The MO and MC both
                            opened their cab doors and shouted warnings for the work group to clear the
                            track.
                         56 Members of the track repair work group heard the horn and shouting from the
                            cab and realised that the RRV was not able to stop. One witness reported that
                            it appeared to increase in speed as it approached. Members of the work group
                            quickly moved the tools and equipment off the trolley. Two members of the work
                            group then lifted the trolley and threw it into the cess beside the track, where it
                            landed at an angle and, unknown to the work group, it remained foul of the RRV’s
                            path.
                         57 All members of the work group were clear of the track as the RRV approached
                            them. Witness accounts of the RRV’s speed vary widely. Its likely speed is
                            discussed further at paragraph 93. As the RRV passed, its front right rubber tyre,
                            which extended beyond the rail (figure 11), clipped the corner of the trolley. The
                            trolley spun round and struck two members of the work group.
                         58 The site supervisor and another member of the work group were measuring the
                            track beyond the point of collision. They were not affected because they had
                            heard the RRV’s horn and the shouting and had moved to a position of safety.
Report 12/2024                                      22                                       October 2024
                         Brading
                                                                                                           The sequence of events
Figure 11: An RRV of the same type showing the overhang of the rubber tyre in relation to the rail
(courtesy of Sonic Rail Services).
59 The MO and MC believed the group and trolley were clear of the track when they
   started to pass them. The MO and MC were unaware that the RRV’s tyre had
   struck the corner of the trolley as they did not feel the impact. They were also
   unable to see the collision due to the view from the RRV’s cab being obstructed
   by part of the machine.
60 After the RRV came to a stop, the MC got out via the rear cab door to check the
   RRV wheels for a possible cause of the RRV’s poor stopping performance. They
   did not find anything of concern.
Events following the accident
61 After the accident, the COSS went to the RRV and informed the MC that a
   collision had occurred. The RRV moved back towards the work group to shine its
   lights onto the area (figure 12). The MO and MC observed that all members of the
   work group were standing up and stated that they were not informed that there
   had been any injuries.
Report 12/2024                                     23                                       October 2024
Brading
The sequence of events
Figure 12: Location of accident looking south.
62 The ES had earlier been contacted by the work group on Ryde Pier and asked
                            to pick up some track clips from Ryde St Johns depot and deliver them to Ryde
                            Esplanade. They were fulfilling this task when the site supervisor phoned them
                            and stated there had been an incident.
                         63 The COSS phoned the ES at 01:54 and reported the accident straight after the
                            RRV hit the trolley. They also checked on the welfare of those who had been
                            struck. The COSS decided that the track repair work group should stop work and
                            return to the access point at Rowborough Lane bridge. The group subsequently
                            returned to Ryde St Johns depot for welfare checks.
                         64 Although the ES had been informed of the circumstances of the accident, they
                            were unaware of its severity and did not implement procedures to obtain or
                            protect evidence. The RRV was allowed to carry on working, and subsequently
                            moved to the next planned site of work close to Rowborough Lane bridge and
                            started cutting vegetation. Work was stopped when the ES contacted the MC a
                            short time later, having become aware of the full extent of the accident.
                         65 The accident was not reported internally promptly in accordance with SWR
                            procedures, and RAIB was not notified until more than 12 hours after the
                            accident. In addition to this late reporting, critical evidence from the accident was
                            not preserved by SWR. These issues are discussed further in paragraph 111.
Report 12/2024                                   24                           October 2024
                         Brading
Analysis
Identification of the immediate cause
66 The track repair work group was given insufficient warning to be able to
   safely remove the trolley from the track when the RRV approached.
Identification of causal factors
67 The accident occurred due to a combination of the following causal factors:
     a. The COSS of the track repair work group had not been informed of the RRV’s
        movement before it approached (paragraph 68).
     b. The RRV was unable to stop in the expected distance once the MO realised
        the track repair work group was ahead (paragraph 81).
     These factors are now considered in turn.
Communication between ES and COSS
68 The COSS of the track repair work group had not been informed of the
   RRV’s movement before it approached.
69 This causal factor arose due to a combination of the following:
     a. The ES was unaware that there was an RRV movement that created a
        potential risk to the track repair work group and so did not warn the COSS
        (paragraph 70).
     b. The safe system of work adopted by the work group relied on the ES warning
        the COSS of any RRV movements (paragraph 76).
     Each of these factors is now considered in turn.
ES’s risk awareness
70 The ES was unaware that there was an RRV movement that created a
   potential risk to the track repair work group and so did not warn the COSS.
71 Rule Book HB12 states that only the ES can authorise a train movement to enter,
   or be made within, a work site. It also states the ES has to agree the safe system
   of work with each COSS, recording these details on their RT3199 ‘Work- site
   certificate’. HB12 also permits an ES to allow machine movements to run at
   caution (that is, be able to stop within the distance the operator can see above
   5 mph (10 km/h)). But this is conditional on the ES giving specific instructions
   to the MC, and dependent on any agreement made with COSSs. No specific
   agreement was made with the COSSs during this possession.
Report 12/2024                             25                               October 2024
Brading
           72 Clause 7.1 of Rule Book HB15, ‘Duties of the machine controller (MC) and
Analysis
on‑track plant operator’, issue 6 dated September 2022, states that OTP
              movements can only enter or take place within a work site when the ES gives
              permission. The ES stated however that they would not have required the MC to
              seek their authorisation to move the RRV between its sites of work if there were
              no other work groups on the track in those areas. In this possession, unlike in
              some possessions during the preceding 5 weeks, there was a work group moving
              within a site of work extending between 3 miles 33 chains and 4 miles 40 chains
              (paragraph 39). However, as the ES believed the track repair work group would
              be at Brading (4 miles 55 chains), they did not consider that there was a risk of a
              conflicting move due to the RRV having to pass the work group a second time.
           73 No details of the position of the track repair work group were provided to the MC
              in the SWP (RRV), with this and the SWP (track) being separate documents,
              each covering covering several possessions and with limited cross-referencing
              (paragraphs 39 and 41).
           74 The MC stated that their understanding from the pre-work briefing provided by
              the ES was that this gave them the necessary authorisation for movements
              between the sites of work listed, negating any requirement for the MC to call
              the ES before any RRV movements. This arrangement had been applied during
              previous possessions and the MC stated they would only expect to call the ES in
              exceptional circumstances, for example, if points needed to be moved. On this
              basis, the MC did not attempt to contact the ES before permitting the MO to move
              the RRV from its first site of work near Ryde to its second site of work located
              near the access point at Rowborough Lane bridge.
           75 Despite having knowledge of the track repair work group’s earlier location, from
              having previously passed them, the MC and MO believed that the work group
              would be moving south towards Brading. They were unaware that the RRV’s
              second site of work was also within the track repair work group’s site of work,
              so they were not expecting to need to stop. This meant that the presence of the
              work group ahead of the RRV was unexpected, reducing the time and distance
              available to the MC and MO to react to it.
           Safe system of work
           76 The safe system of work adopted by the work group relied on the ES
              warning the COSS of the RRV movements.
           77 For a COSS to treat their safe system of work as safeguarded, Rule Book HB9
              requires them to establish with the ES that either there will be no OTP movements
              at their site of work, or that any movements will be made at no greater than 5 mph
              (10 km/h). The COSS is also required to ensure that they and their group are in a
              safe position before any OTP passes through their site of work.
           78 The list of sites where the RRV was due to work included two locations north of
              Brading. These required the RRV to pass the work group’s location twice and the
              COSS was aware of this.
Report 12/2024                            26                                October 2024
           Brading
79 At the start of the possession, the ES instructed the COSS to wait until the RRV
Analysis
   had passed on its outbound journey before going onto the track. The COSS
   stated that they were expecting the ES to call and warn them for any movements
   where the RRV was going to pass their work group. This understanding
   essentially reflects the requirements of Rule Book HB12 and HB15 that the ES
   authorises each OTP movement within a work site, and of HB9 which requires the
   COSS to establish if there are any OTP movements which could affect their group
   when working under a safeguarded system of work.
80 The COSS and ES worked together frequently but it is not clear if this specific
   issue had ever been recognised as a risk or if it had been briefed or discussed.
   In this case, the lack of a clear understanding about the process to be followed
   for OTP movements meant that these movements were not being specifically
   authorised by the ES, and that the COSS was not being warned about potentially
   conflicting moves with their group.
RRV braking
81 The RRV was unable to stop in the expected distance once the MO realised
   the track repair work group was ahead.
82 The MO and MC travelled in the RRV between sites of work. The MO drove
   using the line-of-sight principle, meaning they would stop the RRV and wait if
   they saw an obstruction or people on the line ahead. The speed would be low but
   not necessarily below 5 mph (8 km/h). Because they were working line-of-sight,
   the risk of an accident occurring at the location where the track repair group was
   working was increased as it was on a curve with restricted visibility. The risk was
   also increased due to the relatively steep descending gradient at the site, which
   would extend braking distances. Both SWPs indicated that there was a gradient
   of 1 in 78 where the accident occurred and identified the risk of RRV runaways on
   a gradient steeper than 1 in 100.
83 This causal factor arose due to a combination of the following:
     a. Low wheel/rail adhesion at the location was almost certainly created by
        environmental conditions on the night (paragraph 84).
     b. The MO and MC were not aware that there was a risk of low adhesion
        conditions affecting the braking of the RRV to the degree that it did
        (paragraph 91).
     These factors are now considered in turn.
Low adhesion conditions
84 Low wheel/rail adhesion at the location was almost certainly created by
   environmental conditions on the night.
85 On the return journey, as the RRV approached the work group and the MO took
   their foot off the RRV’s accelerator pedal to slow it down, its rail wheels locked
   and began to slide (paragraph 54).
Report 12/2024                            27                                 October 2024
Brading
           86 Wheel/rail adhesion conditions at the time of the accident are not known as no
Analysis
rail or wheel contamination samples were taken after the accident occurred (see
              paragraph 112). Weather conditions were cold and damp (paragraph 29) which
              was typical of an autumn night. It is likely that the relative humidity of the air was
              high, causing dew to collect on the rails. It is also possible that contamination of
              the RRV’s rail wheels occurred during the earlier vegetation flailing activity and
              that this also affected the available wheel/rail adhesion.
           87 The accident occurred during the autumn leaf-fall period and although no
              adhesion status notices were applied at the time of the possession, Network Rail
              and SWR had issued a red alert warning for poor railhead conditions for the two
              days before the accident (paragraph 30).
           88 Although the MO and MC had never previously had any difficulty in stopping the
              RRV, they reported they had had trouble getting the RRV to climb the gradient
              at the location where the accident occurred during a possession the previous
              week (paragraph 37). Photographs taken the day before the accident by the
              section manager as part of an unrelated site inspection show no obvious railhead
              contamination (figure 13). However, guidance published by the Rail Delivery
              Group ‘Managing low adhesion – seventh edition (May 2024)’ states that the
              adhesion profile along any stretch of line can vary within metres, and temperature
              and humidity levels can also change rapidly. As such, adhesion levels can vary
              rapidly in terms of both time and location.
Figure 13: Railhead condition near the site of the
                                  accident on 21 November. Image also shows
                                  a chainage marker plate provided at regular
                                  intervals along the Island Line (courtesy of South
                                  Western Railway).
Report 12/2024                                 28                               October 2024
           Brading
89 There are no signals in this area and train drivers would not normally be required
Analysis
   to apply their brakes approaching the location of the accident site. Any possible
   low adhesion conditions at this location would therefore possibly not be apparent
   to a train driver unless wheel slip occurred ascending the gradient. Documentary
   evidence supports this as there was no evidence of train drivers making reports of
   low adhesion (ROLA) on the Island Line in the period before the accident.
90 The Island Line has no recorded history of problems with low wheel/rail adhesion
   and its infrastructure team was not routinely informed of low adhesion conditions
   by SWR. This resulted in the Island Line having no effective low adhesion
   management process (see paragraph 102).
Risk awareness
91 The MO and MC were not aware that there was a risk of low adhesion
   conditions affecting the braking of the RRV to the degree that it did.
92 The MO was aware that there may have been leaf mulch on the railhead near the
   accident location on the RRV’s outbound journey (paragraph 46). However, the
   RRV did not experience any slipping, and the MO and MC did not perceive any
   increased risk of poor adhesion.
RRV braking performance
93 The speed of the RRV as it approached the track repair work group is unknown,
   but witness evidence was that the RRV was in second gear, so it was probably
   travelling at between 5 mph (8 km/h) and 15 mph (24 km/h). The MO and MC
   believed they had the ES’s agreement to exceed 5 mph (8 km/h) (paragraph 51).
94 The relevant Rail Industry Standard for OTP, RIS-1530-PLT, ‘On-Track Plant,
   Trolleys and Associated Equipment’, issue 6 dated December 2015, states that
   a powered machine shall be capable of stopping a fully laden machine on level
   track and in dry and uncontaminated conditions in the following distances:
     • 5 mph: stopping within 6 metres
     • 10 mph: stopping within 18 metres
     • 15 mph: stopping within 36 metres.
95 In the absence of evidence of the actual speed of the RRV, the exact location
   where the MO first attempted to slow the vehicle, or the prevailing level of
   wheel / rail adhesion, it is not possible to accurately estimate the braking
   performance of the vehicle on the 1 in 78 falling gradient on which the RRV was
   approaching the group. However, witness evidence shows that the location where
   the MO first attempted to slow the RRV was sufficiently far from the work group
   to allow the work group time to react, clear the trolley and lift it off the track before
   the RRV passed (paragraph 54). The RRV eventually stopped around 100 metres
   beyond the point of collision (paragraph 8).
96 A wheelset inspection, wheel torque test and static brake test were undertaken
   on the RRV later that same day and did not identify any immediate defect with the
   RRV’s wheels or braking system. It passed dynamic brake testing requirements
   for OTP set out in RIS-1530-PLT, although this testing was not undertaken until
   late January 2024, 10 weeks after the accident. In the test, the RRV was able to
   stop well within the distances required by RIS-1530-PLT. Brake tests were also
   performed at 10 mph (16 km/h), which showed that the RRV was able to stop
   within the allowable limit as per RIS-1530-PLT.
Report 12/2024                               29                                  October 2024
Brading
           97 This suggests that the normal stopping distance of the RRV was increased to a
Analysis
significant degree, by low wheel/rail adhesion and the effect of the gradient.
Identification of underlying factors
           Possession planning
           98 SWR’s process for planning and managing possessions did not effectively
              manage the risk of OTP movements and the risk of OTP and trolley
              collisions.
           99 Before the accident, the process used on the Island Line for planning possessions
              did not include a pre-possession review meeting to identify and deconflict works
              within the possession. There was also no recognised method to manage OTP
              movements.
           100 This lack of a pre-planning meeting meant that those responsible for the planning
               and delivery of the work potentially missed an opportunity to consider the RRV’s
               movements through other sites of work within the work site and to consider how
               these could be safely managed.
           101 The lack of co-ordinated planning also meant that the track repair work group
               and the RRV personnel were using different safe work packs with minimal
               cross‑referencing between them, resulting in a limited shared awareness of
               potential conflicts. For example, while the SWP (track) identified the risk from
               RRV movements and the gradient, effective control measures were not identified.
               The SWP (RRV) gave no information on the location of the track repair work
               group during the possession because it was a generic document covering
               multiple possessions.
           Management of low adhesion risk
           102 SWR had no effective process for managing low wheel/rail adhesion risk for
               maintenance work on the Island Line.
           103 SWR operations manual IL-AP23 ‘Autumn leaf fall arrangements’, dated August
               2023, was marked as applicable to engineering and infrastructure as well as train
               service delivery. Despite this, it only contained instructions for the safe operation
               of service trains. It covered the period from 1 October to 13 December 2023 and
               was to be accompanied by briefings for train drivers and guards. A report of low
               adhesion would require the site to be inspected and cleaned if necessary. There
               were no high-risk sites listed for low adhesion on the Island Line.
           104 The arrangements in this document were that low adhesion was to be managed
               by the on-call duty manager making spot checks and following up on driver
               reports. However, SWR believed that the Island Line was not affected by
               problems with low adhesion as the reporting system used by train drivers had not
               resulted in any reports being received. This may have been because train speeds
               on the line are relatively low, and it would be unusual for a train to need to stop
               between signals or stations.
           105 The Island Line infrastructure maintenance team had hand scrubbers to remove
               leaf debris from the railhead, but no jetting equipment. There was no proactive
               cleaning programme, and the scrubbers had never been used before the
               accident, due to the lack of reports about low adhesion.
Report 12/2024                              30                                 October 2024
           Brading
106 The autumn adhesion management process that is routinely used on the
Analysis
    mainland by Network Rail and train operators was not applied to the Island Line.
    This was because SWR had no previous reports of low adhesion and did not
    believe that it was an issue on the Island Line. It may also be because SWR is
    primarily a train operating company, and so did not have a good awareness of low
    adhesion risk for OTP operating on the Island Line.
Possession assurance
107 SWR’s assurance of possession management on the Island Line did not
    identify the extent of informal working practices present.
108 RAIB’s investigation found that maintenance activities on the Island Line did
    not always comply with the requirements of the Rule Book modules relating to
    possession activities. For example, the ES did not correctly observe the rules
    for controlling RRV movements (paragraph 72). RAIB also found that the ES
    did not have a written record of the track repair work group’s location or the
    limits of their site of work even though these should have been recorded by
    them on form RT3199, along with the safe system of work being used by each
    COSS (paragraph 71). Rule Book HB9 states that the ES must enter the agreed
    details on form RT3199 and get the COSS to sign it. This is to confirm shared
    understanding and agreement of the arrangements in place.
109 Informal work practices may have developed due to the isolated nature of the
    Island Line and because the work was organised and implemented by small
    teams who were familiar with working together.
110 The fact that processes were not always being applied correctly and that some
    informal work practices existed was not detected or corrected by SWR. This was
    because SWR did not undertake any assurance activities on how Island Line
    maintenance activities complied with the requirements of the Rule Book modules
    relating to possession activities.
Observations
Post-accident actions
111 The actions taken in response to the accident led to a loss of evidence and
    did not follow industry standards or legal requirements.
112 Following the collision, the COSS initially responded by ensuring the welfare of
    the work group. The site supervisor and the COSS both notified the ES of the
    accident by phone. Although now aware of the accident, the ES was unaware
    of its severity and did not take the lead or provide guidance to the COSS in
    identifying or protecting evidence. This meant that critical locations at the accident
    site were not marked or photographed, and the railhead was not examined for
    possible contamination. The requirement for drugs and alcohol testing for the staff
    involved was not considered until after some of them had left site.
Report 12/2024                              31                                 October 2024
Brading
           113 The site supervisor took the lead in reporting the accident. After returning to
Analysis
Ryde St Johns depot, they rang the signaller to obtain details for the Island Line’s
               on-call manager. The signaller advised this information should be found in the
               published weekly operating notice (WON). The site supervisor contacted the
               Island Line’s on-call manager at 03:45 (the collision occurred approximately at
               01:50) and informed them that a near miss had occurred and that no one was
               injured. At that point no member of the work group had reported an injury. The
               on- call manager requested drugs and alcohol testing but was told that the staff
               had left site.
           114 The site supervisor was unaware that SWR’s reporting arrangements had
               changed in 2020 to match arrangements on the mainland. Although the WON
               instructed that the on-call manager was to be contacted first, SWR required
               incidents to be reported to the SWR duty control manager first. The on-call
               manager reported the incident to SWR’s duty control manager at around 10:30,
               the delay being attributed to the on-call manager managing the aftermath of an
               unrelated break-in at Ryde St Johns station. The on-call manager also assumed
               that the site supervisor had already reported the incident to the duty control
               manager.
           115 Island Line infrastructure maintenance staff and contractors were not familiar
               with the M&EE Networking Group industry codes of practice for OTP, specifically
               COP0019, ‘Code of Practice for action to be taken in the event of an accident
               or incident involving OTP’, issue 6 dated March 2022, which includes the
               requirement to arrange post-incident dynamic brake testing. This meant that
               the dynamic brake test of the RRV was not undertaken until 10 weeks after the
               accident, in January 2024.
           116 RAIB was not notified of the accident for more than 12 hours. The initial
               notification stated that an RRV had slid and struck a works trolley, but that neither
               vehicle had derailed, no injuries had occurred and that there was no damage.
               Further enquiries revealed that people had been struck in the accident.
           117 Regulation 4 and Schedule 1 of the Railways (Accident Investigation and
               Reporting) Regulations 2005 (as amended) require that accidents and incidents,
               that in slightly difference circumstances could have led to serious injury or worse,
               should be immediately notified to RAIB. RAIB would, therefore, expect the type of
               accident seen at Brading to have been notified immediately. RAIB’s guide about
               notifying accidents states that if there is any doubt about whether an accident is
               notifiable to RAIB, then duty holders such as SWR should notify anyway.
           118 Regulation 7 of the 2005 Regulations also requires duty holders to preserve
               evidence relating to accidents and incidents for examination by RAIB. Failing to
               preserve evidence can hamper safety investigations and reduce the opportunities
               to learn important lessons from accidents and incidents.
           Gradient information
           119 Gradient reference information was inaccurate.
           120 Gradient information available to SWR and SRS was not accurate in the area
               where the accident occurred. RAIB’s post-accident measurements at the site
               indicate that the start of the gradient on which the accident occurred is around
               300 metres north of the location stated in reference data held by Network Rail and
               used to prepare the SWPs.
Report 12/2024                             32                                  October 2024
           Brading
121 Further discrepancies were identified in SWR document ‘601 complete map’
Analysis
    which shows the track as level at the accident location, and a historical ‘5-mile
    line diagram’ which shows the gradient as 1 in 300. The inaccuracy and disparity
    in these sources of information may reduce SWR’s ability to plan work safely,
    particularly where vehicles and trolleys are involved.
Report 12/2024                            33                                October 2024
Brading
                         Summary of conclusions
Summary of conclusions
Immediate cause
                         122 The track repair work group was given insufficient warning to be able to safely
                             remove the trolley from the track when the RRV approached (paragraph 66).
Causal factors
                         123 The causal factors were:
                              a. The COSS of the track repair work group had not been informed of the RRV’s
                                 movement before it approached (paragraph 68). This causal factor arose due
                                 to a combination of the following:
                                  i.   The ES was unaware that there was an RRV movement that created a
                                       potential risk to the track repair work group and so did not warn the COSS
                                       (paragraph 70, Recommendation 1).
                                  ii. The safe system of work adopted by the work group relied on the
                                      ES warning the COSS of any RRV movements (paragraph 76,
                                      Recommendation 2).
                              b. The RRV was unable to stop in the expected distance once the MO realised
                                 the track repair work group was ahead (paragraph 81). This causal factor
                                 arose due to a combination of the following:
                                  i.   Low wheel/rail adhesion at the location was almost certainly created by
                                       environmental conditions on the night (paragraph 84).
                                  ii. The MO and MC were not aware that there was a risk of low adhesion
                                      conditions affecting the braking of the RRV to the degree that it did
                                      (paragraph 91).
Underlying factors
                         124 The underlying factors were:
                              a. SWR’s process for planning and managing possessions did not effectively
                                 manage the risk of OTP movements and the risk of OTP and trolley collisions
                                 (paragraph 98, Recommendation 1)
                              b. SWR had no effective process for managing low wheel/rail adhesion risk for
                                 maintenance work on the Island Line (paragraph 102, Recommendation 1)
                              c. SWR’s assurance of possession management on the Island Line did not
                                 identify the extent of informal working practices present (paragraph 107,
                                 Recommendation 2).
Report 12/2024                               34                                October 2024
                         Brading
Additional observations
Summary of conclusions
125 Although not linked to the accident on 22 November 2023, RAIB observes that:
     a. The actions taken in response to the accident led to a loss of evidence and did
        not follow industry standards or legal requirements (paragraph 111, Learning
        points 1, 2 and 3).
     b. Gradient reference information was inaccurate (paragraph 119,
        Recommendation 3).
Report 12/2024                            35                                October 2024
Brading
                                                                           Actions reported as already taken or in progress relevant to
Actions reported as already taken or in progress relevant to this report
this report
                                                                           Actions reported that address factors which otherwise would have
                                                                           resulted in an RAIB recommendation
                                                                           126 SWR has reported that it has:
                                                                                a. introduced a formal planning meeting for maintenance activities including
                                                                                   the use of whiteboards during pre-possession planning showing the relative
                                                                                   location of works and the works phase which has improved the management
                                                                                   of possessions
                                                                                b. introduced an ES briefing form which is handed to the COSS in addition to
                                                                                   the verbal briefing and requirement for the COSS to sign the RT3199 form to
                                                                                   confirm their understanding
                                                                                c. provided a briefing to Island Line infrastructure maintenance staff on
                                                                                   post‑incident actions and the requirement to preserve evidence
                                                                                d. undertaken a new risk assessment for machine movements
                                                                                e. issued a briefing to all infrastructure staff on machine movements
                                                                                f. reviewed its post-incident response for Island Line incidents which has
                                                                                   included establishing competency requirements
                                                                                g. taken steps to address the deficiencies found within its assurance processes
                                                                                   for monitoring compliance with the requirements of the Rule Book modules
                                                                                   relating to possession activities.
Report 12/2024                             36                                    October 2024
                                                                           Brading
Recommendations and learning points
Recommendations and learning points
Recommendations
127 The following recommendations are made:1
1     The intent of this recommendation is for South Western Railway to
            review how it manages safety during infrastructure work on the Island
            Line.
            South Western Railway should undertake a risk-based review of its
            arrangements for:
            a) planning and management arrangements for possessions, work sites
               and sites of work
            b) the movement of on-track plant, including risks relating to gradients
               and low wheel/rail adhesion.
            This should include the applicability of the provisions of GERT8000 (the
            Rule Book) for managing Island Line infrastructure works.
            Following this review, South Western Railway should develop a
            timebound plan to make any appropriate changes identified to standards,
            processes and its organisational structure (paragraphs 123.a.i, 124.a,
            124.b).
2     The intent of this recommendation is for South Western Railway to
            review its assurance processes.
            South Western Railway should review assurance processes to
            understand if they are effective at detecting informal, non-compliant and
            unsafe practices during infrastructure work on the Island Line.
            Following this review, South Western Railway should develop a
            timebound plan to make any appropriate changes identified to standards,
            processes and its organisational structure (paragraphs 123.a.ii, 124.c).
1
  Those identified in the recommendations have a general and ongoing obligation to comply with health and safety
legislation and need to take these recommendations into account in ensuring the safety of their employees and
others.
Additionally, for the purposes of regulation 12(1) of the Railways (Accident Investigation and Reporting) Regulations
2005, these recommendations are addressed to the Office of Rail and Road to enable it to carry out its duties
under regulation 12(2) to:
(a) ensure that recommendations are duly considered and where appropriate acted upon; and
(b) report back to RAIB details of any implementation measures, or the reasons why no implementation measures
are being taken.
Copies of both the regulations and the accompanying guidance notes (paragraphs 200 to 203) can be found on
RAIB’s website www.gov.uk/raib.
Report 12/2024                                           37                                            October 2024
Brading
Recommendations and learning points
3     The intent of this recommendation is for South Western Railway to
                                                 provide its infrastructure maintenance staff and contractors with accurate
                                                 information about its infrastructure.
                                                 South Western Railway should establish the accuracy and completeness
                                                 of gradient information used for planning possession works on its
                                                 infrastructure so that the risks associated with runaways and low
                                                 adhesion can be understood and managed. The revised information
                                                 should be provided to Network Rail Technical Authority to enable industry
                                                 reference information to be updated (paragraph 125.b).
Learning points
                                      128 RAIB has identified the following important learning points:2
1     Transport undertakings and on-track plant operators are reminded
                                                 of the importance of applying industry codes of practice in the event
                                                 of an accident or incident involving on-track plant. This includes
                                                 COP0019 ‘Code of Practice for action to be taken in the event of an
                                                 accident or incident involving OTP’, published by the Rail Safety and
                                                 Standards Board (RSSB) on behalf of the M&EE Networking group
                                                 (paragraph 125a).
2     Duty holders are reminded to promptly report serious and potentially
                                                 serious accidents to RAIB in accordance with the Railways (Accident
                                                 Investigation and Reporting) Regulations 2005 (as amended). Failing to
                                                 do so can result in evidence loss and reduced opportunities for safety
                                                 learning (paragraph 125a).
3     Duty holders are reminded of the importance of having well-established
                                                 processes and procedures for dealing with post-accident evidence
                                                 collection and testing (paragraph 125a).
2
                                        ‘Learning points’ are intended to disseminate safety learning that is not covered by a recommendation. They are
                                      included in a report when RAIB wishes to reinforce the importance of compliance with existing safety arrangements
                                      (where RAIB has not identified management issues that justify a recommendation) and the consequences of failing
                                      to do so. They also record good practice and actions already taken by industry bodies that may have a wider
                                      application.
Report 12/2024                                         38                                          October 2024
                                      Brading
Appendices
Appendices
Appendix A - Glossary of abbreviations and acronyms
Abbreviation / acronym                                         Full term
CCTV                                            Closed-circuit television
COSS                                             Controller of site safety
ES                                               Engineering supervisor
MC                                                    Machine controller
MO                                                    Machine operator
OTP                                                       On-track plant
PICOP                                    Person in charge of possession
RRV                                                    Road-rail vehicle
RSSB                                    Rail Safety and Standards Board
SGC                                                  SGC Rail Solutions
SRS                                                 Sonic Rail Services
SWL                                                    Safe work leader
SWP                                                      Safe work pack
SWR                                             South Western Railway
WON                                             Weekly operating notice
Report 12/2024                 39                             October 2024
Brading
             Appendix B - Investigation details
Appendices
RAIB used the following sources of evidence in this investigation:
             • information provided by witnesses
             • safe work packs
             • RRV test reports and certificates
             • RSSB industry guidance including rule book handbooks
             • site photographs and gradient measurements
             • gradient reference information
             • weather reports and observations at the site
             • SWR red alerts and seasonal briefings
             • SWR standards and procedures
             • a review of previous RAIB investigations that had relevance to this accident.
Report 12/2024                            40                                 October 2024
             Brading
This report is published by the Rail Accident Investigation Branch,
Department for Transport.
© Crown copyright 2024
Any enquiries about this publication should be sent to:
RAIB                                         Email: enquiries@raib.gov.uk
The Wharf                                    Telephone: 01332 253 300
Stores Road                                  Website: www.raib.gov.uk
Derby UK
DE21 4BA

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