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Bridge Strikes - Risks and Consequences 1 April 2011 Bridge Strikes – Risks and Consequences Keith Ross, National Bridge Strike Champion
Bridge Strikes - Risks and Consequences 1
April 2011
Bridge Strikes –Risks and Consequences
Keith Ross, National Bridge Strike Champion
April 2011 Bridge Strikes - Risks and Consequences 2
Contents
• Bridge Strike statistics• Consequences of a bridge
strike• Management of bridge
strikes–prevention of bridge
strikes–mitigation– response to a reported
bridge strike
Bridge Strike StatisiticsSection number to go here
April 2011 Bridge Strikes - Risks and Consequences 4
Bridge Strike Statistics
Bridge Strikes at Rail over Road (Underline) Bridges
1538 1613 16781914 1898
20201890
20222161
1736
14391593
0
500
1000
1500
2000
250019
99/2
000
2000
/01
2001
/02
2002
/03
2003
/04
2004
/05
2005
/06
2006
/07
2007
/08
2008
/09
2009
/10
2010
/11
Year
Num
ber o
f rep
orte
d B
ridge
St
rikes
April 2011 Bridge Strikes - Risks and Consequences 55
Bridge Strike Statistics
Bridge Strikes at Road over Rail (Overline) Bridges
103 111100
122
142152 146
126143
115 11398
020
406080
100120
140160
1999
/200
0
2000
/01
2001
/02
2002
/03
2003
/04
2004
/05
2005
/06
2006
/07
2007
/08
2008
/09
2009
/10
2010
/11
Year
Num
ber o
f rep
orte
d B
rdig
e St
rikes
April 2011 Bridge Strikes - Risks and Consequences 6
Number of Bridge Strikesby Vehicle Type
• Majority of strikes by LGVs
• Light vehicles (small lorries and larger vans)
– often wedged under single lane bridges
• Buses– passengers at risk of injury
• Low loaders carrying plant– can cause significant bridge damage
Bridge Strikes by Vehicle Type at Underline Bridges
0
200
400
600
800
1000
1200
1400
1600
1800
2000
/01
2001
/02
2002
/03
2003
/04
2004
/05
2005
/06
2006
/07
2007
/08
2008
/09
2009
/10
2010
/11
Year
Num
ber o
f Veh
icle
s
Bus and coach
LGVs
Light Goods vehicle
Plant vehicle
April 2011 Bridge Strikes - Risks and Consequences 7
Bridge Strike Statistics
Bridge Strikes at Underline Bridges by Permitted Vehicle Height
0
100
200
300
400
500
600
700
800
900
100020
00/0
1
2001
/02
2002
/03
2003
/04
2004
/05
2005
/06
2006
/07
2007
/08
2008
/09
2009
/10
2010
/11
Year
Num
ber o
f rep
orte
d B
ridge
Str
ikes
< 2.5 metres 2.5 - 3.9 metres4.0 - 4.5 metres
> 4.5 metres No Height Recorded
April 2011 Bridge Strikes - Risks and Consequences 8
Performance Loss
£3,918£3,900£4,975Average Cost per Bridge Strike
£4.81m£6.82 m£9.6 mAnnual Cost of Delay
132 minutes130 minutes174 minutesAverage Delay per Bridge Strike
162,348minutes
220,465 minutes
335,500 minutes
Annual Delay (minutes)
170423551930Number of Reported Bridge Strikes
20010/112007/082005/06
Consequences
Section number to go here
April 2011 Bridge Strikes - Risks and Consequences 1010
Safety Risk and Costs• Safety risk
– vehicle drivers– members of public– trains and travelling public
• Cost– delay and disruption to
the community– delays to train services– bridge examination– repair of bridge damage– repair of vehicle damage
April 2011 Bridge Strikes - Risks and Consequences 1111
Rail Safety Risk - Watling Street 1972
April 2011 Bridge Strikes - Risks and Consequences 12
Rail Safety Risk – Oyne 1978
• only derailment due to bridge strike in UK
– Oyne, Aberdeenshire– Seven injured
• vehicle involved– excavator on low loader
April 2011 Bridge Strikes - Risks and Consequences 1313
Rail Safety Risk - Buxton
• bridge and track displaced9 inches
– freight route 1 train a week
– found by track inspection team day before train due
– strike not reported by vehicle driver
– bridge ballasted with3 main girders
• 500 Ton crane necessary to reposition bridge
April 2011 Bridge Strikes - Risks and Consequences 1414
Fenny Compton 15th February 2011• bridge struck by crane hoist
on low loader• vehicle struck bridge when
exiting from under bridge• bridge carried redundant
siding• other bridges over road
carried main line• track carried on longitudinal
timbers supported in trough beam
• bridge signed to show permitted height 13’ 3’’
April 2011 Bridge Strikes - Risks and Consequences 15
Fenny Compton 15th February 2011
April 2011 Bridge Strikes - Risks and Consequences 16
Damage to Metallic Bridge Decks
• buckles in flanges • tears to flanges
– rail bearers would require to be replaced
• loss of rivets and bolts to flanges
• holes in webs• gouges• torn or bent stiffeners• paint scrapes
April 2011 Bridge Strikes - Risks and Consequences 17
Damage to Bridges
• loss of arch spandrel and/or parapet
• loss of bricks to arch rings• gouges in arch barrel• displacement of voússoir
stone• cracks in arch spandrel and/or
parapet
April 2011 Bridge Strikes - Risks and Consequences 18
Risk to Vehicle Drivers• skip lorries can rotate
and hit underside of bridge crushing driver’s cab
• risk of injury if vehicle overturns
• lorry may jack knife if travelling at speed
• risk of loss of control of vehicle
• disruption due to road closure for vehicle recovery
April 2011 Bridge Strikes - Risks and Consequences 1919
Overturned Vehicles• vehicle travelling at
speed at skew bridges• risk of severe injuries
to driver• risk to innocent
drivers on other carriageway
• damage to vehicle • damaged loads• disruption due to road
closed• vehicle recovery
necessary
April 2011 Bridge Strikes - Risks and Consequences 20
Buses and Coaches• risk of injury to passengers
• risk to following vehicles
• if travelling at speed risk of loss of roof
• danger to passers-by from broken glass
• bridge rarely significantly damaged
• disruption due to road closure
• vehicle recovery necessary
April 2011 Bridge Strikes - Risks and Consequences 21
Innocent Road Users• risk to occupants of
other vehicles passing in opposite direction from:
–vehicles overturning at skew bridges
– falling loads
• risk to pedestrians
• disruption due to road closure for vehicle recovery
April 2011 Bridge Strikes - Risks and Consequences 2222
Vehicles Wedged
• vehicle travelling at speed
• severe damage to body of vehicle
• risk of suspension collapse
• disruption due to road closure
• vehicle may need to be cut up to be removed
• vehicle recovery necessary
April 2011 Bridge Strikes - Risks and Consequences 2323
Cost to the Community Damaged Loads• risk of injury to passers-by from
load falling from vehicle• disruption due to road closure for
load recovery• businesses affected awaiting for
delivery of replacement goods
April 2011 Bridge Strikes - Risks and Consequences 2424
Prevention of Bridge Strikes• Education
– increase awareness– guidance– revisions to driving theory
test and driving skill books• Engineering
– road traffic signs and markings
– traffic management– improve visibility
• Enablement– route planning– height measurement
• Enforcement
April 2011 Bridge Strikes - Risks and Consequences 2525
Better Driver AwarenessGood Practice Guides
April 2011 Bridge Strikes - Risks and Consequences 26
Guide for Foreign Drivers
• English
• French
• German
• Spanish
• Italian
• Bulgarian
• Russian
• Polish
April 2011 Bridge Strikes - Risks and Consequences 2727
Protocol for Highway Managers• developed for Bridge Strike
Prevention Group–CSS Bridges Group–Network Rail–Department for Transport
• Highway Authorities responsible for :
–measuring and determining permitted height shown on road traffic signs
– installation and maintenance of road traffic signs
April 2011 Bridge Strikes - Risks and Consequences 2828
Protocol Scope
• correct signage on, adjacent to and in advance
– provision, visibility and maintenance
– Protocol has appendix showing examples of ‘where improvements could be made’
• works in vicinity of low bridges
• liaison with Network Rail
April 2011 Bridge Strikes - Risks and Consequences 29
Problems with Signs – Flat Soffits• lack of signs at low
bridges–no or incorrect
chevrons– triangular instead of
roundel at flat soffit bridges
• no advance warning signs
• damaged signs• incorrect dimension• inverted or alternate
chevrons• lack of sign maintenance
April 2011 Bridge Strikes - Risks and Consequences 3030
Problems with Signs –Arches
• double white lines through arch conflicting with signed vehicle limits
• chord marking wider than road marking for arch
• roundels not triangular signs
• lack of black and yellow hazard markings
April 2011 Bridge Strikes - Risks and Consequences 31
Problems with Signs - Obscuration
• vegetation growth will obscure signs if not controlled
• signs need to be visible to be effective
• other illumination may obscure signs at night
April 2011 Bridge Strikes - Risks and Consequences 32
Problems with Signs - Thinking about the Driver
• multiple messages on a sign could cause confusion leading to a wrong decision
• Alternative route should not lead to another bridge lower than the one signed
April 2011 Bridge Strikes - Risks and Consequences 33
Good Practice –Challoc/Dunragit
April 2011 Bridge Strikes - Risks and Consequences 34
Good Practice –Challoc/Dunragit
April 2011 Bridge Strikes - Risks and Consequences 3535
Mitigation
• collision protection beams fixed to bridge to be part of structure
• reconstruction to resist bridge strikes
April 2011 Bridge Strikes - Risks and Consequences 3636
Response to a reported Bridge Strike• Bridge Strike reported to Network Rail Control
– bridge identification plate shows telephone number to be used
– telephone number varies according to bridge location
• Signaller implements Operating Instructions
– underline bridge based on
• robustness of bridge
• vehicle type
• number of trains over bridge since strike occurred
– Overline bridge – Rule Book
• Control arranges for bridge examination
• Control advises Highway Authority if road traffic signs damaged
April 2011 Bridge Strikes - Risks and Consequences 3737
Operating Instructions Underline Bridges• Signal box special instructions
– based on robustness of bridge to vehicle impact– tracks on bridges over roads are colour coded to define the
action to be taken by Signaller
• Red – Stop trains – this is the default• Amber – First train examines track at 5mph. If track
alignment not affected and no debris trains are permitted at 20 mph until the bridge is examined
• Double Amber – As for Amber but subsequent trains at Normal Speed
• Green – Continue to operate at Normal Speed – applies to very high bridges and massive structures
• light vehicles – cars, vans and motor cycles– train movements not stopped unless vehicle on fire
April 2011 Bridge Strikes - Risks and Consequences 3838
Examination• Bridge Strike
Nominees (BSNs)
– Operations staff
– checks against defined damage limits
• Bridge Strike Examiners (BSEs)
– confirms BSNs decision
– able to carry out close examination
– not subject to damage limits
– can instigate repairs
April 2011 Bridge Strikes - Risks and Consequences 3939
Response to a Bridge Strike at a Bridge over the Railway
• developed with:–County Surveyors’ Society
(now ADEPT)–Highways Agency–Police organisations
• provides advice to minimise the risk to the operational railway and road users from a bridge strike:
–when damage is caused to the bridge parapet
– to enable train services and road traffic movements over the bridge to be restored safely
April 2011 Bridge Strikes - Risks and Consequences 40
Principle• prevents incursion of road
vehicles on to the railway prior to installation of an acceptable temporary safety barrier
• interim arrangements of road safety management enable train services to be restored:
–with minimum delay–maintain the safety of the
railway and the highway pending reconstruction or repairs
–must be sufficient to prevent an errant vehicle from landing on the railway
• responsibilities of each stakeholder listed
April 2011 Bridge Strikes - Risks and Consequences 41
