Space weather and rail : outlook and finding, 16-17 September 2015, London, United Kingdom.
Date: 2015-11-27
Institutions: Institute for the Protection and Security of the Citizen
Subjects: EU research policy, inland waterway transport, meteorology, satellite navigation, transport infrastructure

Space Weather and Rail: 
Findings and Outlook 

An event co-organised by the European Commission’s Joint Research Centre,

the Swedish Civil Contingencies Agency,

the UK Department for Transport, and

the NOAA Space Weather Prediction Center

16-17 September, 2015, London, UK

Elisabeth Krausmann, Emmelie Andersson, Terry Russell, William Murtagh

2 0 1 5

Report EUR 27523 EN

 
 
 
 
 
 
 
European Commission 
Joint Research Centre 
Institute for the Protection and Security of the Citizen  

Contact information 
Elisabeth Krausmann 
Address: Joint Research Centre, Via E. Fermi 2749, 21027 Ispra (VA), Italy 
E-mail: elisabeth.krausmann@jrc.ec.europa.eu 

https://ec.europa.eu/jrc 

Legal Notice 
This publication is a Science and Policy Report by the Joint Research Centre, the European Commission’s in-house 
science service. It aims to provide evidence-based scientific support to the European policy-making process. The 
scientific output expressed does not imply a policy position of the European Commission. Neither the European 
Commission nor any person acting on behalf of the Commission is responsible for the use which might be made 
of this publication. 

Image credits: Modern high speed train: ©Oleksiy Mark – Fotolia.com  

JRC98155 

EUR 27523 EN 

ISBN 978-92-79-52749-4  

ISSN 1831-9424 

doi:10.2788/211456 

Luxembourg: Publications Office of the European Union, 2015 

© European Union, 2015 

Reproduction is authorised provided the source is acknowledged. 

Abstract 

Space weather caused by solar activity can disrupt and damage critical infrastructures in space and on the ground.
Space-weather  impacts  to  the  power  grid,  aviation,  communication,  and  navigation  systems  have  already  been
documented.  Since  society  relies  increasingly  on  the  services  these  critical  infrastructures  provide,  awareness  of
the space weather threat needs to be increased and the associated risks assessed. While most research on impacts
of space weather focuses on the power grid, the Global Navigation Satellite System (GNSS), and aviation, railway
networks  are  also  a  potential  area  for  concern.  Anomalies  in  signalling  systems  have  been  observed  during
geomagnetic  storms,  and  rail  transport  depends  on  power,  communications,  and  progressively  on  GNSS  for
timing and positioning. 
In order to raise awareness of this topic, and to further explore the vulnerability of rail systems to space weather,
the  European  Commission’s  Joint  Research  Centre,  the  Swedish  Civil  Contingencies  Agency,  the  UK  Department
for Transport, and the US National Oceanic and Atmospheric Administration jointly organised the “Space weather
and rail” workshop in London on 16-17 September 2015. The workshop was attended by representatives from the
railway  sector,  insurance,  European  and  North  American  government  agencies,  academia,  and  the  European
Commission. This report presents the main findings and conclusions of this workshop. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Space Weather and Rail: 
Findings and Outlook 

An event co-organised by the European Commission’s Joint Research Centre, 
the Swedish Civil Contingencies Agency MSB, 
the UK Department for Transport, and 
the NOAA Space Weather Prediction Center 

16-17 September 2015, London, United Kingdom 

Elisabeth Krausmann*, Emmelie Andersson †, Terry Russell+, William Murtagh‡  

*European Commission Joint Research Centre, Institute for the Protection and Security of the 
Citizen, Italy 
†Swedish Civil Contingencies Agency (MSB) 
+Department for Transport, UK 
‡Space Weather Prediction Centre, NOAA, USA 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Executive Summary 

Space weather caused by solar activity can disrupt and damage critical infrastructures in space and on 
the  ground.  Space-weather  impacts  to  the  power  grid,  aviation,  communication,  and  navigation 
systems have already been documented. Since society relies increasingly on the services these critical 
infrastructures provide, awareness of the space weather threat needs to be increased and the associated 
risks  assessed.  While  most  research  on  impacts  of  space  weather  focuses  on  the  power  grid,  the 
Global Navigation Satellite System (GNSS), and aviation, railway networks are also a potential area 
for concern. Anomalies in signalling systems have been observed during geomagnetic storms, and rail 
transport depends on power, communications, and progressively on GNSS for timing and positioning. 

In  order  to  raise  awareness  of  this  topic,  and  to  further  explore  the  vulnerability  of  rail  systems  to 
space weather, the European Commission’s Joint Research Centre, the Swedish Civil Contingencies 
Agency,  the  UK  Department  for  Transport,  and  the  US  National  Oceanic  and  Atmospheric 
Administration  jointly  organised  the  “Space  weather  and  rail”  workshop  in  London  on  16-17 
September 2015. The workshop was attended by representatives from the railway sector, insurance, 
European and North American government agencies, academia, and the European Commission.  

The main workshop conclusions are: 
•  Extreme space weather has a global footprint and can affect multiple infrastructures at the same 

time.  

• 

Interdependencies between infrastructures need to be better understood and assessed to improve 
the resilience to cascading effects due to extreme space weather. 

•  While there is evidence of past space-weather impacts on rail, awareness in the rail sector appears 

to be limited. 

•  Documented rail-system anomalies linked to space weather are confined to high latitudes. 
•  Vulnerabilities  in  rail  networks  exist  via  direct  impacts  on  track  circuits  and  equipment,  and 

indirectly via dependencies on power, communications, and GNSS. 

•  Due  to  different  system  architectures  and  approaches  to  operations,  the  vulnerability  of  rail  to 

space weather varies from country to country. 

•  The  move  towards  more  automation  in  future  rail  traffic  management  will  likely  add 

vulnerabilities to space weather to the rail network. 

•  Timing and synchronisation are key aspects for rail networks that will be increasingly provided by 

GNSS. Redundancies to mitigate the risks of GNSS loss are required. 

•  The  rail  sector  needs  to  identify  its  vulnerabilities  and  subsequently  the  early-warning 

requirements necessary to better protect its assets. 

•  There  are  US  and  European  space-weather  forecasting  capabilities  that  provide  24/7  early 

warning of space-weather storms. 

•  Further research is needed to close knowledge gaps on consequences and probabilities of extreme 

space weather. 

•  Assessing  the  space-weather  risk  can  help  to  create  preparedness  and  response  capabilities  that 

can also be applied to other hazard domains.  

•  For  extreme  space  weather  the  distribution  of  responsibilities  should  be  clarified  to  define  the 

obligations of each stakeholder in risk reduction, emergency response and recovery. 

• 

International  cooperation  for  response  planning  is  necessary  to  cope  with  extreme  events  that 
could overwhelm national response capacities. 

 
 
 
 
Table of Contents  

1. Introduction ......................................................................................................................................... 1 
2. Space weather and its potential impacts ............................................................................................. 1 
3. Impacts of space weather on rail ......................................................................................................... 3 
3.1 Direct and indirect effects of space weather on rail ...................................................................... 3 
3.2 Vulnerability of heavy rail to GIC and loss of GNSS and communications ................................ 5 
3.3 Vulnerability of other types of rail infrastructure to space weather ............................................. 7 
3.4 Potential long-term effects of space-weather impact on rail ........................................................ 8 
4. Mitigation of impacts – present and future ......................................................................................... 9 
4.1 Forecasting and crisis management .............................................................................................. 9 
4.2 Mitigation options for current and future vulnerabilities ............................................................ 11 
5. Discussion ......................................................................................................................................... 13 
6. Conclusions ....................................................................................................................................... 14 
ANNEX 1: Survey ................................................................................................................................ 15 
ANNEX 2: Agenda ............................................................................................................................... 17 
ANNEX 3: Participants ......................................................................................................................... 21 

 
 
 
1. Introduction 

The  Sun  as  the  main  source  of  energy  in  the  solar  system  sustains  life  on  Earth.  However,  solar 
activity also affects the space environment near our planet and influences the Earth’s magnetosphere 
which  helps  to  protect  life  from  the  effects  of  space  radiation.  This  phenomenon  is  termed  space 
weather.  When  extreme  space  weather  batters  our  magnetosphere  and  interacts  with  the  Earth’s 
magnetic field, disruptions and damage to critical infrastructures in space and on the ground can be 
the result. Space-weather impacts to the power grid, aviation, communication, and navigation systems 
have already been observed and documented. Since society relies increasingly on the services these 
critical infrastructures provide, awareness of the space weather threat needs to be created and the risks 
from extreme space weather should be assessed.  

While  most  studies  on  the  impact  of  extreme  space  weather  on  infrastructures  are  dedicated  to 
understanding the risks to the power grid and the Global Navigation Satellite System (GNSS), there is 
evidence  that  railway  networks  are  also  a  potential  area  of  concern.  During  geomagnetic  storms, 
anomalies in signalling and train control systems have been observed, and rail transport depends on 
the  availability  of  power,  communications,  and  progressively  on  GNSS  for  timing  and  positioning, 
technologies which can be degraded or disrupted during space-weather storms. 

In order to address this topic, and to further explore the vulnerability of rail systems to space weather, 
the  Joint  Research  Centre  (JRC)  of  the  European  Commission,  the  Swedish  Civil  Contingencies 
Agency  (MSB),  the  UK  Department  for  Transport,  and  the  US  National  Oceanic  and  Atmospheric 
Administration (NOAA) jointly organised the “Space weather and rail” workshop in London on 16-17 
September  2015.  The  event  aimed  to  raise  awareness  of  the  space-weather  risk  in  the  rail  sector, 
discuss the potential impacts on the rail network, in particular through interdependencies with other 
critical infrastructures, and to identify possible mitigation options for current and future systems. This 
workshop  is  the  latest  in  a  series  of  dedicated  awareness-raising  events  which  have  previously 
addressed the potential impacts of space weather on power grids and on financial systems. 

The workshop was attended by over 50 participants representing the railway sector in Europe, railway 
associations,  insurance,  European,  Canadian  and  US  government  agencies,  academia,  and  the 
European  Commission.  This  report  summarises  the  main  conclusions  of  the  event.  Prior  to  the 
workshop,  a  survey  among  rail  operators  in  Europe  and  North  America  was  conducted  by  Natural 
Resources Canada to capture differences in rail system types and their associated vulnerabilities. The 
results of this survey are shown in Annex 1. The workshop programme and the list of participants are 
provided in Annexes 2 and 3. 

2. Space weather and its potential impacts 

Space weather is often considered an emerging risk for which awareness is limited. In the first session 
of  the  workshop,  speakers  from  NOAA’s  Space  Weather  Prediction  Centre  and  the  Rutherford 
Appleton  Laboratory  in  the  UK  presented  an  overview  of  space  weather  providing  both  a 
phenomenological and consequence perspective.  

There  are  different  mechanisms  through  which  solar  activity  can  affect  critical  infrastructures.  The 
most  important  phenomena  that  create  space  weather  are  solar  flares,  solar  radiation  storms,  and 
Coronal Mass Ejections or CMEs. CMEs are large quantities of magnetised solar plasma consisting of 
charged particles that can cause geomagnetic storms if they impact Earth. Of greatest concern are fast 
CMEs  with  speeds  of  up  to  3,000  km/s  that  carry  a  predominantly  southward  magnetic  field.  The 
often cited Carrington storm of 1859, which is a canonical example of extreme space weather and, by 
many  accounts,  the  largest  solar  storm  recorded,  was  triggered  by  a  fast  CME  that  slammed  into 
Earth’s magnetosphere. Major damage to telegraph systems and auroras visible as far south as Cuba 
were the result. Additional past evidence of space-weather related infrastructure damage and outage 

1 

 
 
 
 
 
shows that space weather has a global footprint and can affect multiple infrastructures simultaneously. 
It is therefore believed that if a geomagnetic storm similar in severity to the Carrington event were to 
occur nowadays the immediate and cascading effects could cause a significant and possibly long-term 
disruption  of  critical  infrastructures  with  potentially  catastrophic  economic  consequences.  Such  an 
event would seriously challenge a single nation’s response capacities. 

Extreme  space  weather  is  rare  but  it  can  have  critical  impacts  due  to  society’s  dependence  on 
vulnerable  technologies.  Geomagnetic  storms  caused  by  CMEs  have  potentially  significant 
consequences on different types of infrastructures in space and on the ground. They can affect satellite 
operations  via  both  surface  and  internal  charging  and  create  problems  with  orientation  and  satellite 
tracking,  while  aviation  can  experience  disruptions  of  communications  and  navigation.  The  power 
grid and other grounded infrastructures, such as rail networks or pipelines, can incur damage due to 
the flow of geomagnetically induced currents (GIC) which is a quasi-DC electric current generated by 
space-weather  induced  changes  to  the  geoelectric  field.  The  GIC  in  the  power  system  can  lead  to  a 
cascading failure due to the loss of reactive power and subsequent voltage collapse. The blackout of 
the  Hydro-Québec  power  transmission  system  during  a  severe  geomagnetic  storm  in  1989  is  an 
example. The worst-case scenario usually assumed under space-weather impact are local or regional 
power outages of hours up to a few days. However, if GIC induction damages power-grid components, 
such  as  high-voltage  transformers,  sustained  and  extended  power  loss  is  possible.  Geomagnetic 
storms can also affect the ionosphere, generating ionospheric storms and scintillation, which affects 
the signal propagation from the GNSS, causing time delays, position shifts, and in the worst case loss 
of lock, creating major impacts on timing and positioning. 

Solar flares can trigger radio blackouts and disturb the GNSS network, radar, and communications on 
the ground and in space. Solar radiation storms, on the other hand, can affect the electronics in digital 
systems  through  penetration  of  microchips,  causing  single-event  effects,  and  thereby  compromise 
satellite operations and digital systems on Earth. For aviation there is the additional risk of exposure 
to increased radiation doses for crew and passengers. 

The predictability of extreme space weather is still limited and there is no evidence that its occurrence 
depends on the solar cycle1. In fact, on several occasions strong impacts have been observed during 
solar  minimum.  In  addition,  the  low  occurrence  frequency  of  extreme  space  weather  renders  a 
quantitative risk assessment very difficult. In some infrastructure sectors there is increasing awareness 
of the space-weather threat and their vulnerability is fairly well understood (satellite and power-grid 
operations,  aviation).  In  contrast,  interdependencies  between  vital  infrastructures  require  a  better 
understanding and routine assessment to improve the resilience to possible cascading effects from this 
type of risk. 

In the United States, reducing the country’s vulnerability to space weather is a national priority. Space 
weather  is  considered  one  of  the  most  challenging  risks  and  was  identified  as  a  hazard  that  could 
potentially pose a significant threat to the US economy and security. Consequently, the US National 
Science and Technology Council, a White House Cabinet-level Council, was tasked with developing a 
National  Space  Weather  Strategy  whose  aim  is  to  define  high-level  strategic  goals  for  increasing 
preparedness  to  extreme  space  weather.  Recognising  the  potential  for  major  regional  and  even 
international consequences in case of a Carrington-type storm, the Strategy also includes international 
cooperation as a goal to foster a coordinated global response.  

The key messages from Session 1 are: 
•  The susceptibility of society to space weather is increasing due to its reliance on services provided 

by vulnerable infrastructures and interdependencies between infrastructures. 

1The solar cycle is a periodic 11-year change in the sun’s activity and appearance. The peak of the solar cycle is 
known as solar maximum and the valley of the cycle is known as solar minimum. 

2 

 
 
 
 
 
 
                                                 
• 

• 

• 

In some infrastructure sectors there is increasing awareness of the risks related to space weather 
and their vulnerability is fairly well understood. 

In contrast to other natural hazards, extreme space weather is a large-scale event that can lead to 
multiple failures in different critical infrastructures simultaneously. 

Interdependencies  between  critical  infrastructures  need  to  be  better  understood  and  assessed  to 
improve the resilience to potential cascading effects caused by space weather. 

•  Due  to  the  global  footprint  of  extreme  space  weather,  there  should  be  multilateral  and 
international cooperation for response planning to cope with extreme events that could overwhelm 
national response capacities. 

•  The US is developing a National Space Weather Strategy to define high-level strategic goals for 

increasing preparedness to extreme space weather. 

3. Impacts of space weather on rail 

The  second  part  of  the  workshop  was  split  into  four  sessions,  each  of  which  aimed  to  address  a 
specific issue associated with space-weather impacts on the rail network. Three of these sessions were 
organised  as  parallel  discussion  groups  of  up  to  9  persons,  each  of  which  addressed  the  same 
questions posed by the session moderator. 

3.1 Direct and indirect effects of space weather on rail 

In  this  session,  four  speakers  from  Natural  Resources  Canada,  the  Finnish  Meteorological  Institute, 
the  UK  consultancy  Atkins,  and  Luleå  University  of  Technology  in  Sweden  presented  the  current 
state of understanding of space-weather impacts on rail technologies. 

For Swedish and Russian rail operations at high latitudes there is historical evidence of a number of 
anomalies in signalling systems that coincided with the occurrence of geomagnetic-storm conditions. 
The  signalling  systems  reported  false  blockages  (right-side  failure)  in  sectors  where  no  trains  were 
present.  Statistical  analyses  using  Russian  data  indicate  that  the  occurrence  and  duration  of  these 
anomalies correlated well with the local geomagnetic index and showed a 5-7 times higher probability 
of occurrence during strong geomagnetic storms. The impacts lasted from 1 to several hours. Voltage 
fluctuations  were  observed  on  both  feeding  and  relay  circuits  of  the  signalling  system,  and  impacts 
concerned only electrified railway parts that made use of specific transformer types, and which had 
different  shield  wire  arrangements.  This  suggests  an  increased  susceptibility  to  space  weather  of 
certain types of design. The trigger of the signal anomalies is believed to have been induced currents 
and/or stray currents from the ground during strong geomagnetic storms. Under these conditions, the 
natural electric field is large enough to reduce the operating voltage on the relay. 

Studies carried out jointly by Natural Resources Canada and the Finnish Meteorological Institute aim 
to  understand  how  geomagnetic  disturbances  can  affect  track  circuits.  These  studies  are  based  on 
knowledge  gained  from  geomagnetic  induction  in  the  power  grid  and  pipelines,  and  use  existing 
information  on  AC  interference  on  railway  signalling.  The  results  suggest  that  in  case  of  balanced 
track circuits, GIC and stray currents would create common-mode interference in which the voltages 
in  the  two  tracks  would  cancel  each  other  and  track-circuit  operations  would  not  be  affected.  A 
different situation arises for unbalanced track circuits which are characterised by a short to the ground 
or  between  two  tracks.  In  this  case,  AC  studies  indicate  that  the  unbalanced  track  circuit  would 
experience  differential-mode  interference  where  each  track  has  a  different  voltage.  This  voltage 
difference  can  impact  rail  operations.  Further  studies  are  needed  to  understand  this  effect  in  more 
detail, in addition to determining the level of geomagnetic disturbance needed to produce an impact 
on track-circuit operations. 

3 

 
 
 
 
Atkins carried out a multi-disciplinary study to identify the types of rail technologies and systems in 
the UK that may be vulnerable to extreme space weather. The study assumed that a Carrington-type 
event had occurred and aimed to determine the possible impacts with respect to safety and operability. 
Issues  were  identified  related  to  power,  signalling,  train  traction,  GNSS,  radio  communications  and 
track-side staff. Power can be impacted via DC induction that puts transformers at a risk of failure, 
and loss of traction current would strand electrically powered trains. While train batteries would last 
90-120 minutes in the best case, toilets, air conditioning, heating and main lighting would lose power 
much sooner. Stations could also be affected by a power disruption. Signalling may also be disrupted 
by a power outage. Damage to track-circuit feed transformers may lead to loss in train detection and 
hence  to  right-side  failure2.  Currents  induced  or  directly  coupled  into  a  rail  may  cause  wrong-side 
failure. It was underlined that these conclusions were not based on detailed calculations but rather on 
expert  judgment.  Also,  experience  showed  that  the  failure  might  mutate  when  the  train  moves.  The 
location of a train within the network could change the probability of right- versus wrong-side failure. 
Train  traction  issues  may  be  related  to  DC  in  overhead  line  equipment  that  would  also  flow  in  the 
rolling stock main transformer where it could lead to overheating. Sensors that detect this temperature 
anomaly  might  trigger  train  shut  down.  The  quasi-DC  could  also  be  interpreted  as  incorrect  train 
operations by line current monitoring equipment which would also cause the train to shut down.  

While  loss  of  GNSS  is  not  considered  a  safety  concern  for  the  UK  rail  network  it  could  lead  to 
disruptions as many dependencies are built into train systems. Systems that would be affected are the 
wireless GSM-R3 (a sub-system of the European Rail Traffic Management System ERTMS) and the 
telephone transmission systems as they rely on GPS for timing. In addition, Selective Door Opening 
(SDO) uses GPS to detect a train’s location on a network and locks out sets of doors depending on 
where the train is. The Variable Traction Current Limiting also relies on GPS to activate the limiting 
in the train’s propulsion software. Radio communication systems, such as GSM-R, that use directional 
antennas  would  only  be  disrupted  during  sunrise  and  sunset,  but  their  loss  could  be  critical  during 
emergencies.  The  UK  National  Radio  Network  and  Cab  Secure  Radio  which  are  in  the  process  of 
being phased out are more vulnerable and would also be affected in daytime due to their use of dipole 
antennas.  Lastly,  potential  issues  related  to  track-side  staff  are  associated  with  rail  system 
maintenance  activities  during  geomagnetic  storms  due  to  the  potentially  unexpected  activation  of 
protection systems. 

The Atkins study recommends further research to close knowledge gaps on single-event effects and 
their potential impacts, track-circuit interference, and GNSS dependency, in particular to understand if 
backup  oscillators  for  timing  are  good  enough  to  support  vital  train  functions,  such  as 
communications.  This  includes  a  refinement  of  impact  scenarios  based  on  geographic  variation  and 
the potential for cascading effects. In addition, historical data on disruptions and failures in railway 
assets should be reviewed to identify potential space-weather links. The study also calls for the setting 
up of systems to notify track-side staff of space-weather related dangers to allow the implementation 
of  appropriate  safety  measures.  The  UK  Association  of  Train  Operators  and  Network  Rail  has 
expressed interest in understanding how they would respond to space-weather alerts, e.g. issued by the 
UK Met Office Space Weather Operations Centre.  

The  Swedish  railway  network  is  exposed  to  space  weather  due  to  its  high-latitude  location.  In  the 
north  of  the  country  a  lot  of  lines  are  single  track  with  consequences  on  network  congestion.  The 
availability  and  operability  of  these  lines  is  therefore  critical.  The  objective  is  to  achieve  24/7 
availability  and  no  rail-traffic  disruptions  by  2040.  The  rail  network  is  becoming  more  and  more 
complex with a number of dependencies on other infrastructure services that are space-weather prone. 
For  example,  geometry  cars  and  maintenance  machines  cannot  be  used  if  GPS  is  lost.  This  is 
particularly  critical  because  in  Sweden  maintenance  activities  are  restricted  to  2-3  months  per  year 
due  to  weather  and  there  are  questions  as  to  how  much  maintenance  capacity  is  lost  every  year 

2A  right-side  failure  is  a  failure  condition  in  railway  signaling  that  results  in  a  safe  state.  Wrong-side  failure 
causes an unsafe state. 
3GSM-R: Global System for Mobile Communications – Railway 

4 

 
 
 
 
                                                 
because of space weather. Track information or data from on-board data collection are transmitted to 
data  repositories  where  the  information  is  merged  for  further  use.  This  requires  cloud  services  and 
connections whose availability is uncertain during extreme space weather. Instrumented bearings can 
also  be  affected  as  their  electronics  are  vulnerable  to  GIC  loading.  Space  weather  is,  however, 
considered  a  black  swan  event 4  and  as  such  it  is  not  included  in  asset  integrity  management 
considerations. Potential risks stem from the ground conductivity and the use of DC track circuits that 
exhibit a low resistance between joint insulations, a vulnerability that is magnified by the presence of 
iron powder or snow. Another risk is track degradation with material losses due to GIC. While there is 
as yet no proof that this is indeed due to space weather, rail tracks close to pipelines with noticeable 
space-weather degradation appear much more corroded. 

A  project  has  been  launched  to  address  space-weather  impact  on  the  rail  network  in  Sweden. 
Expected outcomes include the dissemination of information on space-weather issues to suppliers of 
instrumented bearings and rail operators, collection of mitigation techniques, as well as a review of 
incident data tailored to identify failure mechanisms typical of space weather in Sweden’s OFELIA 
system.  While  OFELIA  collects  data  on  disturbances  and  failures  related  to  the  rail  network,  space 
weather is not included as incident trigger. For a number of incidents the cause is unknown and there 
are questions as to whether they might have been triggered by geomagnetic activity.   

The main conclusions of this session are: 
•  Historical  evidence  suggests  that  space  weather  has  affected  the  rail  network  in  the  past  via 

disturbances of the signalling system. 

•  Documented rail-system anomalies linked to space weather are confined to high latitudes. 
•  Preliminary  studies  on  the  susceptibility  of  track  circuits  to  GIC  or  stray  currents  from 
geomagnetic  activity  suggest  that  problems  can  arise  when  GIC  creates  differential-mode 
interference in unbalanced track circuits. 

• 

It is unknown if GIC loading in track circuits would always lead to right-side failure or wrong-
side failure, thereby creating a significant safety risk. 

•  While awareness of the space-weather risk in rail appears to be limited in general, some countries 

have started to analyse the vulnerability of their infrastructures. 

•  A systematic study on the impacts of a Carrington-type space-weather event on the rail network in 
the  UK  has  identified  power,  signalling,  train traction,  GNSS,  radio  communications  and  track-
side staff as potential problem areas. 

•  The Swedish rail network is subject to an elevated space-weather risk due to its location, ground 

conductivity and the use of DC track circuits. 

3.2 Vulnerability of heavy rail to GIC and loss of GNSS and 
communications 

In this session, six parallel discussion groups tried to identify the possible vulnerabilities of heavy-rail 
infrastructure to GIC induction, loss of GNSS and communications and their immediate consequences 
during an extreme space-weather event. All groups discussed the following questions: 

1.  Which rail infrastructure components and systems may be affected by GIC? 

2.  Are there systems dependent on GNSS? If there are, how may they be affected in case of loss of 

GNSS both in the short and long term? 

4 A black swan event is an event which is extremely rare and unexpected but has very significant consequences. 

5 

 
 
 
 
 
                                                 
While  the  discussants  agreed  that  rail  system  architecture  and  operations  and  hence  also  overall 
vulnerabilities  are  country  specific,  some  universal  issues  related  to  space  weather  were  identified. 
With respect to GIC loading, most groups considered transformers (both inside the rolling stock and 
for  traction  feeding)  to  be  vulnerable.  The  rail  sector’s  power-grid  dependency  in  general  was 
highlighted  as  an  important  vulnerability  due  to  its  direct  impact  on  the  rail  network,  but  also 
indirectly as a power outage can affect ticketing machines, lighting, passenger information systems in 
the station, etc. From a safety criticality point of view the most important systems potentially affected 
by GIC are signalling and traffic control systems. This is a particular problem considering the increase 
in track-circuit lengths and longer trains. Issues related to the diversity in AC/DC rail systems need to 
be  better  understood.  Axle  counters  and  train  detection  systems  were  also  mentioned,  as  well  as 
personnel  protection  systems  that  use  track  circuits  to  activate  warning  sirens  in  case  of  incoming 
trains. Other rail equipment and components potentially vulnerable to GIC impact are wayside cables, 
bearings  of  rolling  stock,  telecom  and  lineside  circuits,  batteries  and  backup  systems,  CM  systems, 
point circuits and location cabinets. 

During  extreme  space  weather,  potentially  prolonged  loss  of  GNSS  services  is  possible.  GNSS  is 
increasingly  being  used  for  timing  and  synchronisation  of  the  network,  positioning,  rail  condition 
monitoring and maintenance, telecommunications, power control, or supplier spares tracking. In the 
short term, GNSS disruption could lead to a loss of communication, timing and positioning, and loss 
of command and control systems. The latter is of particular importance because even a short loss of 
command  and  control  could  have  impacts  that  are  bigger  than  anticipated,  and  regaining  command 
and control can be a lengthy process. The availability of a backup system could mitigate the loss of 
GNSS, however, the mitigation capacity of backup systems is not well understood. 

In  case  of  extreme  space  weather,  systems  in  the  railway  network  that  depend  on  timing  would  be 
affected, although some uncertainty was expressed as to what the full range of these systems would be. 
Precise  timing  is  crucial  for  train  control  and  signalling,  and  it  can  be  disrupted  via  GSM-R.  Since 
ERTMS  uses  this  technology,  rail  network  management  could  become  more  vulnerable  to  space 
weather in the future. Train positioning seems to be less of a problem currently as GNSS is not the 
prime technology used for this purpose just yet (e.g. due to the presence of trees or tunnels). However, 
different  location-dependent  operations,  such  as  speed  control,  SDO,  land-slip  detection  and 
maintenance heavily rely on GPS. 

In the long term, there is pressure to move more and more towards using GNSS services which will 
require  a  good  understanding  of  where  dependencies  are  embedded  in  the  rail  infrastructures,  an 
assessment  of  the  associated  risks,  and  definition  of  the  necessary  redundancies  to  be  built  into  the 
network to mitigate the risk. It was pointed out that railways can learn from the aviation sector (e.g. in 
terms of practices and standards) which has a good understanding of the problems created by space 
weather. 

The key points from this session are: 
•  Vulnerabilities to extreme space weather exist via direct impacts on rail and through dependencies 

on other critical infrastructures. 

•  Direct impacts result, e.g., from GIC loading in transformers, overhead line equipment, and track 

circuits, or via damage to electronics. 

• 

Indirect impacts are created by the rail network’s dependence on the power grid, communications, 
and GNSS. 

•  Due  to  different  system  architectures  and  approaches  to  operations,  the  vulnerability  of  rail  to 

space weather varies from country to country. 

• 

In some countries, the disruption of GNSS services could lead to loss of communication, timing 
and positioning, and command and control. 

6 

 
 
 
 
 
•  Backup systems could mitigate loss of critical-infrastructure services, but the mitigation capacity 
of backups is not well understood. In addition, backup systems also need to be hardened against 
space-weather impact. 

•  There  is  increasing  pressure  to  use  GNSS  services  which  requires  an  understanding  of  where 
dependencies  are  embedded  in  the  rail  network,  an  assessment  of  the  associated  risk,  and 
definition of the necessary redundancies to mitigate the risk. 

•  Rail can learn from other sectors (e.g. aviation) on how to manage the space-weather risk. 

3.3 Vulnerability of other types of rail infrastructure to space 
weather 

The  discussion  groups  in  this  session  analysed  the  vulnerabilities  of  rail  infrastructure  other  than 
heavy  rail  and  tried  to  understand  how  space  weather  might  affect  new  technologies.  The  groups 
addressed the following questions: 

1.  Which  space-weather  impacts  can  be  expected  for  a)  light  rail,  b)  diesel  trains,  c)  underground 

systems, d) others? 

2.  How would new technology be affected? 

The workshop participants agreed that other rail systems would probably face difficulties similar to 
heavy  rail  during  extreme  space  weather.  General  problems  would  relate  to  loss  of  power  and 
communications, disruption of signalling systems, and command and control issues. In addition, light 
rail is often automated and depends on GNSS in the absence of a driver. Light rail transformers might 
also be vulnerable. While diesel engines are probably more resilient, the disruption of signals would 
require  driving  by  sight,  thereby  increasing  the  risk  of  collisions.  This  is  especially  problematic  as 
communication  systems  may  also  be  affected.  Also,  there  is  uncertainty  as  to  whether  trains  would 
stop  if  there  were  no  signals  at  all.  In  case  of  longer-term  disruptions,  supplying  fuel  for  diesel 
engines might be a challenge. 

Space-weather  impacts  on  underground  systems  raise  a  number  of  issues  related  to  emergency 
planning and crisis response. The risks are higher due to potentially more people getting isolated or 
stranded  and  cascading  effects  caused  by  short  stock.  De-training  and  rescue  during  power  outages 
with impacts on lighting, ventilation systems, pumps, lifts and escalators would prove to be extremely 
challenging.  Other  types  of  rail-based  systems,  such  as  trams,  would  experience  problems  if  road 
signals were knocked out, and unpowered trams could block roads. 

Among  the  new  technologies  susceptible  to  space  weather  the  one  that  stands  out  as  a  key 
vulnerability is the increasing dependence on GNSS. Risks are exacerbated when system owners are 
not  aware  of  the  GNSS  dependence  possibly  embedded  in  their  systems  and  the  associated 
vulnerability. There is also a trend towards more automation in rail traffic management, and ERTMS 
Level 3 relies heavily on GNSS. In parallel, alternative traffic management systems that are not space-
weather prone are being phased out as the ERTMS moves along. The obvious solution to tackle this 
problem  would  be  the  implementation  of  resilient  backup  systems,  however,  this  is  contrasted  by  a 
trend to reduce redundancies due to the high reliability of system components nowadays. Fibre optics 
are increasingly used to improve the resilience of communication systems but the power requirements 
of  optical  cables  also  render  them  vulnerable  in  a  space-weather  context.  The  use  of  inductive 
charging  systems,  e.g.  for  light  rail  or  buses,  raises  the  question  of  potential  problems  in  terms  of 
power-system connection.  

The main messages from this session are: 
•  Light rail, diesel trains and underground systems would probably face the same problems during 

extreme space weather as heavy rail. 

7 

 
 
 
 
 
 
•  While  not  relying  on  the  power  grid,  diesel  trains  could  be  affected  by  signalling  issues  and  a 

possible lack of fuel in case of extreme space weather. 

•  Underground  systems  pose  a  particular  challenge  to  crisis  response  in  a  situation  where  de-
training and rescue would have to be implemented during power outages with impacts on lighting, 
ventilation, lifts and escalators. 

•  The  move  towards  more  automation  in  future  rail  traffic  management  will  likely  add 

vulnerabilities to space weather. 

•  Operators  should  be  aware  of  GNSS  dependencies  in  their  systems  and  alternative  traffic 

management systems should be considered as a backup. 

•  There is a trend towards reducing redundancies due to the high reliability of system components 

nowadays. 

3.4 Potential long-term effects of space-weather impact on rail 

The last session in the second part of the workshop aimed to shed light on longer-term effects in rail 
operations  in  the  aftermath  of  an  extreme  geomagnetic  storm  that  has  caused  a  nationwide  power 
outage. With this boundary condition in mind, the participants discussed the following issues: 

1.  What will be the consequences of a power outage lasting a) 2 days, b) 1 week, c) 1 month? 

2.  Is there a risk of logistics problems and if yes what type? 

3.  How  would  that  affect  a)  electricity,  b)  communication,  c)  control  systems,  d)  fuel  logistics,  e) 

spare parts? 

4.  What would be the consequences on passenger rescue? 

5.  Are  there  critical  businesses  that  depend  on  rail  transport  and  what  would  be  the  potential 

consequences for them? 

The discussants agreed that a 2-day power outage would be recoverable from a railway point of view, 
although  several  challenges  would  have  to  be  faced.  Command  and  control  would  be  lost, 
communications  would  be  down,  and  no  information  could  go  out  to  staff  and  passengers.  The 
signalling  system  would  have  to  be  re-established,  and  old  systems  need  to  be  reset  manually.  The 
first priority would be to localise trains on the network and start evacuating people. While there are 
contingency  plans  for  evacuation,  they  do  not  consider  scenarios  in  which  several  trains  stop  at  the 
same  time.  If  external  evacuation  takes  too  long  and  no  information  can  be  transmitted  to  the 
passengers on board the stranded trains then self-evacuation would likely start with a risk of injuries 
and panic. The start-up of the power grid after a major geomagnetic storm would depend on damage 
to grid components and most importantly to transformers as they cannot be easily replaced.  

In  case  of  a  widespread  power  outage  lasting  for  one  week,  business  effects  on  freight  customers 
would  become  important  with  potentially  big  financial  impacts.  Also,  the  lack  of  resources  would 
start to be felt as people would not be able to get to work. Electric trains would shut down where they 
stopped  and  might  not  be  able  to  restart  with  their  batteries  flat.  Time-dependent  maintenance 
activities  might  cause  problems  for  planning.  In  addition,  there  might  be  issues  related  to  the 
replaceability of services and the continued availability of specialist knowledge, skills and equipment. 
From a logistics point of view, limitations on the availability of fuel and spare parts would become 
evident.  During  a  large-scale  power  outage  that  lasts  several  days  there  would  be  competition  for 
scarce  resources.  In  such  a  context,  restoration  of  the  rail  network  might  be  considered  of  low 
importance  as  national  recovery  priorities  would  probably  be  on  road  traffic  due  to  security 
considerations (military use). The amount of service that could be restarted after 2 days or a week is 
country-specific  and  depends  on  system  architecture.  The  interconnection  between  countries  in  the 
European Union implies a coordinated transboundary approach to recovery.  

8 

 
 
 
 
A  power  outage  lasting  for  one  month  would  constitute  a  major  national  disaster  that  could  drive 
private  train  companies  into  bankruptcy.  Recovery  priorities  would  be  on  restoring  power  and  the 
moving of food and fuel. Once the rail network starts up there would likely be a large demand. Freight 
would be prioritised under the circumstances to mitigate supply-chain impacts. It is believed that rail 
transport recovery times would be similar to blackout times. 

Businesses  that  rely  on  the  transport  of  passengers  and  goods  would  be  heavily  impacted  by  rail 
network disruptions. This can have strong detrimental effects in entire regions where economies are 
largely  export-based.  Passenger  effects  would  mostly  involve  workers  that  cannot  commute  to  their 
work place but also emergency services that might partly rely on rail to move around. Disruption of 
freight  transport  could  lead  to  limited  availability  of  fuel  (including  coal  and  oil),  food,  medical 
supplies  and  chemicals.  Interestingly,  in  some  regions  where  power  is  produced  from  coal,  the 
unavailability of rail transport to move coal could affect the power grid, which in turn impacts trail 
transport.  Businesses  might  also  be  affected  by  a  shortage  of  spare  parts  which  are  generally  not 
stored anymore but procured when needed. Another issue that was raised concerned the transport of 
nuclear  waste.  Should  a  power  outage  occur  when  the  waste  is  already  on  the  network,  safety  and 
security concerns would quickly emerge. 

The main conclusions of this session are: 
•  A two-day power outage is considered recoverable from a railway point of view. 
•  While there are contingency plans for evacuation, they do not consider scenarios in which several 

trains stop at the same time. 

• 

In case of a one-week nationwide power outage, limitations on the availability of fuel and spare 
parts would become evident. There might also be issues related to the replaceability of services 
and the availability of specialist knowledge and skills. 

•  A one-month power outage would constitute a national disaster and recovery priorities would be 
on restoring power and moving food and fuel. Once the rail network starts up, freight would likely 
be prioritised to mitigate supply-chain effects. 

• 

It  is  believed  that  rail  transport  recovery  times  would  be  similar  to  the  duration  of  the  power 
blackout. 

•  The interconnection between countries in the EU implies a coordinated transboundary approach to 

service recovery. 

4. Mitigation of impacts – present and future 

The  third  part  of  the  workshop  was  dedicated  to  the  prevention  and  mitigation  of  impacts.  Two 
sessions discussed aspects related to space-weather forecasting and early warning, options to render 
current and future technologies less vulnerable, and crisis management. 

4.1 Forecasting and crisis management 

In  this  session  four  speakers  from  NOAA,  National  Resources  Canada,  the  Swedish  Civil 
Contingencies  Agency,  and  the  UK  Met  Office  discussed  the  opportunities  provided  by  forecasting 
and  early  warning,  examples  of  crisis-response  processes,  and  the  challenges  surrounding  data 
availability and uncertainties. 

NOAA’s Space Weather Prediction Center (SWPC) is the US’s official source of space-weather alerts 
and  warnings.  Government  but  also  different  infrastructure  sectors  rely  on  NOAA’s  forecasts  to 
manage  their  space-weather  risks.  The  forecasting  process  starts  with  probabilistic  forecasts  of 

9 

 
 
 
 
 
conditions favourable for triggering solar activity. Once an event occurs, e.g. a strong flare, coronal 
observations  are  used  to  understand  if  a  CME  has  been  produced,  where  it  is  headed  and  how  fast. 
This is followed by a prediction of CME arrival at Earth. Once the CME hits the ACE and DSCOVR 
satellites, predictions can be refined before event onset on Earth. This is also the moment when the 
CME’s  magnetic  field  orientation  can  be  confirmed.  It  was  stressed  that  DSCOVR  data  are  not 
proprietary  and  are  made  freely  available  to  the  scientific  community.  While  forecasting  is  still 
fraught with uncertainties, both in terms of storm potential and severity, SWPC’s customers are aware 
that  there  are  uncertainties  and  they  act  on  potential  consequences  to  avoid  the  risk  of  major 
infrastructure damage or service outage. Predictive capabilities for “big and obvious” events are fairly 
good, but it is very difficult to distinguish very big from extreme in the forecasting process. 

Space weather can manifest itself in different ways and impacts on modern technologies are complex 
and  potentially  very  costly.  The  blackout  of  the  Hydro-Québec  power  grid  during  a  geomagnetic 
storm in 1989 resulted in direct costs of over $10 million for Hydro-Québec and about $8 million for 
PSE & G in New Jersey. The overall losses for the Québec economy amounted to about $2 billion due 
to ripple effects to other sectors from the power outage. The direct effect of space weather on pipeline 
surveys  is  $2-5  million  per  year,  not  counting  losses  due  to  enhanced  corrosion.  A  risk  mitigation 
strategy  to  protect  critical  infrastructures  requires  forecasts  of  geomagnetic  disturbances  and  other 
space-weather  events,  robust  information  services  to  government  and  vulnerable  infrastructure 
operators,  hazard  assessment  for  critical  infrastructures  that  includes  the  space-weather  threat,  real-
time  simulations  of  system  effects,  and  research,  in  collaboration  with  industry,  on  understanding 
system  impacts.  NRCan  contributes  to  the  mitigation  of  catastrophic  power-system  blackouts  by 
providing  forecasts  of  space-weather  events  and  real-time  alerts  via  specifically  developed  GIC 
simulators.  For  pipeline  operators,  NRCan  has  set  up  a  customised  online  service  that  supports  the 
assessment  of  space-weather  hazards  to  their  infrastructures,  and  it  provides  dedicated  forecasts  for 
planned pipeline survey times to increase their success. It also supports long-term hazard assessments 
for  planned  pipeline  routes.  NRCan’s  forecasting  services  are  part  of  the  Canadian  Hazards 
Information Service. 

The Swedish Civil Contingencies Agency’s (MSB) remit is to prevent emergencies and crises from all 
causes  and  to  be  prepared  to  manage  their  consequences  together  with  various  public  and  private 
stakeholders. From a crisis-management perspective, key issues relate to understanding the potential 
consequences  of  an  adverse  event  to  enable  effective  prevention  and  mitigation  actions  and  the 
assigning of resources if necessary. In this context, it is necessary to deal with the real crisis but also 
with people’s perception of it as shaped by the media to curb speculations and rumours. Continuous 
information  sharing  with  and  among  the  stakeholders  including  the  public  will  be  important.  When 
different  stakeholders  share  responsibilities  related  to  the  protection  of  a  critical  infrastructure,  it  is 
crucial that a person in charge or a point of contact is identified for the crisis-management process to 
unfold  smoothly  and  quickly.  In  the  space-weather  context,  interdependencies  are  particularly 
challenging  due  to  the  high  likelihood  of  cascading  effects  and  the  downing  of  lifelines 
(telecommunication networks, power grid) essential for effective crisis management. 

The UK Met Office, which owns the space-weather risk on behalf of the UK government, has created 
its own 24/7 forecasting capability to support industry users and government. It has engaged in strong 
collaboration  with  UK  and  international  partners,  and  produces  daily  space-weather  forecasts  with 
UK-centric advisories. For example, while the Met Office also uses the NOAA space-weather severity 
scales,  it  has  added  customised  impact  descriptions  that  reflect  infrastructure  architectures  and 
vulnerabilities in the UK. The services the Met Office provides are focused on customer needs and are 
provided free of charge to infrastructure operators, including rail. Sector-specific pages provide space-
weather related raw data but also analyses prepared by Met Office teams. Feedback from industry on 
their requirements with respect to the type and timing of alerts is crucial for the Met Office to better 
support  operators.  Preparedness  plans  for  severe  events  contain  defined  escalation  and  management 
processes including protocols for communicating with government and industry stakeholders, as well 
as with the public and the media. These plans are exercised regularly. 

10 

 
 
 
 
 
The key messages of this session are: 
•  There are US and European space-weather forecasting capabilities that support the early warning 

of governments and vulnerable industries. 

•  The rail sector needs to identify its vulnerabilities and the early-warning requirements necessary 

to better protect its assets. 

•  Space-weather  impacts  on  critical  infrastructures  can  be  potentially  very  costly  due  to  ripple 

effects to other sectors. 

•  Targeted  research  efforts  in  collaboration  with  industry  are  necessary  to  close  knowledge  gaps 
with  respect  to  the  consequences  and  probabilities  of  extreme  events,  and  to  understand  how 
standard preparedness assumptions would be challenged under these conditions. 

•  Scientists  need  infrastructure-specific  data  from  industry  for  model  verification  and  scenario 

development. 

•  Extreme  space  weather  can  be  an  enormous  challenge  for  crisis  management  as  lifelines  (e.g. 

power, communications) needed for responding to an event may not be available.  

4.2 Mitigation options for current and future vulnerabilities 

In  this  session  four  speakers  from  Bombardier  transportation,  the  Joint  Research  Centre  (JRC),  the 
Swedish Transportation Administration, and the Austrian railways ÖBB discussed which engineering 
solutions  and  risk-reduction  approaches  could  mitigate  the  impacts  of  space  weather  on  the  current 
and future rail network. 

The  rolling  stock  uses  equipment  potentially  vulnerable  to  damage  from  space  weather.  Impact  on 
electronics  and  hardware  could  possible  lead  to  FPGA/soft  errors  where  ionising  radiation  causes 
unintended  changes  to  state  values  of  memory  or  storage  elements.  Moreover,  the  standard  rolling-
stock main transformer for the rail industry is single phase and as such particularly susceptible to GIC 
impact, as experiences from the power grid have shown. Current safety standards require the rolling 
stock transformer to be protected against the thermal effects of solar radiation; however, they do not 
contain clear requirements on immunity, monitoring and protection for quasi-DC induction.  

Engineering  options  to  address  space-weather  risks  in  rail  exist  but  solutions  need  to  be  adaptable, 
fulfil customer and market requirements and convince decision makers. Monitoring of GIC levels on-
board  and  wayside  could  help  mitigate  the  space-weather  risk,  with  preferably  local  measurements 
considering  that  the  GIC  depends  on  location  and  system  architecture.  Protection  levels  on-board 
could  be  tuned  based  on  vehicle  design  and  susceptibility  of  power  components  while  wayside 
infrastructure could be used to monitor and protect the traction power supply. For example, measures 
could be implemented to trip the rolling stock transformer when GIC is detected. From a prevention 
perspective, it is conceivable that GIC levels could be decreased by reducing the section length, both 
for the catenary and the rail, through isolation. This could be a temporary measure applied only during 
strong solar activity, although the associated design requirements are unclear. Topics that still need to 
be  addressed  in  more  detail  are  radiation  damage  to  sensors  and  hardware,  and  reliability  and 
availability  aspects  considering  that  more  hardware  and  software  functions  would  have  to  be 
monitored during geomagnetic activity. Also, it should be investigated if existing monitoring systems 
in rail could be utilised to increase GIC protection levels. 

For railway networks, precise timing and synchronisation is a key aspect. As mentioned before, GNSS 
is  increasingly  used  to  provide  this  service,  although  it  introduces  additional  vulnerability  into  the 
system.  Measures  to  mitigate  this  risk  in  railways  exist  and  are  not  too  costly,  considering  that  in 
addition to space weather there are other threats to GNSS service availability (e.g. multipath, jamming, 
tunnels,  urban  canyons)  that  need  to  be  mitigated.  Alternative  timing  and  positioning  methods  and 
backups  should  be  considered,  e.g.  eLORAN  where  available,  more  precise  Inertial  Navigation 

11 

 
 
 
 
System  (INS)  sensors  (odometers,  accelerometers,  etc.),  or  the  integration  of  new  positioning  and 
timing  services  from  future  mobile  broadband  network  infrastructures  (e.g.  LTE)  provided  they 
remain functional during power outages. The quality of backup systems is essential, and benchmark 
exercises for GNSS timing receivers have highlighted a rapid performance degradation (time drifts) 
during GPS outage when low-quality holdover oscillators were used. Another method to mitigate the 
space-weather risk to GNSS services is the development of receivers that are more resilient, and the 
definition  of  new  receiver  standards  in  railways  and  time  distribution  networks  (e.g.  dual-antenna, 
dual-frequency,  multi-constellation).  Benchmarks  for  ionospheric  scintillation  events  that  can 
potentially impact rail can be established by deploying GNSS receivers or bitgrabbers at high latitudes 
and  in  the  equatorial  regions.  Interestingly,  receivers  can  also  be  used  to  monitor  the  status  of  the 
ionosphere  for  forecasting  purposes.  The  JRC  has  deployed  a  monitoring  station  near  the  Polar 
Region  in  Trondheim  and  has  plans  to  deploy  others  in  Alaska  in  the  framework  of  a  collaborative 
effort  with  NOAA  and  in  Antarctica.  The  JRC  hosts  a  repository  of  intermediate  frequency  data 
sourced from these stations during periods of high ionospheric activity. This data is freely available 
for download to the research community. 

The Swedish Transportation Administration addresses existing vulnerabilities and mitigation options 
in railways and defines needs for future-proofing this critical transportation infrastructure. Currently, 
space weather has not been identified as a high-priority risk to Swedish railways although there is not 
much information on its vulnerabilities and potential impacts. No detailed GIC impact assessment has 
been carried out so far as there is no robust data on which to base such an assessment. The current 
railway  network  uses  an  architecture  whose  space-weather  proneness  is  believed  to  be  minor 
(differential mode, opto cables). The vulnerability of power components is considered manageable as 
transformers are not loaded to full capacity, and the standard for electromagnetic compatibility (EMC) 
requirements for railway applications has been implemented. The future system foresees, e.g., audio 
frequency  track  circuits  with  an  improved  response  to  space-weather  impact  due  to  a  higher 
operational frequency, and the implementation of ERTMS Level 2 which uses GPS and an alternative 
system for positioning, so redundancies will exist. The GSM-R dependence of ERTMS is, however, 
critical.  In  the  future  system  architecture,  the  Swedish  Transport  Administration  is  interested  in  the 
implementation of an early-warning system to ensure that trains will receive timely warning in case of 
danger to avoid stopping in tunnels or under bridges.  

In  Austria  the  railway  sector  is  considered  safe  in  principle  with  respect  to  space-weather  impact 
although questions related to service availability and shielding, e.g. against transformer damage from 
GIC  loading,  remain.  Tracks  and  equipment  follow  current  standards  to  avoid  electromagnetic 
interference, for example in high-voltage areas. GPS is currently used to support train operations that 
are not safety-critical. Loss of GPS is therefore not considered significant from a safety point of view. 
In  case  a  failure  occurs  (e.g.  disruption  of  safety systems  like  control  units,  axle  counters)  the  train 
would  stop  automatically.  The  emergency  braking  system  is  mechanical  and  does  not  contain 
components  that  could  be  affected  by  geomagnetic  activity.  In  addition,  the  train  driver  or  traffic 
controller would take immediate and appropriate action to ensure the safety of the passengers. Power 
is  not  needed  to  drive  trains  out  from  under  bridges  or  tunnels  in  case  they  came  to  a  stop  there. 
Currently  but  also  with  a  view  to  future  infrastructure  developments,  operational  guidelines  on  the 
management of disturbances and emergencies are considered adequate and staff is trained on handling 
them.  It  is  believed  that  even  if  10%  of  trains  were  damaged,  operation  following  a  nearly  normal 
timetable would be possible. From a service-availability perspective, a potential loss of GPS, power 
and communications during an extreme space-weather event needs to be better understood. 

The main outcomes from this session are: 
•  The standard rolling stock transformer is single phase and as such particularly susceptible to GIC 

loading. 

•  Engineering  options  to  address  space  weather  are  available  but  solutions  need  to  be  adaptable, 

fulfil customer and market requirements, and convince decision makers. 

12 

 
 
 
 
•  Timing and synchronisation is a key aspect for rail networks that will be increasingly provided by 

GNSS. Redundancies to mitigate the risks of GNSS loss are required. 

•  Compliance  with  European  regulations  and  standards  protects  assets  under  normal  operating 
conditions. It is inconclusive if these norms would also protect against hazards that lie outside the 
boundary conditions for which they were made. 

•  For  extreme  space  weather  the  distribution  of  responsibilities  should  be  clarified  to  define  the 

obligations of each stakeholder in risk reduction, emergency response and recovery. 

5. Discussion 

During  the  two  days  of  the  workshop,  the  discussions  among  the  multi-disciplinary  group  of 
participants raised a number of important issues with respect to the current and future vulnerability of 
the rail network to space weather. The main tenor of the discussions revolved around understanding if 
the  different  manifestations  of  space  weather  could  affect  vital  functions  in  rail  transport,  both  in 
terms  of  safety  and  availability,  and  how.  For  example,  it  is  of  the  utmost  importance  to  know  a 
train’s  location,  and  would  we  lose  the  ability  to  make  this  determination  during  extreme  space-
weather conditions? Another important question relates to what would happen once an extreme event 
occurs.  Could  passengers  be  rescued  easily  in  the  general  chaos  following  an  extreme  geomagnetic 
storm with its likely disruptions of the power supply and communications? 

Significant  gaps  in  understanding  the  space-weather  risk  to  rail  have  been  identified,  the  most 
important  of  which  concern  track-circuit  issues,  the  potential  for  transformer  damage,  and  the 
increasing  GNSS  dependency  for  timing  and  synchronisation,  as  well  as  positioning.  It  is  as  yet 
unclear if GIC or stray currents in track circuits could cause wrong-side failures in signalling systems. 
It is also unclear if GNSS dependencies might be embedded in systems unbeknownst to the operators, 
or what the consequences of short or long-term losses of GNSS would be.  

Track-circuit technology is an on-going research area that is far from being standardised in Europe. 
Compliance with European safety regulations and standards provides very high protection levels, e.g. 
against  electromagnetic  interference.  However,  rail  operates  at  frequencies  that  are  higher  than  the 
quasi-DC of GICs, and it is uncertain if the protection afforded by the European norms would extend 
to operating conditions much beyond to what is considered routine day-to-day operations. 

Rail network architecture and operations vary from country to country and as a consequence so does 
the associated vulnerability. In some countries, reliance on mechanical systems versus electronic ones 
adds  resilience.  Redundancies  and  backups  for  critical  systems  can  also  increase  the  resilience  to 
space weather. For example, good-quality holdover oscillators are a fairly cheap mitigation option for 
timing errors due to loss of GNSS. However, system analyses need to determine how much backup 
capacity is needed and where, and backup systems also need to be hardened against space weather to 
avoid common-cause failures of important system functions. This goes against a trend that has seen a 
reduction in backup systems due to the high reliability of systems and components industry has grown 
accustomed to. 

In  contrast  to  other  natural  hazards,  the  large  scale  of  extreme  space  weather  can  lead  to  multiple 
failures  in  different  critical  infrastructures  at  the  same  time,  thereby  challenging  standard 
preparedness  planning  assumptions.  While  single  equipment  failures  or  disruptions  can  be  managed 
fairly  easily,  multiple  events  most  likely  cannot.  Assessing  the  risk  of  space-weather  impacts  can 
contribute towards a better understanding of interdependencies and the creation of preparedness and 
response capabilities that can also be applied to other hazard domains.  

There was consensus that the issue of extreme space weather and rail cannot be viewed in isolation 
but requires a more holistic risk-management approach that also addresses potential dependencies on 
other  sectors.  This  is  of  particular  importance  for  new  technological  developments  and  the  move 

13 

 
 
 
 
 
 
towards  more  automation,  e.g.  with  the  adoption  of  the  ERTMS  in  the  EU  and  the  PTC  (Positive 
Train Control) in the US, which might add vulnerability to space weather into the rail network.   

Information on the nature of extreme space-weather impact on the rail network and its probabilities is 
needed to map the risk in operator disruption and emergency plans. The current state of knowledge is, 
however,  insufficient  for  this  purpose.  Targeted  research  efforts  in  collaboration  with  industry  are 
necessary  to  shed  light  on  this  issue.  In  this  context  it  is  important  that  operators  grant  scientists 
access  to  infrastructure-specific  data  to  facilitate  model  verification  and  scenario  development  that 
will eventually help industry to better protect their assets from extreme risks. 

Despite  limitations  due  to  uncertainties  inherent  to  space-weather  forecasting,  dedicated  early-
warning  products  are  available  and  are  integrated  in  various  infrastructure  sectors  (e.g.  aviation, 
power  grid  operations,  navigation,  and  drilling).  While  this  warning  capability  is  in  principle  also 
available  for  rail,  further  studies  with  the  involvement  of  industry  actors  are  required  to  tailor  the 
system  to  the  needs  of  the  rail  sector.  This  includes  the  definition  of  the  events  and  threshold 
magnitudes for which a warning should be triggered, warning contents and time lines, and appropriate 
operational response procedures. 

Due to the potentially global impact of extreme space weather, the need for international collaboration 
was mentioned on several occasions during the workshop. Railway authorities have contacts to their 
counterparts  in  other  nations,  and  Sweden,  for  example,  exchanges  daily  with  the  competent 
authorities of Denmark and Germany on issues of concern. For space-weather related information to 
be included, protocols specifying the type of information to be communicated need to be established. 
Also,  a  common  level  of  awareness  is  necessary  to  ensure  that  messages  are  understood  across 
borders. 

6. Conclusions 

Space weather has affected aviation, the power grid and other types of critical infrastructures in the 
past.  Historical  evidence  suggests  that  rail  networks  are  also  susceptible  to  space  weather  through 
direct  impact  on  systems  and  components,  and  it  is  reasonable  to  assume  indirect  impacts  via 
dependencies  on  other  vulnerable  infrastructures.  In  case  of  extreme,  Carrington-type  events,  the 
consequences might not be easily foreseeable due to the multitude of affected infrastructures and the 
simultaneous impact. 

Currently,  knowledge  of  this  type  of  risk  appears  to  be  limited  in  the  rail  sector,  and  creating 
awareness  among  operators  and  decision  makers  is  the  first  step  towards  reducing  the  risk. 
Subsequently,  potential  vulnerabilities  and  the  necessary  redundancies  can  be  identified  to  help  rail 
operators better protect their assets and update their preparedness plans. In this regard, the rail sector 
can  build  on  the  experiences  and  lessons  learned  from  other  affected  infrastructure  sectors  (e.g. 
aviation) which have started to tackle the space-weather threat with some success. It should also be 
acknowledged  that  moving  towards  more  automation  in  the  future  might  inadvertently  introduce 
vulnerabilities into the system. 

With space weather being a complex initiating event for disruption and failure, knowledge gaps need 
to be closed through further research on the dynamics and consequences of GIC impacts on rail, and 
the  assessment  of  dependencies  between  systems  with  respect  to  safety  and  availability  during 
extreme  geomagnetic  activity.  This  would  help  operators  to  weigh  the  benefits  of  hardening  their 
systems to space weather against the potential costs of inaction. 

14 

 
 
 
 
 
 
 
 
ANNEX 1: Survey 

As a contribution to the space weather & rail workshop, David Boteler of Natural Resources Canada 
carried out a survey among European and North American railway operators prior to the workshop to 
allow  a  better  understanding  of  the  differences  in  rail  system  types  and  their  associated  potential 
vulnerability to space weather. Austria, Denmark, Sweden, UK, USA and Canada sent replies to the 
survey. The results are shown in the following summary prepared by David Boteler. 

Survey Questions 

1.  Type of rail system 
2.  Is your signalling based on track circuits? 

- 

If yes, is this DC or AC? 

3.  Is your signalling system based on axle counters”? 
4.  Do you use GNSS (for example GPS) to determine train locations? 
5.  Do you use GNSS for timing of railway systems? 

Results 

“mixed” = combination of freight and passenger traffic 

Additional Comments 

• 
• 
• 
• 

• 

• 

Denmark is changing from track circuits to axle counters and GNSS in 2010. 
In Sweden, axle counters only used at entrances to tunnels and before a detector hub. 
In UK, GNSS is used but “not in any safety related function”. 
In US, half of track is “dark”, i.e. no track circuit; train control is done by other means, e.g. 
written orders to go from A to B. 
In US, “Positive Train Control (PTC)” is being developed to augment existing systems. Uses 
radio to communicate with train drivers (220 Mhz used more or less exclusively for railways). 
Canada is introducing PTC as well. 

15 

 
 
 
 
 
 
 
 
 
 
 
 
Information for Other Countries  
(provided by Sam Alibrahim, Federal Railway Administration, US) 

• 
• 
• 
• 

France uses AC and DC track circuits. 
Japan uses AC and DC track circuits. 
Australia uses AC track circuits. 
China uses track circuits for freight traffic and axle counters for passenger traffic. 

16 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ANNEX 2: Agenda 

Day 1  16 September 2015 

12:30-13:00 

Registration 

Session/time 

Topic 

Welcome and introductions 
Chair: Miles Elsden, UK Department for Transport  

13:00-13:45 

•  Miles Elsden, Chief Scientist, UK Department for Transport  

•  Jean-Baptiste Simonnet, Senior Adviser, The Community of 
European Railway and Infrastructure Companies (CER) 

•  Georg Peter, Head of Unit, Joint Research Centre of the European 

Commission (JRC) 

Objective 1: To develop shared understanding of space weather and its potential impact 

Session 1 Introduction to space weather 

Session chair 
Elisabeth Krausmann, JRC 

Presenter 
•  William Murtagh, NOAA 

Style 
Presentations followed by Q&A  

•  Mike Hapgood, RAL Space 

13:45 – 14:30 

•  What is space weather? 

•  What are the elements which might affect critical national or 
transnational infrastructure including the rail sector, including 
GICs and GNSS? 

14:30-14:45 

Coffee Break 

Objective 2: To develop shared understanding of potential vulnerabilities of impacts on 
the rail network to space weather 

Session 2a: Introduction on potential direct and indirect effects of space weather on rail 

Session chair 
 Mark Gibbs, UK Met office 

Presenters 
•  Larisa Trichtchenko, Natural Resources 

Style 
Presentations followed by Q&A  

Canada 

•  Geoff Darch, Atkins 

17 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14:45-15:45 

•  What is the current state of our understanding of the risk for the rail 

sector?  

•  Risto Pirjola, Finnish Meteorological Institute 

•  What sort of systems might be affected by severe space weather 

and why? 

•  Differences in how general impacts might be experienced between 

Europe, North America and other parts of the world? 

•  Q & A 

Session 2b: What are the possible vulnerabilities for rail as a result of Geomagnetically 
Induced Currents and loss of GNSS and communications systems in the initial stage? 

Session moderator 
Chris Felton 

Style 
Table discussions and feedback to 
plenary  

Discussion leads5 
Geoff Darch, Atkins 
Janet Benini, US Department of Transportation 
Mark Gibbs, UK Met office 
William Murtagh, NOAA 
Mike Hapgood, RAL Space 
Seth Jonas, Science and Technology Policy 
Institute 

15:45–17:30 

•  What equipment/systems may be affected by geomagnetically 

induced currents? 

•  Are there systems that are dependent on GNSS? If so, how may they 
be affected if there is a GNSS disruption (short term and long term)? 

Day 2  17 September 2015 

Recap of day 1 Moderator Elisabeth Krausmann, JRC  

09:00-09:05 

•  Summary of day 1 discussion and main themes for day 2 

•  Add any new comments related to yesterday's session if 

09:05-09:25 

necessary 

•  Dr Diego Galar, Swedish Luleå University of Technology  

Session 2c: Are there any vulnerabilities of other types of railway infrastructure and 
vehicles? 

Session moderator 
Terry Russell, UK Department for 
Transport 

Style 
Table discussions and feedback to 
plenary.  

Discussion leads 
Mark Gibbs, UK Met office 
Robert Rutledge, NOAA 
Barbara Barr, US Department of Transportation  
Claudia Lally, UK Government Office for Science 
Pär Söderström, SJ 

5 Discussion leads are those with particular expertise which will be distributed amongst tables or called on by 
moderator during the discussion. 

18 

 
 
 
 
 
 
 
 
 
                                                 
09:25–10:15 

•  What type of effects can be expected on for example  

a. Light rail b. Diesel driven trains c. Underground systems  

d. other?  

•  How may new technology be affected?  

Session 2d: What are the possible long-term effects on rail of wider impacts of space 
weather? 

Session moderator 
Emmelie Andersson, MSB 
Style 
Table discussions and feedback to 
plenary.  

Discussion leads 
William Murtagh, NOAA 
Mike Hapgood, RAL Space 
Janet Benini, US Department of Transportation 
Georg Peter, JRC 
Robert Rutledge, NOAA 
Geoff Darch, Atkins 

10:15–11:35 

•  What will be the consequences of a long-lasting power outage 

lasting: a. 2 days b. A week c. A month? d. Potential problems during 
system start up?  

• 

Is there a risk of logistic problems? What type? 

•  And how will that affect for example: a. trains dependent on electricity 

b. Communications c. Control systems d. Fuel logistics? 

•  May there be difficulties getting hold of spare parts? 

•  Rescue of passengers? 

•  Are there critical businesses that are depending on rail traffic? What 

are the potential consequences for them?  

11:35-11:50 

Coffee Break 

Objective 3: How can we mitigate the potential impacts? 

Session 3a: Forecasting & crisis management 

Session moderator 
William Murtagh, NOAA 

Style 
Panel presentations and discussion 

Panel members 
Robert Rutledge, NOAA 
Larisa Trichtchenko, NRCan  
Emmelie Andersson, MSB 
Catherine Burnett, UK Met office 

11:50-12:45 

•  Can we establish benchmarks for space weather events? 

•  What are the consequences of action and inaction for a severe event?

•  What planning could be put in place to manage an event? 

•  How can forecasting and alerting help? 

•  What operational mitigations exist? 

19 

 
 
 
 
 
 
 
12:45-13:30 

Lunch 

Session 3b: What are the potential mitigations to existing vulnerabilities or scope for 
future proofing infrastructure and railway vehicles? 

Session moderator 
Chris Felton, UK Home office  

Panel members 
•  Surajit Midya, Bombardier transportation 

Style 
Panel presentations and discussion 

•  Joaquim Fortuny-Guasch, JRC 

•  Stefan Niska, Swedish Transport Administration

•  Robert Weber, Austrian railways  

13:30-14:30 

•  What engineering solutions exist? 

•  How might future technological developments be made less 

vulnerable to the effects of space weather? 

•  How much would mitigation cost? 

Objective 4: Agree next steps 

Session 4: Round up, conclusions and next steps  

Chair: Söderström Pär, SJ & Emmelie Andersson, MSB 

14:30-15:00 

•  Recap discussion and agree next steps 

The end 

20 

 
 
 
 
 
 
ANNEX 3: Participants 

Name 
Andersson Emmelie 
Backman Anders 
Benini Janet 
Bisi Mario 
Bjorkqvist Stefan 
Bock Hans-Hermann 
Burnett Catherine 
Christensen Ole 
Cid Consuelo 
Cook Adam 
Darch Geoff 
Dixon Richard 
Donnelly Bryan 
Durand Eric 
Elsden Miles 
Fairbank Jeremy 
Felton Chris 
Fortuny Guasch Joaquim 
Galar Diego 
Gibbs Mark 
Guo Jianguang 
Hapgood Mike 
Hayes Darren 
Hoad Richard 
Huckle Guy 
Jin Jianhong 
Jonas Seth 
Jones Lewys 
Knights David 
Krausmann Elisabeth  
Lally Claudia 
Lampen Daniel 
Lobo Leon 
Lovegrove Peter 
Midya Surajit 
Mitchison Neil 
Murtagh William 
Niska Stefan 
Peter Georg 

Affiliation 
Swedish Civil Contingencies Agency (MSB) 
Swedish Transport Administration 
US Department of Transportation 
RAL Space, UK 
Swedish Transport Administration 
Deutsche Bahn AG (DB), Germany 
UK Met Office 
Banedanmark, Denmark 
University of Alcala, Spain 
UK Civil Contingencies Secretariat 
Atkins, UK 
DB Schenker Rail UK 
ATOC, UK 
Swiss Re 
UK Department for Transport 
Network Rail, UK 
UK Home Office 
European Commission Joint Research Centre 
Luleå University of Technology, Sweden 
UK Met Office 
China Meteorological Administration (CMA) 
RAL Space, UK 
Atkins, UK 
QinetiQ 
Network Rail, UK 
RSSB, UK 
US Science and Technology Policy Institute 
Network Rail, UK 
RSSB, UK 
European Commission Joint Research Centre 
UK Government Office for Science 
UK Department for Business, Innovation and Skills 
National Physical Laboratory, UK 
ATOC, UK 
Bombardier Transportation, Sweden 
Formerly European Commission Joint Research Centre 
NOAA, USA 
Swedish Transport Administration 
European Commission Joint Research Centre 

21 

 
 
 
Pirjola Risto 
Proctor Andy 
Rameder Stefan 
Russell Terry 
Rutledge Robert 
Sawh Tony 
Siapkidou Elli 
Simmonet Jean Baptiste 
Söderström Pär 
Thaduri Adithya 
Trichtchenko Larisa 
Velji Shamil 
Weber Robert 
Wright Anthony 

Natural Resources Canada 
Innovate UK 
Austrian Railways (ÖBB) 
UK Department for Transport 
NOAA, USA 
UK Department for Transport 
RSSB, UK 
CER 
SJ AB, Sweden 
Luleå University of Technology, Sweden 
Natural Resources Canada 
RSSB, UK 
Austrian Railways (ÖBB) 
UK Department for Transport 

22 

 
 
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European Commission 

EUR 27523 EN – Joint Research Centre – Institute for the Protection and Security of the Citizen 

Title: Space Weather and Rail: Findings and Outlook 

Authors: Elisabeth Krausmann, Emmelie Andersson, Terry Russell, William Murtagh 

Luxembourg: Publications Office of the European Union 

2015 – 29 pp. – 21.0 x 29.7 cm 

EUR – Scientific and Technical Research series – ISSN 1831-9424  

ISBN 978-92-79-52749-4  
doi:10.2788/211456 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
L
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JRC Mission 

As the Commission’s  
in-house science service,  
the Joint Research Centre’s  
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and technical support  
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Working in close  
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through developing  
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and standards, and sharing  
its know-how with  
the Member States,  
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Serving society  
Stimulating innovation  
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doi:10.2788/211456

ISBN 978-92-79-52749-4