Communication error and railway incidents

1. Communication error and railway incidents W. Huw Gibson Senior Human Factors Specialist RSSB UK

2. Overview • Context of communication and railway operations • Learning from incidents and errors • Communication protocols to reduce errors • Non-technical skills to underpin communication developments

3. Rail Safety and Standards Board Signaller (person responsible for traffic management) Maintenance Infrastructure Projects Freight trains, Passenger trains RSSB includes Railway Group Standards & Rule Book Safety intelligence Expertise to the industry Research and development National Programmes

4. My Background • Collection of human error probability data: • Air Traffic Control • Nuclear • Railways • Human error quantification techniques • Railway Safety • 2-4 hour shift phenomenon • Ladbroke Grove advisor • Industry communications working group • Railway communications research • Investigator for trackside fatalities and signals passed at danger • Visual inspection of train axles • Train cab alarms and indications

5. The Driver

6. The signaller

7. The track maintainer

8. Communications Background • Language is how we think • We are experts • Communication is a socially agreed contract with rules • presenters’ rules, work rules, home rules, party rules • Changing communication behaviours is not like redesigning the driver’s train cab • Some elements of communication are mechanistic information transfer • Railway communication is at least as much about problem solving or communicating under uncertainty – non-technical skills are crucial

9. Railway Communications • Moving trains is the main business of the rail industry • Trains are normally moved without the need for communication. Signalling systems are interlocked to prevent human error by signallers and drivers. • Railway communication is more for non-routine tasks: • Signalling failures • Train failures • Managing incidents • Handing track over to maintenance • (Depot work) • (Shift handover) • Air Traffic Control uses communication routinely without signal interlocking (but with mitigating alarms)

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11. Rail Communication Real communication, transcribed and recorded by actors

12. Bounding the communication problem • Communication is everything so where do we start? • Communication for the operational railway: • Moving trains/stopping trains • Handover/handback track to maintenance • Handover • Briefing on what you are doing today • Verbal • Not competence, not management, not procedures • Understanding the contribution of communication to incidents through classification

13. Learning from incidents and errors

14. Learning from Errors in Incidents Signaller 53% Comms

15. Learning from errors in operation • Errors do not always lead to incidents • Why understand errors, regardless of whether they lead to incidents?: • understand risks which exist in the system, ‘latent errors’ • understand human resilience and how we recover from error • get a feel for the extent to which errors are recovered by providence • identify ways to improve the process • gain a better understanding of incidents

16. Communication reliability • Communication slips • Saying ‘one five zero’ when ‘one six zero’ intended • Saying ‘left’ for ‘right’ • ‘Jones’ for ‘Smith’ • Slips are a key risk • Slips are generally within the same semantic class • E.g. Numbers for numbers • Transposable units • Way the brain is wired/arranged • Subtle enough to not be self-recovered • Mitigated with read back

17. Slip reliability • Recorded Air Traffic Control and railway conversations • Transcript analysis - writing down the communication word for word. Can identify key forms of slip. • Not all slips identified in transcripts: some simulation work at EUROCONTROL; checks against railway documentation.

18. Slip Human Error Probability Data • UK rail, different types of airspace for air traffic control • Example values: • 8,444 opportunities for error • Slips in readback – 19 • Slip errors not recovered – 7 • Human error probabilities: • Read back slip likelihood – 0.002 • Likelihood of not recovering an incorrect read back – 0.37

19. Learning from the probability data • Thousands of communications a day • Large number of communication errors out there, latent errors • Why there is signal interlocking for trains • Why there is separation for aircraft • Manual data entry can be less reliable than this communication rate • Verbal communication systems have weaknesses, due to how we work, and we cannot change that • Why is readback not effective: • We hear what we expect to hear • Errors are in the same class • Hear something correct 1000 times, difficult to hear when it is not correct • What is the value in read back as a recovery mechanism?

20. Communication protocols

21. OPS TSI Communication Methodology • Communications protocols – communication rules • Technical specification for interoperability relating to the operation subsystem – European Legislation • Safety-related communications between personnel involved in the subsystem: • Repeat back and acknowledgement • Forms for key procedural messages • ‘Over’ and ‘out’ for turn taking • Standard words – e.g. ‘error’, ‘say again’ • Phonetic alphabet • Numbers stated singly • Identifying self – e.g. driver name and train number

22. Reliability for communication protocols • Failures to apply protocols from transcript analysis – 0.1 • Failure to use the phonetic alphabet or state numbers singly (Railways): • 36 errors • 514 opportunities • Human Error Probability: 0.07 • Anticipate this has improved based on initiatives • Air Traffic Control also has significant variability in this area as well

23. Learning from data • Humans are not well suited to formalising communication • Railway communications are not well suited to formalisation as they tend to occur when things go wrong • Communication is what we do and changing it is a very effortful process • However, communication protocols can improve communication reliability: • Error recovery through repeating back • Reduce ambiguity (standard words, phonetic alphabet)

24. Protocols can create problems?

25. Changing communication practices • Language is how we think • Communication is socially agreed • It is a challenge to change communication practice • The protocols have required change: • Structure of communications – starting readbacks • Words used • Lead responsibility • Recording and monitoring of communications

26. A step change in communication practice • Get groups together – one day training course • Company culture – office staff use the protocols • OpsWeb – Communication information prominent • Safety critical communications week • Communication error stories for briefings and training • Competence management systems • Selection for communication skills • Recording and monitoring of communications • Cross-industry communications working group, taken forward by Operations Focus Group • Research programme

27. Protocols are only one part of the solution • Protocols create ‘technical skills’ for communicators to minimise misunderstandings • Communicators need other skills in the context of non-routine railway communications. These are non-technical skills: • Assertiveness • Planning communication • Understanding the needs of others

28. Non-technical skills (NTS) Generic skills that underpin and enhance technical tasks and improve safety by helping people to anticipate, identify and mitigate against errors

29. Conclusions • Communication practices are difficult to change • Communications are socially agreed • Some elements of communication are about information processing • Some elements are about problem solving and developing a shared understanding • Understand communication risks – incident and error data collection/review • Create a strategy which manages the risks • Carry out research • Manage information processing errors • Look at non-technical skills which underpin communication

30. Classifying communication error • Communication as the “virus”: • Ambiguity – ‘near miss’, it’s over ‘there’, ‘the driver’s OK’ • Verbal slips – ‘up’, ‘down’, 140, 150 • Misunderstandings – hearing what we want to hear • Communication as the carrier of the “virus”: • Misperceive the colour of a signal and verbally communicate that reading error • Make a poor decision and then verbally communicate that decision error to someone else • Communication is not all, maintain the other dimensions of human error classification: • Human Error Type • Person/Task • Underlying Factors (competence, procedures, equipment design)

31. c ryanair 6 6 3 right turn heading 3 0 0 p right at(?) 3 0 0 ryanair 6 6 3 c jetset 2 5 delta descend to flight level 1 2 0 p descend flight level 1 1 0 jetset 2 5 delta Readback Readback Readback