Using in-cab monitors during departure
Train driving is a highly skilled profession. Drivers need to be able to maintain high levels of concentration, retain information, identify and anticipate risk and have good attention to detail.
This is particularly the case when trains leave stations, and especially in Driver Only Operation or Driver Controlled Operation, where the driver is taking responsibility for operating the doors and completing relevant safety checks in the process of dispatching the train and proceeding on the journey.
In some situations, the driver will use an on-train camera/monitor system (OTCM), where images of platform and the side of the train are fed to in-cab monitors for the driver to view, from cameras fixed on the side of the train. This space is known as the 'dispatch corridor'.
Before moving the train to leave the station, the driver will perform safety checks using the in-cab monitors to oversee the closing of the doors and check the area around them, and to get an overall view of the side of their train alongside the platform.
The most common practice is for the monitors to then switch off automatically as soon as the driver takes power to move the train, to avoid distraction.
However, leaving the monitors can give the driver the chance to spot late-presenting hazards such as passengers who subsequently become trapped or harmed while the train leaves.
We conducted research to assess the impact on safety of leaving the OTCM on during departure.
Our expert risk analysts use "event tree analysis". This is a way of measuring the risk of different outcomes by taking into consideration the different steps that might lead you there. The risk was measured for two different monitor operating states: monitors remaining on for departure until the train has fully left platform, and monitors remaining on until the driver takes power to start moving the train (so switched off for departure).
We also conducted simulator testing to measure and compare the difference in driver performance for reaction to hazards on the line, again, in these two different scenarios, leaving the monitors on, and switching them off. For both scenarios the assumption was a train dispatched by driver only from an unstaffed platform. Consideration was then given to what could happen at the platform-train interface and the potential consequences of not observing signals on the line ahead.
The work also took into account a review of operating practices, analysis of human performance, analysis of incident data and trials.
We found that there is no increase to the overall system risk if monitors are left on when the train is departing the platform.
This is really useful as it means the option of leaving the monitors on is now available to train operators. However, this has to be subject to local risk assessment and be considered as part of the bigger picture, including all the arrangements for managing risk related to train dispatch and the platform-train interface. There's also a need to balance this with the driver's attention to any local operational risks which need their focus.
This is a really important point – the fact that the overall system risk is not increased simply opens up the option of leaving the monitors on. To actually go ahead and implement this requires a suitable and sufficient assessment of the local conditions the driver will face at each station. This may require some rigour. For instance, this could be to monitor a level crossing, observe higher risk signals or observe track workers. These hazards cannot be assessed at a network level as the risk is a local one, and so could well be different from place to place.
With this is mind, it's really important to emphasise that the priority for the driver is to focus on the driving task at hand – and as soon as the train starts to move, that means looking out the front and acting on conditions, signs and signals as appropriate.
The monitored images provide the driver with an extra opportunity for late-presenting hazards to be spotted, but these are an added bonus and it should not be assumed that the driver can definitely spot all late-presenting hazards on departure. The balance of risk between the monitors remaining on or off can be affected by the ability of the driver to view hazards at the PTI. Therefore, image quality should also be considered when making the decision to use the monitors when departing.
What this means for train operating companies
We recommend safety and operational decision makers read the full report, which will provide a full technical explanation of the research and what we found.
We can also provide additional support to train operators seeking to get a better understanding of the research and how they can best apply it.
Consider the option of leaving the monitors on but remember to think about what this will mean in local situations. Is there a level crossing straight after the station, or a signal – and if so what is the risk of it being passed at danger?
There may well be stations where the monitors are left on to give the driver the opportunity to see hazards on departure, but in other cases, they may need to be given less priority or switched off to avoid distraction – this will be down to each operator and their own assessment.
Train operators will also need to involve the companies who supply, manufacture and lease their trains so that the OTCMs can be configured to stay on or switch off at the desired times. This research is informing an update to the Rail Industry Standard for Driver Controlled Operation On-train Camera/Monitor Systems (DCO OTCM) RIS-2703-RST, due to be published in December 2018, to ensure there is sufficient flexibility to configure the systems as appropriate. This is part of a fuller update to make the standard a bit more comprehensive on the issues – so watch this space.
Remember to involve front line staff to determine the type, frequency, level of risk and attention required for local stations or specific situations, and develop appropriate local instructions.
The research report includes a list of local considerations to help operators make the decision concerning the use of monitors when departing – these include the levels of station footfall, train loading and crowding.
This work brings some real benefits to the railway – as it opens up the opportunity to giving the driver a view of their train as it leaves, and to spot incidents that unfold once the train has started moving. This could also give the driver a greater sense of security, for example if they were concerned about behaviour on the platform immediately before departure. Clearly its application must be properly thought through in the specific, local context and the workforce has to be involved, but the opportunity is there for the taking.
Talk to us
If you would like to discuss this research further, or request access for non-RSSB members, please contact us via the customer self-service portal.