Written evidence submitted by Network Rail
What technological innovations are you adopting to understand the vulnerabilities in your systems, and their interdependencies with other systems?
- New technological solutions offer an opportunity to better understand asset performance and risks under extreme weather, provide early predictions and warnings of asset failure, model the effectiveness of solutions, and communicate with response organisations and passenger and freight users.
- Through research and development, we will continue to adopt new remote monitoring and remote sensing technologies. This is alongside other solutions such as automated inspections and data recording from dedicated survey trains or in-service trains, drone footage, algorithms and the use of AI to interrogate the new data.
- We are delivering our monitoring through our Intelligent Infrastructure programme. Where we have embedded monitoring equipment into assets, these sensors report back to a central system which is reviewed 24/7 by technicians who assess the condition of the asset and provide guidance to front-line teams to mitigate potential failures.
- We also use monitoring that is not fixed to a particular asset but is instead carried by trains travelling over tracks. We now have 13 dedicated vehicles measuring the profile, depth and
internal and external cracks in rails as well as the track’s geometry. Across 9000 miles of track, pixel-width images are recorded at up to 70,000 times a second across seven cameras. The machine processing of these images enables defect reports to then be shared with section managers. We aim to expand this monitoring to a further 5000 miles of track.
- We carried out our first national aerial survey of our network in 2016 and have continued to collect valuable data in this way. Through our Air Operations team, we have obtained high- resolution and 3D images of terrain as well as data on the condition of surfaces. This has enabled us to see changes on the lineside that could pose risks, such as the shape and structure of earthworks and the condition of lineside infrastructure.
- Our innovations are improving our insight into the changing state of our assets. We are delivering reduced safety risks to staff and passengers, improved decision making, reduced costs, improved resilience and performance and improved customer experience and satisfaction.
Technology, rainfall and drainage risks
- Sudden and heavy rainfall is a particular challenge to the reliable and safe operation of the railways as it can cause the collapse of railway embankments and/or result in rail lines being flooded. In some regions, stronger increases in short-duration, extreme rainfall have been identified, up to twice what would be expected from atmospheric moisture increases alone.
- Many of our drainage systems were built during the Victorian era (some 150 years ago) without the design standards and modelling tools that we have today.
- To help reduce these risks, we are developing and trialing new earthwork monitoring systems,
including surface ‘tilt meter’ technology to warn of sudden earthwork movement. We have also recently completed work involving using machine learning to enhance our risk assessments of our earthworks, improving targeting of our interventions. Data recording points have now been installed at more than 200 locations.
- To go further, we will be sharing best practice in our use of technology with other earthwork asset owners such as the Highways Agency and Environment Agency, as recommended by Lord Mair’s task force report following the tragic incident at Carmont.
- Our weather forecasting and alert system has been in use for several years. Working with Train Operating Companies (TOCs), we employ a weather forecast provider to monitor and alert us to adverse and extreme weather events in line with our weather risk thresholds.
- To improve our performance and enable us to respond in a timely way to extreme weather, we have been making improvements to our forecasting system. Our Network Rail Weather Service project involved re-specification of our weather forecasting contract to include bespoke forecasting tools for overhead line equipment icing, conductor rail forecasting, adhesion, coastal flooding and precipitation.
- Our Weather Risk Task Force is now developing and will implement a new digital platform with enhanced weather data, as one of the Dame Julia Slingo recommendations to support the management of the railway’s operations. In Wales, we will also continue to use our ‘Assetcoast’ and ‘Forecoast’ tools to monitor and manage the risk to their estuarine and coastal assets respectively.
- A convective rainfall alert tool (CAT) has been deployed nationally. Route controls staff now have much better notice of extreme rainfall and can communicate this directly to the train cab. We have also published our drainage technical strategy and drainage resource calculator, which is helping our regions build dedicated drainage teams.
- As an interim, short-term measure, our national weather team have enhanced our weather services website, which is the forecasting tool used by all operational controls, maintenance delivery, train operators and freight operators. Additional guidance has been developed and provided to each route to interpret the forecasts and structure decisions about operational restrictions.
- We are working collaboratively on forecasting with partners outside of the industry, such as the Met Office and the National Highways Agency, and have become a member of the Natural Hazards Partnership Steering Group. We are developing a weather academy for our staff and those across other transport modes to become ‘informed clients’ when it comes to weather management.
- Forecasting in the UK is currently undertaken on a sector-by-sector basis. There could be significant benefits from a more integrated single system which provides detailed and relevant information to multiple sectors across the UK on weather forecasting and early warnings.
What percentage of a customer ticket is currently spent on resilience and how is that likely to change in future?
- It is difficult to make a direct comparison between ticketing revenue received by train operating
companies and the amount that we invest into the resilience of the railways’ infrastructure.
- We are investing increasing amounts to manage weather resilience on the ground and to improve our ability to manage it better in future. In total for CP6, we will invest £1.274bn to maintain and renew earthworks and drainage, supporting improvements in weather resilience. This is a real term increase of 20% on Control Period 5 (CP5: 2014-2019) and nearly doubling that of Control Period 4 (CP4: 2009-2014). For CP6, we also identified in 2018 the potential to use £185m of our risk fund as further needs emerged, including for responses to extreme weather events.
- Also included within our plans is £33m to increase remote monitoring and diagnostics for earthworks and drainage and £31m on research and development specific to earthworks, drainage and resilience. Much of this activity is in collaboration with other operators to broaden access to knowledge and insights and forms part of a prioritised research and development portfolio that balances investment across all of the challenges we face.
- So far in CP6 we are ahead of programme in terms of the volume of work completed and expenditure. Reprioritisation of activities by our regions has added £210m more to base resilience plans as the need to respond to weather-related events has been greater than we forecast and this has resulted in additional operational expenditure.
- Between 2019 and 2024 we are also investing over £30m to improve our infrastructure’s resistance to extreme rainfall, £13m targeted at known flood sites, £40m for scour protection under bridges and £25m invested in vegetation management.
How many drains have been installed by outside contractors?
- While the drain at Carmont was not built to design by our contractor Carillion, which is no longer trading, it is important to not generalise from this regarding the standards of work of other contractors. Our railway is one of the safest in Europe and tragic incidents such as the one that took place at Carmont are thankfully incredibly rare. We are fully committed to doing all we can to implement the Rail Accident Investigation Bureau’s (RAIB) recommendations regarding the incident and will work with our regulator, the Office for Rail and Road (ORR), to endorse the action plans for each one.
- From the time of Carmont to March this year, 48,148m of off-track drainage has been installed by external contractors to protect vulnerable earthworks or alleviate flooding. We have undertaken 64 major earthworks projects and made 399 earthworks more resilient. In total, £89,595,024 has been spent in this time period on this work alongside protecting 34 bridge foundations from collapse due to scour.
- We continue to identify high risk drainage sites as part of our work on asset resilience. Immediately after the incident, we identified 584 sites which share some characteristics with the drain installed at Carmont through having been constructed from soil cuttings with track drainage. We have also considered whether there are any other local features at drainage sites that may lead to be them posing a particular risk to earthworks, using our existing lists of sites which are vulnerable to adverse and extreme weather.
- Supported by in-house engineers and specialist contractors, we inspected all 584 of the sites similar to Carmont using aerial surveys and checked for significant defects (for example blocked crest drains which can affect the stability of slopes). We completed these inspections on 28 August 2020. The 584 specialist inspections did not identify any significant issues requiring emergency intervention. At around 1% of the sites, we identified assets with defects that had deteriorated and required action sooner than originally planned.
- We have experienced a few other landslips on the network since Carmont, including rapid cutting failures where trains have collided with washed out material. Defects such as blocked drains are significant factors in causing these incidents and are the types of defects we look for in preventative inspections. However, slopes can fail with little indication of distress prior to failure if a sufficiently high volume of water falls locally.
19 April 2022