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‘Digital’ is still the buzz word for the modernising of railways as indeed it is for many other industries. Yet, with all that is written about digital systems, what does it actually mean in practice? Many people would struggle to provide a fully understandable answer. A recent online seminar organised jointly by the IET and Siemens Mobility examined the issues and produced some surprising answers.

The seminar’s chair, Rob Morris, who has been an engineer for all of his career and is currently the managing director for Rail Infrastructure at Siemens Mobility, offered a definition as ‘the ability to test and analyse systems in laboratory conditions’. As a broad statement, this seemed a good start, but adding to this the ability to see what would happen if changes are made and the concept of digital twins (of which more later) are certainly a bonus.

The opportunity for simulating services, passenger behaviour, journey planning and suchlike are definite benefits. A recurrent theme of the seminar was that digital systems provide a much better platform for collaboration between partners and improved sharing of ideas. This is much more difficult to grasp as is the concept that digital systems should make things less expensive.

So, what is the experience of people and organisations who have implemented digital systems? Some quite different thoughts and opinions emerged.

An industry transformation?
Getting people to work differently, especially engineers, is a major challenge. To help this, Melissa Zanocco OBE, the head of programmes at the Infrastructure Client Group, explained the vision that had emerged in April 2021. In this, the focus shifts from creating built environments to understanding the outcomes enabled by them. Two examples of rail projects which are in line with this thinking are:

  • East West Rail from Oxford to Cambridge, which will be part of developing the UK equivalent of Silicon Valley.
  • The Levenmouth line in Scotland, to regenerate an area with high unemployment levels and little opportunities for work.

Both of these projects are being delivered in accordance with the Project 13 delivery model which is an industry-led initiative to upgrade performance and focuses on achieving better outcomes for both people and the environment. The built systems provide the ability to offer up better services and improved integration, but the digital technology needs to be applied wisely to achieve the desired outcome. The route to be followed is Policy Strategy Action Vision. This is somewhat different to what many people would expect, in that it is the vision that delivers the end result.

A cross-government change programme is in place with input from government departments, industry, and academia. From this has been created the Infrastructure Client Group that has many constituents including Network Rail, Transport for London, East – West Rail, and others, including non-rail industries. Drilling down further is the Digital Transformation Task Force (DTTG) with the three focuses of Strategy, Benchmarking, and Share / Adoption. In each of these, the use of existing expertise on Building Information Modelling (BIM) and Digital Twins techniques, will be a major element.

Analysing the present understanding within industry of where the weaknesses are revealed considerable ignorance in many disciplines:

  • Skills shortage – 53% do not understand the skills gap.
  • Decision making – 86% are not equipped to make the right decisions.
  • Need for Investment – 75% do not understand the need.
  • Resilient organisation – 85% of industry does not possess this.

Project 13 aims to improve these weaknesses. Some of the changes needed will not sit comfortably with those who are used to the traditional way of doing business.

The old method of progressing projects has always been: Consultant Client Contract Contractors. However, the new method being put forward is Owner Advisors Integrators Suppliers. This implies a whole new approach to procurement where sharing of technical and engineering knowledge will be required from the outset. In other words, transactional business models will be replaced by collaborative ones. Network Rail is reported to be using this methodology on the Trans Pennine upgrade.

One might reflect on all of this with the various methods that have been tried in the past – hub and spoke contracts; lead/main contractor in charge of sub-contractors; professional consultants in charge of contract teams; client control of a works programme. Pre-tender meetings often resulted in stony silences with the prospective contractors wary of giving away any perceived company advantages, technology developments, or even admissions of weakness. There is no doubt that change is necessary as engineering costs remain too high. A new mindset will however be required from many of the participating organisations.

The Crossrail experience

The Elizabeth Line opened in a blaze of glory but, behind the publicity front, there remain some significant challenges still to come. In an excellent and honest appraisal of the project, Mark Wild, the former CEO of Crossrail, gave an insight into how digitalisation had impacted on the project and not always for the better.

In terms of statistics, Crossrail is twice the size and twice the speed of traditional tube lines and can be likened to the German S Bahn and the Paris RER networks. The 30-metre depth of tunnelling proved to be very difficult as did some of the station construction integration to other underground lines. Critical to the seamless travel envisaged is the signalling (perhaps better described as control and command) with a CBTC system in the centre section from Paddington to Abbey Wood, interfacing to ETCS out from Paddington to Heathrow and Reading, and to TPWS / AWS on the Great Eastern line out to Shenfield. These latter connections have still to happen but are programmed for later this year.

To give a scale of the data consumption, the SCADA system has around 60,000 inputs and outputs, monitoring all infrastructure conditions: power, ventilation, platform screen doors, fire protection, and many others. The line has a state-of-the-art customer information system, but this too has to interface to the other information systems at the five underground interchanges which in turn have had to be modified to provide Elizabeth Line information.

All of this is a digital minefield, and it was the realisation of this back in 2018 that caused the project to be delayed another four years. Mark had to grapple with the problems of digital engineering when appointed to the job. He gave three key lessons that others should take note of for similar size major projects.

First, adopt a concept of the minimum viable project. Crossrail had over specified requirements in that it had wanted everything to be available on day one. This overwhelmed the project and gradually a re-specifying of the digital requirements to a minimum level provided a realistic way forward.

Second, beware of promising outcomes for the operator. This caused over complexity in the rule book that no-one really understood. Starting again with what the operator actually needed should have been the concept. The technologists got carried away with offering things that were not necessary.

Third, be mindful of the need to produce value. Too many ‘gizmos’ were put forward that created bespoke engineering and would add little value. The aim must be to produce much more modularity so that standardised deliverables can be adopted at every possible location.

When questioned about the three signalling systems, Siemens commented that, with hindsight, using ETCS with ATO similar to that deployed on Thameslink would have been a better solution. However, at the time the decisions were being made, the ETCS ATO package was undeveloped and there was considerable doubt as to whether the system would have been able to offer the train throughput required. It remains to be seen how reliable the resulting interfaces will perform in everyday service.

Modelling and simulation
An interesting presentation from Andy Woods of Siemens and Mick Vere of Graffica gave insight into the simulation being produced for the ETCS programme. Inputs to the modelling include train speeds, headways, braking distances, speed restrictions, and journey times, all used to produce a model of how a route such as the East Coast Main Line (ECML) would function. It was admitted that ETCS on its own cannot deliver an optimum performance, as the impact of other trains on the route is not within the ETCS function. The addition of Traffic Management Systems (TMS) must be part of the overall simulation.

Digital engineering attempts to create a digital representation of how a system will work but the development of modelling concepts is an ongoing exercise. For rail, it is all about taking the track and rolling stock components and interfacing these to the command-and-control system, viz the signalling. Managing functional complexity is part of the challenge and leads to the creation of what is called an ‘Abstract Architecture Layer’. Bringing all this together should lead to optimising the original design, which Graffica is working on with Siemens for the ECML project.

Much is made nowadays of Digital Twins, the process by which modelling takes place on two separate digital platforms, with new ideas being developed on one platform and fed back into the other to see whether it will produce the expected benefits for the project. This is a continuing process and can extend forward even after the system has been commissioned when often a debugging exercise is needed when systems don’t perform as anticipated.

The ECML digital experience
Reference to this project has already been made for which Siemens Mobility has the task of designing and supplying. An article on the ETCS provision was produced for Rail Engineer in Issue 189 (March/April 2021), following a discussion with the Network Rail programme manager. This suggested an eight to nine year timescale to complete and remove traditional lineside signals on the section from Kings Cross to Stoke Tunnel just south of Grantham. The project has progressed since then and Steph Neath, the BIM manager at Siemens Mobility explained some of the work being carried out to simplify the tasks that have to be undertaken.

Digital engineering services aim to unlock the value from the masses of centrally managed data that is being accumulated and to make this available on desktop or mobile devices for engineers doing the design and implementing equipment on site. The use of digital twins has been mentioned but this facility is being used in three different ways. Firstly, a project twin to create and model the asset; secondly, a connected twin to monitor asset operation and maintenance; and thirdly, a prospective twin to consider the eventual replacement or renewal of assets.

Minimisation of site visits by undertaking digital survey work with the results directly transferred to the signalling design data is one benefit. Another is to produce 3D designs which lead to digital equipment sighting being used for digital rehearsals and works planning, and finally delivery and handover to the implementation teams including RAM assessments. Once commissioned, the data assembled will be used for real-time updates and assessments that can be given to passengers when disruptions or line possessions occur.
The development of digital techniques is ongoing and will go hand-in-hand with the ECML project. However, a digital railway between Kings Cross and Grantham with no lineside signals is not expected until 2029, some seven years from now.

Final thoughts
Whilst this online seminar gave real indications as to how digital technology can make projects easier to progress, the stated benefits of lowering costs and shortening timescales have still to be realised. Rail projects in general, and signalling projects in particular, seem to be taking much longer to fulfil than in times past. Little doubt that nowadays this is due in part to the myriad of regulations requiring certification and safety assessments to be in place. Can digital techniques assist with all this procedural overhead?

The declared intention of having ETCS fitted to all the UK main rail routes looks as far away as ever, with the risk that skilled staff will reach retirement age before many of these projects have even started. A rolling programme with a guaranteed continuity of work would seem to be called for, such that hard won digital expertise can be used to maximum benefit.

What is also clear is that ETCS in itself will not produce the operational reliability that a digital railway needs. The whereabouts and timekeeping of trains is a vital ingredient and thus systems such as TMS and Connected Driver Advisory Systems (C-DAS) have all got to be integrated at the design and implementation stage, regardless of who is supplying the different piece parts. A question asked was whether, when using digital twins, people need railway knowledge or software expertise. The answer is both, and the lessons from Crossrail should be heeded by all.

Image credit: istockphoto.com

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