Dynamic Integration Testing

?? Chapter 5 of 5 ??

We are now getting to the end of this mini series on the Testing & Commissioning Process in the context of the construction and commissioning of a new railway line, although a lot of what was discussed in part 1 to 4 also apply to other industries across the world.

The Dynamic Integration Testing phase is the last phase before Commissioning Hand Over to the end client takes place.

Although the railway won't be ready to be opened to passengers' services at the end of Dynamic Testing - this will only be the case after Trial Operations are complete - technically the railway could be fully operated following Dynamic Integration Testing and this is the main reason why we will not develop a sixth chapter to cover what Trial Operations are about and how they should be conducted, for now.

Principles

When all Acceptance Certificates (ACs) for all the relevant elementary systems have been issued, and the Traction Power system has reached a stable state several weeks into first energisations, this is when the Dynamic Integration Tests phase may commence.

Often referred to as Phase 4 of the Testing and Commissioning programme, this phase should only start when all the various systems have been connected together, tested and energised (where relevant) during the previous phase 3. Basically in an ideal world, one would have fully demonstrated that these systems work holistically independently from any train running on the line and only require the trains to eventually run on the newly built infrastructure before everyone involved in these operations can safety confirm that the railway is fit for purpose for Trial Operations to start.

It must be noted that Phase 4 is not supposed to be a phase when the Rolling Stock - assuming it is new - will start to be tested. During this phase, only tests that are required for the train to 'integrate' properly with the infrastructure should be carried out, in particular tests that are impossible to replicate in an Integration Facility or on a Test Track away from the main project infrastructure.

Integration Facility

Major railway projects rely heavily on what we call an 'offsite' Integration Facility. In the UK as an example, the Crossrail Project built one - the CIF or Crossrail Integration Facility - and HS2 will have theirs too.

Complex railway projects operate under tighter schedules than ever before and with limited access to tracks to run tests. In that difficult context systems integration needs to happen off-site before in can be tested on-site. Relying on a fully automated off-site testing facility is extremely valuable. It will increase efficiency, cost effectiveness and probably more importantly for the technical minded among us, it will increase the resilience of certain key systems throughout a railway project life-cycle before they are tested in situ. You want to know how systems will behave as you add layers and layers of complexity, ultimately simulating the trains running in that mix, before you discover the potentially negative impacts too late into the project.

Without getting into too many details, systems integration facilities of this kind allow for thorough off-site interface, integration, timetable and transition testing, as well as simulation of faults to understand the system’s behaviour under degraded and emergency situations. In this day and age, one cannot do without the extremely valuable insights such facility can provide.

A railway line is a very complex system. Simulating systems integration scenario is adding a layer of confidence that you are progressing in the right direction and that software debugging will be mostly achieved by the time the actual trains enter the picture.

I say 'mostly' because, unfortunately, there are cases where debugging has taken an exceptionally long time. This is often due to the complexity of naturally antagonistic signaling systems, the interfaces between route-wide and on-board systems, and the involvement of two or even three different contractors, all of which have the potential to delay projects' programmes by months or even years.

Test Running Preparations

As mentioned in the previous paragraph already the purpose of the integration facility is to test and validate system interfaces before installation and deployment on site. It is not supposed to replace any steps in the testing and commissioning phase of the project, but rather to support it by identifying and mitigating defects as early as possible so that you can do something about it.

Beyond the need to test as many scenario through the Integration Facility between the trains, the signaling system, the telecommunication system and possibly the Platform Screen Doors systems, one has to organise the preparation of the actual test runs themselves because however sophisticated the Integration Facility is, it will not replace the absolute requirement to carry out some tests 'for real', out in the field. Not even mentioning that not all railway systems can be tested in such a facility anyway.

Therefore one has to seriously contemplate two key aspects moving forward, as a minimum:-

1. What are all these tests that still need to be carried out with the use of test trains on site, including what the priorities are and who is going to be the nominated Test lead contractor for each test?
2. How to safely organise the effective movement of these test trains, from one at a time to several, on the newly built infrastructure, in order to satisfy the full list of tests that a myriad of contractors will need to carry out to meet their own requirements for validation.

Item 1) is obviously heavily dependent on the number of systems installed on the railway as well as the level of testing and commissioning the Rolling Stock manufacturer has achieved off site. As an example, if there are no Platform Screen Doors anywhere on the line, there won't be a need to test any related interface with the trains.

The level of Rolling Stock testing is an important factor. When and where possible the trains should be tested off site, months if not years before they are allowed to reach your project site for Dynamic Integration Testing. A number of key early stage tests should really be done elsewhere on a dedicated 'Test Track' for the purpose of testing the Rolling Stock's unique features as far as reasonably practicable. In an ideal world, the train units used as test trains would reach your site only after having completed some significant mileage.

On the Glasgow Subway Project where 3ECO Ltd is involved, Stadler new train units are transported by road to the 'Test Tracks' in Glasgow so that they can be tested without affecting the existing passengers' service.

Once the trains are on site we carry out the daily energisation/isolations of the 3rd rail and we move the trains into position for test purposes. Stadler test team then carry out all the tests they need for the trains to interact with the lineside signaling and telecoms equipment. Only once a train unit has been fully tested on the Test Tracks can it be transferred to the client, in this case Strathclyde Partnership for Transport (SPT), for further integration before being put into service

Item 2) is a major endeavour and it is made more complex as the line speed of the railway increases.

This requires an in depth understanding of the major risks involved with running trains on a new bit of railway infrastructure. And the risks of something terrible happening are absolutely real. On 14 November 2015, a TGV test train derailed in France due principally to a late braking sequence, while performing commissioning runs on the second phase of the LGV Est high-speed rail line, which was scheduled to open for commercial service five months later. The derailment resulted in 11 deaths and 42 injuries. It was the first fatal derailment in the history of the TGV during Dynamic Integration Tests.

This tragic event reminded every one in the industry that Dynamic Integration testing is no joke. It is not just an exciting and rewarding phase of any railway project, it is also a very dangerous one that must be taken eminently seriously.

The preparation phase must therefore be top of the agenda of the Testing & Commissioning Manager. The 'gospels' must be documented in extensive details into the commissioning part of the Construction & Commissioning Railway Rulebook (see part 3). The concepts must be adapted to the reality of the layout, the infrastructure concerned and your internal and external project constraints.

Trivial issues such as ever changing scaffoldings positioning right in the rail corridor or construction vs testing boundary changes on a daily or weekly basis can make your life extremely difficult if not miserable. Forget about the natural and much safer option of relying on a finish site, expunged of any remaining construction activities, to start running trains. One would hope this is the norm. Experience dictates it is actually the exception although it should not be.

Months before Dynamic Integration Testing starts, you will have to review the Construction & Commissioning Railway Rule Book (CCRRB) to satisfy yourself that it is adequately addressing the safety requirements involved in moving a train from A to B in specific commissioning running conditions. This also means having to move that test train before the operational signaling system is fully validated throughout, however extensive and successful the testing may have been at the off-site Integration Facility.

Thus you need to be thinking creatively in order to substitute some fail safe elements normally addressed and fully covered by the signaling system with...something else. And to ensure you are still maintaining the level of risks to As Low As Reasonably Practicable or ALARP doing so. The 2015 testing accident has naturally increased the level of precautions that must be taken and as a result the way certain tests were permitted to take place is definitely something of the past.

Note that trains operations will progressively increase throughout Phase 4. At some point, when running more than the minimal number of trains becomes necessary, you will more and more rely on the signaling system. Still, until Commissioning Hand Over takes place the procedures detailed in the Construction & Commissioning Railway Rule Book will remain your 'sacred' reference for any movement of trains. Although rare, signaling-related systems can fail during testing operations. Therefore, it is essential to have a strategy in place to manage degraded or emergency situations when they arise. This necessity makes the CCRRB exceptionally valuable.

And the ORR certainly think so too! On CTRL with HMRI at the time, on the East London Line project then and finally on the Crossrail Project, it took two years in average of building trust and relationships with their inspectors to finally being able to demonstrate unambiguously that we had established a very solid, a very safe and effective process as captured in the CCRRB to deal with movements of Test Trains up to and including line speed, whatever that speed was, which in the case of an High Speed line is...a lot.

That trust translated into a 'Non-Objection' to operate from HMRI in 2007 and ROGS and License exemptions gained for both the East London Line Project and Crossrail in 2010 and 2017 respectively, without which it would have been extremely difficult to deliver the Dynamic Integration Testing phase of the works.

Test Runs Dossiers

A key element for conducting effective and safe operations during Dynamic Integration Testing is the notion of Test Runs Dossiers.

They are to be produced in advance for each series of test runs, taking into consideration the status of the signaling system, including the absence of one if necessary, and stating in minute details as a minimum who is involved and authorised for a specific test, where people will be located in what role for which responsibility, the extent of the line under test vs the part that is excluded, the position and status of each switching and crossing for each run, the access and egress, emergency phone numbers and referenced operating instructions, the purpose of the test and the various train speed limits that must be complied with at each of the key locations along the route.

A dedicated section of the dossier must address the Traction Power configuration for the series of runs. If the configuration has to change at some point during the shift, the Test Run Dossier will have to allow for that to happen.

Your dossier must describe how the different roles and responsibilities would be deployed at the different locations on site and on-board the train(s) to allow the safe moment of test trains within the rail corridor. Very strict communication protocols must be adhered to, and no test trains should commence a run until the appointed authority formally grants permission to proceed.

Basically the purpose of the Test Runs Dossiers is to provide an unambiguous picture as to what the test runs are about for a particular shift, how they shall be conducted, what the line and power configurations should be and who is welcome and who should not even be there for those runs. Do not underestimate the eagerness of 'tourists' to join the test trains during the early stages of Dynamic Integration Testing. It is crucial to minimise their presence if you cannot eliminate it, and only allow those who have a compelling reason to be involved during this high-pressure period.

Finally never forget that in the absence of a Test Run Dossier no test trains should be allowed to move, other than for positioning it to and from the yard or its stabling position. If a run is missing and has not been properly thought through before the event, substitute the run or cancel the shift altogether and get back to the drawing board. We would not recommend you proceed until you have taken the time to think about the consequences, have managed to print another version of your dossier and have properly briefed the test team about the changes you have been forced to make and why. If you do that seriously as you should, we assure you it will be faster to just cancel the runs and do it another day another time with a clearer mind.

As a matter of principle, never rush anything that involves running a train at potentially high speeds on what remains a construction railway where a lot of things could go wrong very quickly.

Test Track Arrangements

Running a Test Train involves organising the railway slightly differently than when it is used for construction activities. The recognised model for such arrangements relies on the implementation of what we call a 'Test Track' and 'Test Area'.

The Test Area is usually the same or wider than the Test Track. The Test Track cannot extend beyond the Test Area.

It is a similar concept to the Test Track the Rolling Stock manufacturer should use as described previously, still it is a bit different. The main reason it is slightly different is because the project has to allow outstanding construction activities to continue and the Test Track arrangements must be temporary to allow the over and back transfer of the existing line in a strictly controlled manner for a particular section of the time within a 24 hours period. The Test Track the Rolling Stock manufacturer relies on can be a Test Track 24h a day 365 days per year with no consequences. There are usually no interfaces to manage other than the ones requiring testing, and no scaffolding in the way, to name just one 'interesting' example. There is rarely a need to shorten or extend that Rolling Stock manufacturer Test Track either, something we do all the time on a construction railway during Dynamic Integration testing.

Before commencing Test Runs, the test parameters detailed into the Test Run Dossier must be clearly understood by all. It will indicate where the Test Track commences and where it ends. It will highlight the various existing access along the route that must be condemned or controlled for the duration of the runs. And it will indicate the opening times and closing times in between which the line will be operated in a very different way than the way it is operated when a Test Track is not in place.

The safe execution of this process relies on the full cooperation of railway operations specialists who will work in dual roles. One role focuses on safeguarding the interests of the construction railway, while the other the best interests of the commissioning railway. A controlled handover process between the two roles will be implemented at the start and at the end of the Test Track operations. The process is governed by the CCRRB and the details for the shift are contained in the Test Run Dossier(s).

This is the case for 'simple' operations. If the Test Track has to extend into someone else's territory such as an External Railway Network, this adds a significant layer of complexity to your Test Run Dossier and your CCRRB procedures that would take its own article to address.

The people involved with the setting up of the Test Track consist mainly of Rail Movement Controllers (RMC), Test Track Managers (TTM), Ground Shunters, Locomotive Drivers and Work Sites Supervisors / Work Area Supervisors. They ensure there are no lineside obstacles and/or debris in the rail corridor in the way of the test train(s), that all the relevant gates, accesses are secured, that nobody who is not part of the test remains within the Test Area and that the line is thus clear for the Test Track to open and the Test Runs to commence.

Radio Communications

Temporary Construction Radio communications form the backbone of the CCRRB. One cannot implement the requirements of the CCRRB without an operational radio system.

During the Dynamic Integration Testing period, the same temporary radio system, albeit slightly enhanced to cope with Test Trains running at line speed, will be in use. At least until the permanent radio system has been fully tested and can be relied upon for the purpose of running the test trains. Considering this will unlikely happen until after Dynamic Testing has started, you need to ensure you can rely on a temporary radio systems able to cope with the new configuration for the purpose of commissioning with trains.

From experience, provided you rely on an already reliable system during the construction phase of the project, you won't need to make major alterations to the temporary construction radio system to be able to use it during the Dynamic Integration Testing period.

From experience again, this temporary communication system is temporary in name only because people will continue to use it well into Dynamic Integration Testing, in particular to manage the setting up and closing of the Test Tracks, if not during Test Running itself.

The people most likely to use the temporary construction radio system until Commissioning Hand Over or the introduction of the permanent radio system, in addition to the rail specialist people already mentioned in the previous paragraph, are Test Train Leaders (TTL)/Pilotman and Train Managers (TM). These individuals are located on-board the Test Train(s) and rely on their radios to communicate with the relevant stakeholders during the Test Runs.

It must be noted that, depending on the nature of the runs, a number of teams on site or off-site must be coordinated with by the Test Track Manager (TTM). The TTM is the single point of contact from whom 'Authority to Proceed' emanates. Nothing moves until they say so.

Radio communications on the Test Track and Test Area must occur on an open call channel that is recorded for safety purposes and essentially in case of an accident/incident. The ability to explore the tapes after the event to understand what could have possibly gone wrong is critical in order to avoid another occurrence down the line.

Test Train as a Mobile Laboratory

Depending on the nature of your project, it will likely involve the installation of some sort of on-board instrumentation that will need to be installed on a Test Train for the purpose of measuring a number of parameters. Doing so will transform some parts of your train into a mobile laboratory.

At a bare minimum, especially if your project involves traction power and sensitive signaling and telecommunication systems, instrumentation related to identifying / measuring Electro Magnetic Interference and Electro Magnetic Compatibility (EMI/EMC) should be installed both on board and at remote locations along the line. Capturing the EMC signature of a new trainset and understanding its potential impact on other systems within the rail corridor and beyond is a task that engages many specialists.

For railways that involve higher speeds the need to install sensors and other accelerators on board the Test train is a must as these instruments when connected to their IT systems will significantly increase the level of safety of the movement, with their ability to detect an anomaly in real time that would require for the runs to immediately stop or at least for the speed to diminish.

High Speed line projects all over the world are familiar with this concept. In the UK the Channel Tunnel Rail Link Sections 1 & 2 (HS1) used a fully instrumented Eurostar train and so did the Crossrail Project with Bombardier - despite not being high speed. For the East London Line Project however, the instrumentation on board the C378 test train was limited to EMC/EMI related measurements and no track related sensors or accelerometers were installed.

In future, Dynamic Integration tests of HS2 will definitely require full instrumentation for at least the track and the OCS systems in addition to EMC/EMI related aspects, as was the case for HS1.

Conclusion

The Dynamic Integration Testing phase concludes our mini-series on the Testing and Commissioning process for New Railway Lines, which we began in early June 2024, almost exactly a month ago.

There are several T&C topics we haven't covered however, which may be featured in future articles if the interest arises. Given the niche nature of the subject, it may not resonate with everyone.

We believe that the Testing and Commissioning phase is a truly fascinating period in the life of a project. It should begin as early as possible and continues until the end of the project, when Commissioning Handover occurs, or even later if the employer or end client requires support during Trial Operations.

This phase can be extremely rewarding, but also frustrating and exhausting. Its success largely depends on the T&C team you work with, as well as other stakeholders, suppliers, subcontractors, and partners. Moreover, the attitude and trust of your direct client representative play a crucial role in how your judgment and experience are valued.

We hope this five-part mini-series has provided you with valuable insights and has sparked your interest in this field. We believe it is the best job in the world, and we encourage you to explore it further to see why we hold it in such high regard!