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Future train radio – What’s possible?

Throughout the world, many railways use the interoperable radio communications network, GSM-R (Global System for Mobile Communications – Rail), for operational voice communications and to provide the data bearer for ETCS (European Train Control System). Within the European Union, and for all infrastructure managers wishing to adhere to European standards such as ERTMS, this is legally mandated via Technical Specifications for Interoperability (TSI).

GSM-R is a technology system based around standardised commercial GSM (Global System for Mobile Communications) equipment (also known as 2G) used worldwide but enhanced to deliver specific ‘R’ (railway) functionality. GSM-R technology is very reliable and has been suitable for serving the railway’s needs over the past decade. However, network demands, coupled with new efficiency requirements and the fact that the GSM technology is not going to be around forever, is driving a need for the next radio technology to serve the railway.

In this context, the International Union of Railways Union (UIC – Union Internationale des Chemins de fer) decided, in 2012, to set up the Future Railway Mobile Communications System project (FRMCS) to prepare the necessary steps towards the introduction of a successor for GSM-R.

As well as being a major player in the provision of 2G, 3G, 4G-LTE and 5G equipment used by all mobile network operators globally, Nokia is also a leading supplier of GSM-R. So, it’s no surprise that the company is a leading participant in the definition of this new standard, which it believes will initially be based on the Long Term Evolution (LTE) telecommunications technology.

Safe hands

Nokia was a pioneer in the GSM-R field, being the first company world-wide to contract a commercial GSM-R project in Sweden for Banverket (now Trafikverket) in 1998, commencing operations in 2000. Since then, the company has deployed over 29 GSM-R networks worldwide, from a full ‘turnkey’ deployment (design, radio planning and deployment) through to end-to-end GSM-R network operations as a full managed service – such as the ADIF high speed railway GSM-R system in Spain and the Prorail GSM-R system in Belgium.

To assure interoperability with other vendors GSM-R, Nokia’s GSM-R system has been developed according to the relevant open standards (EIRENE, MORANE and ETSI). Extensive interoperability tests have been performed to verify network-to-network interoperability including full certified interoperability with the Kapsch GSM-R core. This proven and deployed interoperability enables a step-by-step network-wide transformation to a digital platform.

4G, 5G and the railway industry

Railway operators of all types typically run a mix of narrowband and broadband communications technologies to support their safety-critical, safety-related and passenger services. GSM-R is the most widely adopted radio technology for mission-critical voice and train control data. These services typically require low bandwidth, low latency and high availability, which suits GSM-R well.

However, as new requirements emerge, for example to facilitate automatic train operation (ATO), with more video streams from and to the train, a narrow-band technology such as GSM-R will struggle to support these applications.

Migrating to LTE (Long Term Evolution, 4G and 5G) technology has the potential to support broadband services and high-speed mobility, and also to consolidate all communications needs onto one single, highly flexible but secure and resilient network. Furthermore, the high throughput and low latency performance and stringent Quality of Service (QoS) characteristics of LTE will enable the railways to deliver better services for passengers whilst reducing operational costs.

Nokia has been innovating in LTE for 19 years with many world firsts, and is currently the global number one supplier of commercial LTE equipment with its LTE 4.5G Pro, 4.9G and 5G offerings, all of which have the potential to revolutionise communications, including how public safety is ensured and how industrial processes are run.

Technology choice?

Close to 800 operators are investing in LTE in more than 200 countries serving commercial, private and public safety networks. By 2020, LTE is expected to connect more subscribers than any other mobile technology. It can be served on licensed and unlicensed spectrum and continuously evolves via the standardised 3GPP (3rd Generation Partnership Project) governing body. A Nokia LTE network will support 5G and is designed for evolution over the coming decades.

As a well-established technology that is supported by a solid and growing ecosystem, LTE has a long future ahead of it. Even when the much-vaunted 5G technologies start to be deployed, LTE will provide a long-term foundation for 5G networks.

Technology migration is not trivial and takes time. However, the sooner the capabilities of LTE are brought into operations, the sooner rewards will be reaped in terms of lower operational costs and new revenue opportunities from passenger services. One of the ways these benefits can be realised is through a Private LTE network (PLTE). This simply means the railway having access to an LTE network that only services railway users.

A Private LTE network can support both human and machine communications on a single, reliable network that offers mobility without cumbersome portable radios and opens up the world of the Internet of Things (IoT). Complementing Ethernet and Wi-Fi, Private LTE will help to enable digital transformation in many industries and pave the way towards the adoption of even more capable 5G mobile technologies.

Future

Nokia, which leads the way in 4G LTE technology with a clear and software-driven path to 5G, leverages its AirScale product for the building of a smooth evolution path to 5G with 4.5G Pro and 4.9G evolution of the 4G standard. The evolution from 4G to 4.5G to 4.9G and 5G is tightly controlled by Nokia and adheres to the global 3GPP set of standards that all telecom vendors follow.

5G will initially be made available through evolution in LTE technologies. It will be followed, later in the evolution of the standards, by the introduction of a new air interface that will be backward compatible with the LTE interfaces, the transport function and the core function.

It is likely that 5G-ready devices will start to become available from early 2019, fast tracking to an era where the internet starts to migrate from a communication platform primarily for people, into a platform allowing devices and assets to connect. Going further, it will give consumers the ability to download a UHD movie to their smartphones in a few seconds. 5G will enable offices, cars, trains and assets to seamlessly connect to each other and the cloud.

In terms of track-to-train broadband, this is something that Network Rail Telecom has been investigating. Nokia’s Bell Labs R&D team has already developed the software algorithms required to deliver 10Gbit/s to a moving train at up to 500km/h using mmWave 5G radio, and the company is currently planning trials on a railway test track within the next 12 to 18 months. (NOTE: 5G radio is not the same as 802.11ad mmWave WiFi standards-based radio.)

If you think about the evolution of 4G, an example of achievable speeds is roughly as follows:

4G – 300Mbps

4.5G – 1Gbps

4.9G – 3Gbps

5G – over 10Gbps

The key point to take away is that the different ‘G’s above are all supported by the same Nokia LTE core, which also supports the full Nokia Wi-Fi portfolio, the GSM-R over LTE transformation and the 3GPP 5G mmWave being developed.

An investment now in an LTE core will serve the future of Digital Railway for many years to come and it is this key point that removes the risk to rail – the migration path can be steady and controlled with a very clear 20-year-plus roadmap.

The other key points are the term LTE (Long Term Evolution) which is ‘what it says on the tin’, and 4G/5G is a standard specified by the 3GPP for use all over the world.

The mantra of the moment is “build it once and build it right” for the railway’s future telecommunications infrastructure.

Autonomous vehicles

Much is being reported that the latency performance of 5G is required for autonomous vehicles. However, in Australia, since commencing trial operations in 2008, trucks fitted with autonomous vehicle technology, communicating via 4G LTE, have already moved more than one billion tonnes of material.

In 2017, Rio Tinto’s autonomous fleet accounted for about a quarter of the total material moved in the Pilbara mines. On average, each autonomous truck was estimated to have operated about 700 hours more than a conventional haul truck during 2017, with around 15 per cent lower load and haul unit costs. There have been zero injuries attributed to autonomous haul trucks since deployment, highlighting their significant safety advantages.

Norwegian airport operator Avinor is developing autonomous snowploughs with the aim of increasing efficiency and reducing delays at airports. In March 2018, these autonomous vehicles were tested for the first time at a snowy airport 200km north of Oslo.

Autonomous vehicle technology for rail is already being planned on routes around the world. Rio Tinto is also developing fully autonomous, heavy-haul, long-distance trains for transporting iron ore (see News in this issue) and, in the Netherlands, Prorail has announced it is also planning to trial automated operating freight trains. The CEO of German operator Deutsche Bahn, Rüdiger Grube, has publicly stated the objective of DB is to introduce driverless trains by 2021.

Massive MIMO

Massive MIMO (multiple-input and multiple-output) is used in many radio technologies and, in fact, was invented by Nokia’s Bell Labs in America. A basic antenna will have both a transmit and a receive element, and data is transmitted and received via these elements. It follows that, if you employ more antennas, you can transmit and receive more data.

In Massive MIMO, Nokia does just that, using 64 transmit and 64 receive antennas packed into an array to boost capacity and coverage. Massive MIMO is often seen as a future technology to support 5G networks, but Nokia is making it available for deployment within LTE now. Using existing spectrum and base station sites, the Nokia AirScale Massive MIMO adaptive antenna delivers far more capacity than conventional antennas and radios and can be used as part of the railway to deliver secure, guaranteed data streams.

Massive MIMO antennas are capable of handling very large amounts of data. The processing of this data is therefore intensive, requiring a paradigm shift in processing power at the base-station (where the data from the distributed radios is processed). The Nokia answer is the new “ReefShark” chipset contained within the Airscale base-station platform. Made entirely in-house, this bespoke silicon packs more functionality into 50 percent smaller hardware compared to products that use discrete components; it decreases mMIMO antenna size by half; cuts energy use by 85 percent and boosts the intelligence and performance of MIMO antenna, all based on 3GPP 5G New Radio specifications.

Massive MIMO technology is one of the key enablers to deliver the step-change in mobile broadband performance.

UK first deployment of 5G

Nokia has products to deliver a number of wireless and fixed telecoms technologies now, including Wi-Fi and 4G LTE, and is at the forefront of 5G development.

BT and Nokia recently demonstrated the first UK public deployment of 5G. People in Bristol experienced the next generation of wireless technology in a public urban environment. This included spectacular 3D-like projections, a virtual reality dance piece, and a guided tour on which people walked through time.

The public part of the trial only lasted two days, but the trial continues to include Nokia’s Massive MIMO radio access solutions, network slicing (splitting a single physical network into multiple virtual networks) and edge computing nodes functionalities.

Cormac Whelan, CEO of Nokia in the UK and Ireland, said: “As 5G comes ever-closer to commercial reality, the opportunity to contribute to a ‘real world’ test of the technology in Bristol is invaluable. With the UK’s exciting ambition of becoming one of the first European markets to launch 5G, Nokia is thrilled to be working with the University of Bristol and with BT to make this public demonstration happen and to evaluate how the technology will work in a smart city such as Bristol.”

Nokia are therefore ideally placed to guide the rail industry on the roadmap to what is possible for the future of train radio.

Read more: Footbridges of the future?

 

Footbridges of the future?

While not exactly ten-a-penny, footbridges can be found everywhere on the railway. They connect platforms at stations, are used to replace pedestrian level crossings, join communities cut in half by a railway line and give access to beaches and car parks. Network Rail alone owns just under 2,400 of them.

Many are quite old, and so a programme of repair and replacement always forms part of Network Rail’s plans for any control period.

Rail Engineer has often covered the more interesting footbridge projects. In recent memory, there have been articles on the first Grade II-listed fibreglass footbridge at Dawlish (issue 99, January 2013), bridges in South Wales at Port Talbot (issue 142, August 2016) and Newport (issue 69, July 2010), the transfer deck at Reading station (issue 103, May 2013) and even a bridge with blue lighting (issue 158, December 2017).

Even footbridge refurbishments can be interesting; witness the one at the longest station name in the UK – Llanfair­pwllgwyngyll­gogery­chwyrn­drobwll­llan­tysilio­gogo­goch, Llanfairpwll for short, which was described in issue 154, August 2017.

But these were the exceptions. The vast majority are everyday working structures, painted either in dark green or rusty grey and in varying states of repair.

Reading.
Reading.

Design competition

Not unnaturally, Network Rail has a standard design which it uses when replacing these bridges, but it’s not very inspiring.

“We’ve got one official standard design for a station footbridge,” explained Anthony Dewar, Network Rail’s professional head of buildings and architecture, “and that design probably hasn’t changed in its aesthetic form for over a generation.

“The unofficial standard design is the one that’s used for ‘Access for All’ bridges, and that again hasn’t changed in its aesthetic for maybe 10 years.

“For both of those designs, one could question now, with modern architectural and structural engineering, how much of a design legacy we are leaving with those structures.”

To improve matters, Network Rail has launched a footbridge design ideas competition, in conjunction with the Royal Institute of British Architects (RIBA), seeking new ideas for the design and installation of fully accessible pedestrian footbridges across the UK rail network. The competition is open internationally to practising architects, structural engineers, civil engineers as well as students of these design disciplines.

The selection process is seeking ideas to contribute towards and influence new standard designs rather than a solution that will necessarily be implemented. The design ideas competition will be held over a single stage, with a design fund of £20,000 to be awarded to the submission judged to be the best response to the design challenge.

Although Network Rail’s portfolio of footbridges includes both those at stations and on rights-of-way, this competition is seeking to generate proposals with an elegant and effortless means of providing accessible footbridge provision within urban built station environments. It’s an area where considerable money is already being spent. Network Rail has built over 200 Access for All bridges since 2006 with an average price tag of £3 million each.

However, the competition brief continues, in addition to this principal anticipated use, the footbridge design will also need to be potentially applicable and aesthetically sympathetic to a range of other conditions and contexts including at-grade open platforms, crossings away from stations, embankments and in more rural locations across the UK rail network.

Whilst primarily not intended for use in conservation areas or listed building settings, the footbridge’s design aesthetic should offer the potential to do so.

Anthony Dewar continued: “The competition is there to encourage new creative talent from both qualified and unqualified professionals and students to introduce new creativity into a concept for footbridge design.

“We’ve worked hard to develop a technical remit for the competition that doesn’t just give a plethora of railway standards that one has to comply with, which can discourage creativity. We’ve set high-level technical parameters in the hope that it will encourage creative submission – not just in the structural and architectural worlds but we’ve also put in high-level parameters in respect to lifts and lighting across the bridges – and we hope that the creative submissions we get will be the holistic design requirements for a footbridge.”

Newport.
Newport.

One size doesn’t fit all

One of the most striking features of the current Access for All bridge design is the height of the lift machine rooms that extend above the bridge profile itself. They are very prominent and add to the impression of bulk that one gets when looking at one of these bridges.

Anthony Dewar hopes this area will be challenged with the competition entry, but, as a separate workstream, his team is also looking at Network Rail policy and standards for escalator and lift design. There are alternatives, such as hydraulic lifts, but he doesn’t want to change the design and then encounter problems such as maintenance and reliability challenges, so the topic is still under consideration.

Whatever the result of the competition, Anthony doesn’t just want to update, revise or even replace the existing standard footbridge design.

“We currently have a one-size-fits-all approach,” he stated. “I want to move away from the term ‘standard design’ because, for public consultation, I think it suggests that we as a business are only going to give one type of option. We want to move to a catalogue of typologies of designs for station footbridges, and we are looking at innovative and creative ways to do that.”

“One of the ways we are looking to do that is through the competition, but we’re also going through a more traditional route through the architectural and engineering frameworks to come up with design topologies.”

Anthony admits that most railway footbridges give the appearance of having been designed by structural or civil engineers. With the new typologies, he wants to get into a position that the engineering under the skin is both proven for safety and for ease of assembly, but that the architectural appearance can easily be altered to blend in with its environment.

But, at the end of the day, the resulting typology must have the variability to allow for context but also be efficient to build in the railway environment. But that’s the challenge, and no challenge is easy.

Dawlish.
Dawlish.

Choosing a winner

Design submissions have to be received by RIBA by 18 September 2018. Evaluation will start immediately with the judging panel due to meet early in October. All design submissions will be identified solely by a registration number, so the entries can be judged anonymously.

The judging panel will be chaired by Paul Finch, programme director of the World Architecture Festival and editorial director of both the Architectural Review and Architects’ Journal. In addition to Anthony Dewar, the panel will include Network Rail colleagues Ian Grimes, principal engineer, and Trevor Wilson, senior architect.

Jonathan McDowell of Matter Architecture will act as the RIBA architect adviser and he will be joined by Andy Savage, executive director of the Railway Heritage Trust; Chris Wise, senior director of Expedition Engineering; Rowan Conway, director of innovation and development at the Royal Society of Arts; Margaret Hickish, managing director of Design 4 Inclusion and Kay Hughes, founder of design consultant Khaa.

A design fund of £20,000 will be available for award at the discretion of the judging panel, and it is currently envisaged that £20,000 will be awarded to the submission judged to be the best response to the challenges outlined in the competition brief.

The judging panel may also identify a series of highly commended schemes which will be acknowledged in all associated publicity, but will not attract a monetary award.

It will be exciting to see what suggestions come through. Anthony is certainly looking forward to it. “Network Rail is committed to promoting design excellence. That’s why we’re challenging the architectural and engineering community to come up with new and innovative ideas for footbridge structures that will be both functional in form and sympathetic to the communities that they serve.

“The winning design concept will also need to protect and enhance the great legacy of engineering design that is inherent in railway history. We’re excited to see the solutions that will be put forward.”

Full details of the competition can be found by visiting www.ribacompetitions.com/networkrailfootbridge.

Read more: The annual Stapleford trials

 

Tunnel lighting comes of age

Working in tunnels brings with it one obvious difficulty – a lack of light. In a railway environment, that’s actually not as big a problem as it sounds. Most work has to be undertaken at night, so it matters little, from a light point of view, whether the job site is in a tunnel or in fresh air.

But still, there are complications with working in a tunnel.  All of the equipment, including lighting, has to be brought in from one end, usually on hand-pushed trolleys or on trailers towed behind road-rail vehicles.

Fumes can be a hazard, so petrol-powered and even diesel-powered generators may be anti-social. Better to have freestanding lights cabled in from a generator in the open air. But then the cables can be a trip hazard, and lineside neighbours might object to the noise from the generator if it runs all night.

Then quartz-halogen lights put out quite a bit of heat, and that can be undesirable in a confined space.

Who said it was easy?

Innovative solution

Fortunately, technology can help mitigate all of these ‘challenges’.

Using LED light heads is the obvious solution to the heat problem. LEDs (light-emitting diodes) put out no heat at all in practical terms, so having the light on or off makes no difference.

They also consume far less electricity than an old-fashioned quartz-halogen lamp, so now using batteries becomes an option.

That’s exactly what leading worksite lighting manufacturer Morris Site Machinery, a well-established family owned business with a rich engineering heritage, has done. It has taken its traditional product, a generator with a telescopic mast topped by high-intensity lights, and brought it up to date.

The light head of the new TL55 Battery is made up of four 60W LED arrays operating at 24V DC. These are positioned on top of a 5.5 metre telescopic mast which emerges from what looks like a typical wheeled-trailer-generator, but is actually a battery pack containing six 150Ah deep-cycle lead acid batteries.

Lateral thinking

When first developed, the batteries took 11 hours to recharge from a standard 240V supply, and would power the lights for 54 hours. However, with the light unit often being on site for several days, even more battery life was thought to be desirable. So it was back to the drawing board and time to apply some lateral thinking.

What the design team came up with was a simple, yet remarkable, solution. PIR sensors were built into the light head to detect movement in the lit area. If none was detected, indicating that no one was working in the immediate area at that time, then the lights would be dimmed, saving energy. The lights were still on, so workers could see to re-enter the area, but the level was reduced enough that battery life went up, to as much as 500 hours in some cases.

Morris Site Machinery recently took part in a Network Rail “fuel-free site” experiment at the Tuxford Rail Innovation and Development Centre in Nottinghamshire. The company’s battery-operated lights were used to illuminate work taking place using battery-operated tools as Network Rail demonstrated how it could work at night even in urban areas, without disturbing the neighbours.

In the TL55 Battery, Morris Site Machinery has produced a worklight that is silent, cool, bright, and lasts in excess of a complete shift – several shifts if used in an area where work is intermittent.

So now there can be light in the middle of the tunnel, as well as at the end.

Read more: New bridge on bridge street

 

New bridge on Bridge Street

The Great Western route modernisation and electrification project represents the biggest investment in the Great Western Railway since Isambard Kingdom Brunel built it more than 150 years ago. Once completed, the modernisation of the line will stimulate economic growth along its length, particularly in South Wales where there is strong economic and political pressure to complete the modernisation work in a timely and efficient manner, as well as to minimise disruption and keep costs for the programme down.

One of the UK’s most important arterial routes, Network Rail is electrifying the line by installing 25kV AC Electrified Overhead Line Equipment (OLE). As part of the scheme, an iconic road bridge on Bridge Street in Newport was scheduled for reconstruction to accommodate the increased height of the OLE.

The bridge, which sits between Newport station and the town centre, is an important one that connects the affluent northern suburbs with the city centre. It is surrounded by businesses and residential homes, so the necessary road closures to remove the original structure and replace it with a new bridge would be challenging for businesses, residents and commuters.

Removal

Network Rail and its principal contractor ABC Electrification (Alstom-Babcock-Costain) appointed Cleveland Bridge UK not only to fabricate and install an innovative bridge structure, but also to remove the existing bridge in a short time window. Both elements of the project were to be delivered to strict and very constrained timescales when the train line was temporarily taken out of operation.

Cleveland Bridge is highly experienced in delivering complex steel structures to exacting timescales to ensure that new projects are completed to deadline and existing road and rail networks experience minimal disruption. Recently, the company has worked on the Forth replacement crossing, as well as Reading, London Bridge and Bond Street stations.

It was vital for the city that the replacement programme was carried out within the critical time allowed and with minimum disruption as, due to the nature and location of this work, it would be almost entirely carried out during rail possessions, under the close-scrutiny of residents, council and media.

The first stage was to remove the old bridge. To meet a short, six-hour deadline for the removal, Cleveland Bridge fitted additional steelwork to the 105-year-old bridge to strengthen the structure before it was lifted out in a single piece by a 600 tonne-capacity crawler crane, which is one of the largest of its kind in the UK. The old bridge was then dismantled in the temporary works area for recycling.

Replacement

The new structure which replaced it is a 228-tonne, 50-metre skewed, weathering grade steel road bridge that could accommodate the increased height of the OLE. Designed as an improvement on its predecessor, the new bridge is able to accommodate heavier vehicles, to ensure it is fit for modern day city centre traffic, and has a wider footpath for pedestrians and cyclists. It also has improved road alignment for better accessibility.

The new structure has some striking architectural aspects in the shape of the stiffeners and main girder top flanges, which give a pleasing look to the bridge elevation.  The shaped stiffeners, when in sunlight and sunset, cast a waving shadow along the face of the bridge.

This geometrically challenging new structure was designed and fabricated at Cleveland Bridge’s extensive production facility in Darlington. As bridge-building pioneers, the company designs, manufactures and installs steel bridges of every type, including beam, truss, cable and modular bridges.

In the world of construction, Cleveland Bridge manufactures, fabricates and installs load-bearing and architectural steel elements for large-scale commercial and civic buildings, industrial buildings, heavy transfer structures and iconic stadia from its County Durham base. The combination of its highly-skilled designers and engineers with technically advanced manufacturing facilities on its 22-acre site enables the company to produce 50,000 tonnes of precision-engineered steel every year.

Following a complete trial assembly within Cleveland Bridge’s 27,000 square metre fabrication facility, to ensure ‘fit-first-time’, the steelwork was loaded onto trailers and transported 280 miles by road to Newport, where it was assembled prior to installation in the trackside temporary works compound at Godfrey Road, adjacent to the railway station.

Installation of the new bridge, which took place during a 54-hour abnormal weekend possession of the railway line, also utilised the crawler crane and was successfully completed within three hours of receiving confirmation of the line closure. This provided sufficient time for follow on activities, including installation of the 90 pre-cast concrete deck units before the line was reopened.

Although the local population had been inconvenienced by the road bridge closure, there was a great deal of interest when the new structure was installed, with many residents staying awake throughout the night to witness it.

Preparation and professionalism

Cleveland Bridge approached this project with the highest levels of preparation and planning, and the professionalism shown at all stages was borne out through successful delivery within the very tight timeframe and with an exemplary Health and Safety record, including no Riddor-reportable accidents.

Working closely with its customer ABC and with Network Rail, Cleveland Bridge was able to successfully complete the project maximising on its strategy of close collaborative working and early contractor involvement at the design stage, which added certainty to the design, ensuring the most financially efficient methods of fabrication could be adopted.

As a result of these high levels of planning and delivery, the bridge removal and replacement was conducted on time, in full, to client satisfaction. Rob Fancourt, ABC’s head of civils, congratulated the team for “an excellent performance and lots of very hard work over the past few months ensuring a very challenging structure was ready for the lift.”

This positive feedback from both ABC Electrification and from Network Rail further reinforces Cleveland Bridge’s continuing role in the development of UK transport infrastructure.

Read more: Extending Worcester’s Battenhall Bridge

 

Building a world heritage tunnel in Switzerland

Photo: Keith Fender.
Photo: Keith Fender.

It is not only the Swiss main line railways that are benefitting from tunnel investment. The Rhätische Bahn (or Rhaetian Railway) is an extensive metre-gauge network in the southeast of the country. The section from Tirano (in Italy) to Tiefencastel via Pontresina has been declared a UNESCO World Heritage site, and it is easy to see why.

With origins dating back to 1889, the line was initially built to promote the tourist trade and offered a spectacular route traversing the northern valleys in the canton of Grisons (Graubünden). With many spirals to gain height in this alpine region, especially in the Albula Bernina area, the highest point, at 1,800 metres above sea level, is crossed by the 5,864 metre long single-track Albula tunnel, linking the stations of Preda and Spinas, which opened in 1903.

Originally operated by steam traction, the line was later electrified with the standard Swiss 15kV, 16²⁄³Hz system.

Having given over a century of service, the condition of Albula tunnel was assessed in 2006 and it was deemed to need significant renovation as rock falls were becoming an ever-present threat. This would have meant considerable disruption for the 7.4 million passengers, including 2.3 million commuters, and significant volumes of freight that use the line every year.

As an alternative, building a brand new tunnel alongside the old was duly evaluated and, in 2010, was adopted as the best solution.

The area is typical of the Swiss Alps, with considerable snowfall in the winter months that severely limits access to the tunnel site between mid December and the end of February. As such, construction work is suspended during this period but proceeds with 24-hour shift working during the rest of the year.

The new tunnel cannot be a replica of the old as current standards now prevail and safety considerations tend to dominate. Thus the tunnel bore is much larger and has to accommodate the provision of walkways plus the latest clearances for the OLE fixtures.

Constructing the tunnel

Construction work follows conventional practice for boring a tunnel through rock. Firstly, and most importantly, a construction site has to be established close to each of the portal areas. These are major undertakings in their own right, with machinery and conveyor systems capable of handling all the material needed for the boring activity plus the disposal of the excavated spoil as the tunnel progresses.

Whilst road access is available, the local infrastructure would not be suitable for numerous lorry movements, so rail sidings and engineering trains are needed to cater for the main material removal. The site is extensive and, with the number of workers involved, a strict safety regime is needed. This includes protecting the staff during engineering train movements, with radio-based Schweizer portable trackside warning systems being used for this purpose.

Having established the portal locations, ingress into the mountain is by the normal routine of drilling, blasting, spoil removal and securing the worksite ready for drilling the next section. It sounds straightforward, but these activities have to be accompanied by other engineering ancillaries to ensure safe progression.

Grisons (Graubünden) canton and the Rhätische Bahn network. Map: Alyssa James.
Grisons (Graubünden) canton and the Rhätische Bahn network. Map: Alyssa James.

Firstly, there needs to be fresh air. Air is pumped into a tube that takes it to the rock face where it creates a slightly higher pressure in the tunnel atmosphere. This then helps to blow out the dust and diesel fumes as the excavation takes place.

Secondly, and like most tunnels, water ingress is considerable and channels are needed for this to flow down to the portals. Thirdly, the sides and roof have to be stabilised, this being achieved by ‘shotcreting’, or the spraying of wet-mix concrete.

Conventional tunnel machinery is used, so no temporary rail tracks are provided, the profile of the tunnel being sufficiently large and the floor of the tunnel being flat enough for road vehicles to journey to and from the rock face.

Even with all this, it is a wet, dusty and unpleasant environment. Progress on an average day is 6.5 metres.

Whilst the geology of the tunnel is mainly ‘Albula granite’, a 110-metre section close to the Preda portal consists of three different types of rock, known as cellular dolomite. A 20-metre section consists of a fault zone where a soft porous version of the dolomite is encountered, the material being akin to silty fine sand. It was found impossible to extract any solid material and thus the risk of tunnel collapse became a real threat.

The solution has been to drill freeze holes into the surrounding ground to a depth of 60 metres. The freeze zone must be at least 2.5 metres thick outside of the excavation area, this being strong enough to absorb the ground and hydraulic pressures. Once freezing has occurred, excavation can take place in that cross section followed by a 120 cm thick reinforced shotcrete lining applied within seven days of excavation.

The result is a strong tunnel profile that will withstand the expected pressures. However, because of the geological complications on this section, the progress rate through the frozen ground is only about 0.7 metres per day.

Spoil removal

Even though the new tunnel will be slightly shorter than the original at 5,860 metres, a tunnel of this length creates a vast amount of waste material for disposal. In a sensitive environmental area with world heritage status, this presents a considerable challenge.

As the waste is brought out through the portal on a conveyor belt system, it is graded into varying categories. The solid granite is broken down into manageable lumps, the larger of which can be used for future track ballast. Medium and smaller lumps are useful for making concrete.

However, it is the slurry and loose shale that causes the problem as this has to be dumped. Whilst a suitable site has been found during the construction period, it is a controversial longer-term dilemma. Either the waste has to be transported elsewhere, which is an expensive exercise, or it has to be blended into the nearby landscape.

Looking forward

From detailed planning work that began in 2010, it will take 12 years for the project to be completed. Construction began in 2014 for a period of 8½ years with breakthrough expected to happen in October 2018. Some 244,000 cubic metres of solid rock will have been excavated.

When completed in 2022, 15,000 trains will traverse the tunnel each year at a maximum speed of 120km/h. Total cost is estimated at 244 million Swiss Francs, equivalent to £188 million sterling.

The old tunnel will not be abandoned, however. Twelve cross passages are being excavated from the new tunnel to the old at intervals of 450 metres, stopping short of break out into the old tunnel until it is closed for rail traffic. Once the new route is commissioned, the cross passages will be opened up to allow access to the new tunnel, both for maintenance purposes and to provide a safe egress route should a train in the new tunnel ever need to be evacuated. Repair work to the old tunnel will be carried out so as to stabilise the walls and roof.

The Albula tunnel represents an impressive commitment to the local Swiss economy, which is difficult to see being replicated in the UK or other European countries. Maybe the Ffestiniog Railway Moelwyn tunnel, built during the 1960s, is the nearest comparison to be made but the standards and finances for heritage and commercial railways are very different.

The new portal at Preda.
The new portal at Preda.

Read more: Tunnel management, Swiss style

 

The Articulator: a new way to manipulate lineside structures

The modern world of rail is full of increasingly complex shapes, yet the technology used in handling these awkward and weighty items has been very limited to date.

Slings, chains, hoists and ropes are all still used trackside for the handling and placement of masts, with or without complex gantry and crane systems. It seems bizarre that, in 2018, the rail industry is still using such primitive methods to lift sections and structures.

From a health and safety point of view, having human beings underneath or in the vicinity of enormous and potentially lethal long swinging masts is far from ideal. So the industry needs a more scientific, safer and more economical way of handling these masts and structures.

Simple manipulation

Sandhurst has been in the excavator-mounted attachment business since 1979, trading at first in hydraulic attachments and then renting them out. One of the founding companies of the sector, it has remained at the forefront of this new technology. The Sandhurst name is now synonymous with attachments and, over the years, the company has developed a strong relationship with the rail industry, carrying an extensive inventory of rail equipment reflecting its customers’ needs.

Tim Dean, the company’s CEO and founder, told Rail Engineer: “Sandhurst is extremely involved in the rail sector and will continue to develop it.”

He pioneered and encouraged the use of manipulators in rail engineering and maintenance, and the manipulator concept has now become a popular attachment for the accurate positioning and safe handling of stanchions, signal posts and more. However, the products currently available are limited by their design, to square and oblong sections up to 3.75 tonnes, or round sections up to 1000kg.

In addition to these restrictions on the shape and size of the items being handled, customers also reported volatility in responsiveness, which Sandhurst identified as being caused by the number of hydraulic cylinders and their poor performance in co-ordination. There have also been problems with safety lookouts in the existing offerings, which make operators wary of using them.

Design brief

In response to these reports, Sandhurst set its engineering department a challenge two years ago, with a design brief to explore a next-generation manipulator with much more flexibility than anything seen before. Engineering director Neil Beard explained that the brief was to develop a product that could handle a multiplicity of forms, from square to circular to tapered, for carriers such as excavators and truck cranes with the capability to articulate and position loads up 5000 kg WLL (working load limit).

Just taking the capabilities of various manipulators and combining them into one tool would, in itself, have represented a significant advance, but Neil wanted to go further than that.

To pick up irregularly shaped items, the clamping elements would need to be independently actuated. Sandhurst’s engineering team began by sketching out different ideas, looking at how the legs should actuate in varying scenarios. The model they decided to run with would have three independent actuations – two leg pairs and a central ram – which would perform separately but combine to grab the work piece. Paired with this grabbing and clamping flexibility would be a tilt rotator, giving 360° rotation and tilting through 100° left and right.

The design brief’s working load limit (WLL) meant that the team would need to complete finite element analysis (FEA) on components to ensure each would cope with static loading to 5,000kg. Further FEA and duty cycle testing was undertaken to ensure the durability of all components, including the moving parts.

Although the grades of steel to be used were an important factor, as were the fabrication procedures that would be employed, intelligent design ensured that the attachment itself as a whole was both strong enough and load sensitive.

With the manipulator attachment counting as part of the load on the machine, any weight saved would naturally increase lifting capacity. As a result, the geometry was optimised to ensure maximum durability and rigidity while saving weight. The final product would weigh in the order of 1,350kg, meaning that a structure weighing 3,650kg could be lifted and manipulated given an overall WLL of 5,000kg. In practice, this lifting capacity would vary depending on the radius in each particular case.

To allow for careful handling, the clamping pressure would need to be adjustable within reasonable limits.

Successful demonstration

The result of all this work is the Articulator 5000, a prototype of which was demonstrated to potential customers recently. With just two circuits, it’s an elegantly simple plug-and-play solution.

Safety was a crucial factor in the design work. The failsafe is that the legs won’t move without a positive electrical current, so, if there’s a power cut, the legs won’t move. This means that, whatever the present situation in the workplace may be – whether an item is held or the Articulator is empty – it will be maintained. What’s more, an anti-burst valve is placed as close to the central pad’s cylinder as possible, so that, if there’s any change in hydraulic pressure, the legs will not move.

Fitted to the unit are two electronic spool valves that are actuated by a control box which sits inside the cab and is fitted with both a visual and audio alarm. This confirms that the clamping element can then be activated.

Cost efficiencies and time savings are likely to be substantial, considering that to erect and place a single stanchion is currently very labour intensive. With masts for new lines being placed at 15 to 18 metre intervals, the use of a tool like the Articulator could increase efficiencies dramatically, with placement possible in a matter of minutes.

The Articulator can be seen in action at the Sandhurst website, and has its own site, r-tick.com, where it is shown lifting long steel sections, awkward uneven and weighty structures and cumbersome concrete pipes.

Demonstrated at a recent industry event, the Articulator drew a crowd of enthusiasts, with Neil Beard pleased to hear from rail industry colleagues that it was a very “well thought out” piece of equipment. Rail professionals were quick to spot the potential of the Articulator for multiple applications including electrification, the handling of stanchions and timber baulks, and placing concrete piles and pipes. At the same time, professionals from other sectors enthused over its potential for use in such areas as drainage and in erecting highways’ lighting structures.

Testing and approval

As the Articulator 5000 continues to go through comprehensive pre-production testing, including proof load testing and duty cycle testing, Sandhurst is reporting an overwhelming response to its website and advertising of the Articulator 5000.

“There’s a sense that something like this is long overdue and I think a feel-good factor that an innovation like this, which will be so useful in rail and other sectors globally, was designed in Great Britain,” said marketing director Louise Dean.

“Within two weeks of posting, we had close to 20,000 views of our film of the Articulator in action on LinkedIn, with comments from our friends in rail that it looks very impressive indeed. We’re really looking forward to showing it at work to those who have been in touch and have suggested to prospective customers that they get in touch with us in advance of our demonstration day to let us know what they’d like to see it lifting.”

Sandhurst is inviting all who have displayed their keen interest, of whom there are many in all sectors, to a live demonstration day shortly after production begins. The venue will be courtesy of the Rail Alliance, which Network Rail will attend as part of its approvals process.

Looking forward, there are plans for further models of Articulator, to handle smaller and larger weight classes and a cantilevered version for suspension from cranes. There will also be an ‘inclinometer’, for accurate positioning in the vertical or inclined planes. A dual-axis monitoring system, with a visual, cab mounted display, will ensure perfect placement of the loads handled which will be monitored from the operator’s position inside the cab.

Tim Dean was keen to make the point that, as always, Sandhurst will be driven by its customer needs. “We listen to our customers, and provide solutions,” he said.

Certainly, the Articulator represents a big leap forward for safe and precise handling, trackside or otherwise.

Read more: Tunnel management, Swiss style

 

High Speed One renewals programme

High Speed One (HS1), originally known as the Channel Tunnel Rail Link, is reaching an interesting point in its history. Section 1 of HS1 opened in September 2003, running for 74 kilometres (46 miles) from Fawkham junction, near Gravesend in Kent, to the Channel Tunnel. High-speed services from France and Belgium then joined the conventional network and ran through to Waterloo.

To complete the line, Section 2 opened for business in November 2007, making up a total of 109km (68 miles) of 300km/h (186mph) high-speed railway which runs to the transformed St Pancras International we know today.

The whole route was designed and built based on French experience but adapted for the UK. Whereas the main British rail network is modern only from the track formation upwards, roughly speaking, with the basic infrastructure being mainly Victorian in design and construction, HS1 has the advantage of having recently-designed structures, embankments, cuttings and drainage that behave themselves very well by comparison with most similar railway assets elsewhere in the country.

HS1 Ltd holds the concession from the Government to operate, manage and maintain the high-speed railway infrastructure until December 2040. In July 2017, HS1 Ltd was acquired by a consortium comprising of funds advised and managed by InfraRed Capital Partners Limited and Equitix Investment Management Limited.

The railway infrastructure and three of the stations are contracted to be maintained, operated and renewed by Network Rail (High Speed) Limited. The three stations are St Pancras International, Stratford International and Ebbsfleet International. One of the key route performance requirements is that the delay minutes per train be five seconds or under.

Routine maintenance

Network Rail (High Speed), an organisation with over 400 staff, has the specialist knowledge to maintain a high-speed line with French high-speed switches and crossing. The infrastructure manager works towards the asset management objectives of safety, availability and cost, as set by HS1 Ltd.

There is a small team of track staff that make up the track engineering and maintenance divisions. The key track maintenance activities are inspections, componentry changes and heavy mechanical interventions such as tamping and grinding. For a high-speed line, the track geometry needs very tight tolerances. As an example, the line speed of 300km/h requires the vertical alignment (top) to be maintained to 9mm tolerance and the three-metre track twist to 6mm tolerance, which are tighter or equivalent to the construction standard for the classic network, ±10mm and ±6mm, respectively.

The tamping campaign also has a limited window due to weather and risk. Traditional long-wavelength tamping occurs in April and the short-wavelength geometry correction, also known as sprinter tamping, takes place in September to deal with localised defects that must be rectified quickly before they deteriorate into actionable faults.

Grinding is an important activity for geometry and wheel/rail interface management, in terms of ride comfort, RCF (rolling contact fatigue) and noise. RCF is a particular problem with freight and new rolling stock.

Time for renewal

Due to the normal deterioration of the track asset due to ageing, it is coming to the point where a serious amount of heavy maintenance or renewal will be required. A renewal strategy is being formulated and renewal plans refined as deterioration rates and failure modes become apparent. At the same time, maintenance strategy is evolving and being adapted to suit. Whilst technologies and processes are adopted, new associated competencies have to be developed for the team and new plant and tools product-approved to keep up with the changes.

One example is the current need for the replacement of a section of rail, typically an 18-metre length roughly once a month somewhere on the route. Until very recently, such rail replacements were required only about once a year. Head defects such as squats or failed insulated block joints (IBJs) are typical drivers of such works.

Rail-head damage may be caused by ballast flying up in the train slipstream, landing on the rail head and being run over by train wheels. More typical is damage caused by snow and ice on the rail, termed ice pitting, slightly different in appearance but equally harmful and specific to high-speed rail. Rail grinding and possibly rail changing become necessary to cure these faults.

Another example is the need to deal with poor track quality at track stiffness transitions. These occur at the change points between slab and ballasted track, at the ends of bridges and viaducts and even where the track passes over under-track crossings.

Deterioration can also occur in the highly canted curves found on some sections of the route (up to 160mm). These sections have tended to move under traffic and, like the stiffness transitions, necessitate extra tamping and realignment work. This extra tamping results in increased ballast damage that is shortening the life of the ballast in the affected areas.

Further problems arise where rail welds are proud of the rail table for any reason. A height difference of more than 0.5mm on the high-speed line will cause voiding under the adjacent sleepers. If not arrested, this deterioration develops and spreads as train wheels respond by vibrating and causing forces on the rails ‘downstream’ of the weld.

Damaged by ice.
Damaged by ice.

40-year plan

All of these issues mean that the overall level of asset degradation now requires the maintainer to consider responding in an alternative way, and it is therefore tailoring its approach accordingly. They also indicate a future requirement for heavy maintenance and the early development and implementation of HS1’s first renewals programme.

Network Rail (High Speed) is working on the development of a 40-year renewals programme. HS1 is regulated very differently from the Network Rail infrastructure and, for HS1, Control Period 3 (CP3) begins in April 2020. While the main renewal effort is to begin in CP3, there are a few minor track renewals taking place earlier on some parts of the HS1 infrastructure.

An early site is the St Pancras S&C layout, which was constructed to the old RT60 design that has been shown to have inherent problems. Although only around 10 years old, the track maintenance team has recently ordered spares based on accumulated experience from the classic network that these units have an average service life of only eight to 15 years, depending on tonnage and speed.

The plan is for renewals at St Pancras to commence with one S&C unit in 2018 and then continue at a rate of three per annum from 2019 until the whole layout has been covered. The renewals are expected to be like-for-like, but taking advantage of the improvements that Network Rail has made to the underlying design, for example by using crossings that embody the revised and improved design of casting now available.

Network Rail (High Speed) also maintains some of Eurotunnel’s infrastructure at Dollands Moor, which is older than the rest of the route. It is planned that the first full track renewals should take place there. A 1-in-24 vertical 113A crossover, dating back to 1990, is to be the first complete renewal. It is suffering from damage to the common crossing, track geometry quality issues and degradation of fishplates.

The renewal programme in CP3 is to include the use of a high output ballast cleaner (HOBC) on Section 1. Principally, this will be to deal with the deteriorated ballast on the highly canted sections where a large amount of tamping has taken place. The challenge for this is the approval of equipment as the HOBC has not been used previously on HS1.

Looking elsewhere

This is not the sole area where the distinction between HS1 and the main Network Rail network comes into play. HS1 is under very much greater pressure to keep the line open to traffic at all times. There is no possibility of blockades, for example, as can be employed at times elsewhere. These kinds of factors mean that renewals on the route require a different approach than that used by Network Rail on the rest of the network.

HS1 is therefore working with a number of possible suppliers besides Network Rail’s own Infrastructure Projects track team, with the intention of going out to competitive tender for the works at the appropriate time.

Few UK contractors have yet had experience of renewing high-speed railway track, and this has to be seen as a great opportunity for gaining experience and building a reputation in this kind of work. In addition, of course, there is a major workload ‘up for grabs’ in the CP3 renewal programme.

While all this is under consideration, there is also the matter of track standards for HS1. It is now time for a review and revision of the standards, to bring them into line with evolving modern practice.

HS1 has been in discussions with European consultants that have extensive knowledge and practical experience of high-speed rail systems in their own countries and elsewhere. The intention is to work with them to update standards for HS1 in time for the standards to be utilised during the CP3 renewals programme.

With the development of the 40-year renewal plan, and with new technology being sought out and applied for the infrastructure manager to become more efficient in maintaining the asset, including the upskilling of staff, it is an exciting time for HS1 and all at Network Rail (High Speed).

Read more: Slab Track Austria: now a serious contender?

 

Digital Railway: delivering differently

Following the announcement in May by Secretary of State for Transport Chris Grayling and the chief executive of Network Rail, Mark Carne, that all new trains and signalling will be digital or digital ready from 2019, the Railway Industry Association, Network Rail and the University of Birmingham recently hosted an event to explore what this will mean for the supply chain and to examine the early plans for Digital Railway deployment in CP6. The University of Birmingham also explained how it is supporting innovation in the rail sector.

The event, held over two days, was attended by over 250 representatives from Network Rail, the supply chain, rail operators and other key stakeholders from across the industry. It was advertised as a networking event for potential suppliers and, in that respect, it was a great success. Attendees included the main signalling contractors, together with a good number of small and medium-sized enterprises (SMEs) and sub-suppliers.

Network Rail explained how it will engage suppliers through a variety of frameworks and emphasised that its approach will be to specify outcomes, rather than having detailed technical specifications. The five-year Control Period (CP6, 1 April 2019 – 31 March 2024) spend on signalling will be £5.5 billion, compared to £3.3 billion in CP5 (1 April 2014 – 31 March 2019), so new ways of working and innovation are required for commercial as well as engineering reasons.

The success of the digital rail programme will be reliant on the collaboration between government, regulators, suppliers, industry associations, professional institutions, infrastructure managers, train operators and academia, including research, which is one reason that the event was held at Birmingham University.

BCRRE’s DSIC

Professor Clive Roberts, director of the Birmingham Centre for Railway Research and Education (BCRRE) at Birmingham University, opened the event by explaining that the Digital Systems Innovation Centre (DSIC) at the University will bring together existing academic and industry capabilities to innovate in new areas and to support transformational change in rail technology – not only in the UK but across the globe.

The Centre builds on the expertise of the BCRRE and the UK’s industrial base to deliver a step change in rail systems capability. Securing a world-leading position in the sector to deliver jobs, growth and inward investment, both nationally and internationally, it will focus on all aspects of Digital Railway innovation and provide a system-wide approach to development and innovation.

Initial areas of technological focus will include future railway operations and control, data integration and cyber security, smart monitoring and autonomous systems, together with introducing innovation and better system integration testing to speed up approvals.

All of these technical transformations have a part to play in the delivery of a more cost-effective, customer and carbon-friendly railway that safely delivers more capacity. The development of the centre of excellence in these areas will help the rail industry to “get there sooner”, thus improving the industry’s bottom line and reputation as well as supporting the UK’s export agenda in the post-Brexit world.

The Centre will house openly available facilities and have the ability to host bespoke research for specific sponsors that enable the railway and its interactions to be accurately represented. Connected models, simulators, assets and humans will enable system, sub system and component levels to be developed, integrated and optimised for performance, capacity, resilience, sustainability, usability (customer satisfaction) and cost.

This will include optimisation of existing network and asset base management, as well as the technical and business evaluation of introducing technology change, together with the staging plans to enable seamless implementation.

LNW Route

Martin Frobisher (pictured above), Network Rail’s LNW route director, reinforced the message that the technology behind the digital railway is proven, for example as demonstrated by the recent success of the Thameslink ETCS ATO operation. The political support is solid and the ORR CP6 draft determination, released the week before the event, was in general very positive, so the industry has the technology, political support and the money.

He explained that the LNW route is the economic backbone of Britain as it connects six of the top eight cities in the country. Compared to some other routes, the LNW has been one of the last to identify digital signalling opportunities, but plans now include digital signalling both for East-West Rail, ideally without lineside signals to save £30 million, and north of Crewe as part of the interface with HS2. Other schemes to enable new train services are also under development and may lead to further early deployments of digital signalling.

Castlefield Corridor in Manchester is a congested route that also includes freight services, so digital signalling traffic management may provide part of the solution. Traffic management will also be rolled out throughout the rest of this busy route and, as well as performance and capacity, Martin reminded everyone that digital signalling is also about safety.

On many lines in the route, a level crossing may be located in a very long mechanically signalled block, with no way of an operator knowing where a train is in relation to the crossing. This makes if very difficult to advise a user to cross until the train has cleared the long block, so the user may be tempted to use the crossing when it is not safe to do so. Digital technology will positively know where trains are and will safely interface with level crossing operation. Twenty percent of all train industry risk is still associated with signals passed at danger and, while TPWS has made a dramatic improvement, it will require ETCS to deliver the next step in risk reduction.

Rail Sector Deal

BCRRE director Alex Burrows and David Clarke, technical director of the Railway Industry Association (RIA), gave an update on the Rail Sector Deal.

As part of its industrial strategy, the government is working in a number of sectors to reach agreements with business on ‘sector deals’. These deals are intended to be agreements that help each sector meet its key challenges and allow business to invest and grow accordingly. This is an important opportunity for the rail sector to push for the necessary support to drive forward the UK rail supply chain.

The rail industry is complex, with a total workforce of 600,000. But the supply chain alone employs 250,000, which makes it one of the largest sectors – larger than, for example, train operators.

The Rail Supply Group (RSG), in partnership with the Rail Delivery Group (RDG), has been working with the government to develop an industry-leading and transformative Rail Sector Deal proposal that will enable new businesses, collaborating with other complementary industrial sectors, to sell innovative products and services to rail in both the UK and export markets.

By working together with the broader industry, the RSG and RDG are developing a proposal that has the potential to transform the railway and enable the UK’s supply chain to become truly world leading. The aim is to persuade the government to prioritise the sector and help unlock its future potential.

RIA and its members are active in a number of areas to improve efficiency in the industry. This includes the Renewals Cost Challenge and the Electrification Cost Challenge, which aim to show that both government and industry, working together more efficiently, can reduce unit costs. RIA successfully lobbied for an additional £200 million of renewals funds to be released to Network Rail during CP5 to help avoid the traditional ‘boom and bust’ scenario of stop/go funding. This has a negative impact on efficiency and unit cost as it creates uncertainty and does not encourage suppliers to invest and innovate.

Supply chain

Two of Network Rail’s commercial directors, Digital Railway’s Phil Bennett and IP Signalling’s Martin Robinson, explained the procurement approach for CP6. The work bank mix will have a greater emphasis on life extension and refurbishment than in CP5, preparing some routes for the digital signalling rollout in later control periods. However, the Signalling Equivalent Unit (SEU) volume count will still increase to 8,329 from the 6,000 delivered in CP5.

The contracting strategy for CP6 signalling will be based on one procurement system to promote efficiency within both Network Rail and the supply chain. This will be achieved by adopting flexible and easy-to-use frameworks to facilitate the best delivery mechanism for each project/programme, and to develop a wider supplier base, with more competition and lower supplier overheads.

The proposed supplier engagement model will encourage engagement, innovation and early contractor involvement. The model will enable alliances or partnerships, if required, for discrete projects/packages of work. It will also facilitate the transition to the stated future Digital Railway position of Design, Build & Maintain (DBM).

The major framework re-signalling strategy, including relocking and re-control, is proposed to be packaged into two contract areas – North (LNE/EM, LNW, Scotland routes) and South (Anglia, SE, Wessex, Western, Wales). The geographical split would be guided by asset population density and will be a blend of frameworks and competitive tendering (around 30 per cent). The contracts will be known as Tier 1 and will be for four years with options to extend. There will be parallel procurements for OEM professional services and support contracts.

Tier 2 framework contracts will be for targeted interventions, including level crossings renewals and related telecoms. This would combine the existing CP5 ‘Type C’ signalling frameworks with ‘Level Crossing’ and the ‘IP Telecoms’ frameworks into one S&T framework contract. The packaging strategy will be of five areas: Scotland, Western & Wales, LNE/EM, LNW, and SE/Wessex/Anglia. In some routes, delivery for Tier 2 works could be done in house or in conjunction with a contractor.

To support the large increase in refurbishment and minor signalling works proposed in CP6, Tier 3 contracts will be established for framework route-based minor activities with little or no design, and to support ‘in-house’ delivery. Essentially, these are for component renewals with the design requirements limited to route-based low-complexity works, typically up to £500,000 in value. There will generally be two suppliers per route and the strategy will support the government’s SME agenda and help to develop the signalling supply base.

Software as a Service

The current plan for the initial contracts for signalling in CP6 are:

  • ECML – July 2018 onwards, to include ETCS and Traffic Management;
  • Feltham ETCS – Autumn 2018;
  • Crewe ETCS – late 2018/early 2019;
  • Northern, Anglia, Wessex Traffic Management – Autumn 2018.

New innovative contracting strategies will also be established, one example being the Traffic Management Package (TMP) for the East Coast main line (ECML). This will be a 10-year Software as a Service (SaaS) contract, let using the Crown Commercial Service (CCS) Model Services Contract, covering the ECML from King’s Cross to Doncaster South, where it will interface with the transPennine traffic management scheme.

The TMP is expected to interact with both train-side and trackside components, therefore delivery of the TMP will interface with ETCS and rolling stock fitment suppliers. Apart from ensuring system availability, the TMP supplier will also be accountable for system integration, sustainment, optimisation and alteration of the system (to comply with group standard changes), training, performance reporting and obsolescence management.

Traffic management has been chosen to be procured as a service rather than as a capital asset, owned by the infrastructure manager, because there is no safety critical component, and the accounting rules allow for software to be costed as operational, rather than capital, expenditure.

The responsibility for second and third-line maintenance of the system would lie with the TMP supplier, including the training of maintenance staff. Training for operational staff will be the responsibility of either the TMP supplier or Network Rail, depending on the location of the equipment or operations.

Lessons learned

One of the most interesting and important discussions during the day was on lessons learned from the Digital Railway projects already completed, or under way, both in the UK and around the world. A panel with representatives from Network Rail, Ansaldo, Siemens and Alstom gave their thoughts and answered questions on the deployments and in-service experiences of digital rail installations on the Cambrian Coast, Thameslink and Crossrail.

Items that were highlighted included that the interface and interworking between interlockings and the radio block centre (RBC) are not very well defined and that interworking between suppliers can be challenging. Off-site laboratory testing was considered key in proving interoperability. The requirement for space for on-board integration of equipment was another learning point, and that it is important to choose optimal TSI (Technical Specification for Interoperability) radio interface features and not UK-specific ones.

A number of the team commented that early on-site collaboration and involvement with operators and maintainers is key, together with collaboration with the supply chain. Many of the answers to problems are not yet available in a book on the shelf, so projects will need to identify who may have the answer from wherever in the industry. “Use ‘industry’ and not just ‘project’ delivery and involve everyone” was the message.

Infrastructure data must be complete and accurate, and defining the method of operation must be carried out early in a project. The types of trains and their performance, and the impact of ETCS on the system performance, together with a robust and reliable timetable, will also be essential. Extensive soak testing and many miles of shadow operation was another key point. Questions from the floor established the need for a central repository that should be available to anyone. Network Rail representatives confirmed that this is something they are looking into.

Alex Burrows and Clive Roberts explained lessons learned that had been obtained from around the world, which included Singapore, Netherlands, Denmark, Mexico and Australia. These included that the requirements for business change when implementing Digital Railway technology must not be underestimated, together with a requirement for rigorous and realistic testing for integration and throughput. The need for a system approach with off-site laboratory testing was mentioned a number of times.

It was noted that a CBTC system in Singapore had a number of problems and was such a high-profile and important project to the city that someone knew a non-engineering friend who could quote in detail how a CBTC system should work. It was commented that Network Rail must avoid ETCS becoming a social conversation subject for the wrong reasons in a few years time!

Final thoughts on the event

Questions throughout the day were thorough and challenging. Vivarail chairman Adrian Shooter, formerly head of Chiltern Railways and London Overground Rail Operations, made the point that, while there was much talk of system engineering, it was disappointing that there were not many train operators or rolling stock providers present at the event. Network Rail responded that there was very close working with train operators at local route level, and that Network Rail would address the concern in future networking events.

With regards to how suppliers would be engaged by specifying outcomes rather than having detailed technical specifications, delegates asked how a signalling supplier could deliver the required outcomes (such as XX trains per hour capacity) as many of the constraints are system related, not signalling. For example, the type of traction and operation will be a major component of performance, and one which a signalling contractor may not be able to influence. Indeed, a ‘signalling plus ETCS’ operation could deliver worse capacity than at present if it is not designed as a system. It’s also great getting more trains through a network, but narrow platforms with poor entrance and egress facilities at some stations will just move the congestion problem somewhere else.

Platform dwell times are already a constraint in some parts of the network, so how will this be tackled if the Digital Railway does provide more train paths? Some quite simple things might reduce dwell – not requiring the guard to set foot on the platform before enabling the doors (a driver could enable them) and speeding-up door operation on some classes of train spring to mind.

System engineering, collaboration, innovation, efficiency, better use of data and laboratory off-site testing were terms frequently used throughout the event, and it will be interesting to see these concepts integrated into the CP6 delivery of the digital railway.

All in all, it was a good networking event. Rail Engineer looks forward to attending the next one, when there should be more operators and rolling stock representatives present, to continue to report on how delivering differently is making a difference.

Read more: The annual Stapleford trials

 

The annual Stapleford trials

The Stapleford Miniature Railway’s lawnmower had temporarily lost its magneto as it had been fitted to the University of Huddersfield’s Railway Challenge team’s locomotive. Thus, the team’s ingenuity in borrowing and adapting this magneto enabled its locomotive to be ready for the competition’s dynamic tests.

Unfortunately, this resourcefulness was not to be rewarded as, once the locomotive reached the trial site, its chain drive failed, and it had to be recovered by the miniature railway’s rescue locomotive. For the Huddersfield team, which had spent months preparing its locomotive and had the reputation of being previous winners to live up to, this was a bitter blow. Yet it was a good example of how the IMechE’s Railway Challenge reflects the reality of the full-sized railway and, although Huddersfield was unable to win the competition this time, the team still gained much from it.

The teams

As regular readers will know, the Railway Challenge is an annual competition in which teams of graduates and students design and build a 10¼-inch gauge locomotive to take part in various trials. Rail Engineer has been a firm supporter of the Railway Challenge since the first event was held back in 2012.

As shown in the table, a total of 15 teams have entered the challenge since its inception. It is interesting to note half of the challenges held since 2012 were won by new entrants – one judge suggested that this may be because new entrants pay closer attention to the competition’s rules and specification.

This year there were three teams of industry graduates, five university student teams and two joint industry/university teams. 119 took part in the challenge with team sizes ranging from five to 15. The largest team was from the University of Sheffield’s ‘Railway Challenge at Sheffield’ club which, unlike other university teams, is an extra-curricular activity.

Although twelve teams entered the competition, two teams dropped out some time before the competition weekend and the Siemens/Southampton University team was not present as its locomotive had suffered a power failure and could not be repaired in time. The team was, however, given credit for its design and innovation reports.

Of the nine locomotives present, seven took part in the dynamic trials. As well as Huddersfield University’s chain difficulties, the joint Bombardier/Derby University locomotive was also unable to take part due to brake problems. It was, however, given an opportunity to run over the three-kilometre miniature railway after the completion of the dynamic trials, although one bogie derailed on plain line track and the locomotive had to be recovered.

The locomotives

The locomotives were designed to a performance-based specification based on the challenges specified in the competition’s rules. As such, it is not surprising that there are some similarities between them. Of the nine locomotives present, seven had a single body with two four-wheeled bogies. The exceptions were Birmingham’s locomotive, which was mounted on two wheelsets, and Sheffield’s three-unit locomotive with each unit mounted on two wheelsets.

Five locomotives were powered by petrol generators. Of these four had generators of about three kilowatts with traction power supplemented by a battery whereas Huddersfield’s seven-kilowatt generator was the sole normal power source.

Birmingham and Aachen had hydrogen-powered/battery hybrid locomotives whilst Transport for London (TfL), Warwick and Bombardier/Derby had battery-powered locomotives. This was the first time that battery power had been allowed, as a change to the rules allowed for refuelling to be done within 120 seconds, which could include the replacement of energy storage assets.

The most important challenge, with twice the available marks of the others, is the energy storage challenge, during which teams have to recover energy while braking to a stand and then use that energy to propel their locomotives as far as possible. As shown in the table, for this challenge, six locomotives were fitted with supercapacitors whilst Aachen used its traction battery and Huddersfield had a unique axle-mounted coil spring energy recovery system.

Other than Ricardo, each team had previously entered a locomotive. Such teams are required to modify their locomotives to comply with changes to the rules as well as enhancing them to improve the previous year’s performance, as shown in the table.

Sheffield tackles the maintainability challenge.
Sheffield tackles the maintainability challenge.

The innovations

To encourage innovative thinking, each team had to submit a paper, in the format of an academic journal, which describes an innovative aspect of its locomotive design. The teams came up with a number of interesting innovations that are worth listing in detail.

Aachen’s locomotive was fitted with a sensor to detect objects and potentially simplify shunting by enabling an autonomous locomotive to follow its driver.

Huddersfield’s entry has a digital self-levelling suspension system, which uses an ultrasonic proximity sensor.

An innovation from Ricardo, a team which included three automotive graduates, was the use of a Controller Area Network (CAN) which is standard automotive practice. This has a serial communication protocol that eliminates the need for wiring harnesses, allows for easy addition of additional components and provides a standard coupling interface.

The Visual Wheel Condition Monitoring System (VWCM) fitted to SNC Lavalin’s locomotive uses a camera that is computer-controlled to capture a series of images of the entire wheel circumference at low speed (2.8km/h). VWCM has an image processing system to detect thermal cracks on the wheel tread.

TfL presented a proposal for a trainborne system that could measure adhesion at precise locations along train routes.

Warwick had considered the use of novel polymer traction gears for its locomotive. However, after a study, which included testing on a special rig, it was concluded that steel is the most wear-resistant gear material.

Ricardo's locomotive.
Ricardo’s locomotive.

The specification

Locomotives are built to a technical specification that also specifies the requirement for systems assurance and a design report, which must include a compliance matrix against technical requirements and as-constructed drawings. This report must also contain performance, structural and wheel-unloading calculations.

The requirement is to produce a locomotive that can operate for three hours without refuelling at five kilometres an hour hauling a 400kg load up a two per cent gradient. It must also be able to haul and start a trailing load of 1,800kg on a two per cent gradient. As far as possible, the specification is performance-based to encourage innovation by giving the teams the discretion to determine the configuration of the locomotive and its motive power.

The prescriptive technical requirements are generally those that enable the locomotive to run on the Stapleford Miniature Railway, for example loading gauge, axle weight and type of coupler.

Aachen's entry.
Aachen’s entry.

The rules

The competition rules cover general requirements and the challenge specifications. General rules include eligibility (an engineering student or graduate of no more than two years or a current or passed out apprentice of no more than two years) and safety requirements which includes the requirement for a team safety supervisor, risk assessments and method statements.

Before competing in the track-based challenges, the locomotives have to pass scrutineering, to confirm that they are built to specification with the required supporting documentation. This requires the locomotive to pass 31 different checks to enable it to collect the following different coloured stickers, as follows: evidence of reliability (1), calculations and safety documentation (6), user guide (1), inspection of markings (3), physical inspection (6), demonstration of performance (10) and demonstration of indications (4).

There are nine challenges of which six are track-based (energy recovery, traction, ride comfort, noise, maintainability and reliability) and three are presentations (design, business case and innovation). The maximum points for each challenge is 150, except for the energy storage challenge for which 300 points are available. This gives a maximum possible score of 1,500.

In this way, teams must consider all performance aspects of their locomotives as well as try to persuade the judges to buy their machines in the business case challenge that, unlike the other challenges, provides a commercial focus. One judge commented that, although some teams understandably focus on the difficult engineering aspects of their locomotives during their business presentation, in the real world there’s no point in building it if they can’t sell it.

A new requirement in this year’s competition was for the business case presentation to be supported by an A0 poster. To encourage audience participation, spectators were given the opportunity to vote for the best poster, although this was an unscored aspect of the competition.

The railway

The Stapleford Miniature Railway (SMR) dates from 1958 when the second Lord Gretton purchased, second hand, two 4-4-2 steam locomotives and 2,000 feet of 10¼-inch gauge track as an additional family attraction for his stately home and grounds, which were open to the public. The following year, the Haven station was built as the line was extended to the lakeside.

The line was so popular that an additional locomotive was soon acquired in the form of a replica Warship diesel locomotive powered by a Ford petrol engine, which entered service in 1962 and acts as the rescue locomotive during the Railway Challenge.

Further attractions were added in the 1960s in the form of two large-scale passenger-carrying model liners on the lake as well as a lion reserve and zoo. In the 1970s the balloon loop from the Haven was built.

Lord Gretton’s death in 1982 saw the railway closed to the public at the end of that season and put into storage. After the untimely death of the third Lord Gretton, Lady Jenny Gretton agreed to allow a small group of enthusiasts, including those who had previously operated the railway, to look at the feasibility of restoring it. In this way, the Friends of the Stapleford Miniature Railway (FSMR) was formed in 1992.

The group had much to do to make the locomotives serviceable again and restore the line, including rebuilding the tunnel under the drive to the house, before the railway could re-open in 1995 as a private railway with a limited number of open days each year.

The railway is an ideal location for the Railway Challenge as it is not normally open to the public and its three kilometres of track, with a balloon loop and a 1 in 80 gradient, are ideal for the locomotive trials. It also has plenty of hard standing at the station for work on locomotives and much open space for contestants to camp out. The competition is also dependant on the unstinting efforts of the FSMR’s volunteers who operate the railway and provide the rescue locomotive and steam-hauled spectator trains.

Working on TfL's locomotive.
Working on TfL’s locomotive.

The organisation

It needs 26 people to organise and run the Railway Challenge, 23 of whom are volunteers. These are a team of eight scrutineers, twelve judges and three controllers.

Sandra Balthazaar is the IMechE staff member responsible for the event. As well as dealing with the logistics of the event, she and her small team work to attract entries and the essential sponsorship to fund the event. This year’s sponsors were Network Rail, RSSB, Young Rail Professionals, Eversholt, Angel, Porterbrook and Beacon Rail Leasing.

The Railway Challenge Steering Group is led by Professor Simon Iwnicki, who conceived the idea of the competition in 2011. This coordinates the work of other groups including the rules and development committees.

The competition takes place over three days. The programme broadly devotes day one to scrutineering while day two is taken up with test runs, presentation challenges and the maintainability challenge, in which teams compete to remove and replace a wheelset in the shortest possible time.

Day three is the dynamic track challenges and the spectator day. This requires a detailed operational plan that has two locomotives undergoing different trials at the same time at the test area by the lake. Into this timetable are fitted a series of steam-hauled spectator trains from the station to and from the Haven, and the movements of the rescue locomotive, all under the control of the SMR signalling system as the FSMR control all movements, which are made at the request of the dedicated Railway Division’s controller.

The results

As everyone gathered in the marquee for the announcement of the results, it was not clear who would be the overall winner despite the scoreboard showing how each locomotive had fared in its track-based challenges.

Master of ceremonies for the prize giving ceremony was head judge Bill Reeve, who considered that the event had “without doubt been the best challenge so far”. He announced that SNC Lavalin had won the traction, ride comfort, innovation and design challenges. TfL had won the noise and business case challenges.

Ricardo had won the energy storage challenge and that, “with an amazing performance”, Sheffield had won the maintainability challenge as well as getting most votes for its business case poster. Ricardo, SNC Lavalin and FH Aachen University of Applied Sciences had completed all the challenges without any reliability issues and so were joint-winners of the reliability challenge.

Bill also advised that the judges wished to commend the Bombardier/Derby and Huddersfield teams which had shown “sheer bloody determination” to fix the problems on their locomotives. He also mentioned that the judges look out for teamwork and support and had particularly noted the support that Ricardo and FH Aachen had given to others.

Immediate past-president of the Institution, Carolyn Griffiths, presented the overall winner’s cup, but before doing so she stressed how the IMechE’s Railway Division had been a great support throughout her career. She recommended that anyone starting a career in railway engineering should become involved with the Division where they will find someone to support them.

She felt that the Railway Challenge was an example of this. The Railway Division had organised a fabulous event that helped young engineers make the transition from learning to doing with a demanding project and gave them the opportunity to learn from each other. Carolyn stressed that there were absolutely no losers in the competition and that all the railway engineers present would have been proud to have built the locomotives entered.

She then announced the overall results in reverse order until it became clear that first-time entrants Ricardo was the overall winner.

2017 Swedish Challenge winner.
2017 Swedish Challenge winner.

The Swedish Challenge

The IMechE’s Railway Division is to be congratulated in organising its Railway Challenge which is starting to attract worldwide interest. It is a unique event that replicates many of the challenges which replicate the issues faced by the real railway. Yet it is not the only event that challenges students to build an award-winning railway vehicle.

An electric battery-powered rail vehicle challenge has been held at Delsbo in Sweden since 2010. This requires students to build a passenger-carrying standard gauge rail vehicle of the highest possible energy efficiency.

Last year’s winner was the University of Dalarna with a team that built a 100kg railcar powered by a 500 watt motor that carried five people. It consumed 0.76 watt hours per passenger kilometre over the three kilometre course which took twenty minutes to complete. During this time, the motor was only used for 110 seconds.

The Railway Challenge team has considered whether its competition could include an energy efficiency challenge. However, whilst it is relatively straightforward to measure the energy consumption of battery powered locomotives, precisely measuring energy consumption over a short distance for the variety of traction encouraged by the Railway Challenge is a different matter.

The future

Sandra Balthazaar advises that the competition is attracting international interest with groups from Australia, Pakistan and Thailand considering how they can establish their own Railway Challenge. Indeed, this year’s event had a delegation from Thailand present to see how this could be done.

Also present at this year’s event was a team from Poland which wishes to enter next year. A team from Egypt had intended to enter this year’s event, and Rail Engineer understands that Network Rail is also likely to enter a locomotive next year. With such interest, and increasing awareness of the event in the UK, Simon Iwnicki is confident that, in a few years’ time the event will have thirty or so entries.

Yet this year, it took most of Sunday for seven locomotives to complete their trials. With smart operating, the most that the Stapleford Railway could put through the trials in one day is fourteen locomotives. Like the real railway, the Railway Challenge suffers from a lack of capacity.

This problem has been considered by the competition’s development committee, which has developed a plan to enable 30 locomotives to enter the competition. This plan, which has been discussed and agreed in principle with FMSR and the current Lord Gretton, involves building an additional chord at the balloon loop junction, some double-tracking and a turntable, with sidings and hard standing, to accommodate additional locomotives at the station. Surveying for this additional track is to start this summer.

The rules committee has almost finalised the rules and specification for the 2019 competition, which could include two additional challenges – an auto-stop trial that will require the locomotive to come to a stand a precise distance from a marker and a track damage trial to measure the locomotive’s impact on the track.

Whatever the future holds for the Railway Challenge, it is certain to continue to support the development of over a hundred young engineers each year and show them the support that is available from the IMechE’s Railway Division. Equally importantly, it is hoped that it will attract much-needed budding young talent to the railway industry.

It is good to see industry support for the competition with Bombardier, Ricardo, Siemens and SNC Lavalin entering the competition. In addition, there is its sponsorship from Network Rail, RSSB, Eversholt, Angel, Porterbrook and Beacon Rail Leasing, with other companies sponsoring individual teams.

However, much more could be done, and Rail Engineer looks forward to seeing some new teams lined up when it attends the 2019 Railway Challenge.

Read more: Rail Engineer August 2018 – Infrastructure focus

 

Tunnel management, Swiss style

Anyone who has travelled the railways of Switzerland will know that tunnels abound in the alpine regions. Most date back from the late 1800s or early 1900s and were marvellous feats of engineering for that period of time. Provided primarily on north-south routes that connected the country across the Alps, they were often spirals inside mountains in order to gain height before the final crossing near to the summit. As such, the rail routes were circuitous and journey times were lengthy.

The Swiss authorities decided at the start of the twenty-first century that a faster means of crossing the Alps was required and that this entailed building new tunnels much deeper down inside the mountains. So emerged the ‘Base Tunnel’ projects, to both shorten the route and to allow much higher speeds. Beginning with the 34.7km long Lötschberg tunnel that opened in 2007, a bigger challenge emerged with the Gotthard base tunnel that would be longer and needed to carry high levels of traffic.

An article on the control and communications systems in this tunnel appeared in issue 146 (December 2016), just prior to the tunnel opening, but managing the total tunnel operations involves much more than controlling train movements. Running from Erstfeld in the north to Biasca in the south, it is the longest rail tunnel in the world at 57km in length and carefully thought-through processes have to be in place to ensure the best possible safety arrangements with evacuation procedures that are fit for purpose in the event of any emergency.

The IRSE (Institution of Railway Signal Engineers) convention in May 2018 was based initially in Lugano, from where descriptions of the technologies and site visits to the tunnel were provided. The result was a fascinating insight into the factors that make up modern day tunnel management.

The three Swiss base tunnels.
The three Swiss base tunnels.

Gotthard base tunnel traffic

The route from Zurich to Lugano is part of the main freight artery from northern Europe, including the important ports of Antwerp, Rotterdam and Zeebrugge, through to Italy and its main industrial centres. Getting more capacity on the route with reduced journey times has become vital.

The old Gotthard tunnel, with its circuitous and steep gradients on both the south and north approaches, had become a bottleneck on traffic throughput, hence the need to build and operate the new tunnel.

The specification required the route to accommodate six freight and two passenger trains every hour in each direction, speeds for the freight trains being 150km/h and 250km/h for passenger trains. Achieving this with ETCS Level 2 is nowadays straightforward, hence the provision of this system with its associated GSM-R radio bearer supported on the associated radiating cables.

Driving trains at the maximum permitted speed is part of the traffic planning activity so as to allow extra train paths to be inserted if need be. Not only are the trains more frequent and faster but also longer, enabling greater loads to be transported.

Simulating a fire.
Simulating a fire.

Managing the tunnel

The Gotthard base tunnel is in fact two single bores of generous dimensions to allow for a walkway at train door level for use by maintenance personnel, also for train crew and passengers should any evacuation need to happen. Two intermediate ‘Safety Stations’ at one-third and two-thirds the distance from the portals are provided at locations known as Sedrun and Faido. These accommodate rail crossovers to allow trains to cross to the opposite tunnel if any single line working is needed, an arrangement that is similar to the Channel Tunnel. The stations are, however, much more than just a rail transition.

Each has a separate access tunnel bored into it (around 2km in length) from the outside of the mountain, equipped with an independent ventilation system. This permits access (or egress) to the tunnel independent of the end portals. In addition, cross passages link the two running tunnels at 325 metre intervals to allow escape from one tunnel to the other in an emergency as well as providing space for housing equipment.

The biggest risk is fire, both on passenger and freight trains, particularly the latter if they are carrying dangerous goods, and the safety stations and cross passages are all aimed at evacuating people safely and in the fastest possible time. However, fire precaution measures come first in the planning activities and these include:

  • A high level of automation of all tunnel systems including signalling;
  • Minimising the amount of ‘active’ equipment in the tunnels, for signalling there are only balises and axle counters;
  • Backed-up power systems in a ring formation to ensure continuing equipment operation;
  • Sophisticated telecommunication networks to give fixed-line and radio communication, the latter comprising both GSM-R and public 3G and 4G services, all served by resilient fibre optic and IP transmission bearers, plus radiating cable for the various radio systems;
  • All trains to be checked before entering the tunnel;
  • Monitoring of train speed against planned and possible speeds;
  • Keeping a defined distance between trains;
  • Containment of smoke and blowing smoke away from evacuation areas;
  • Provision of portable rail-mounted tunnel ‘doors’, to further segregate people from any incident and minimise smoke drift.

The evacuation of passenger trains is the most challenging, as this may have to occur in either direction and may involve the reversing of a train. The plans foresee a maximum time of 90 minutes to complete an evacuation, so fire containment has to be designed around this target.

Ceneri tunnel portals at Camorino.
Ceneri tunnel portals at Camorino.

Tunnel control and traffic management

Resilience of the equipment is key to continued operation and safety management. The main control centre for the Gotthard tunnel is located at Biasca, close to the south portal, and is a purpose-built modern secure building. A similar centre exists at the north portal, to ensure the appropriate level of redundancy.

The operating floor looks like most others, with its multitude of display screens, but these are focussed primarily on monitoring and controlling the various tunnel electrical and electromechanical systems, primarily ventilation, power, light and communication, as well as providing the necessary information for the maintenance of these systems.

‘Tunnel Safety’ sits above the normal command and communication systems needed to operate a railway and is structured in a layered approach that can drill down directly to the sub systems if need be. At the highest level is an Emergency Response System, brought into use should any incident occur when it would become the tool of the incident commander in such circumstances. Needless to say, the control centre is staffed on a 24/7 basis.

Traffic management sits alongside the ETCS signalling (the interlockings and radio block centres) and provides an additional set of rules to prevent the signaller from taking any action that would contravene tunnel safety requirements for train movements.

An additional interface known as TAG sits between the TMS and the signalling movement control to continually supervise train traffic. This has the intelligence to recognise an irregular emerging occurrence, followed by an alert to the operator and to finally suggest measures that should be taken to prevent any escalation of the problem. The process is focussed on: prevention  –> early detection –>  risk containment –>  event management –>  return to normal. That sounds good, but it is acknowledged that the exact source of a problem is not always known. An example would be a train proceeding at a slower speed than expected, which may or may not indicate a potential problem.

Gotthard base tunnel control room at Biasca.
Gotthard base tunnel control room at Biasca.

Wayside Train Monitoring System (WTMS)

Mention has been made of checking trains before they enter the tunnel for any dangerous conditions and to provide an appropriate intervention. This is not as onerous as it sounds. The process has taken 10 years to develop and is not solely for the Gotthard tunnel but is (or will be) installed at all the base tunnel locations. The one at Erstfeld, to the north side of the Gotthard tunnel, is typical.

The checks take place at line speed, up to 250km/h for passenger trains, and around 10,000 pieces of rolling stock pass the monitoring system every day resulting in 25,000 measurements from which, typically, 25 alarms are generated. The system checks on:

  • Hot axle boxes;
  • Wheel load checks including any axle overloads;
  • Fire and explosive gas detection;
  • Train profile and antenna detection, looking for out-of-gauge loads or loose cladding;
  • Dragging equipment;
  • RFID – radio frequency identification.

Many of these tests involve proprietary equipment that has been available for years, such as hot axle box detectors, which have four sensors, two outside the running rail and two inside.

Others are less commonplace. Strain gauges attached to the rail will detect wheel flats and incorrectly loaded wagons. Three-dimensional images taken of the train will ascertain any out of gauge obstruction, these being coded red = severe and train to stop immediately and green = safe to proceed but examine train when next it stops. Ideally, the checks should take place sufficiently far away from the portals for a train to be stopped before entering the tunnel

If an alarm is raised, an analysis of the condition is generated to determine the severity of the condition and a message is sent to the train over the GSM-R radio. The control centre operator will decide whether to stop the train, instruct it to reduce speed, or take no action. Any speed reduction requirement should be advised before the train is in the tunnel, this being done by both a verbal message and a change to the ETCS Movement Authority. If the train has entered the tunnel with an alarm raised, then the main consideration is to keep the train moving at reduced speed so as to exit the tunnel.

The alarm system itself must be reliable, with 97 per cent currently being achieved and with a high priority response to rectify any failure. SBB has designed and built the WTMS equipment in-house using commercial equipment for the various components.

Camorino Ceneri Tunnel Viaduct
Camorino Ceneri Tunnel Viaduct

Completing the route – the Ceneri base tunnel

The Gotthard Massif is not the only alpine range on the Zurich – Lugano route. There also exists Monte Ceneri to the south of Gotthard, the rail line also having a high altitude tunnel with limited-speed approach routes. Not as dramatic or circuitous as the old Gotthard route, it is nonetheless a limitation and the building of a new Ceneri Base Tunnel is well under way. This will be two 16km single bores, one ‘Safety Station’ midway, the latter not including a rail crossover, and regular cross passages between the two running tunnels.

The tunnelling ‘break through’ was achieved in 2016 and work is proceeding to equip the tunnels with track, power supplies, the overhead catenary, telecommunications and safety systems including the ETCS signalling. Installation work will be completed by mid 2019, allowing rigorous testing to take place during 2020 with an end of year opening.

The project is more than just the new tunnel – the new approach routes at both ends have required the construction of impressive concrete viaducts, major undertakings in their own right. Once completed, a journey time of three hours from Zurich to Milan will be possible, together with a considerable increase in capacity.

In summary, congratulations must be given to the Swiss rail and government authorities for having the vision, commitment and determination to see these projects through to a conclusion. Comparisons with the Channel tunnel will be made, where safety processes also have to be rigorous. Tunnelling under a mountain does not require a service tunnel to be provided but the intermediate ‘safety stations’ fulfil a similar role.

Read more: Securing a future for one of England’s longest disused railway tunnels

 

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