With its continuing drive for increased efficiency and the resulting cost savings, Network Rail has encouraged its contractors, and their sub contractors, and THEIR subcontractors, to invest in the latest equipment which can deliver more for less.
In the latest control period, for example, efficiency has to increase by 20%. That means every shift has to produce 20% more work, or a set project has to be delivered 20% more quickly and 20% more economically.
It’s a tall order and one which, frankly, Network Rail is struggling to achieve. But that doesn’t ease the pressure on contractors. If anything, it makes it more intense.
This need for speed reaches right across the railway. Every infrastructure project is looking for these savings. Traditionally, one of the more time-consuming elements of a project is the groundwork. With access to the railway limited, and with contractors often having to set-up and then break down the site so that trains can run during the day, the need to achieve more in a shift has never been more intense.
Investment is the key
During its 30-year history, Van Elle Group, based at Pinxton, Nottinghamshire, has established a reputation for delivering high-quality piling and ground engineering solutions for its clients.
A key element in the Group’s activities is its involvement in railway projects. This division has gained significant experience and expertise in both design and construction, enabling it to undertake rail projects of all sizes and complexities for Network Rail and its contractors.
To carry out its piling and foundation work, Van Elle has invested around £15 million in plant and equipment during the last few years.
This substantial investment has resulted in the purchase of various rail- related machines including a number of DX impact piling hammers from British firm BSP International Foundations. Based in Ipswich, BSP is one of the world’s leading manufacturers of piling hammers and related equipment.
BSP has specifically developed the DX hydraulic drop hammer to drive tubular steel piles to support electrification staunchions, gantries and other railway projects requiring foundation piling. It has been designed as an attachment for mounting on road/rail or tracked hydraulic excavators with an operating weight of around 32 tonnes or more.
When mounted to the machine’s boom and dipper arm configuration, the hammer can be quickly erected from a horizontal transport position to vertical. Side tilt adjustment of five degrees left and right allows it to cope with the track’s cant. During piling, the hammer is automatically guided or crowded in the vertical plane.
Facts and figures
Three compact models are available from the Ipswich-based manufacturer. The DX20, DX25 and DX30 models offer dropweights of 1.5 tonnes, 2 tonnes and 2.5 tonnes respectively with maximum impact energies of 20kNm, 25kNm and 30kNm. Blow rate at rated energy for all the models is approximately 60 blows per minute.
As standard, each hammer is fitted with an 800mm diameter drive cap which is well suited to the common application of driving 762mm and 610mm diameter tubular piles used in the construction of electrification stanchions. It also accommodates other common sizes, such as 457mm, 406mm and 305mm steel piles.
Important features of the DX range include a hydraulic double-acting cylinder which produces high impact energy and a fast blow rate with a low hydraulic power requirement. The new models have the ability to drive piles with an ultimate load bearing up to 1800kN and, during operation, there is total control over hammer stroke and blow rate. Weighing from 4.5 tonnes for the DX20 up to 5.8 tonnes for the DX30, the hammers can be transported easily and be operational on site in a matter of minutes.
According to Van Elle Rail, the BSP hammers, mounted to a tracked/ wheeled excavator or the company’s Colmar RRVs, are the best solution for driving steel tube piles accurately, quickly and safely. They can be used to work alongside the company’s vibrating hammers as piles can be lifted, positioned and vibrated down before the BSP impact hammer completes the installation process using a rapid blow- rate. This pile installation system offers principal rail contractors and Network Rail an unrivalled solution to OHLE signal and gantry bases.
Recent rail projects involving the DX hammers include the installation of 610mm and 762mm diameter driven piles for the Great Western’s OHLE work on behalf of Amey, and piling for both Birmingham New Street and Reading stations for Volker Fitzpatrick and a Costain/Hochtief JV respectively.
Van Elle Rail’s investment in new rigs, equipment and staff training ensures that it has the resources to carry out rail projects of all sizes and complexities successfully and safely. The company is also a Network Rail plant operating scheme provider and a principal contractor’s licence holder.
Now that the TransPennine and Midland main line electrification projects are being resumed, and with HS2 to come, Van Elle’s investment in new plant and equipment, particularly the new range of BSP hammers, has been made at just the right time.
Square pegs in round holes: they don’t fit – at least not without a large hammer. The same principle works for the integration of light and heavy rail systems. Tramways are designed in isolation, they’re not intended to interact with trains or other operators.
On 10 December, Sheffield Supertram unveiled its first new tram-train. Creeping out of the main shed at Sheffield’s Nunnery Depot, it is the first of seven which are being built in Spain by Vossloh, which is now owned by Swiss manufacturer Stadler, as part of a joint two-year pilot tram-train programme being delivered by the Department for Transport (DfT), Stagecoach Supertram, Network Rail, Northern Rail and the South Yorkshire Passenger Transport Executive (SYPTE).
The introduction of tram-trains will allow Supertram services to travel on the national rail network. Passengers will be able to board one of the new vehicles at Sheffield Cathedral and travel directly to Parkgate Retail Centre in Rotherham, via Meadowhall South and Rotherham Central station, in about 25 minutes.
It is the first tram-train to be built for the UK, but the project is drawing on the experience of tram-train systems in Europe, specifically Karlsruhe. The Karlsruhe Model is often cited as the first tram-train system in Europe and has been the basis of other projects around the continent. The German city has also recently begun operating a new fleet of Vossloh Citylink tram-trains similar to those being trialled in Sheffield.
Although it will be the first tram-train vehicle to operate in the UK, the tram-train concept isn’t new to Britain. Manchester Metrolink trams run on what were the Bury-Victoria and Altrincham- Piccadilly lines connected by an on-street section of tramway through the city centre. As a result, the current Bombardier M5000 fleet have specially designed wheel profiles.
Working with the University of Huddersfield, which was also involved in Manchester Metrolink, Sheffield’s project team has developed a wheel that fits the rail head profiles of both systems, reducing wear rates and mitigating against the risk of derailment, specifically around switches and crossings. As a non-standard profile, permission had to be sought from the RSSB for the new wheelset design before it could be used during the testing and commissioning process.
Automatic Power Control
What really makes a tram-train is its ability to adapt to different electrification and signalling systems. Sheffield’s Class 399 vehicles are dual- mode, allowing them to operate under the 750V DC catenary on the Supertram network and the national network’s standard 25kV AC OLE. The route to Rotherham will be electrified at 750V DC – a project due to be completed by the end of 2016 – but a dual-mode vehicle was seen as essential given plans to electrify the Midland Mainline to Sheffield by 2023.
The switching process is automated. An Automatic Power Control (APC) system, which uses magnets embedded in the ground outside of the rail, separates the two power supplies with a neutral section of track. As the vehicle travels over the first magnet it triggers the circuit breakers to open. The tram-train then coasts through the neutral section before detecting the new voltage and closing the circuit breakers. Although it is an automated process, there is a manual override which would allow the driver to close the circuit breaker if needed.
The signalling system, on the other hand, relies on a manual driver action. On the Supertram network, drivers will use the same visual signals and the vehicle identification system (VIS) employed by the conventional tram vehicles, but the new tram-trains are also fitted with TPWS and GSM-R equipment. Although the TPWS is active at all times, the driver will be required to activate the GSM-R as they pass onto the main line network. “It’s a bit of a reminder that they are now driving a train rather than a tram,” said Rob Carroll, major projects manager at Stagecoach Supertram.
Static testing has already started at Nunnery Depot. By next summer, the operator hopes to have received three of the vehicles from Vossloh’s factory in Valencia. Initially the tram-trains will be used to provide extra capacity in busy periods, with regular passenger services slated for early 2017.
Testing and validation of the wheel-rail interface began before Christmas and the first vehicle will begin testing on the tram network by the end of January. The 37-metre, bi-directional vehicles are made up of three articulated sections with three motor bogies and one trailer bogie. Each unit has a capacity for 88 seated and 150 standing passengers. Notable features include pneumatic suspension and rear-view camera displays in the driver’s cab.
Alongside the testing of the new vehicles, various infrastructure projects must be completed to allow tram-trains onto the network. Approval has now been given for Tinsley Chord – a 160-metre section of new track linking the two networks together. New stops are also being added at Meadowhall South and at Rotherham Parkgate, platforms are being extended at Rotherham Central station and the entire Supertram network is being re-profiled.
Over the Christmas period, the first of five LED integrated Lightweight Signals (iLS), which are being supplied by Unipart Dorman, was installed by Carillion on the line to Rotherham.
Setting an example
The tram-train pilot will run for two years. The reliability and popularity of the service will be carefully scrutinised and its success could determine to what extent tram-train technology is adopted and embraced in this country.
Rob said that Sheffield’s tram-train project team was being approached by organisations around the UK. “Manchester has been very interested from the start, so we’re currently having quarterly meetings with Manchester just to relay what we’ve learned.
“We’ve now had a few meetings with Glasgow for the airport link, and South Wales are also interested.”
Glasgow is hoping to introduce a tram-train service between the city centre and Glasgow Airport. A tram-train is preferred over a conventional light rail system between Glasgow Central station and Paisley Gilmour Street. In South Wales, a mixed heavy and light rail network around Cardiff has been on the agenda for some time.
With aspirations to create a light rail connection between Nottingham and Derby, and with numerous tram extensions planned in Birmingham, no doubt other cities will watch Sheffield’s tram-train experiment with interest.
Most of us probably haven’t tried it, but driving a tram along busy inner-city streets can’t be the easiest of jobs. Sometimes it’s hard enough in a road vehicle. Other drivers just seem to do the daftest things, don’t they? Stopping dead for no reason, jumping the lights, pulling out without warning, doors being flung open – it’s all a bit tricky. And at the same time there are all those pedestrians and cyclists weaving about.
Every tram driver is equipped with the highly effective Mk I eyeball of course, and light rail vehicles do have very effective braking systems, but what if the driver is distracted for a moment?
Let’s not overplay it – light rail is a very safe means of transport. In fact, a 2009 report by the International Association of Public Transport (UITP) showed that accidents per kilometre are more than four times lower for trams than for cars. Safety remains a top priority for operators, but even so, driving a tram on sight for a whole shift can be challenging, especially at night or during poor weather.
A study in Hannover undertaken from 2005 to 2010 revealed a significant rise in the number of collisions. These involved impacts with road vehicles, other trams and with buffer stops. In Hannover alone the cost of accidents involving light rail vehicles is estimated to have been €6 million over the past ten years.
Early warning
Driver assistance systems (DAS) that can provide early warnings to drivers are one way to try to reduce traffic accidents. Indeed, some vehicles now on our roads use them for distance warning or collision avoidance. It hasn’t been very affordable until recently, though, to develop them specifically for light rail use due to the relatively low volume. However, interest is growing and requirements for their introduction are becoming clearer. Because their operating environment is partially unsegregated from other forms of transport, trams and light rail vehicles are emerging as a key field for the application of DAS.
Now Bosch Engineering Group has developed a new ‘Forward Collision Warning’ system for light rail vehicles that combines a radar sensor with a video sensor to detect cars, buses, nearby rail vehicles and other obstacles on the tracks. The idea is to use the system to identify potential accident situations and give drivers reliable warnings of dangerous situations. This should increase safety, prevent downtime and avoid accident-related costs.
Cost effective
Taking into account the annual repair costs of collisions, it has been calculated that a DAS installation could pay for itself within just two years. The systems work by alerting drivers to potential collisions, allowing them to gain precious reaction time. According to data provided by Stephan Lewisch, leader of the UITP group on safety in light rail, it is estimated that the braking distance can be reduced by 20% to 40%. As well as providing alerts for obstacle detection and collision avoidance the DAS systems can also prevent driver errors, such as over-speeding and SPAD (signal passed at danger) incidents.
In developing DAS systems there has been collaboration between operators and suppliers. This has been especially important to ensure the efficiency and effectiveness of the human machine interface. If the system is not designed properly there is a danger that false or unnecessary alerts could either confuse or irritate drivers instead of providing support.
The Bosch Forward Collision Warning system has been trialled in Frankfurt by tram operators Verkehrsgesellschaft Frankfurt am Main (VGF) and in Hannover by üstra Hannoversche Verkehrsbetriebe AG (üstra).
Both operators had started looking into the potential of DAS in 2012. A feasibility study was successfully completed in the summer of 2013 and Bosch, VGF and üstra agreed to cooperate. Field testing of the Bosch Forward Collision Warning system in vehicles for passenger service began at the start of 2014.
Double vision
Simultaneously, an alternative system based on the use of stereo cameras was tested by VGF in Frankfurt. Bombardier, together with research partner AIT (Austrian Institute of Technology), has produced a DAS based on a specially-developed optical 3D sensor system. The device has a set of three video cameras of high spatial resolution mounted at the top of the windscreen. One camera recognises the rails and a stereoscopic pair can detect and range any object that might foul the envelope of the vehicle.
Both VGF and üstra have decided to go forward with the Bosch system. However, following successful testing in passenger service, the Frankfurt Transport Authority has also decided to equip 74 bi-directional Flexity vehicles with 148 of the Bombardier driver assistance systems while the Bosch system will operate on the 38 Siemens R-vehicles.
Data from the trials has helped Bosch Engineering with further refinement of its system in preparation for the start of series production from the end of 2015.
Alert
It became apparent at an early stage that DAS hardware used in the automotive sector could be applied to light rail, albeit with some modifications. Bosch has made use of pre-existing automotive technology by using a radar sensor to detect the movement of road and rail vehicles, and the presence of obstacles on the tracks ahead.
In the light rail system, a video camera is used in addition to detect the rails and thus the path that the tram will take. A high-performance rail control unit running application-specific software calculates the trajectories and speeds of the detected objects relative to the tram’s own speed and predicted path. Within defined parameters, the potential for a collision will cause a driver alert to be raised. If the system detects that an object is coming dangerously close, or that the vehicle needs to brake to avoid an object in its path, it gives the driver a visual and acoustic warning.
The precise nature of the alert can be user defined, but in the trials it was found that combining a sounder with one or two lights was effective. Taking into consideration the speed of the light rail vehicle, one light illuminates for far objects and two lights if more urgent action is needed. The nature of the alert therefore enables the driver to make decisions about braking early enough to avoid a possible collision.
Returns
The radar operates on a frequency of 76-77 GHz and has a beam spread of 70°. The effective radar range is 160-metres, but only information from the first 80-metres is used. Beyond that distance, it is thought that there are too many variables for reliable predictions to be made. Bosch Engineering recognised that false or unnecessary alerts could very much dilute the effectiveness of the system. It needs to provide valuable assistance to the driver, rather than being an annoyance.
For this reason, the system ignores radar returns from moving pedestrians – human behaviour is deemed to be just too unpredictable! Interpretation of the radar returns is software defined and can be tailored to suit specific requirements.
During the trials, the radar scanner was mounted externally, immediately above the front coupler, as it had been found that there was too much attenuation of the microwave RF signal by the carbon fibre body panelling for the scanner to be mounted inboard. The video camera was mounted behind the windscreen. Production versions will have these items mounted either as a retro-fit kit, or incorporated into the design of new vehicles.
The Bosch system has been well received by both VGF and üstra. “It is already clear that we are at the beginning of a promising technical innovation to increase the safety of railway and especially LRT systems,” commented Michael Rüffer, head of rail operations and safety manager at VGF. “We chose the Bosch camera- radar combination because it was important for us to know that the components are taken from large-scale automotive production. Now we are working together to refine the system in our prototypes, applying the know-how and experience of our tram driving instructors.”
As part of this process, VGF is optimising the functions of the system so that they support the drivers in every situation to avoid collisions and accidents.
Driverless trams?
It has been legally possible in Germany for the driver assistance systems to be trialled on light rail passenger vehicles in the busy city streets of Frankfurt and Hannover because they don’t affect the principle of driving on sight – the driver is always ‘in charge’. With further technical progress anticipated within the automotive sector, particularly through the development of driverless cars, the question inevitably arises as to whether we can expect driverless trams in the future.
Currently, DAS activation will generate vigilance warnings and can lead to the automatic activation of any safety device such as applying the service brake or sounding an internal warning or the external horn. In the VGF prototype, DAS activates the loop of the driver’s safety device, but this can be over-ridden within two seconds by depressing a button on the master controller. If driver intervention doesn’t take place within that time, a safety braking sequence (as opposed to emergency braking) is initiated. This system is in effect a query of the driver’s vigilance.
The integration of the driver assistance system into the loop of the driver’s safety device makes it simpler to implement DAS braking into existing vehicles. In new vehicles, DAS could easily be integrated into the vehicle control software.
This would allow the implementation of speed limitation, interruption of the traction power, activation of different braking systems and, of course, the generation of optical/acoustic warnings.
It would be possible for further developments to increasingly take control away from drivers, but the recommended strategy seems to be to take a step-by-step approach. In any case, without segregation from other traffic, moves towards a high level of automation would require a radical change in the legal environment.
In the meantime, Forward Collision Warning has proved its worth to VGF and üstra and now looks set for wider adoption. The technology is readily available and has become commercially attractive, so it’s highly possible that it could become an industry standard before long.
Its adoption and the realisation of its further potential might even be providing us with a vision of what the future holds for light rail operation in our city centres.
The Year in Infrastructure 2015 Conference was billed as a global gathering of leading executives in the world of infrastructure design, construction, and operations. Organised every year by Bentley Systems, a leading global provider of software for advancing infrastructure, the event attracts leading figures from the world of infrastructure design, construction, and operations. It features a series of presentations and interactive workshops exploring the intersection of technology and business drivers, and how they are shaping the future of infrastructure delivery and investment returns, spread over four days.
The 2015 conference took place recently in London, and it was a huge affair by UK standards, with over 110 media attendees, several hundred conference delegates and attendance at the awards dinner in the order of 600 people. Rail Engineer was there to find out what it was all about.
BIM, or CIM?
For a good while now, Bentley Systems has been providing software for the use of project teams including surveyors, engineers, architects, construction companies and more. The company offers a comprehensive range of products in the field of Building Information Management, or BIM. Given the commitment of the UK Government to mandate the use of Level 2 BIM for all projects with government funding in the next 12 months or so, Bentley Systems must be well placed to take advantage of these developments.
Confusingly, delegates were informed at the conference that, in the USA, everyone speaks of CIM rather than BIM- civils rather than buildings, that is. Despite this slight difference of approach, Bentley’s products are used for building works as well as civils ones, and there seem to be signs of convergence between the civils and buildings fields in the adoption of the philosophy of BIM/CIM.
An interesting aside in all this was the ‘Bentley Infrastructure 500 Top Owner’ list produced by the company. It gives some perspective to the UK’s place in the world to see that the top ranked infrastructure owner in this country is UK Highways, placed 7th in the world. BP is the UK’s next organisation on the list at 11th, Network Rail comes 29th and the MoD is immediately behind at 30th. The National Grid is only 58th in world ranking, and TfL just 86th.
The two big features of the conference were Bentley’s product update announcements, presented by CEO Greg Bentley and COO Malcolm Walter and their team, and the company’s ‘Be Inspired Awards 2015’. The awards finals were judged during the conference, with the announcement of the winners and prize presentations taking place at a dinner one evening.
Common CONNECTion
This year’s big product news, presented by Greg Bentley, was the introduction of a new generation of its software, the CONNECT Edition. This provides a common software environment for project delivery. Bentley’s ProjectWise, MicroStation and Navigator software packages are now all generally available to users. These are cloud-based services which now link together seamlessly.
ProjectWise CONNECT Edition is a work sharing workhorse, which now enables complete collaboration across a project team enabling comprehensive project delivery.
MicroStation CONNECT Edition is an advancement of Bentley’s common modelling environment, giving unified support for design modelling, analytical modelling, construction modelling and modelling of reality.
Navigator CONNECT Edition allows the extension of the common connected experience from office based users out to users on site or in the field. Model-based visual reporting and issue resolution through ProjectWise are enabled by this application.
Comments from users such as Arup suggest that this new development by Bentley is expected to help them to extend their BIM capabilities by improving collaboration and communications across project teams, increasing productivity and reducing the room for errors.
Associated with the CONNECT Edition, which will be extended rapidly to include other products in the Bentley portfolio, is a cloud- based subscription program, giving access to Bentley products, services and apps. It also manages users’ subscriptions and accounts.
Other developments
Various other software systems have been improved and updated, for example AECOsim Building Designer has been updated to include conceptioneering and optioneering, bringing together analytical and modelling design for the conceptual stages of projects. Other packages with new features include OpenPlant and OpenRoads.
A very exciting new development announced was the launch of ConceptCapture, the first release by Bentley of the Acute3D software that the company acquired earlier this year. ConceptCapture enables the easy production of high-resolution 3D models of almost anything, using just photographs taken with almost any digital camera. Obviously, the accuracy and definition of the model is affected by the number and quality of the photographs, but the use of expensive survey cameras is not required. The results can be very realistic, clear and geometrically very accurate. The software is ideal for use with photographs taken by UAVs (drones) as well as terrestrial and aerial cameras. Models of almost any size are feasible, right up to city scale.
The conference was shown an impressive example of a 3D model produced by Acute3D by taking images from a UAV of an electricity substation on the EDF network in France. By supplementing the UAV images with some taken at closer range with hand held cameras, the model was able to show details such as legible details of the manufacturer’s plates on equipment housings.
In association with ContextCapture, Bentley has introduced ContextCapture Centre for ‘grid computing power’ to reduce processing time for large models, able to handle 30 gigapixels of imagery and more.
UK success
The Bentley ‘Be Inspired Awards 2015’ attracted over 300 entries from all over the globe. There were 18 categories including ‘Rail
& Transit’, the one likely to be of most interest to Rail Engineer readers. Congratulations go to London Underground, as the winning project in this category was its Bond Street to Baker Street tunnel remediation project – relining 215 metres of the tunnel whilst leaving the line open to traffic in normal operational hours (pictured below).
To achieve this, work had to be carried out in the very short overnight engineering window of only two and a half hours each night. In this time, the project team had to replace the existing 1970s segmental concrete tunnel lining, which was considered unsafe because of the ground conditions around it, with a spheroidal graphite iron one. The project used Bentley software including AECOsim Building Designer, Bentley Descartes, Bentley Pointools, Bentley Navigator and ProjectWise to create geospatially accurate, fully coordinated 3D and 4D models, enabling LU to realise an estimated saving of 15% on the project cost whilst completing it safely on time.
A second UK project was one of the other two finalists in the same category, this being a project for Network Rail. Track Access Services was tasked with undertaking a laser positional video survey for Crossrail West, which meant surveying the intensively trafficked railway west of London for Network Rail’s infrastructure improvement project between Paddington and Reading. A geo-tagged 3D point cloud was collected using a train-mounted Topcon IPS2 scanning rig together with a synchronised HD video. The data will be used to support the project’s design stages. Bentley’s ProjectWise and MicroStation were crucial to this £40,000 project which, it is estimated, saved 75% of the cost of producing the information by other means, and also completely avoided the need for anyone to go on track.
In the category Innovation in Asset Performance, the Network Rail LADS Programme was a finalist. The entry was unfortunate to be up against a great winning project from South Australia, involving the management of a water supply network by innovative means. Commiserations to Network Rail for missing out this time, as its project might well have won had it not encountered such great competition.
There was another British winner, however, this time in the category Innovation in Power Generation. MWH Global won this category with its entry – Tyseley Resource Recovery Centre. It might not be a rail project, but we rail people do know where Tyseley is!
Challenging times
Altogether the conference was a great few days, with an incredible amount of information being thrown at delegates. This report is only able to give a very brief sketch of the whole week.
Talking exclusively with Greg Bentley, it is clear that he sees the UK as being ahead of the rest of the world in many aspects of the application of BIM. Crossrail is using BIM, amongst many other reasons, to enhance the supply chain and to encourage innovation. He added: “The UK rail requirements stress test what we create.”
Clearly, Greg sees the UK as challenging him and his company but, from what was displayed at this conference, Bentley as a company is challenging the rail industry to find new and innovative uses for its software and BIM in general.
In the UK, we are seeing trams taking passenger connectivity to new levels, bringing manifold benefits to the environment, the economy and local communities. Passengers seem to agree, with nearly 240 million passenger journeys in 2015 on Britain’s eight light rail systems.
Since falling out of favour in the receding years of the 1900s, recent governments have backed light rail, especially trams, to provide better, smarter municipal transportation at a lower cost per mile, whilst also improving the environment.
Light rail, trams and other rapid transit systems, even trolleybuses, are a key part of an overall strategy to get people out of their cars, to reduce congestion and emissions in our major conurbations. Croydon Tramlink, for example, affected a modal shift from cars of 20 per cent.
The fact that not one tramway system in the UK looks the same is indicative of a mode of transport that can be tailored to fit the specific needs of a community and provide a sensible solution for addressing public transport ambitions. Crucial for local authorities looking to make huge benefits to their public transport networks without making huge dents to their coffers.
The Docklands Light Railway, for instance, has grown into an essential piece of east London’s infrastructure, connecting the City with Canary Wharf and providing connections to the tube network and London City Airport, the Olympic Park and High Speed 1.
Although it was in New York where the first tramway appeared in 1832, Europe now enjoys the densest implementation of light rail. From Germany’s tried and tested U-Bahn system, and the five-line Grenoble tramway, to the Edinburgh Tramway, on which WSP/Parsons Brinckerhoff was the designer.
This latter example shows how trams can play a massive part in inter-connecting multi-modality, in this case linking mainline rail with Edinburgh Airport and the city centre. Again, the passengers seem to agree, with nearly five million using it in its first year.
However, rail technology doesn’t stand still for long and communities that are considering new tram systems as part of their public transport solutions should look beyond the well-worn systems for their inspiration.
Indeed, one of the largest advantages of these lighter, cheaper modes of transportation is their flexibility to be modified for the unique applications of each new system.
Equally, modern braking systems feature multiple routes to failure, therefore removing the need for trams to be parked on level ground when unattended. These sorts of considerations, although seemingly small, demonstrate that tram technology is constantly looking to innovate and improve, forcing promoters to keep their eyes on the horizon.
Qatar is upping the stakes further with its Education City tram, built primarily to transport students. Its trams are advancing the traction power system through the use of hybrid-storage capacitors coupled with batteries that provide a catenary-free operation. Its batteries can also be recharged by overhead electrical conductor rails found at any one of the 24 stations/stops via an electrical pick up found on top of the tram (the pantograph).
This innovative approach allows the tram to operate without the risk of catenary wire strikes by vehicles on roads, and also allows partial recharge of the energy storage system whilst stationary in the tram stops. This tram system comes replete with features to allow its electrical equipment and its passengers to cope with the searing, 50+ degrees heat and intense sunlight. The low-floor rolling stock even includes natural colours that will promote calm among its passengers.
The move away from catenary power, as the delivery path for our electric trams, to internal rechargeable hybrid-capacitors and batteries is an area of technology that is the focus of great innovation and improvement.
It is largely inspired by naval, submarine technology, where battery and associated recharge technology continues to be improved, especially regarding power-to-weight ratios. Indeed, the batteries on Qatar’s state- of-the-art 11.5km network will store and re-use the energy that is generated as the tram brakes.
The kinetic energy recovery system (KERS) that adds further green credentials to light rail owes a lot to Formula 1, where it has seen much development.
Looking further afield, our global vision for ‘smart cities’ has transport at its heart. Imagine a smart transport system where commuters are connected to real-time transport information and purchase tickets as they travel, without having to make a physical transaction or queue for tickets.
The powerlines that drive trams are ideal conduits through which to stream large bandwidths of data, which will help cities realise the potential of the ‘internet of things’.
Passenger information systems that are tuned in to traffic and incident management systems in real time are better able to take evasive action and avoid creating congestion spots and exacerbate pinch points.
Trams are getting faster, better and cheaper. As we find ever more sophisticated and innovative solutions to meet the pressing need for smarter public transport solutions, it is not hard to imagine that the golden era of the tram may still be to come.
Written by Sherman Havens, rail technical director at WSP | Parsons Brinckerhoff.
A significant challenge facing the rail industry today is the mandate that all centrally funded government infrastructure projects should be BIM Level 2 compliant by April 2016. Whilst the software tools used in the construction sector are quite mature and evolved, those currently utilised for linear projects such as rail electrification are still developing.
Due to the complex nature of BIM on linear projects, companies range from being rather progressed and having a mature set of processes and protocols to those still developing their information requirements. To help address this, and in anticipation of customer requirements, a team of Balfour Beatty engineers has devised a new software package known as RED (Railway Electrification Designer), which provides the ability to deliver BIM Level 2 in the rail industry electrification sector.
BIM Level 2
BIM stands for Building Information Modelling. In its simplest form it is the method, means and processes by which anyone can understand a building, specifically a digital model of a building.
Level 0 is where designs are 2D, usually paper based and no collaboration occurs. Level 1 sees the introduction of some 3D modelling and sharing of data through a common data environment.
At Level 2, fully collaborative working is introduced, each party using its own individual 3D model and paying particular attention to how information is exchanged and shared. These individual models can be assembled into a multi-disciplinary or federated model.
The challenges
The BIM Level 2 mandate generates the necessity for a clear definition of BIM for rail, not just the acronym itself but the design change methodology it spawns – the shift from creating 2D ‘flat’ drawings to delivering ‘intelligent’ 3D models with attached information. The level of detail required in each model must be defined according to its type and, more specifically, what stage it’s at within the design lifecycle. The exchange of this information must also play a vital role in the whole design process; and it must be done in a common format that all parties can understand.
There is also a need to define BIM in relation to the provision of linear assets, as its foundations were laid in the vertical world of buildings. A building consists of easily definable spaces and the materials used to create them, floors, rooms, windows and furnishings.
Naturally, as the building design progresses, a whole host of information is generated, attached to a model and organised by spaces into what constitutes an asset – the building is the asset, singular and definable.
However, if the project is to electrify a stretch of railway, things get a little more complicated. There is more difficulty in defining assets along a 50km route of railway; is the whole 50km route the asset? If not, is it broken down into discipline-specific assets – track, signals, and civils? There are no floors, no rooms and arguably, in an OLE (Overhead Line Equipment) project, there is no easily and singularly definable asset.
Additionally, unlike the building market, there is no national BIM library for OLE, so all suppliers have to model and attach asset information to each component, which takes a significant amount of time. There are, therefore, additional challenges to overcome. How are 3D models drawn quickly and efficiently without the creation of a component library, and how is information attached to that 3D model easily?
There is a general consensus within the rail industry in relation to achieving BIM Level 2 – assets need to be defined, assets should be modelled in 3D and each asset should have the relevant information attached to it. One further step closer to the successful implementation of BIM is to look at BS1192. This British standard guides the industry on how to manage, collaborate and understand asset information. In fact, if parties can create 3D models, attach information to them and collaborate using these models in what is defined as the ‘common data environment’, they are well on the way to achieving BIM Level 2.
With this in mind, three engineers from Balfour Beatty Rail Engineering Technology Solutions, based in Balfour Beatty’s Electrification Design Hub at Alaska House in Liverpool, have, over the last 12 months, developed their own ground breaking BIM platform – RED (Railway Electrification Designer). RED is a stand-alone software application for Microsoft WindowsTM that integrates with Bentley’s MicrostationTM CAD package and it simply removes the 3D modelling and asset tagging challenges by automating and streamlining the OLE modelling process.
3D models
RED can generate 3D solid OLE models in real-time, enabling a significant reduction in 3D draughting time whilst maintaining engineering integrity and eliminating the need to draw 3D OLE components manually. By using RED, the time taken to create a complex OLE structure is significantly reduced compared to traditional methods. RED has been designed to be easy and intuitive to use, enabling rapid component creation. So, not only does it enable efficient working in 3D, it does so without the need to have an extensive library of pre-prepared components. Furthermore, if any adjustments are required, editing a 3D model using RED is easy as it permits modification to components without the need to completely redraw them.
RED promotes collaboration as it can be used in design meetings such as inter-disciplinary reviews and signal sighting reviews. Users can make OLE design changes on-screen, reducing iterations and making the process lean. RED is also configurable for each OLE project – it is designed to be fully configurable to comply with any relevant CAD standards.
Additionally, it is worth noting that 2D elevations (cross sections) and 2D plan views (layouts) are created in parallel as part of the 3D RED model. Each time an edit is made to the model, the changes are reflected in the 2D extractions. A single 3D RED model, where all the graphical and asset data exists, forms a singular model, a single source of truth.
Asset information and data capture
RED utilises three significant technologies to address asset data capture. The first piece of technology deals with track information – as each structure is created in 3D, RED automatically detects and applies ‘cant’ and ‘high rail’ data using the RED Track Detect System.
Secondly, RED is able to detect ground profile models and understand how these interact with foundations, enabling correct geospatial placement of OLE models.
Thirdly, RED dynamically attaches information to each 3D component as it’s modelled. Currently, RED uses the Network Rail Ellipse data structure to organise asset information. However, RED is flexible enough to be configured for virtually any type of asset information required.
Importantly, information can be augmented and improved upon at each stage in the design life cycle. The supplier might add minor or indicative information at the preliminary or conceptual design phase but, as the model progresses through its life, more and more data may be added. This means that a RED model can be created at concept and the same model can be delivered to the client for virtualisation and 3D driver training at the end of a project.
Whilst RED has a robust, extensible and configurable data framework, where any and all information can be stored, the granularity of what data is required at each design stage remains undefined. When the industry decides on its requirements, RED can easily be adapted.
Information exchange
BIM Level 2 requires that data is exchanged between parties and RED does this effortlessly as it has a built in export engine which allows all OLE and track data to be exported. Driven by user-editable templates, the system can export data to COBie (Construction Operations Building Information Exchange), IFC (Industry Foundation Class) or any other industry standard format. These exports can be transmitted alongside the model and satisfy the BIM Level 2 requirements for information exchange.
RED is a design package for OLE that is both CAD and BIM Level 2 compliant. It is compatible with major electronic document management systems, particularly Bentley ProjectWiseTM, and its model output is compatible with all major CAD packages. RED is a full life-cycle BIM design package and Balfour Beatty is committed to its continued development.
Ian Heague is principle engineer, Peter Evans is design engineer and Jon Mercer software engineer with Balfour Beatty Engineering Technology Solutions. The team can be contacted on 0151 529 7428. To learn more abut BIM in a railway environment, come to the Rail BIM Summit in London at the end of January.
With Network Rail under increased scrutiny for its part in train punctuality performance, reliability of the infrastructure becomes ever more important. One of the recurring themes as to why trains are late and cancelled, along with the old chestnuts of signalling failure and leaves on the line, is that the wires are down. This can be anything from a simple break (although even that can take time to fix), to a train having rolled all the catenary up into a ball over a mile or more.
Frequently such incidents are caused by defective pantographs on the trains, which can inflict significant damage to overhead wires and associated apparatus including, in extreme cases, a catastrophic de-wirement.
Real-time monitoring
Pantographs, and the thin carbon strips they carry to draw current from the overhead contact wire, are usually subjected to thorough manual inspections during scheduled maintenance windows.
In-between these checks, maintenance teams will often rely on a visual check taken from the depot floor. However, with pantographs in constant use and operating under all weather conditions, defects can quickly accumulate.
Remote monitoring technology enables infrastructure owners to identify those vehicles in operation that are at greater risk of inflicting damage to the network’s wires due to general wear and tear. It can then help them to work with operators to take early preventative action and, ultimately, extend the life of both the wires and the pantograph equipment carried by the trains.
The current Panchex system was originally installed during the 1980s but only monitors the uplift forces from passing pantographs. It is now expensive and disruptive to maintain and is considered to be reaching the end of its serviceable life.
Furthermore, its location within the live 25kV catenary system means that some of its components can only be accessed when lines are closed to traffic and overhead lines isolated, adversely affecting the availability of the system.
This led to Network Rail and industry stakeholders looking for a ‘modern equivalent’ successor system, combining reliable round-the-clock uplift monitoring with additional condition-monitoring capabilities, whilst being easier and safer to operate and maintain.
Developing PanMon
Ricardo Rail (formerly Lloyd’s Register Rail) developed PanMon to meet this need. The system uses Sensys’ Automatic Pantograph Monitoring System (APMS) to provide high definition images of each passing pantograph through a combination of radar, laser, video and photo technology, and an innovative new contactless optical Uplift Monitoring system developed by Ricardo Rail in association with Italian-based optical monitoring specialists DMA S.r.l, Turin.
Using specialist pattern-recognition analysis software, the system automatically interprets the data to provide ongoing condition reports of each passing pantograph. This includes identifying the remaining thickness of carbon strips or any damage to the pantograph’s head, aerofoils or end horns, which can affect a vehicle’s ability to maintain good contact with overhead wires.
The system can also measure the uplift of the contact wire resulting from the force applied by the pantograph – uplifts exceeding specified limits can cause considerable damage to both the pantograph and catenary.
Approval trials commenced at Cheddington, in Buckinghamshire, in March 2013. During these, the system was assessed against Network Rail’s criteria that it should:
» Measure a minimum of 90% of passing traffic;
» Capture measurements of carbon thickness on pantographs to within 2mm;
» Deliver accurate measurements of uplift forces;
» Consistently detect chips and defects larger than 25% of the carbon surface width;
» Identify each passing vehicle;
» Record and report local weather conditions (wind direction / speed, temperature etc).
Throughout the trials, PanMon proved capable of providing continuous and accurate measurements of pantograph uplift forces and defects (including chips, damaged end-horns and worn carbon strips) from trains passing at speeds of up to 125mph. As a result, the PanMon system is now designated for roll-out as a replacement of the Panchex system.
Network Rail’s project manager for the PanMon trial at Cheddington, Mike Dobbs, was pleased with the result. “Getting new technology to work accurately and reliably in the rail environment can be challenging,” he said, “but Ricardo Rail has worked closely with us to overcome the difficulties and we are now able to start the process of replacing our old Panchex systems with a twenty-first century solution.”
Apperley Bridge Station – on the line between Leeds and Bradford Forster Square – has been formally opened, five days after the introduction of a half-hourly train service.
It is one of three new stations opening in West Yorkshire over the next few months, the others being at Kirkstall Forge – further up the Airedale line towards Leeds – and Low Moor, between Halifax and Bradford Interchange. A southern entrance at Leeds Station is also close to completion.
In this short video, Dave Taylor, who acted as Project Director for construction contractor Spencer, reflects on some of the engineering challenges involved.
Electrified railways in the UK have existed for well over a century and much has been written on the types of system and their voltages. The merits and downsides of overhead lines versus third rail, and DC versus AC, continue to be a topic of conversation when traction engineers meet both at seminars and social gatherings.
In contrast, the methods by which the traction current is controlled attract little attention, but without a robust system, the electrification would be unmanageable. Electric power is delivered to the railway from the national grid, although it was not unknown in earlier times for rail companies to build their own power stations. The method of distribution supply is very different for AC and DC systems, although both need periodic connections to national grid lines.
AC systems
The architecture of AC electrification is simple. Feeder Stations are the grid in-feed locations where the high voltage grid is transformed to 25kV (or 50kV for the latest auto transformer systems) from the high voltage national grid at sites where pylon routes cross the railway. These are positioned about 40km apart and thus feed current for around 20km in each direction.
Where the ends of adjacent grid in-feeds meet, there is a neutral section, which is a very short piece of unpowered catenary. These prevent out-of-phase paralleling between grid supplies which would replicate fault conditions.
Track Sectioning Cabins (TSCs), positioned at feeder stations and intermediate locations, are where switching of the discrete electrical sections to individual catenaries can be implemented. Should a Feeder Station lose the grid in-feed, then emergency feeding arrangements can be put in place by extending the power from adjacent feeder stations, thus lengthening the feeder distance to around 40km.
Significant voltage regulation issues may occur at the extreme ends of the sections, and the voltage can drop to as low as 17kV. This is not a major problem unless rail traffic levels are high, when train regulation restrictions might have to be put in place.
DC differences
A DC system, with its lower voltages, requires a more complicated arrangement. Since load current values are high, voltage regulation requirements dictate that feeder points have to be, typically, 5km apart. It would be operationally and commercially impractical to have grid connections at such short distances, so an AC network is provided by the railway to create an internal distribution network. The infrastructure owner thus owns a ‘mini grid’ supply to the substations where the power is rectified and DC current is fed to the overhead line or third rail.
On the extensive UK ex-Southern Region third-rail system in Kent, Sussex and Wessex, the AC network is predominantly at 33kV although, in remoter areas, it can be 22kV or 11kV. Power from the grid is obtained from around 40 supply locations with switching stations not always adjacent to a Network Rail site, maybe up to two kilometres distant.
The AC distribution cables are carried in trackside cable routes separate to any other lineside application, such as signalling. Each substation rectifies the AC voltage to DC, either at 1500V for overhead lines (Tyne & Wear Metro) or 750V for third rail. Nowadays, the equipment to do this is solid state but, in the past, rotary convertors and mercury arc rectifiers were used. Unlike AC, the DC electrical sections can be continuously connected and paralleling is used to assist power supply regulation. Between substations, Track Paralleling Huts (TPHs) are located that allow localised switching of power to different overhead catenaries or third rail tracks.
Controlling the power supply
For both AC and DC, the electrification system must be capable of being controlled from an Electrical Control Room (ECR). In the event of fault conditions such as a short circuit, automatic circuit breakers at the feeder station or substation(s) will trip to disconnect current from the catenary or third rail.
In an emergency, typically a person in danger of electrocution by being in contact with the catenary or third rail, the current may need to be switched off quickly and manual intervention from the ECR controller is required. The control room also undertakes routine planning and implements tasks such as isolations for maintenance work, monitoring the level of supply current and liaison with the national grid authorities for any prime source power problems.
Since electrification systems go back over a hundred years, many different technologies and practices for control of the electric current have emerged. On AC systems, the usual arrangement has been the provision of data links (known as ‘pilots’) from the ECR to the traction power locations. These low capacity data links are carried on telecom circuits provided by the S&T department.
The requirement for resilience is met by having A and B pilots routed in different cable or transmission systems in diverse routes. On occasions and for pragmatic reasons, it was known that the two pilots were borne on different cables within the same trough route but this was sub- standard practice.
On other legacy systems (typically the older DC network), the traction power sites use a separate cable transmission network provided entirely by the electrification and plant engineers. These are located in trough routes, separated from any high voltage feeders by different compartments and thus minimising the risk of mutual contact.
Thirteen ECRs currently exist at the following locations:
» AC lines – Romford, York (some DC), Rugby (some DC), Crewe, Cathcart; » DC lines – Lewisham, Selhurst, Raynes Park, Eastleigh, Brighton, Paddock Wood, Canterbury, Sandhills (for Merseyrail).
Strangely, the combining of ECRs with modern signalling power box locations never happened, maybe because departmental preferences compartmentalised the thinking. Network Rail is implementing a national SCADA (Supervisory Control and Data Acquisition) system that will integrate electrical control into the new Rail Operating Centres (ROCs). The main contractor for this project is Telent, which has a long pedigree of supplying railway telecommunications systems.
Project scope
The goal is to create a single, unified electrification control network for the main line railways of Britain, but with a staged approach to match other electrification works. The majority of the thirteen existing ECR sites have control equipment that is becoming life-expired. The oldest systems still employ discrete switches and mechanical switchgear and even the earlier screen-based systems are obsolete. Spares are often difficult to obtain and familiarity with the ageing technology can be a problem.
Couple this with the new electrification projects – Great Western route modernisation (GWRM), Welsh valleys, Midland main line, North West, Trans-Pennine, Edinburgh to Glasgow – and a clear need has emerged to provide a unified means of control for both the existing and new sections of electrified railway. This is set out in the requirements of CP5 as a principle for new electrification schemes. It is also recognised that much of the remote equipment associated with the existing ECRs that control the AC lines is still relatively new and does not justify renewal at the present time.
The project is thus partly renewal- driven and partly to support new electrification deployment. The new control equipment will be installed, initially, at the existing ECR sites. There are nine ECRs that will retain their legacy remote equipment including the associated communications or pilots. Four ECRs on the DC network will require more significant works to provide both the new control network and the replacement of existing electro-mechanical switching equipment at 250 of the substations and TPH sites.
In time, a rationalisation of the existing ECRs will occur, with transfer of control to the ROCs. With the creation of a single resilient UK unified control platform, this transfer of control location will be made possible by the flexibility of the transmission architecture. Telent will undertake this work on behalf of Network Rail, including the electro-mechanical control replacement at the older sites on the DC lines.
The SCADA requirement
SCADA technology has been around for some time but application on a national scale within Network Rail has only become a practical proposition with the provision of the NRT (Network Rail Telecom) Fixed Telecom Network (FTN) and its associated fibre cabling and digital transmission systems. FTN is currently being upgraded to FTNx that embraces IP (Internet Protocol) addressing and technology. Within this will be structured a WAN ‘cloud’ for the SCADA project.
FTNx will have ‘points of presence’ and fibre connections at all the ROC and ECR sites. NRT provides access links on an ‘as required’ basis so, if fibre does not exist at places where a break-out point is required, then new fibre links, installed under a separate Network Rail contract, will be terminated, tested and integrated by Telent. The use of IP will also permit a voice facility to be superimposed upon the data network (VoIP – voice over Internet protocol), thus creating a virtual private telephone network for those needing to interface with ECR operations.
The SCADA project will have data centres at Manchester and Three Bridges ROC sites (two are needed to provide a resilient system) that will service the existing ECR sites using new control equipment together with screen based GUIs (Graphical User Interfaces) displaying all the external supply and switching locations. These will have two large screens showing the diagrammatic layout of the electrification system for the area plus two smaller screens detailing alarms, event logs, out of course occurrences and suchlike.
Controllers will be able to interrogate the screens to show the status of individual switching locations and thus open and close circuit breakers as required using a mouse control. Identical arrangements will be provided at the ROC sites as these come on stream as and when ECR operation transfers to these sites.
Not all ROCs yet control areas of electrified railway, for example Didcot, Cardiff and Derby, but these will have the same capability so that electrification projects will have a ‘natural home’ for control when the time comes. Since the WAN cloud is a single entity, it will be relatively easy to add or delete sites as electrification policy unfolds. Data rates will vary according to need but two 100Mbit/ sec links will connect the Three Bridges and Manchester data centres.
Progressing the project
Network Rail has been keen to adopt a systems engineering approach to establish both the technical configuration and the method of operation. This has involved consultation with subject matter experts from the end user community. With the many complex requirements of the project, one of the first steps made by Telent has been the building of a reference system at their Warwick premises. This enables both supplier and customer both to assist with the development of the design and integration and to have the ability to make adaptations and fully test them as and when necessary to suit local circumstances at particular sites.
The first area to be transferred will be the electrified Heathrow Express service currently under the control of Romford ECR. With GWRM electrification and Crossrail well underway, it makes sense to transfer this to Didcot (Thames Valley) ROC and this will happen in 2016 so as to be ready for the GWRM ‘power up’. No doubt there will be both technical and operational lessons to be learned as the new system is introduced, with the electrification controllers assisting the process of familiarisation, thus learning lessons for later sites.
After that, the first ECR site to be converted will be Romford, covering the whole of the Anglia electrified lines. Paddock Wood will follow, which will yield experience on the DC lines. Thereafter, a rolling programme will be implemented taking account of the progress of new electrification schemes and the condition of existing assets.
Safety and security
It must always be remembered that electrified railways carry both high voltages and large currents. Safety factors have always been a high priority and part of this project has been to fully assess the safety aspects. The existing configuration has very little over-arching control redundancy and, should an ECR be disabled, then no effective control of the network will exist other than to staff the individual feeder stations and switching locations.
The new SCADA system will enable dual redundancy across the entire network with the ability to control a disabled site from another location if a disaster was to happen. This is a major improvement as much needed resilience is provided. The requirement to quickly switch off power in an emergency will be assured by both the IP-based telephone service and improved links to the NRT Railtel (ETD – extension trunk dialling) phone network and the 17x emergency call numbers to the ECRs.
Pressure to give the SCADA system a SIL (Safety Integrity Level) rating has been robustly assessed to guard against the introduction of overstated and ultimately meaningless complications. The assessment has led to a SIL 0 designation that will be reviewed by Ricardo Rail (formerly Lloyd’s Register Rail) acting as the independent safety assessor.
Cyber security is another important consideration. The CPNI (Centre for Protection of National Infrastructure) has been consulted as the SCADA network falls into this category. The system has been designed and will be implemented with the CPNI guidelines for cyber security adopted and the system will be independently penetration-tested for potential security breaches. Encryption of the sensitive elements of the network is one such measure, another has been to security clear all Telent staff working on the project.
Contractual responsibilities
The Network Rail specification for the project includes some 6,000 requirements, many arising from a robust systems requirements review post contract award. Collaboration between Network Rail and Telent is pivotal for success but Network Rail has many other stakeholders needing to be consulted to attain the necessary approvals.
Telent has 95 people engaged on the project covering design engineering, system engineering, software development and system integration, with the majority based at its Warwick site while others undertake site installation work. The company is working with Network Rail to get the required telecom infrastructure in place and Cisco will supply the data equipment (routers and terminals) and associated software. Other suppliers working on the project are:
» Vitra for the supply of work station desks;
» Interfleet for the training of electrical control staff at the Three Bridges and Manchester sites;
» CCD for ergonomic considerations;
» CNS for cyber security;
» IP Trade for voice telephony.
The overall contract has a publicised value of £27 million but some variations to this are expected to cover changes in scope. The contract has been in existence since mid-2013 with a completion scheduled for the end of December 2017 for the basic network, by which time it is hoped that every main line electric train in the UK will be drawing traction current controlled by the new SCADA system.
This is a significant project with many inter- activities to other projects. Co-ordination and communication is thus an essential part. The end result will be a power supply network using the latest technology and standards that will be fit for purpose for decades to come. The new Network Rail SCADA system will provide the common national platform for the Digital Railway – SMART grid, leading the way for efficient use of energy and greater operational resilience.
Thanks to Scott Burt, Telent project director, for his time in explaining the project with all its ramifications, and to Saleem Mohammad, head of Network Rail’s national electrification programme, for his input.
Since late summer, the Nottingham Tram network (NET) has more than doubled in size with the opening of its southern and western extensions to Clifton and Toton respectively. 27 new stops have been added, making a total of 51.
The new lines are a mixture of street-running and dedicated routes, the most spectacular feature being the new stop at Nottingham Midland station located on a bridge spanning all six platforms. Those with a longer memory will recall that there was once a bridge carrying the erstwhile Great Central main line across the station at the same spot. Who would ever have placed money on a new bridge being erected some 45 years later for a similar transport purpose.
The NET follows standard practice for tram control with stop/go signals being an illuminated horizontal or vertical white bar – also a diagonal bar to indicate a route divergence – with most points being ‘spring’ operated except for six at key junctions which are motor-controlled with locks. ‘Drive on sight’ is the normal routine, the signals being used at road intersections in conjunction with normal traffic lights and at places where the routes diverge. The pattern of service is from Clifton South to Phoenix Park and Toton Lane to Hucknall, thus integrating the new extensions with the original lines to the north.
A seven-minute service operates on all lines during the morning and evening peaks, with 10 minute frequency during the daytime and 15 minutes in the early morning and late evening.
The extensions involved laying 17.5km of new track and the purchase of 22 new trams, making 37 in total. The entire network expects to see 20 million passenger journeys each year, 55,000 of these being regular commuters.
Controlling the network
The main depot is at Wilkinson Street, north of the city, where trams are cleaned and maintained, and also where the main control room is sited. Most desks in the latter are multi-functional with the operators’ screens being able to access more than one facility.
Trams are equipped with GPS positioning, so the location of every tram in service can readily be seen. A red/green light system on the illuminated route diagram indicates whether a tram is late or running early so that operators can take whatever action is necessary to get back to the scheduled timetable. It has to be remembered that, with the various road junctions and street running sections, there are many occasions when disruption can occur. A video wall provides the controllers with a constant picture of the actual minute-by-minute operation.
A CCTV viewing suite has also been provided at Clifton Park and Ride that can view the CCTV network, and the security officer is able to take control of the cameras from this location. Inside Out Group has also been successful in obtaining the security contract with Nottingham Trams Limited and provides the security services at this site.
Viewing the operation
Constant video surveillance is a necessary part of any modern tram network and Nottingham is no different. For the extension lines, a contract was awarded to Inside Out Group, a local firm that has come to specialise in CCTV monitoring and control. The company’s origin was described in issue 116 (June 2014), the earlier focus being on time-lapse photography which included a record of the new tram bridge being slid into position across the main railway station. The company was revisited recently to learn of the design and implementation of the new CCTV network.
The main contractor for the tram extensions has been Vinci Construction, the civil engineering division of Taylor Woodrow. In partnership, Alstom was engaged to provide the power supply, the overhead line system and the telecommunications network. Inside Out Group had to establish a close working relationship with both these organisations since CCTV provision had to fit in with both building construction and power requirements.
The technical design of the CCTV system is based on IP-specification cameras borne upon transmission bandwidth within the fibre optic cable network provided by Alstom. The cable and transmission network is designed in ring formation that allows full redundancy with automatic re-routing of traffic should a cable get cut. A dedicated four-fibre link is run to each camera from the transmission break out points, ranging from between 5 and 550 metres in length dependant on the distance involved, this being part of the Inside Out Group contract. Typically there are two cameras for each tram stop but more are provided at the main interchanges such as the railway station and at the terminal stations.
The NET extension project is very much geared to ‘park and ride’ encouragement so big car parks have been provided at both Clifton and Toton, with surveillance of these areas being an important requirement. The cameras generally monitor the ticket vending machines and the passenger help points. All have pan, tilt and zoom capability and, should a help point be activated, the associated camera picture will immediately be shown on a control room monitor so that anything untoward can be viewed. Cameras are generally mounted on poles, high enough to be out of reach of vandals and graffiti daubers. Power comes from the station supply, which was part of the Alstom contract. The total number of cameras on the extension lines is 141.
At Wilkinson Street, there are 12 screens in the video wall, eight associated with the two extension lines and four from the original network. Each picture can be called up on the controller’s desk screen from where the camera can be remotely adjusted to zoom in on any incident. The video screens normally show the busy areas of the network such as the city centre and the railway station.
Each camera has an individual IP address to the v4 standard but this might need to be changed to the incoming v6 standard in due course. The zoom capability of the cameras is 22 X optical with digital zoom on top of that if required, the average data rate to each camera being 3.5Mbit/sec. At Clifton, the viewing suite has two large screens, each capable of showing multiple images but able to zoom in on any particular site.
There is continuous recording of all images from every camera with a date and time marker to enable any post- incident analysis to be carried out relatively quickly. The recording capability is huge, with nearly 600 terabytes being needed to meet the 30 day requirement. This requires 14 recorders, each of which can handle up to 250Mbit/sec, which allows for full redundancy and load balancing should a recorder go faulty. The rate of recording for all cameras is full HD 1080 pixels at 25 frames per second every day of the year.
Inside Out Group is not a manufacturer of CCTV equipment and was thus free to select the most appropriate cameras and monitors for the NET requirement. The chosen supplier has been Pelco, a Californian-based company and part of the Schneider Electric Group, with Pro-Vision of Shrewsbury as their UK distributor. These products have more capacity with a better specification and reliability record when compared to others and are proving satisfactory in service.
The future
Inside Out Group is the first to admit that being a local firm was a factor in them being selected as the CCTV contractor. The nearness of its main premises meant a ready base being available for the storage of piece parts, tools and test equipment with experienced engineers immediately available to resolve any technical issues. It also enabled a close relationship with other contractors to be established. The overall NET extension project had a number of delays (the opening was some eight months later than planned) and, with the CCTV having to be one of the last elements to be installed, having the flexibility that a local participant offered counted for a lot.
The original NET lines will shortly have their CCTV monitoring equipment upgraded to the same technical specification as the extension and Inside Out Group is assisting in the design process. This will bring the total number of cameras to around 220. Maintenance of the system will be by specially-trained NET staff. Again, a local presence means that immediate second line assistance can be given if problems arise.
A case study will demonstrate to other customers the Inside Out Group’s capability to provide surveillance systems. It is not a large firm and knows that it must cut its cloth accordingly. Other metro networks and rail depot security are seen as its natural expansion with the knowledge that it will entail providing a facility base at wherever new business is won.
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