Carmuirs Canal Clearance

31st March 2015

Britain’s canals formed the country’s first high-capacity transport network. In their day, the raw materials they carried laid the foundations for the industrial revolution.

In some places, they also transformed passenger travel. Hundreds of thousands of passengers took the eight-hour Swiftboat journey between Edinburgh and Glasgow, hauled by galloping horses on Scotland’s lowland canals.

The alternative was a slower, bone-jarring stagecoach over the rough roads of the time.

Railway canal crossings

Canal engineers faced significant challenges but at least had the advantage of a country almost free from man-made obstructions. Roads carried minimal traffic and could be crossed by simple swing bridges. For this reason, the Forth and Clyde (F&C) canal was able to carry tall-masted ships bound from Glasgow to European North Sea ports across the centre of Scotland. Opened in 1790, this canal was the world’s first sea-to-sea canal.

Railway builders had the canals to contend with. In London, the need to cross the Union Canal resulted in a steep descent from Camden into Euston, a tunnel under the canal before Kings Cross and an elevated station at St. Pancras. The tall ships of Scotland’s F&C canal required railways to pass under it unless a railway swing bridge was provided. When the Scottish Central Railway to Perth was opened in 1850, its passage under the canal at Carmuirs required cuttings and two 40 metre long single-bore tunnels.

The F&C canal was closed in 1963 and re-opened in 2001 as part of a Millennium project which also re-opened the Union canal to Edinburgh and connected the two canals by the Falkirk Wheel which is adjacent to Carmuirs. Unfortunately, in 2002, shortly after the Wheel and its canal basin were opened, there was a slope failure, depositing tonnes of rubble which almost blocked the mouth of the tunnel. This was due to saturated ground and resulted in the line being blocked for 16 days.

Replacing the tunnel

EGIP, the Edinburgh Glasgow Improvement Project, will electrify the Edinburgh to Glasgow route and associated lines, a total of 220 route miles. As with all electrification projects, this requires route clearance to replace or modify large numbers of historic structures well in advance of the electrification works.

In December 2011, BAM Nuttall was awarded a £27 million contract for EGIP clearance works. Since then, it has undertaken route clearance work on 41 structures, including some heavily used road bridges such as the five-span Shore Road for which the company received a commendation at the 2014 Saltire Civil Engineering Awards. Carmuirs is the last EGIP clearance job and presents quite different challenges.

Unlike double-track tunnels that have centre space which can normally provide room for overhead line equipment, the single bore tunnels at Carmuirs do not have sufficient electrification clearance. For this reason, the solution originally proposed in the 2007 GRIP 1 report was to lower the track by 150 to 200 mm and provide slab track.

It was later decided to replace the tunnels with a canal aqueduct. This avoided drainage problems and also the need for slab track. Together with clearance work at eleven other structures, this will achieve W12 gauge on the line and allow freight trains to carry ‘big box’ containers to and from Grangemouth docks.

The aqueduct consists of 36 portal units placed on five cill units on each of the original tunnel abutment walls with wingwalls built in-situ over new bases. These units form a deck over which 34 key wall units are laid to form the canal channel. There is some dead space over this deck as the canal crosses the railway at a 50° angle. To minimise the loading, foam concrete is used for infill behind the portal frame. Outside the wall units, class 6N granular fill provides the base for the towpath and landscaped slopes. On either side of the canal, ducts are provided for existing and future services.

With the new structure and its increased electrification clearance, it is no longer possible to provide a one-metre thickness of puddle clay as required by Scottish Canals. To maintain the required 2.1 metres draft over the portal units, the aqueduct’s canal channel has a waterproof membrane bonded to the concrete face on which there is 400 mm of puddle clay laid on top of a Bentomat sheet.

Getting ready to start

BAM Nuttall’s senior site agent John Edelsten explained that a significant amount of work had to be done before work could start on the aqueduct.

Two site compounds were required. One, of around 4,000 square metres, immediately adjacent to the canal crossing, includes the base for cranes of up to 1,200 tonnes. The other, 150 metres from the canal, is of around 20,000 square metres. John advised that there was initially some doubt that a compound of this size was required.

However, it was proved to be necessary with the requirement for trial assembly of portal units on the cill beams and storage of general demolition material, removed masonry and puddle clay as well as site accommodation and parking.

The first key milestone was the provision of a temporary footbridge. This was put in place by a 450 tonne crane in August last year as a replacement for the canal towpath during the works. This bridge also carries high voltage (HV) and low voltage (LV) electrical cables that have been temporarily diverted from the towpath. Also diverted were BSkyB’s fibre-optic cables although, as a permanent diversion was possible, these were not routed over this bridge.

An earth dam had initially been considered as a way of blocking the canal on either side of the tunnel – the same type of dam which had been used to block the canal for the repairs in 2002. However, with a much longer four-month canal blockage, it was felt that a more robust solution was required so dams formed of sheet piles were used. These are a cantilever design with eight metre deep piles that requires six metres of undisturbed canal bed on the dry side of the dam.

When the canal is re-filled, the piles will be extracted by a vibro-remover with no requirement to repair the canal bed as the puddle clay layer is self-healing.

The canal’s catchment is such that, at Carmuirs, there is a significant flow of water from its summit pond to the sea. Once the canal was blocked, this flow was something else for the temporary bridge to carry. Pipes and pumps were provided for a maximum flow of 400 litres per second – the actual flow at any time is regulated according to weather and Scottish Canal’s requirements.

Fish rescue

Works of this scale required the normal environmental mitigation. As de-vegetation was carried out within the bird-nesting season, it was done in stages and subject to a watching brief by environmental specialists. The tunnel was surveyed for bats and, although none were found, cavities were filled in to prevent nesting immediately prior to the works. No badgers were found during the survey that had been undertaken.

For a railway project, an unusual requirement was the need to rescue fish trapped in the canal once it had been dammed either side of the tunnel. This was undertaken by EcoFish consultants, using a combination of electrofishing and netting under licence issued by Marine Scotland. This was done from a boat that was lowered into the blocked canal section by a heavy-duty fork lift.

As a result, approximately 750 fish, mainly roach, perch and pike, were rescued from the drained 120 metre long section of the canal and released downstream. A further mitigation measure is the fish mesh system on the temporary pumps that maintain the canal water flow.

Immediately north of the compound are thought to be the remains of a temporary construction camp for the nearby Roman Antonine Wall. There are no visible remains of this camp which required no archaeological mitigation measures as the project did not excavate any previously undisturbed ground.

Demolition

After months of planning, the stage was set for the tunnel demolition. John advised that, amongst many other things, risk readiness reviews had identified the requirement for a trial assembly of the portal unit /cill beams and the provision of extra pumps to prevent protective mats floating away in the event of flooding. This possibility was raised as there are known to be existing drainage problems at this location.

The staged demolition sequence had been assessed on the basis of a finite element analysis of the tunnel undertaken by MHB Consultants – designers of the temporary works associated with the tunnels replacement. Demolition contractor was S Evans and Son from Widnes.

Prior to the demolition, the headwalls and towpath had been removed as well as the overburden to within 300mm of the tunnel barrels. This represented around 8,000 tonnes of material, about 35% of the total.

Demolition took place during a 54 hour possession on 25 and 26 December. After the last train on Christmas Eve, a signal north of the tunnel was removed and protective mats laid over the track. During Christmas Day, the tunnel arches and wingwalls were demolished and all spoil removed to expose the tunnel barrels which were demolished overnight with the lower tunnel walls left in place. These formed the abutments on which a total of 10 cill beams were placed on 26 December. After all material had been removed from the track bed and the signal by the tunnel reconnected and tested, the possession was given up ready for the first train on the following day.

The tunnel demolition was a carefully choreographed operation involving around six excavators. As well as demolishing the structure, these machines passed the 16,000 tonnes of excavated spoil to tippers for transport to temporary storage at the adjacent larger compound as landfill sites were not open over the Christmas holidays. This spoil included sandstone masonry from the tunnel portal which is to be re-used by the local landowner.

One legacy from the 2002 cutting failure was that, as part of the tunnel repair, the cutting retaining wall north-east of the tunnel was of reinforced concrete.

As a result, this required much more effort to remove than the other masonry retaining walls.

Construction

The possession over 1 / 2 January required a 1,200 tonne road crane, one of the largest in Europe, supplied by Mammoet. It was used to install the lower wing wall bases and numbers 36 portal units, each weighing between 25 and 40 tonnes. As the smaller compound by the canal was not large enough to accommodate them all, most of the units were placed in the larger compound where a 200 tonne crane lifted them onto lorries for transport to the 1,200 tonne crane.

The precast concrete units were supplied by Macrete of Northern Ireland which had also supplied units for many of the EGIP project’s reconstructed bridges. Delivery of the 46 large heavy units was arranged to a tight possession timeframe over the Christmas and New Year period – an achievement in itself.

After the New Year possession, work was double-shifted due to poor weather and the amount of work required to ensure that the canal would be re-opened on 27 March. Before then, around 1,000 cubic metres of foam concrete backfill was put in place, wing walls were constructed in- situ, the canal walls units installed and waterproofing undertaken. During the weekend of 21/22 February, Mammoet’s 1,200 tonne crane again returned to site to install the 33 key wall units to form the canal wall. The few lifts that would impact on the operational railway were undertaken during normal overnight possessions.

John Edelsten felt that some of the biggest challenges were the interfaces with other concerns. There was a significant amount of utilities work and the project also liaised closely with Scottish Canals both to ensure that the design met its standards and to facilitate inspections at hold points before the canal is re-filled. During maintenance of the Falkirk Wheel the canal water flow had to be carefully regulated as the outlet pipe for the Falkirk Wheel basin is adjacent to one of the sheet pile dams.

John commented that the Carmuirs tunnel work had generated a lot of interest from the passing public who had great views, not the least from the temporary bridge. BAM Nuttall has provided good information boards to keep everyone advised of progress including overhead photographs taken by drones.

Railway and canal revival

165 years ago, the contractor for Carmuirs tunnel and other original bridges on the Scottish Central Railway was Thomas Brassey, in partnership with Robert Stephenson. Their structures were well built and could have remained in place for many years to come had it not been for the need to modernise the railway. As part of the EGIP programme, BAM Nuttall has provided modern replacement structures, of which the Carmuirs aqueduct provides W12 clearance for container trains and overhead electrification due to be energised here in 2018.

Just 200 metres from the new aqueduct is the Falkirk Wheel, opened in 2002 to connect Scotland’s two lowland canals. It replaces eleven locks which were closed in the 1930s. The Wheel is one of Scotland’s most visited tourist attractions and plays an essential part in the revival of its once-derelict canals.

The new Carmuirs aqueduct may not have the tourist pulling power of the Falkirk Wheel. Yet, for those with an interest in modern transport, it is good to see these adjacent modern structures as part of a railway and canal revival.

Finding the real causes

31st March 2015

After nearly ten years of operation, during which it has published 252 investigation reports, the Rail Accident Investigation Branch (RAIB) is well known within the industry. It was formed as a result of a recommendation by the Ladbroke Grove rail crash inquiry, which required the investigation of rail accidents to be undertaken by an independent body as is the case for the air and marine sectors, and became operational in October 2005.

The story of railway safety includes learning from accidents. This is one reason why the industry now has a good safety record with no passenger fatalities in the past eight years.

Paradoxically, as railways get safer there are also fewer accidents from which to learn. This makes it more difficult to assess both levels and areas of risk. Hence the need for a thorough investigation of the rare serious accidents or near misses that do occur from which there may be significant safety lessons to understand.

Different accidents, common themes

As an independent investigation body, RAIB is well placed to undertake such investigations and also ensure that it focuses on safety improvement rather than apportioning individual blame or company liability. By doing so, it can highlight areas of risk not fully addressed by the industry.

In a recent presentation to the IMechE Railway Division in Glasgow, Carolyn Griffiths, RAIB’s chief inspector of rail accidents, illustrated this point through two quite different derailment investigations. These were a broken axle on a Class 222 Meridian train at East Langton, Leicestershire, on 20 February 2010, and the flange-climbing of a wagon wheel on curved track at Camden Road, London, on 15 October 2013. Fortunately, neither accident resulted in any injuries. However, in different circumstances, both were potential multi-fatality events. As will be seen, Carolyn felt these accidents had common themes.

Twist faults at Camden

Prior to the October 2013 wagon derailment, the track at Camden Road on the Up North London line was in a poor condition. It had opposing twist faults and the section manager had recorded that “it is difficult to express on paper how poor and deteriorating the entire patrol (length) is”. The track-recording vehicle (TRV) had last measured track geometry 46 weeks prior to the derailment. A TRV should measure category 3 track, such as the North London Line, at normal and maximum intervals of respectively 16 and 36 weeks.

Asymmetrically loaded scrap machines inside 20 ft container – repacked after the derailment to replicate original weight distribution.

Derailment by flange-climb occurs when the ratio of the lateral force of the wheel flange on the rail (Y) to the vertical wheel load (Q) exceeds a critical limit value which depends on both the coefficient of friction and angle of contact between flange and rail head. This occurred at Camden Road due to the combination of twisted track and uneven wagon wheel loadings.

However this was not the only cause. Wear on the gauge face of the rail and the presence of metal particles indicates that the rail lubricator installed 75 metres before the point of derailment was not fully effective. The resultant increase in friction lowered the critical limit value and so increased the probability of derailment.

A further factor was that there was no check rail on the 187 metre radius curve at Camden Road although relevant standards require them for curves of less than 200 metres on passenger lines. A check rail would have prevented the derailment by preventing lateral force on the flange-climbing wheel.

Hidden hazard inside containers

Although various infrastructure defects contributed to this accident, the report makes it clear that the derailment resulted from a combination of these defects and an unevenly loaded container wagon. The RAIB report notes two similar previous incidents.

Although, as the duty holder, the operator is responsible for safe operation of its freight trains, it cannot check inside the containers which are often customs-bonded. It is therefore difficult to control the risk from unevenly loaded containers. This problem is compounded by the way containers are loaded on the 60 foot container wagons which can take combinations of 20ft, 30ft and 40ft containers which may be empty or fully loaded. As a result, the centre of gravity of the wagon and its containers can be a significant lateral and longitudinal distance from the wagon’s centre, as was the case at Camden Road in October 2013.

A significant part of the RAIB report is devoted to the effects of this asymmetric loading and how this is controlled. With the load in the 20ft container being disturbed as a result of the derailment, it was not possible to directly determine its original centre of gravity (CoG). To estimate the container’s load offset, it was repacked as closely as possible to its original configuration. An assessment was also made on the basis of measurements from a Wheelchex site over which it had passed prior to the derailment. As a result, the container’s CoG was estimated to be offset laterally by between 0.10 and 0.24 metres. Data from a British port indicated that 2% of containers have similar offset loading.

Derailed Class 222 bogie trailing wheelset with broken axle.

The derailed wagon was carrying an empty 40ft container of 3.9 tonnes and the previously-mentioned 20ft container which was loaded with scrap machines and had a gross weight of 28.8 tonnes. As a result, the wagon’s CoG was approximately 3.2 metres towards the front from the wagon’s centre line.

The estimated result of all this uneven loading was that the wagon’s leading bogie was carrying 2.7 times the weight of the trailing bogie and the left-hand wheels were carrying between 1.2 and 1.4 times the load on the right hand wheels.

This asymmetric loading, combined with the poor condition of the track and the lack of a check rail, were thought to be the main causes of this accident. Incidentally, the damage to the track, a viaduct wall and adjacent overhead line equipment that were the result of this derailment, closed the Up and Down North London lines for six days.

Broken axle at 94 mph

In Carolyn’s second example, the broken axle on a class 222 at East Langton, in February 2010, occurred on a train travelling at 94 mph when a hollow axle failed inside a final drive. This was the first such known accident anywhere in Europe. This axle had been in service for 920,000 miles.

Subsequent metallurgical analysis showed that it had been subject to a maximum temperature of around 1,100 to 1,200°C at the seat of the gear end (GE) output bearing, causing a loss of axle bending strength and resulting in its fracture.

As this heat destroyed much of the evidence, the investigation had to consider five possible causes. After a process of elimination, it was concluded that the initial cause of the failure was the GE output bearing stiffening up so that it could no longer rotate normally, resulting in the axle spinning inside the bearing inner race. Computer modelling indicated that this could generate a heat input of around 30kW. After a further process of elimination, it was concluded that the most likely cause of the bearing failure was a loose fit between the GE bearing inner ring and axle.

These conclusions were reached with the assistance of a technical group set up specifically for the investigation comprising of RAIB, ORR, East Midlands Trains, Bombardier Transportation, Eversholt Rail Group, Serco (consultant for failed gearbox strip down and axle investigation) and ESR Technology (consultant for bearing investigation). This group also oversaw various metallurgical examinations and rig testing of final drives with various low GE bearing interference fits. It also investigated six other powered axles with between 0.67 and 1.2 million miles service that were found to have poor GE bearing fits and so could have been potential failures.

Loss of interference

As this was an unprecedented failure of a normally highly-reliable safety-critical component, it was important to understand how a bearing could have lost its interference fit. The design intent was that the inner rings of both GE and non-GE bearings should have an interference fit on the axle of 75 -120μm (1μm = 0.001 mm). However, on this axle, the GE bearing is immediately adjacent to a gear wheel with a heavier fit of 243 – 309μm. Mathematical modelling indicated that this heavier interference fit would shrink the adjacent seat of the GE bearing by between 24 and 30μm on diameter for a hollow axle. The corresponding amount of shrinkage for a solid axle would be between 5 and 10μm.

When the axle was made in 2004, the manufacturer did not have a company procedure for dimensional checking as it does now. The final drive manufacturer also did not check axle bearing seat dimensions. On the failed axle, the undamaged non-GE seat was found to be undersize and tapered. This indicated that possibly the GE bearing seat, which had been damaged in the failure, may also have been slightly under size.

Although the GE output bearing’s interference fit on the axle was probably less than that specified, the axle had run almost a million miles over six years before its failure. This is indicative of a progressive loss of interference fit. The report explains that this could have been caused by a combination of two mechanisms. The first is inner ring growth, a gradual and normal increase of the bearing bore occurring over time due to the bearing’s metallurgy, its operating temperature and loading. The second mechanism is fretting – wear and corrosion that occurs when there are small relative movements between two surfaces in loaded contact.

Evidence of fretting was found on several other GE output bearings in the class 222 fleet. Fretting wear combined with inner ring growth could have reduced the interference fit to a level at which there would be circumferential slip, which then accelerates the loss of fit.

Common themes – whole system

Although a broken axle and an unevenly loaded wagon on twisted track are two quite different derailments, they have common aspects. One of these is the requirement for a whole system approach. The Camden Road derailment was caused by a combination of track and train issues for which the infrastructure controller and freight operating company had separate responsibility.

In its report on the Camden Road derailment, RAIB found that neither company had quantified the risk from unevenly loaded wagons. As a result, it suggested that the industry’s approach to the understanding of risk for asymmetrically loaded wagons had not been effectively co-ordinated and, consequently, the level of risk and required mitigation measures were unknown.

The Class 222 final drive involved in the East Langton derailment was supplied to a specification by the train manufacturer which had overall design responsibility for the train. Its quantified risk assessment did consider the risk of axle failure from an overheating final drive. However, it concluded that having the final drive produced by a reputable transmission manufacturer to industry best practice, a record of satisfactory service on similar fleets, and specified maintenance procedures provided sufficient mitigation.

In fact, while the Class 222 axles were hollow and relatively thin-walled (45 mm), the interference fits for solid axles had been applied. The bearing manufacturer was unaware that its products were to be fitted to a hollow axle and no analysis had been done to assess the effect of the gear wheel interference fit on the adjacent bearing seat.

Common themes – traditional standards

Standards are often derived from lessons learnt from previous accidents. However, such lessons do not always remain relevant.

In common with other railways, track twist is measured over three metres. This may have been an appropriate derailment mitigation when there were numerous three- metre wheelbase four-wheeled wagons. However such wagons were discontinued many years ago. The derailed wagon at Camden Road had a 14-metre bogie spacing with two metres between the axles on each bogie. When the track was measured after the derailment its twist, measured over three metres, was found to exceed the seven-day action limit but was within the 36 hour action limit. There are no corresponding limits for twist measured over 14 metres.

For many years, oil sampling has been used to determine potential failures yet, three days before the East Langton derailment, the failed final drive’s oil sample was well within the then-specified iron content caution limits. However, when the oil samples were retrospectively analysed to determine the cumulative iron over the whole life of the final drive, it was found to be significantly greater than other final drives which had loose GE output bearings.

Furthermore, during the investigation it was found that oil samples taken from final drives with loose GE output bearing fits had a significantly darker colour than normal oil samples, which indicated that colour may be a useful additional parameter to monitor in oil sampling. Prior to the derailment there was no requirement to assess the colour of final drive oil samples.

The real lessons

For those with a technical interest in the issues that led to these derailments, the 69 and 93 page RAIB reports into the Camden Road and East Langton derailments are a fascinating read. They can be found at www.raib.gov.uk and they include appropriate recommendations to prevent recurrence of the causal and underlying factors.

As a result of the work done by RAIB to investigate these derailments and publish reports that clearly show their causes, no doubt much has been and will be done to prevent the recurrence of similar accidents. However the real challenge is preventing apparently-unpredictable rare accidents that could have serious consequences.

In part, this requires acceptance of the common themes of these derailments. One of these is that the required mitigation measures would have been evident beforehand had a robust analysis been undertaken of the interaction between all associated technical factors. The other is the need to challenge standards that may no longer be appropriate or provide all required mitigation.

In the RAIB 2014 Annual Report, Carolyn Griffiths considered that its investigations may bring new focus to areas of risk that are not always evident to the industry. These accident reports support this view and so demonstrate the value of an independent investigation body.

The transition to ERTMS in the UK

31st March 2015

Oh dear, readers will say, not another ERTMS article! Yes, but this is inevitable as the UK gets ever nearer to introducing a main line deployment of the technology. Valuable lessons were learned from the Cambrian line early deployment project but that was limited in scope and many other factors need to be considered before the nation can be confident the system will deliver the predicted benefits and reliability.

A recent conference in London organised by Waterfront managed to attract speakers from all elements of the spectrum, ranging from the advocates who believe that ERTMS will solve all capacity problems, through those that recognise the advantages but see the implementation as difficult, to a few prophets of doom who predict it will be a costly failure.

The up-beat message

Andrew Simmonds, the chief rail systems engineer for Network Rail’s Digital Railway, pronounced ERTMS (the European Rail Traffic Management System) to be a major driver for economic growth. Passenger number forecasts are rising by 3% per annum, meaning that the current 1.6 billion journeys per year will have risen to three billion by 2035. Some examples of the predicted increase per route are WCML 201%, Thameslink 171%, GW Suburban 108%, South West Trains to Woking 154%, Southern Suburban to Caterham 149%. Handling this capacity is not just aligned to signalling but will need to embrace customer interfaces, ticketing, journey planning, infrastructure operations and the whole operational framework.

ERTMS (especially the ETCS – European Train Control System – element) is very much part of this and should yield around a 40% increase in capacity. Spin-offs include a 10% reduction in delay minutes through better reliability, an 80% reduction in SPADs (signals passed at danger), a 50% reduction in the need for lineside work, energy savings from better regulation of trains and improved utilisation of maximum line speed. Needing to go hand in hand with Traffic Management Systems (TMS), ETCS will be introduced on a route-by-route basis with the initial plan covering the period 2019 to 2029, structured around three main phases.

Phase 1 – development of initial routes; primarily Thameslink plus TMS at Cardiff and Romford and connected driver advisory systems (C-DAS);

Phase 2 – provision of electronic compatible interlockings, removal of lineside signals, a robust telecom layer in the ROCs (rail operating centres) and provision of ETCS infrastructure and cab fitments;

Phase 3 – more of the same but progressing to 100% roll out and start of classic train detection removal.

All very impressive but will it go to plan and will the necessary finance be available in CP6/7 and beyond?

More detail emerged on the ECML rollout, itself covered in a Rail Engineer March 2015 article (issue 125). Whilst that primarily looked at the technical implications, Paul Boyle from Virgin East Coast explained how preparations are underway for ETCS.

Visits to Austria, Denmark, Netherlands, Norway, Spain and Portugal have highlighted 13 elements of operation ranging from train fitment and GSM-R provision through to TMS, track worker safety and station operation. The ECML will be the first main line to totally migrate to ERTMS, Great Western being an overlay project. Four constituent activities have to be tackled – operations, safety, fleet and control.

Driver training has already started using simulators with the DMI (driver-machine interface) layout now available on smartphone or tablet screens. A high percentage of Virgin East Coast staff will engage with ETCS in some way and an ERTMS Awareness Day has recently been held at Kings Cross for all operations staff.

Train fitting will require contracts to be let, trains to be released from service and a full change management plan put in place. The programme to fit the Class 43 HST power cars, the Class 91 electric locos and the Class 82 DVTs will run up to 2020 in readiness for the time when lineside signals are removed.

All very impressive but will it go to plan and will the necessary finance be available in CP6/7 and beyond?

Learning from the Cambrian

The Cambrian project, introduced into service initially from Harlech to Pwllheli in February 2010 and on the whole line from Shrewsbury to Aberystwyth / Harlech in March 2011, was reported on at the time in Rail Engineer. It was not an easy introduction and the train service suffered in the early days. Even now, the ETCS system is not as flexible as the RETB technology that preceded it. Matthew Phillips from Interfleet told of the lessons learned and how these will be used for future deployments:

» The project had been engineering rather than operations led;

» Operational changes were underestimated with new rules not reflecting the real world;

» The operational benefits were not optimised;

» Insufficient focus was given to simulation while sub-system integration proved very complex;

» Approvals for on-board equipment need to be phased so as to keep trains in service;

» ETCS reliability (especially on-board equipment) has been worse than expected;

» Whole-life support was not part of the contract.

The cost of retrofitting the Class 158 DMUs (by Interfleet) and the Class 97 (ex-37) locomotives (by Transys) proved very expensive in terms of design and approval costs, especially as the trains had minor variations between units. It took 10 days out of service to fit a Class 158.

The freight dimension

Whilst much of the ERTMS roll out is focused on the passenger railway, the impact on the seven freight operating companies (FOCs) is of vital importance. Simon Gledhill from DB Schenker quoted the statistics: 950 locos of 19 classes, 20,000 wagons and around 5,000 staff. It is a growing business, with £2 billion invested since privatisation, but is very competitive, performance sensitive and has changing market dynamics. The annual turnover is £30 billion with 1 in 4 containers carried by rail plus 50% of the fuel used for electricity generation. Thus any technological change that even minutely disrupts this flow is regarded with suspicion.

ERTMS awareness exists but, for freight, it cannot be linked to any one route. It must take account of the variation in the length, consist and weight of trains, plus shunting and banking activities, and the whole freight operation needing to be based at multiple locations. Locomotive fitting will be crucial and should follow the pattern of ‘first in class’ (FIC) fleet fitment, training and driver familiarisation. Braking data variability is vital and needs a major refinement over the individual expertise used at present.

An implementation programme running from 2015 to 2021 is being developed with operating rules revised by 2016 and fitment beginning in 2017. ERTMS teams within the companies are being assembled. The transition from lineside signals to in-cab data will be difficult, but the FOCs and Network Rail are working well together, recognising that freight has to be part of the National Operations Strategy (NOS).

Passenger train fitment

This is probably the biggest challenge in the ERTMS introduction. Andy Norris from CPC Project Services and the project director for the ETCS National Joint ROSCO Project (rolling stock company) explained the main elements in determining how fleets are equipped. The national deployment map is the starting point but alongside this are franchise considerations and whether these are existing, direct awards or in the course of development. Any delay to franchise letting will have ETCS implications.

There are no spare trains in the UK so fleet fitment will take many years. Procurement of equipment is needed now for fleet fitting over five to six years. Test facilities will be available by April 2016 at Old Dalby for electric trains and Tuxford for diesel locomotives. Network Rail is funding the FIC design and installation with fleet fitment funded primarily via franchise arrangements but with Network Rail backup. Open access operators have to organise their own funding in conjunction with Network Rail.

The progression is to obtain around 30 kits for FIC design and approval, and 1,465 kits for fleet fitment. A maximum of 11 FICs can be handled at any one time, recognising that some classes are essentially similar (such as 158/9, 375/6/7/8, 175/180), and a programme is in place for every class of passenger train. It will be a TOC decision as to whether elderly trains such as Pacers and 313s are fitted.

The TOC requirement is to have no loss of seats, cycle or storage space and thus the kit has to be distributed in roof spaces, under seats or underfloor, which will add cost. The Hitachi product (issue 125, March 2015) is already designed this way. The work will be let competitively and contracts must include aftercare support.

Additional challenges include:

» Getting ETCS software to baseline 3 – Europe is dragging its heels on this;

» Funding certainty and timing;

» Cyber security protection;

» Engaging the supply chain with the urgent need to place orders;

» Skilled resource shortage for both UK and European workload;

» Reliability of the installed kit; » Technical options for DMI.

The Department for Transport will need to enhance clauses in franchises for ETCS commitment. There are many stakeholders including the Government, TfL and Transport Scotland but these and the ROSCOs are working well together currently.

The ORR perception

With ERTMS involving many parties, the ORR is only too aware of its complexity, so says Anna O’Connor, head of projects. Industry does not have an unequivocal shared vision and, even if it did, implementing ETCS technology would still be a difficult task. There is much uncertainty on the time frame and lots of ambiguity, making the project akin to a patchwork quilt. The main risk seems to be with the multitude of interfaces raising big questions on the ability of Network Rail and its suppliers to deliver the programme, particularly when engineering resources are in short supply.

Safety issues have to be all-important and safety legislation is also complex involving ROGTS, Safety at Work, CDM, Workplace Regulations, EMC, Interoperability and others. The detail within these is important but should not be used as an excuse for delay.

In-cab computer-based signalling is a major change and requires four basic steps to be understood:

» Need to assess the risk of the change with associated design optioneering;

» How far can the risks be eliminated and useof ALARP;

» Consideration of the specific statutoryrequirements within the work packages;

» Identify appropriate opportunities -ERTMS should not be a digital like-for-like replacement and the integration of level crossing operation and improved worker protection should be part of the package.

Other opportunities should embrace the accuracy of braking curves, maybe with real time monitoring of braking performance. A list of possible applications should be prepared.

Lessons from Europe

Anyone who thinks that European railways have had an easy ride with ERTMS should think again, according to Kimmo Oostermeijer from Leigh Fisher. Despite significant funding, the deployment is behind schedule, project management has been un-coordinated and appropriate measures have not been taken to prevent delay.

One key lesson is that ERTMS is more about organisation and economy rather than technical. The dictate on TEN-T (trans-European transport network) corridors demands safety, system performance and interoperability to yield the benefits for passenger and freight customers. The risks are higher when implementing the system on an existing railway, mainly due to the retro-fitting of trains, introducing new rules and track worker safety.

The UK may benefit from not being first in the queue. The ORR noted that Sweden has benefited from creating a Systems Authority to make the necessary strategic decisions. Network Rail has considered this in the past but without making any progress. Maybe it should be resurrected, as the lack of a ‘Directing Mind’ appears to be a significant gap in its organisational structure.

Other factors

With the significant number of parties involved, the need for robust contractual frameworks is essential and associated legal safeguards must be in place. Tammy Samuel from Stephenson Harwood listed some of the necessary measures that must be considered and decided:

» Purchase of equipment; what if it is late and/ or doesn’t perform?

» Liabilities imposed by end customers;

» Funding of downtime of trains through failures and proving of cause, interface between track and train and associated delay attribution;

» Who is the customer and the supplier – ROSCO, TOC/FOC, Network Rail?

» Who is responsible for approvals and commissioning?

» How will major system upgrades be managed?

» Intellectual Property and ownership plus issue of licence and the extent of this.

Cyber security is another issue and an assessment should be made of the places where this can occur. Julian Gill from Thales stated that nine possible threats were identified, the main ones being end-to-end communications, train-to-balise interactions, denial/traceability of keys, secure usage of components and the common numbering system within GSM-R. The classic fail-safe criteria of ‘if in doubt, stop the train’ will not necessarily be a workable solution. Seven layers of defence were identified ranging from data configuration through to policies and procedures.

Overall, the conference gave a fascinating, if not slightly worrying, exposure to the main line introduction of ERTMS/ETCS. If nothing else, it achieved a wider awareness of what might go wrong. Many eyes will be watching the first deployments, both for infrastructure provision and train fitment, and the readiness by which the almost inevitable unforeseen situations will be identified and resolved.