Video: Drone’s eye view of Crossrail tunnels
Video footage of a drone exploring the now-completed Crossrail tunnels.
Whifflet Electrification – A RACE to the finish
The Whifflet line. A Cinderella railway dependant on DMU rolling stock despite being surrounded by electrified railways.
The advantages of electrification – a cleaner, faster, quieter and more reliable service for passengers – had somehow passed by this line that runs between Rutherglen to Coatbridge. The route’s electrification had been specified in the Scottish Ministers’ High Level Output Strategy for delivery by 2018, but became an accelerated programme under an alliance between Network Rail and Scotrail. It was delivered by Carillion as a standalone project in 2014.
The RACE (Rutherglen to Coatbridge Electrification) Project involved the design and installation of 26 single track kilometres of 25kV Overhead Line Equipment (OLE) to cater for electric haulage of the existing passenger services, the opportunity to divert passenger and empty stock together with providing the freight operators with the ability to convert from diesel to electric operation.
Series 2
The project used Series 2 OLE, a new system that is designed to reduce both cost and installation time. Traditionally, cantilevers are assembled on site from their constituent parts. However, with series 2, the cantilever is manufactured as one complete component in a factory. This provides numerous advantages in terms of logistics, construction efficiency, quality and consistency of assembly and there is no requirement for manufacturing facilities and expertise on-site.
As this was a Series 2 OLE design, much of the equipment came from Bonomi in Italy, imported through Pace Networks. Agreement was reached with Network Rail to purchase early – as soon as the detailed design was signed off – allowing for bulk stocking and storage of the equipment. This was then taken out and installed on a just-in-time basis.
Given the high vandalism and theft risk in the area, equipment was never left out on the track side. For the same reason, the existing power and signalling cables were buried in the ground. A new buried duct route was installed, but it was very difficult to locate and identify the existing buried cables. This, along with the need to avoid existing obstructions using unplanned diversions and alterations, made the installation of the new duct a tricky civils project in its own right.
The mast foundations were predominantly conventional 610mm pile arrangements and there were occasions where the ground conditions resulted in use of mass concrete footings. Piling was the preferred option as testing is not required prior to mast erection.
Recovery and reuse
The RACE project involved installing one new Track Section Cabinet (TSC) at Langloan and extending the existing TSC at Eglinton Street in Glasgow. TSCs are used to provide remote sectioning capability within the electrified network, to facilitate isolations of apparatus and to assist in managing electrically perturbed circumstances. The project identified that there were two TSCs due to be decommissioned in the Glasgow area and they were duly recovered and reused on this project.
Immunisation issues could have caused serious delays unless carefully managed. To save the time that would otherwise have been spent on intrusive and lengthy cable surveys, it was decided that the most effective solution would be to install a classic booster transformer 25kV system with an aerial earth and also a return screening conductor. This ensured that all the immunisation interfaces could be managed robustly.
The booster transformers are oil filled and the project team learned that there were a number being made redundant in Rugby. Twelve of these were obtained for use on RACE, ticking several sustainability boxes as the assets were reused and not scrapped.
The RACE route can be used as a diversionary route for Virgin Pendolinos. For compatibility purposes, there was a need to install a harmonic damper to smooth interferences in the OLE supply patterns that are principally caused by these trains. Once again, there happened to be one being made redundant in Bourn End and this too was acquired.
The 650V signalling power on this route was upgraded to Class 2. This uses twin-core copper cables rather than three-core, reducing the amount of copper in use with consequential cost benefits.
Keeping it local
The majority of the management and labour that delivered RACE live permanently in the central belt of Scotland. The designers, Hyder Consulting and Siemens, supported the design from their offices in Glasgow, keeping the need for costly people-movements to a minimum. Similarly, local plant hire and material suppliers were used wherever possible.
With substantial amounts of electrification taking place all around the UK, much has been written about the skills shortage. For this project, Carillion addressed the issue by employing and training new entrants to the industry using the recently developed OLEC training qualifications.
This new portion of electrified line is controlled from the existing control room at Cathcart and so communications links were required to interface with the SCADA systems and control displays. By September 2014, the hardware was ready for commissioning – an exercise that involved signalling input and the preparation of a detailed commissioning document which addressed questions of cutting into existing electrified railways at Coatbridge and on the West Coast main line.
Commissioning was successfully completed on the 28 September 2014, the wires were energised and driver training commenced so that all was ready for the new train patterns in the December timetable.
Norway to go Nationwide ERTMS
Like many other countries, Norway has a problem with ageing signalling equipment and needs to undertake modernisation. The infrastructure manager, Jernbaneverket, has taken the decision to adopt ERTMS nationwide with a project lasting from the present day until 2030. It is only the second country to have taken this bold step and it has been influenced in part by its near neighbour, Denmark, which made a similar pronouncement back in 2012.
Many eyes have been watching the progress of the Danish scheme and seeing some of the challenges that are emerging. The Norwegian project is to be based on three major signalling contracts covering the whole main line railway network but with the intention of achieving the same result. So what is it all about and what are the critical factors?
Geography
Norway is a long thin country with a small rail network in comparison to many others. It has 4,000 route kilometres and 4,500 track kilometres, which demonstrates that much of it is single track. There is only a limited capacity improvement achievable by employing ERTMS on such an infrastructure, hence the project is renewal, rather than enhancement, driven.
Suburban commuter routes exist around Oslo but important main line links run to Kristiansand and Stavanger in the south west, Bergen in the west (including the tourist-orientated Flåm Railway), Åndalsnes and Trondheim in the north west and, with a long northern extension, to Bodø. Three eastward lines connect to the Swedish cities of Stockholm, Gőteborg, Malmő and Østersund.
In the far north, an unconnected line to the Norwegian network crosses from Narvik to Kiruna in Sweden primarily for iron ore traffic.
Progressing the project
Since the adoption of ERTMS will essentially be a state-funded project, the processes to satisfy government that there is a sound business case with appropriate contract allocations and ongoing governance have to be gone through. This can be a lengthy task and the timescale for getting costs and ‘invitations to tender’ documents prepared has taken more than two years. However, agreement to proceed is expected to be granted in the summer of 2015 with RFQs being issued later this year.
Part of the process has been to equip an 80km pilot line between Ski and Sarpsborg, south of Oslo, with ERTMS Level 2. Testing on this section has been going on over the past few months in collaboration with Bombardier which was the awarded signalling supplier. Trial running is expected to commence this month with commercial operations using ERTMS beginning in August. Part of the trial will be to examine the applicability of existing operating rules as well as learning the technical and maintenance aspects of the equipment.
Once the full project gets the go ahead, the implementation period will extend from 2020 to 2030. The first lines to be converted will be to Bergen and the far north line from Trondheim to Bodø. The logic is to work from the extremities inwards towards Oslo since this minimises the train fitment, a challenging task that will involve around a dozen train operators.
Some lines around the capital will also be fitted with the Norwegian Class B signalling system using conventional interlockings, lineside signals and track circuits / axle counters in order to progress urgent renewals but without the need to fit trains with ETCS. Jernbaneverket has stated they want to keep the number of new Class B systems as low as possible and much of this technology will be ERTMS compatible. In 2012, Thales Norway and Jernbaneverket signed a framework agreement for delivery of Class B systems lasting for 10 years with 25 more years of technical support on each delivered system.
Technical considerations
The vision of Jernbaneverket is that, by 2030, there will be a single set of parts for all aspects of ERTMS operation. This will cover control centres with their interlockings, radio block centres and MMI panels; trackside equipment such as balises, train detection equipment, point mechanisms and level crossing operation; and on-board train equipment including the VOBC, driver displays, odometry and balise readers.
Thus the intention is to progress as three distinct contracts, for signalling infrastructure, for on-board train fitment and for the traffic management system. The latter is seen as key to modernising train traffic control before the main ERTMS programme begins and will thus progress in the earlier timeframe of 2018/9.
Jernbaneverket will also issue contracts for civil works in connection with new infrastructure required for cable ducts, trackside signalling housings and marker boards, plus safety measures to facilitate removing train dispatchers on railway sections without continuous train supervision. Norway already has a GSM-R radio network but with coverage designed primarily for voice traffic. To be the bearer for ETCS, it is going to need additional base stations to give more robust signal strength and coverage. The prospect of having to find an alternative to GSM-R during the timeframe of the ERTMS project will be addressed when this issue gets resolved within the European Rail community. Although not a member of the EU, Norway is signed up to most EC conventions.
The ERTMS to be adopted will be Level 2 to baseline 3.0.0 software (or latest version at roll out time), a release still to happen but reported as imminent. Key Management, that is the security code that ensures only the correct train receives the relevant information when transmission of movement authority messages are being sent, is seen as particularly important since it has caused considerable proving problems in the deployment of ERTMS elsewhere.
Consideration has been given to an ERTMS Level 3 solution using the experience of ‘Regional ERTMS’ being installed on remote lines in Sweden, but for the moment this is discounted because the risk arising from being the first to adopt such a system would be unacceptable for such a nationally-significant project.
As with any railway, the fitting of rolling stock is a challenge. NSB (the near monopoly train operating company) will be tasked with fitting the existing fleet of between 400 and 600 units and will receive government compensation for this work. New trains ordered after the commencement of the project will be expected to come with ETCS equipment fitted. It is recognised that the design, installation and testing activities for the ‘first in class’ will be expensive. Some trains will need to be dual fitted with ETCS and a Specific Transmission Module (STM) and associated equipment that will allow them to operate to existing signalling systems in the short term. The ‘yellow fleet’ of on track machines will also be included in the rolling stock fitment contract.
In summary
This decision is a brave step for the railways of Norway. It will be one of the most exciting and challenging projects within the country, not just because it is the transition from relay-based to computer-derived signalling but it will also test out ERTMS in challenging topography and occasional harsh weather conditions.
The expected cost of the project is 15-20 billion Norwegian Krone, roughly £1.3-1.7 billion. Much will depend on the reaction of the supply market once the invitation to tender is issued. The business and operational skills required to manage the project will be recruited in house.
As in Denmark, eyes from around the world will be watching this project progress. A project running over such a long period of time will demand a solid and trusting relationship between Jernbaneverket and the supply chain. In the short term however, the ERTMS suppliers need to sharpen their pencils.
Completing the GNGE
The 08:55, departing from Platform 1 at Peterborough on 9 March, was a special service. On board were Network Rail route director Phil Verster, project director Neil Lindley and a selection of local politicians and trade press. At its first stop, Parliamentary Under Secretary of State Claire Perry MP joined the train.
That first stop was at Ruskington and the purpose of the train was to celebrate the completion of the snappily-named GNGE Alliance East Coast Mainline Capacity Relief Project.
As published in issue 116 (June 2014), this was described as the “rebirth of a back-stage line”, the renewal of the GNGE (Great Northern / Great Eastern) joint line paralleling the East Coast main line between Werrington Junction, Peterborough, and Decoy Junction, Doncaster.
The works at Ruskington station were celebrated by the ceremonial unveiling of a plaque on the new footbridge, one of several significant bridgeworks on the project. The Ruskington bridge is of a familiar steel design combining disabled access requirements with long ramps and stairs for non-disabled access. Cleverly, the bridge blends in well with the station and does not intrude as do some compliant bridges.
The celebrations served as an effective showcase for what had been a very positive project to improve the capacity of the network by pragmatic remodelling and reconditioning of some fairly neglected infrastructure which was very much in need of bringing up to current standards. It was fairly typical of many secondary routes with mechanical signalboxes and signalling, very restrictive speed restrictions and underdeveloped infrastructure with renewal more than due. The story of the line is worth quickly revisiting to put the project into context and appreciate the finished product.
The route
To recall briefly, the Great Northern and Great Eastern Joint Railway (GNGEJR) was established in 1879 by the Great Northern Railway and its rival, the Great Eastern Railway. The joint company built a line between Spalding and Lincoln to complete a new, primarily freight, route between Cambridge and Doncaster, a distance of about 123 miles. The main purpose was to move Yorkshire coal into East Anglia, a highly profitable enterprise.
The route has survived except for the section between March, Cambridgeshire and Spalding, Lincolnshire and the Lincoln by-pass line, both of which were closed in the 1980s. The section between Peterborough and Spalding is now regarded as part of the joint line although this is not strictly (historically) accurate. The Sleaford avoiding line had also been left out of action, leading to increasing rail traffic over the level crossings on the line through Sleaford itself.
With the disappearance of the freight business on the railway, the route gradually succumbed to the fate of many non-main lines: seeing little investment and perhaps maintenance optimisation bearing in mind the traffic on the route. As a further economy measure, the signalboxes were no longer manned over three shifts.
The project
With the current rapid increases in demand for rail transport, both pasenger and freight, that situation has changed. This resulted in a specification to increase capacity for freight and passenger trains on the GNGE line, the route to be upgraded to form an effective freight path removing traffic from the East Coast main line and also providing a high quality diversionary route. Accompanying benefits were catching up on maintenance and renewals and enabling a much improved passenger service with the potential for growth.
The project has been undertaken within the umbrella of the GNGE Alliance and Network Rail and delivered in an alliancing partnership with Carillion, Babcock and Siemens. Additional sub-contract services were provided by Balfour Beatty and Kier, reporting directly to Network Rail. It has been a successful illustration of the Alliance principle.
The GNGE Alliance East Coast Mainline Capacity Relief Project remit was to increase capacity for freight and passenger trains on the GNGE line. The project (valued at around £280 million) was basically a phased programme of renewals culminating in a route that reflected the project management philosophies within the present day rail industry.
The high profile gain is the increase in line speed and an accompanying reduction in journey time – speeds up from 60mph to 75mph for passenger trains and raised to 60 mph for freight, resulting in 17 minutes being taken off the end-to-end time on the route. These times are also related to the fact that, with the need to man signalboxes no longer applicable, the line may be held open for 24 hours in the day, control being from the new control centre at Lincoln.
Sixteen signalboxes were decommissioned though we shall see that one or two will have a continuing life as the local communities did not really wish to see these aspects of their local history disappear. Blankney box remains as part of the level crossing infrastructure at Metheringham and Stow Park is a listed structure. Deeping Saint James signalbox has been “palletised”, in the words of the project director, and awaits re-erection at a suitable site near to its old active location.
Other environmental issues have included the not- unexpected colonies of Great Crested Newts and the need to plan vegetation works, often for improved visibility issues, outside the bird-nesting season. The high profile given to neighbour and stakeholder relations has caused some considerable debate over the removal of trees; however the safety requirements for this have been discussed and seem to be accepted by local people.
![DG165437 [online]](http://therailengineer.com/wp-content/uploads/DG165437-online.jpg)
Level crossings
Accompanying the removal of the signalboxes was the large-scale modernisation of level crossings on the route with replacement of both whole and half-barrier installations, the latter being replaced with modern half-barrier arrangements. Journey time gains were made from this change to the infrastructure: the old crossing at Tinsley incurred a permanent speed restriction of 10mph but the change to MCBOD format now allows 75mph line speed at the site. Safety has also been improved for local schoolchildren by the replacement of a pedestrian crossing at Heighington where an underpass has been provided.
Of considerable interest is Blankney level crossing by Metheringham Station where the original signalbox structure remains in use adjacent to the level crossing. Government, and the media, has placed much emphasis on safety at level crossings and a particular concern after the Ufton Nervet derailment where several fatalities were caused by an HST hitting a car stopped on a level crossing.
Blankney crossing has modern full lifting barriers and incursion detection which can detect obstructions on the crossing and prevent the clearance of signals on the approach. The detectors consist of a small transmitter and receiver which look across the crossing at low level, there being four looking across the roadway and covering the at-risk area inside the barriers. The system is designed in line with the Network Rail strategy for level crossing safety improvement and is a result of considerable industry development. The system is one of those being considered for further level crossing upgrades as part of the national strategy.
Significant infrastructure work was undertaken here, including the demolition of a house to improve sightlines and gain a better alignment for the crossing. A 75mph speedboard here emphasises the performance gains for the project and the impact of route improvement works including continuous welded rail, formation upgrading and resignalling.
Other work
However there do remain some works to do, inconveniently driven by access restrictions. An example is Vernatts Drain where the life-expired bridge over the waterway requires renewal but access is through a housing development that has grown up since the railway was built. The works are programmed but will require the use of a 1,000 tonne crane and thus, for the short term, a 40 mph speed restriction remains in force.
Bridges have been a very positive aspect of the value management philosophy on the project where several replacements have been reviewed and refurbishment has been found to be wholly appropriate for long term use. New bridge works have been required to deal with and reopen the Sleaford avoiding line which has been reinstated to allow freight to bypass the town, relieving the level crossings that exist on the town route and minimising road traffic disruption.
Mention of bridges also highlights the achievement of a route-long W12 gauge clearance and passive provision for 25kV electrification, an obvious desire for an East Coast main line diversionary route. The route seems, in the main, to be at low risk of vandalism and it is appropriate that rather than strings of steel palisade fencing in this rural area more conventional post and wire fencing has been installed on much of the route accompanied by a cable route which has not required the anti-vandal treatment seen in more urban areas.
Mention has been made in previous Rail Engineer articles of the proposals for a fly under or over at Werrington junction and the route for this has been identified. The removal of a junction at grade at the south end can only serve to make the use of the GNGE line even more effective. Development work and design for this proposal proceeds apace though at this stage no concrete start has been made.
In summary the engineering has been relatively conventional but with much effort being made to successfully integrate works delivery and at an optimum cost. The project has delivered an excellent example of route refurbishment in a very effective manner through a wholly appropriate alliancing arrangement and the tidiness, and lack of lineside clutter, of the route after completion gives every impression of a job well done and a railway brought up to a standard well-suited to the twenty-first century.
Rail Engineer photographic competition
When preparing articles for publication in Rail Engineer, one of the biggest problems is always the availability of good quality, high-resolution photographs.
Some projects engage professional photographers.
The quality is then usually excellent but they can’t be on-site every day. We therefore get a good snapshot of the situation at one point in time, or two or three if visited several times, but we still need additional images to fill in the rest of the work.
Other projects rely on the project team to take their own photos. Sometimes these are good, sometimes fair, and other times downright poor.
Many times, photos are taken by project staff on smart phones. They see that their phone has a 12 Megapixel camera, or whatever, and assume that will mean it’s good enough. They forget that the lens is minute, and probably dirty, and then they also reduce the size of the image (its resolution) to minimise the file size and save space on their memory card. The result – a photo that looks good on a camera screen but which is totally unsuitable for printing in Rail Engineer.
By careful photography, and maximising the file size, that doesn’t have to be the case. So, to promote good photography on smart phones, Rail Engineer will be running a competition this summer for all staff on the railways.
Send us photos of your project, or work, and we’ll publish the best ones. The overall winner, as chosen by Rail Engineer’s picture editor and by professional rail photographer Paul Bigland, will win a KAZAM Tornado 350 smartphone – with a 13 Megapixel camera.
To help you, Paul Bigland has written an article in this issue giving some advice on taking good photos.
You have until 30 September to get your photos to us – the winner will be announced in our November issue.
The rules:
1. Your entry or entries (you can send as many as you want) must be your own work and taken on a smart phone.
2. All photos must be as-taken with no extra enhancement using computer programmes.
3. All images must be at least 2,000 pixels across in either height or width (not necessarily both).
4. While the image is your property, you give permission for us to reproduce it in Rail Media publications in print and online.
5. Each image must be sent to us in an individual email to [email protected] stating where and when it was taken, what the subject is and the make and model of smartphone used to take the image.
6. Your own employer may want to see any photos you send us – please check for yourself.
7. Entries must be sent before midnight on 30/09/15.
Good luck and good shooting!
What we need is…
How much of our railway network would exist if its Victorian pioneers had been obliged to engage with focus groups and ponderous consultation processes? Even Parliamentary scepticism did not greatly impede Brunel’s progress with his 118-mile ‘billiard table’ – the Great Western Main Line from London to Bristol – which went from promotion to approval to completion in just eight years. The first phase of HS2 – albeit 22 miles longer – will take 16. We just don’t get on with things any more. There’s a whole load of interwoven reasons for this, from our institutional fear of failure to Mr & Mrs Nimby’s loud voices and the now-ubiquitous Great Crested Newt. They all act to elongate timescales.
But what if there’s an obstacle threatening to derail your project – not years away, but weeks? What if there’s nothing in the toolbox that will quite do the job in the time available? You don’t want a talking shop or an options study; what you need is a way forward… today. What you need is Chris Scott and his prowess with steel and hydraulics.
Coalface teaching
I find Chris on the first floor of an innocuous office building, overlooking his workshops on the former site of Barnsley Main Colliery. The desk he’s sat at is as characterful as he is, crafted from pine (the desk, not Chris) and probably salvaged from one of the many pit offices he’s occupied over the years. Scattered across it is a collection of sketches and hand-written notes. Retirement age came and went some time ago without Chris noticing. Whilst his brain remains sharp – and it does seem frighteningly so – there’s no chance of him giving up. He’s got the best job in the world, he reckons: people with problems knock on the door and he doesn’t go to sleep – almost literally – until he’s solved them, theoretically at least. How satisfying is that? Just ask Tesco about the doughnut machines he built for them.
Chris provides something of a counterpoint to a society besotted with qualifications, one which has now created a market for graduates at McDonalds. With no O-levels, he walked away from school at 15 to join the Coal Board as its second-youngest entrant. Ironically, they made him go to college for nine years – “the long ![ChrisScott-021 [online]](http://therailengineer.com/wp-content/uploads/ChrisScott-021-online.jpg)
route” he calls it – studying to become an accomplished mechanical engineer. To that end, he won top prize every year. He left mining after the turmoil of the 1980s, moving to a small steel fabrication firm, Foulstone Forge, which he eventually acquired. Today he’s also a co-director of ISS (Innovative Support Systems) which manufactures a number of rail-facing products. No- one could suggest he hasn’t done alright for himself.
But it would be wrong to give the impression that Chris ploughs a lonely furrow as an innovator. Whilst he is clearly self-motivated – always eager to get his head around the next conundrum – he actually sits at one point of a triumvirate: developing, testing and implementing solutions in collaboration with Colin Sims, a principal engineer within Network Rail who is challenged with resolving many of the problems thrown up by tunnels, and Keith John, AMCO Rail’s senior contracts manager, with whom Chris has a long- standing relationship. AMCO has offered great support over the years – moral, practical and financial – and continues to do so as new ventures emerge.
Tunnel vision
With their mining background, it’s no surprise that many of those ventures have applications underground. Back in 2004, AMCO’s work relining Strood and Higham tunnels benefited significantly from Chris’ handiwork: mobile crash decks, protective workforce shelters and a 10-tonne bogie for transporting materials that ran along the six-foot. More recently, his manipulator and “leg-spreader” coaxed 87 girders into place during the partial rebuilding of Holme Tunnel (see issues 109 and 113 of Rail Engineer), each of them weighing about four tonnes.
That was all bespoke kit – built for a purpose, then dismantled for recycling. Probably his best known off- the-shelf product is RamArch, a support system used for shotcrete reinforcement, comprising curved panels of wire mesh that are bolted together to form an arch.
Each provides a one-metre advance. In 2011, it was installed in Devon’s Whiteball Tunnel to address a rapid deterioration of the brick lining over a distance of 388 yards (see issue 80 of Rail Engineer), about one third of the tunnel’s length.
RamArch itself is quick to assemble; the tougher test from a time perspective comes with the design requirement to secure additional resin-bonded pins in the lining as extra fixings for the shotcrete. At Whiteball, where a possession had been booked for the last Christmas period, this involved drilling more than 6,200 holes into the brickwork at the crown. However, using manual techniques, the need to apply an upwards force of 38kg when drilling each hole was immediately deemed unsustainable in practical terms.
Instead Chris built an elevating platform – christened the “four-poster bed” – and arm onto which Hilti TE76 combihammers were mounted on spears at 750mm centres. The pivot point of the arm could be pushed outwards to reach the tunnel’s centreline and the whole thing then raised to its required working height. Both the positioning and the drilling operation were hydraulically driven and controlled from a panel on the platform. The machinery typically completed an array of six 300mm- deep holes in less than a minute, the TE76s proving remarkably resilient.
Whilst the above might seem a rather mundane task to focus on, it is illustrative of the high-volume activities the railway will need to transform in delivery terms – through technology or mechanisation – if it is to meet its future network availability targets.
The next step for Whiteball will be to shotcrete the haunches; a 4-metre wide strip at the crown having been completed over Christmas. Doing that without significantly disrupting services is a headache now focusing the minds of those involved. Chris has a solution which, if adopted, could change the way minor works are undertaken in tunnels long term. More than that we can’t currently say.
![Milford-117(mod) [online]](http://therailengineer.com/wp-content/uploads/Milford-117mod-online.jpg)
![Milford-131 [online]](http://therailengineer.com/wp-content/uploads/Milford-131-online.jpg)
As for RamArch, it now has two siblings: Aspin RamPad, a simple, lightweight foundation system for structures such as signal posts that obviates the need for wet trades, and RamWall, comprising layers of steel mesh which can be built up and filled with stone to form retaining walls of almost any size and shape. This has recently been used to replace a section of failing revetment protecting the Cambrian coast line from sea erosion at Tonfanau. It also forms the walls of a vertically-sided embankment on Scotland’s Kintyre peninsula where access was needed over a gully to move a 130-tonne transformer. Eye-catching stuff.
Looking for trouble
For many decades, hard-working steam locomotives belched a wealth of unpleasantness from their chimneys, helping to destroy the ozone layer and create thousands of jobs in ‘green’ industries. “Every cloud…” and all that. Although air quality has improved hugely since their demise in the Sixties, they have left a maintenance legacy: the coating of soot on many tunnel linings. Historically, engineers have had to accept this as a fact of life, but the recent onset of electrification work has – amongst other drivers – brought into focus a need to expose the brickwork in order to obtain a clearer understanding of its condition prior to the fitment of overhead line equipment.
For small-scale repointing or repairs, soot accumulations are removed – very laboriously – by the workforce using scrapers and wire brushes; air and water jetting has also been employed. However, due to the inefficiencies involved, wholesale treatment of tunnels by either method would be unrealistic, even if
you could properly mitigate the health and environmental risks they both pose. So it would have been tempting just to bury this issue in the too-difficult pile and hope it was soon forgotten, but, to its credit, Network Rail is tackling it with some vigour. Already doing its business in the East Midlands is Chris’ latest creation – his patented soot scabbler.
Clean sweep
In principle, the machine is not desperately complicated – it has just two main components: a vacuum unit linked by hose to a scabbling head. What’s difficult with such systems is getting the detail right as this determines their ultimate effectiveness.![ChiswickPark(2) [online]](http://therailengineer.com/wp-content/uploads/ChiswickPark2-online.jpg)
Weighing 850kg, the scabbling head is held at the back by a road-rail vehicle and offered up to the intrados. Inside it are 15 wire brushes, comprising 450mm lengths of haulage rope; these are inserted through holes in a solid steel shaft, arranged helically to prevent any impulse loading of the brickwork as they rotate, as well as reducing vibrations due to cyclical harmonics. When they’re worn out, changing one brush takes about five minutes.
The head runs on four, small bearing-off wheels, mounted on sliders which the operator adjusts to provide the optimum interaction between brushes and soot, but the least possible impact with the brickwork itself. Around the head is a gap of 30mm – surrounded by a polyurethane skirt – allowing air to be drawn in at a rate of 15.7m/s. With the brushes rotating at around 200rpm, this configuration prevents anything from escaping, even though the soot gets pulverised almost to dust. “We’re touching on particle physics now”, remarks Chris with a twinkle. The RRV travels slowly through the tunnel, cleaning a longitudinal band 760mm wide. If the head was any larger, the load created by the suction would be sufficient to dislodge any delaminated brickwork. To ensure an even loading over small changes in profile, sliders and springs allow the front of the head to ride the undulations whilst the rest of it is held steady by the roadrailer. The soot is pulled through the 300mm hose into the suction plant where it is deposited directly into 600-gauge visqueen bags inside building sacks. Although the soot is non-toxic, it’s reassuring that the workforce never comes into contact with it.
What we have here is a vacuum cleaner on an industrial scale. As you might expect, development has involved some trial and error in order to get the hardware and operating methodology right. Trials were undertaken in a disused tunnel at Alfreton as well as the Old Dalby test track. What’s emerged onto the network since then is a machine that meets everyone’s best expectations.
Out of the box
In the great scheme of things, those of us who make a living by scattering words about only leave footprints in the sand. Our efforts are transient: you will have forgotten this article tomorrow, even if you’ve stuck with it to the end. But that’s not the case with everyone. In a world besotted with fluff and trivia, it’s reassuring to know there is still a place for muddy-booted folk whose big footprints are set in concrete. Not wishing to overdo it (and I can sense my editor pulling his hair out), they keep the Brunelian spirit alive. With the railway under increasing scrutiny and pressure to reform, it needs pioneers now more than it ever has.
Photos courtesy of Four by Three.
Crossrail’s South East Section
When complete, Crossrail will be a three-legged railway. The western leg will emerge from under London at the Royal Oak portal and run out as far as Reading with a connection off to Heathrow.
To the North East, the portal is at Pudding Mill Lane and the Crossrail route will then go through Stratford and out to Shenfield in Essex.
In the South East, after a couple of open sections at Custom House, the line finally emerges from under the Thames at Plumstead but then runs for only about a mile to the terminus at Abbey Wood.
Currently, Abbey Wood is a simple station on the North Kent line. It has two platforms, set each side of the twin-track railway. Trains to London run into both London Bridge/Cannon Street (six per hour) and Charing Cross (two per hour), while outbound services go to Barnehurst, Dartford, Gillingham and Hither Green.
New islands
Under Crossrail, the two existing platforms will both be rebuilt as island platforms by having a track each installed on the ‘back side’ of them. The northerly island, currently the Down platform to Kent, will be the Crossrail terminus while the current Up platform will become the one for the North Kent line.
Passengers coming in from Kent, which could be from as far away as Dover, Ramsgate and Rochester, will change at Abbey Wood onto Crossrail services.
Consideration was given to having both North Kent and Crossrail lines on each island, so that passengers would only have to cross the platform to catch their connecting trains. However, that would have forced city-bound Crossrail trains to cross the North London line to reach the tunnel portal, so delaying services. Passengers will therefore have to cross the new footbridge (with lifts and escalators) to make their connections.
There is an added complication, and that revolves around the electrification systems. The North Kent is a third-rail DC line, while Crossrail will have an overhead 25kV AC supply. Keeping the two railways apart on their own island platforms will eliminate a lot of potential problems.
The northernmost Crossrail track, on the new platform face, will terminate at buffer stops at the end of the station. The more southerly one, on the existing face, will continue on beyond the platform. Although primarily intended to be a ‘dead train park’ where defective trains can be left until they can be recovered, this track will eventually connect with the North Kent Down line, so giving access for engineering trains.
The approach to that junction will not be electrified at all, so removing any electrical crossover problems, as it is primarily intended for diesel or battery-powered engineering movements.
So that’s the plan. Turn a two-track station into a four track one, and run the two twin-track routes alongside each other for the mile or so to the Plumstead portal. Simple.
Complication
Oh – and what about constructing the new Crossrail inside the tunnels? To do that, access will be needed to the portal to bring work trains in. But they will be coming from the North, not from Kent. And, until the station is complete, the connection between the North London line and Crossrail won’t exist anyway.
To make that connection, it was decided to use the Plumstead Sidings that are just at the London-side of the new portal. One of those would be extended, actually running on top of the concrete box behind the portal, and curve round to join the new Crossrail lines between the portal and the station. Work trains could then reverse into the tunnel.
The station would, in any case, have to be built in stages to avoid disrupting existing North Kent traffic.
And the need for the work train route from Plumstead sidings dictated the order in which things would have to be done.
![86699_Abbey-Wood-Station-Design-Architects-Impression [online]](http://therailengineer.com/wp-content/uploads/86699_Abbey-Wood-Station-Design-Architects-Impression-online.jpg)
Crossrail overground works are being delivered by Network Rail, and it in turn brought in Balfour Beatty as principal contractor under a fixed- price design and build contract worth £132 million. A collaborative team of both Network Rail and Balfour Beatty employees was set up in offices a short walk from Abbey Wood station and two and a half years of design and planning commenced.
Soft going
The team was fortunate in that, although the North Kent line is only a twin track railway, and has always been so, when it was built a generous amount of land was fenced off as railway property. At the time there was little local building and the land quality was quite poor. Although the area is now extensively developed, there was still quite a bit of space available adjacent to the tracks.
This would allow the North Kent lines to be slewed to line up with the ‘new’ southern island platform. But, until that platform was built, there would be no point. Except, it would generate the space for the construction of the tunnel access lines.
So the decision was made that the first phase would be to slew the North Kent line over by about 10 metres, but only for half of the distance between the portal and the station. The rest of the slew would be done later once the platform works had been completed.
As was mentioned earlier, the ground conditions were poor. Aluvia, interspersed with layers of peat, made for soft, damp ground that would rapidly collapse if any weight was applied to it. Evidence showed that the existing embankment had been reworked several times in the past and, although it was now stable, any new work to the side would have the same problems.
Scheme project manager Nick Wilcox outlined the options that were considered. The first was to surcharge the area and deal with the settlement over time. Temporary fill would be placed on the area concerned, forcing it to settle and then topping up as required. The process could be accelerated by installing band drains. However, this would be very time consuming and require a lot of temporary fill.
The second option would be to excavate the uncertain ground and use lightweight fill. If the weight of that fill was half that of the ground removed, then twice the height would only put the same pressure on the substrate as before. It was a neat idea, but the excavation would require temporary works to support the existing embankment and the cost of the fill would be high.
Improving the ground using minipiles with layers of geo- grid trapped between them could form a stable structure when tied into the underlying strata. However, to develop good tension across the geo-grids the embankment would really need to be higher.
So the chosen solution was to go for a series of driven pre-cast concrete piles supporting a concrete slab. In effect, the soft ground would be bridged, albeit at ground level.
Slewing
Work commenced in September 2013. Signalling cables were diverted and equipment cabinets moved from the south side of the tracks to the north side. Once the site was clear, the civil engineers could move in to first of all stabilise the ground and then to build a new line, around 800 metres long, alongside the existing North Kent Up line. This could be done during daylight as the new track was about 10 metres away from the live railway.
While this was going on, an existing footbridge had to be removed and replaced as it would no longer span the enlarged track layout.
Once the track was in place, it was connected into the existing Up line during a 52 hour possession one weekend. The ‘zig-zag’ deviation at the London end would be permanent, the tighter one at the station end would be only temporary until the line could be extended into the station later in the project.
With the Up line displaced, the Down line could be slewed over by the same process, more or less onto the line of the old Up line. However, that old track was lifted and completely replaced – again being connected over a weekend.
Now that the North Kent line had been moved, the first stretch of Crossrail could be built. The old North Kent Down line was lifted and the embankment extended using the concrete slab and piles method mentioned above. Two new lengths of track, again about 800 metres long, were then installed along with a turnout for the line coming in from Plumstead Sidings. This will be installed later by Crossrail’s C610 contractor ATC as part of the tunnel fit-out work.
This first stretch of dedicated Crossrail line was handed over, as planned, on Monday 11 May. Balfour Beatty and Network Rail will now move on to the next phase of this South East Section (SES) project while Crossrail fit-out contractors ATC (Alstom-TSO-Costain joint venture) will complete the link to Plumstead Sidings and take the tracks down into the tunnel itself.
![DSC_9555 [online]](http://therailengineer.com/wp-content/uploads/DSC_9555-online.jpg)
But that’s not all…
Work on phase two of the project has already started, and a lot of that revolves around the station. Once again it is quite a complicated plan, and Balfour Beatty site agent Simon Swaby took care in his explanation.
The station building itself is exactly on the path of the realigned North Kent Lines, so that will be demolished. It is already closed and boarded off. It will be replaced by a completely new concourse which will span the tracks, with passengers accessing the platforms by stairs, escalators and lifts. Access will be from ground level and also from the adjacent road bridge. The bridge itself has room for the three through-tracks, and the piers will be reinforced with collision protection.
Meanwhile, the existing station footbridge has been replaced by a new, steel-framed structure. The bridge connecting the two platforms will be permanent, although it does not yet have its final cladding, and there is a temporary extension to an equally-temporary station building and gate line which will disappear when the main building opens in 2017.
Construction of the concrete rafts that will take the two ‘outside’ tracks is well underway, and the platforms themselves will also be constructed in phases.
First, the new platform face on the current Up platform will be completed, along with its track and an extension from the slew. Trains to London will be rerouted into the new platform face from February 2016.
This will allow the existing Up platform face to be demolished and rebuilt, completing the island platform that will service the North Kent lines.
Next, the Up line will be rerouted from the slew, eliminating the temporary ‘kink’ and completing the North Kent platform. This will free up the other existing platform which will be demolished and rebuilt as a second island platform ready to take Crossrail. At the same time, the Crossrail lines will be extended from their current position through the station.
The end of the line – for now
So that will complete the Abbey Wood terminus for Crossrail. The end of the line in the South East, although an extended route has been safeguarded as far as Ebbsfleet. The width of the existing railway land was convenient, although three properties had to be demolished to maintain signal sight lines and a few local gardens lost four or five metres off their lengths. Three footbridges will be demolished, including the one on the station, and a whole new station building constructed. Two platforms will have become islands and there will be a fence between the two railways, in part to stop maintainers wandering from AC to DC electrified zones.
When Crossrail opens in 2018, 12 trains per hour will run from Abbey Wood in peak periods. These will be in addition to the existing North Kent line services which will themselves be increased as passengers travel from all over North Kent and the Medway to change to Crossrail at Abbey Wood. It is estimated that the number of passengers using the station will treble over the next 15 years, reaching over 10,000 in the morning peak by 2026.
And that’s just from Crossrail’s south- eastern leg.
Access restricted – Situation normal for Corsham
Corsham in Wiltshire is a deceptive town. On the face of it, it has a picturesque main street with aged stone buildings. Gentile shops and olde worlde pubs. It’s a picture postcard town – or so it seems. Sure, there’s the never-ending roar of the A4. After all, this was the old London Road before the M4 was built.
So where’s the mystery? The mystery is underground. Deep in the Oolite limestone in a network of tunnels that would have been – and who knows, might still be – a regional seat of government in the event of nuclear Armageddon. Corsham isn’t as innocent as it appears.
Brunel drove his new Great Western Railway through – or rather just to the south of – Corsham, hacking through the Box Hill – his famous Box tunnel. And it’s from the eastern portal end that there is, or rather was, an access to this other subterranean and secret world.
Electrification is coming
This is just setting the scene. There’s a much more prosaic world of Corsham, of course, especially around the normal Pound Mead housing estate – built just to the south of the underground labyrinth and near to the site of the old Corsham station. This closed in 1965 but there’s still a useful piece of land for railway engineering works. Off Pound Mead runs a footpath to a neighbouring estate, across the railway and over a footbridge.
As all must be aware by now, electrification is coming to the Great Western main line. With it comes the need to ensure correct electrical clearances and, guess what, the old footbridge failed the test. Electrification has been on the cards for so long now that this was not a surprise, but when the green light was given it was time to sort out a definitive scheme. This was worked up from basic requirements by Atkins until a final design involving a standard London Midland steel footbridge was adopted.
The neighbours
Once upon a time, this footpath and bridge was in open countryside, but now it’s smack in the middle of housing with very constrained access. It was obvious early-on that the neighbours needed to be kept informed of all the works and especially what was going to happen when the old bridge came out and the new one was lifted in. The proximity of all these constraints drove the design. Raising a footbridge doesn’t just affect the main span structure. There are ramifications for the approaches as well. Inevitably they need to be longer – but in the case of the bridge at Corsham, the lengthenings were kept to a minimum by hogging the main span to achieve the lift of approximately 800mm.
Despite its lowly origins, the footbridge was well used and so the diversion of 1km during a complete closure had to be sensitively negotiated. A temporary structure was erected which carried the inevitable diverted services – water, electricity, telecomm cables and the like. Diversion works took place from 10 December.
Up and over
The new bridge was fabricated by Nusteel and transported from Kent to the old station yard ready for the 27-hour possession on 21/22 March. Main contractor Hochtief hired a 500 tonne crane from Ainscough and lifted the new span in over the houses. The existing footbridge bank seats were retained so avoiding the need to construct new footings.
The occupants had been given the opportunity to spend the night in a hotel while all this went on. Both the Network Rail and Rail Engineer web sites have an impressive timelapse video of the whole operation.
Relations with the neighbours have remained positive throughout and all that remains now is for the approaches to be completed and the services to be diverted back onto the new bridge. As Minhaz Uddin, Network Rail’s project engineer says, “On the next day we were greeted by residents very pleased with their nice new footbridge – with its ‘holly green’ paintwork!”
Another secret
Normality will return to Corsham although there is the possibility of the old station reopening. And the hidden subterranean world just a few hundred yards away wasn’t affected in the slightest. It just sits there waiting for our next national crisis.
But maybe the best-kept secret in Corsham is ‘Cinnamon’, a really excellent restaurant in the High Street. Well worth a visit.
Maintenance shed pipework: Not just a load of hot air
Refurbishing new rolling stock is an important job – managed in a tough environment where engineers constantly handle potentially dangerous tools in noisy surroundings.
As maintenance sheds age, many rail operators face a real problem with compressed air contamination. Compressed air provides power to some of the most- used applications that keep rolling stock operational, but it is generally contaminated with some of the most natural contaminants known – dirt, water and oil. Further contamination in the form of compressor oil and wear particles then mix with the atmospheric dirt and water to produce an abrasive paste, which has no lubricating properties at all.
Unless this contamination is removed from the compressed air system, operators face reduced efficiency, costly repairs and potential system breakdowns. But by being alert to specific technical triggers, maintenance and procurement teams can identify and resolve problems.
Diagnosis one: tool performance
Engineers working on rolling stock refurbishment projects tend to use a lot of compressed air in their tools.
Electricity is required to manufacture compressed air. The more air required in a facility, the more it costs to make. To keep running costs down, it’s critical to keep internal pipework clean and of a consistent diameter; this maintains optimal airflow and means the compressor doesn’t have to work so hard.
For example, The Carbon Trust’s GPG385 states that “for typical industrial systems, compressed air accounts for 10% of the electricity bill”’ and the British Compressed Air Society estimates that reducing pressure at the compressor by 1 bar is equivalent to using seven per cent less energy.
If the air pressure drop in a shed is too high, this usually means that tools are not running efficiently. It’s difficult for site staff to diagnose a problem against the background noise of a busy shed environment, so a typical response might be to turn the pressure up, or add another compressor. However, neither of these options is likely to offer any benefit. Increasing pressure means that it costs more to make the air, whilst adding a compressor generates extra electricity costs without making any difference, as the pipe can’t physically flow any more air.
Diagnosis two: older steel pipework
Older compressed air systems are typically constructed of galvanized steel pipework, as this material has historically been regarded as the most robust option.
But when steel pipework ages it becomes increasingly prone to rust; and rust inside an older steel pipe leads to the internal diameter decreasing. This leads to a reduction in air flowing through the pipe, and subsequently site engineers may find their tools no longer work as effectively.
Another common problem with badly run systems is the presence of water and condensate in the pipework. Where this happens, droplets come down to the tools and will destroy the tools in a much shorter timeframe. That means higher maintenance costs, and potentially unnecessary spend. So whilst technical teams may see tool repair as an inevitable problem, that’s not always the case; and operators may find that checking tool repair spend patterns over time offers clear insights that something is awry.
Permissible contamination
ISO 8573 is the group of international standards relating to the quality of compressed air, and ISO 8573-1 provides guidance on the permissible amount of contamination (oil, dirt and moisture) in an air system.
Once a rail operator has determined the correct air quality for its environment, it usually works in partnership with an original equipment manufacturer (OEM) to agree measurement capabilities of the equipment and the test levels to be provided.
The approach OEMs take to this task varies. Parker’s Transair system was the first high-strength, aluminium compressed air system launched to market. Successfully tested to the highest expectation of ISO 8573 for air quality, the product is totally modular, leak-free and third-party certified.
Past perceptions around the perceived strength of aluminium compared to steel are now changing. Transair’s consistency of airflow, high burst pressures (ensuring reliability and safety) and ease of replacement is key to this shifting landscape. For example, a Transair drop can be installed within minutes, whereas replacing steel pipework is an extremely time-consuming job (and more likely to disrupt busy schedules), so it’s an economical and reliable alternative to traditional steel networks. What’s more, technicians used to steel claw-type fittings will find it easy to use the valve and male thread combination used with this system.
Parker also has a flow calculator which checks existing pipework efficiency. In the event of any problems, the company can advise on options for pipework replacement, ensuring the correct size of pipe is specified and fitted. An energy calculator supplements this advice by working out an estimated payback of changing the system.