The magazine’s editor, David Shirres, also gave a sell-out Zoom presentation on this topic to the Railway Division of Institution of Mechanical Engineer on 2 July. This was entitled “What is the judicious mix?” in view of the recommendation in the report by the rail industry decarbonisation task force that a judicious mix of electric, hydrogen and battery traction is needed to decarbonise rail traction.
The presentation answers the judicious mix question as well as addressing wider decarbonisation issues such as modal shift to rail, zero-carbon electricity generation and the supply of hydrogen. It showed how the electrolyser plant that supplied Aberdeen’s fleet of ten hydrogen buses offers lessons for hydrogen trains.
The IMechE’s Railway Division has seven Centres throughout the UK (Midlands; Milton Keynes; North East; North West; Scottish; South East and South West) which each provide regular technical presentations. During the Covid emergency, the Centres are planning to hold virtual presentations until at least December.
For further information about these events google the Centre name, IMechE and Railway.
Here at Rail Engineer magazine, we seem to have a thing about tunnels – especially tunnels with blocked drains. Back in 2012, we scrambled through Dove Holes in Derbyshire. For a Christmas treat in 2017, we covered Sevenoaks tunnel. Obviously so impressed, we went back in 2018 – although it might have been that the author had forgotten that he’d written about it only a year earlier!
Same themes – long wet tunnels, clogged drains, bad track.
So, how can we explain the attraction of Kilsby tunnel? It, too, is wet. It, too, is long. It, too, has track issues and, of course, it, too, has a blocked drain.
All the boxes are ticked but, by now surely, these alone can’t be enough.
And what’s the strange title all about?
Groundwater and chemistry
Let us, for a moment, step back (carefully) and look at some basic facts.
Kilsby tunnel is on the southern part of the West Coast main line (WCML) just to the south of Rugby. When it was opened in 1838, at 2,432 yards (2,224 metres) long, it was then the longest tunnel in the world.
It was a challenging tunnel to construct, the work having been frustrated by running sand and groundwater. One hundred and sixty-two years later, the groundwater, at least, is still causing problems. With a high mineral content, anything static that is drenched in water percolating from the tunnel walls and soffit will gradually acquire a coating of calcium carbonate – and probably other ‘stuff’ as well. The track ballast is static and, over time, becomes calcified. The same thing happens to the drains. Everything turns to something as hard and impenetrable as concrete.
This has been going on in Kilsby tunnel for generations. The central drain, in parts, ceased to function. The track was not drained, and track quality suffered. In recent months, in order to reduce the number of ‘rough ride’ reports, an Emergency Speed Restriction of 90mph had been imposed – from a normal linespeed of 110mph.
‘Something had to be done’ as Network Rail was being charged hundreds of thousands of pounds in delay penalties on one of the busiest parts of the national network.
In normal times – and early 2020 was not normal – the repairs to the drain would have taken years to organise. Many repair attempts had been made, but with only 16-hour rules-of-the-route possessions available, these have generally been ineffective.
The idea of a long blockade of Kilsby had, until now, been in the rather difficult pile. It wasn’t going to happen any time soon.
But, as has just been mentioned, early 2020 was not normal. This was the time of the Covid-19 pandemic, when everyone was encouraged to stay at home and not use public transport. By and large, the public did stay at home and very few travelled on the trains. Indeed, the normal passenger loadings of the Avanti services were in single figures or barely double figures. A special, deconstructed timetable was in use.
Rising to a crisis
This is the point when a mundane story about a wet tunnel with a blocked drain takes an abrupt turn into the unexpected. It does so because the rail industry also made an abrupt change in the way it normally worked. There was a seismic shift.
Maybe it was as a result of a chance remark made at the right moment. Maybe it was just a general realisation that now was the right time to suggest the unthinkable, to think about a complete blockade of the WCML – now!
Apart from during times of crisis, railway projects tend to evolve cautiously. But this was a crisis and an opportunity. And the railways always rise to a crisis!
Before anything was done on the ground, there were conversations to be had. The parties involved with this part of the WCML were Network Rail, Avanti – its trains use the ‘old’ line straight through to Rugby and beyond – West Midlands Trains, LNWR and the freight community, which run around the Northampton line.
With a tentative proposal that the line through Kilsby be blocked, Avanti was asked to comment on impacts to their services. The diversion through Northampton adds about 15 minutes to a mainline service and it was this extra time that affects both turnround times at terminuses and unit usage.
Quick analysis showed that the extra time actually helped Avanti in some locations, because terminating trains could be held in a platform instead of having to shuffle out of the way until the return departure time. On some longer services, an extra unit was needed to maintain return timings.
Network Rail looked at the pathing of Avanti trains and points of conflict with slower trains. It was found that, with the less onerous demands of the deconstructed timetable, the Avanti trains could just follow each other via Northampton with very little interruption of the West Midlands or LNWR services. This worked so long as enough time was built into the revised Avanti running.
It is tempting to think that this exercise was an application of an existing contingency plan for when the WCML is blocked because of a major incident. It wasn’t, as contingency plans are based on normal timetables. The Kilsby blockade timetabling had to be started from scratch.
Deconfliction, a process (as the name suggests) of determining where/when train paths conflict, can be a lengthy process, but, because there were fewer trains, one of Network Rail’s signallers ran the simulator and put a ready-reckoner deconflictor together. Every time a conflict was identified, a regulating policy was decided. This boiled down to a view that an Avanti train would go first and the WM train would be two mins late. “We’ll just live with it.”
The mood was positive. In fact, the mood can be summarised in the words: “Do you know what, we will be kicking ourselves in three months’ time if we don’t take this opportunity.” From that point on, the project had a life of its own and there was an almost collegiate approach to make it all work.
The length of the blockade depended on the length of the shopping list, so engineers looked at the core requirements. These were 800 yards of drain renewal, 870 yards of track renewal on the Down line and 650 yards on the Up line.
The track renewals engineers boiled this down to a requirement for a ten-day blockade – from a Monday. What emerged through further rapid discussions was an offer of two full weeks with the weekends at each end. The idea was to engage in maintenance works at the weekends and let the drain and track renewals team work in the intervening time.
Thus, the project was born, industry partners were on board and all was set for a hectic few weeks.
Of course, as word spread that there was going to be a blockade on the WCML, engineers of all descriptions started to amass like bees round a honeypot. Here was an opportunity to carry out work that couldn’t be missed.
To control this feeding frenzy, the blockade was split into four logical worksites – A, B, C and D. Worksite A was the tunnel, with trains coming and going from the North. Worksite B was a mix of renewal and maintenance and therefore had a management structure that controlled it in a renewals-based manner. Worksites C and D, to the south, were predominantly maintenance and so were more ‘high-street’ environments, where people booked in and out and were able to do maintenance and ad hoc activity in a less ‘regimented’ manner.
Whilst many industry norms were being broken in the birth of the blockade, the actual worksites conformed with known and accepted activity templates. When work is planned within a tight timescale, industry processes and protocols have to be used to give the practical impression that it’s business as usual. People are then working in a manner that they recognise.
On the ground
All this happened at a strategic level. Closer to the ground, there was also much activity and it’s worth seeing how everyone’s efforts blended to ensure a successful outcome.
Symon Reid is Network Rail’s infrastructure maintenance engineer. He manages the infrastructure from the 34 mile post in the Cheddington area, near Aylesbury, to just south of Coventry on the Coventry line and just south of Shilton on the Trent valley lines. Kilsby is on a critical two-track section between Rugby and Milton Keynes.
“We’d been doing some drainage inspections in the tunnel and found a run of drainage of about 150 metres that was completely collapsed and clogged with all sorts of silt and calcified ballast.
“Track defects were increasing and we were building up a project to mend the drainage, but the only way to do it was to remove one of the roads and break out the drains completely, to allow it to be renewed.
“The tunnel has had water problems for many years. There is a very high water-table in the tunnel and, with the drain in the six foot being clogged, it is easily overwhelmed.”
The idea of a bold project to tackle the drain was being hatched, but it came as a ‘surprise’ to hear that, not only was a blockade agreed, it was also happening in five days’ time!
His Northampton maintenance team was mobilised and made the most of the extended possession times on this intensively trafficked part of his network.
The phone call
Stevie Welsh is the senior programme manager with the CRSA (Central Rail Systems Alliance) at the Aston depot. His involvement with the project started with a telephone call. There was a simple request. “If there was a blockade of Kilsby tunnel for 15 days, what would we be able to do?” At this stage there was no mention of forward timescales – it was a routine enquiry perhaps. Conversations took place, past specifications were researched, bar charts were drawn up. The reply to the query was sent in.
Then came the start date. Saturday 2 May – in nine days’ time!
“The weekend prior to the start, the team went into the tunnel and did a site walkover to check the specs on the ground and to get the job marked up. There were the plant companies, the labour suppliers, signalling engineers, overhead line engineers and the track maintainer, along with Manta, the tunnel ventilation fan supplier.
“Trial holes along the length of the drain were dug, to see how the two tracks were affected.
“Bringing everyone together gave us the confidence that we could deliver all this work.
“The biggest unknown was the old drainage system, because we didn’t know how difficult it would be to remove. The renewal of the drain would be fine. The renewal of the track would be fine.”
Critical component requirements included all the items needed to install the drain – the pipes, catchpits etc. These were placed on order with the manufacturer, Aqua, which changed its production schedule specially to accommodate the Kilsby job.
The design scheme was by PBH and was based on works previously carried out in the tunnel.
All’s well – until it isn’t!
It was known that the existing drain was of concrete construction and that it could cause difficulties during removal. The team was encouraged by making rapid progress at first, when the first 100 yds went very smoothly………… until it didn’t.
Hydraulic peckers had to be used and, even then, progress became frustratingly slow. It was time to regroup. Bar charts were modified. Contingency times were absorbed. Traincrew times were changed and all the companies involved were put on notice that shift arrangements were likely to be amended. A demolition job that should have taken three days extended to six.
It was time for everyone to hold their nerve. The main priority was to renew the drain. Ending the blockade without renewing the drain would mean that the track would rapidly deteriorate and the prospect of getting another blockade anytime soon was vanishingly remote.
In the end, those tackling the stubborn drain began to adapt to the difficulties and progress accelerated. With the drain out of the way, the remaining tasks – drain and track renewal – were all familiar and predictable. Tensions eased and the possession was handed back at 06:23 on Sunday 15 May, with all work completed as planned.
The Kilsby project was a direct result of the Covid-19 emergency. Without it, passenger numbers would not have plummeted and there would never have been a discussion about a two-week blockade on the WCML in early springtime.
However, with the opportunities came limitations and obligations. Just because the blockade had been agreed didn’t mean that the virus had somehow gone away. The threat still remained and had to be managed.
Social distancing – keeping two metres apart – had to be maintained. Fortunately, disciplines had evolved over the previous weeks and these were incorporated in the work patterns.
Work in Linslade tunnel, a single bore tunnel further south on the WCML, a fortnight earlier had also been carried out under Covid restrictions and measures were found to be practical. These involved reminder signs, sanitisers around the compound area and a removal of sitting down messing facilities to avoid close contact.
Covid marshals, present on site and also at the compound area, made sure that everyone social-distanced. There are tasks where two-metre distancing was not possible. For these activities, air-fed masks were available.
Maintenance work has had to work with Covid restrictions from day one of the lockdown. Again, a mix of distancing and PPE is used. Asked whether this has had an impact on productivity, Symon’s reaction was that, counter-intuitively, it didn’t seem to slow work down at all.
James Dean, route director for WCML South at Network Rail, reflected on the whole project.
“With the wider industry driving devolution to get route structures closer to customers – train operators and freight – we felt that this one, really unusual approach to things had actually created a very devolved approach to life,” he commented.
“What we found was that we had contractors, operations, maintenance, track renewals, the supply chain – we had technical authority – all working in a very quick, fleet-of-foot, prioritised, customer-focussed manner to deliver something that was extraordinary.
“The biggest lesson learnt is that we have found how to work like that. It’s a really good indicator of what can be done when we devolve things more, down into route structures within Network Rail.
“Beyond any doubt, we changed ways that people thought things could be done. Take, for example, ‘simple’ things like procurement. If we need to be doing things like this on a regular basis, we need to look at our procurement methodology. We need to look at how our frameworks with our suppliers can be set up. We need to understand how chains of command can be made slicker.
“Another powerful example was drafting the scope and remit for the work. We sat down and, within a day or two, had written a fairly detailed summary for the contractor to go and deliver. That would take six months normally – it’s just crazy when you think of it. But those sorts of things where people just sit down and have a conversation, rather than a long drawn out GRIP process, is where I think we really identified the benefit of people working in a much more localised manner.”
Gus Dunster, executive director of operations at Avanti West Coast, concurred: “We are pleased to have played an important part to facilitate this unique opportunity for Network Rail to access and maintain the railway between Rugby and Milton Keynes.
“This is a notoriously difficult section of the network to maintain, due to the density of traffic that it carries, and speed restrictions have frequently needed to be applied because of this.
“The scale of work undertaken would usually involve months of careful planning but, with a reduced timetable in operation due to the Covid-19 pandemic, we were able to do this in a matter of days. Working together with Network Rail, we could facilitate access for the project, while ensuring our vital services were protected for key workers and those making essential journeys. We put customers at the heart of our plans and diverted our trains via Northampton to keep them moving and minimise the impact to their journeys.
“The project has been a great achievement in unprecedented circumstances and, with 292 of our trains passing through Kilsby Tunnel on a typical weekday, the restoration of the line will improve reliability for many customers for years to come.”
There we have it. Another story about a wet tunnel with a blocked drain. But the parallel tale is about how railway decision-making can be slick, can be focussed on customers and can achieve remarkable outcomes.
It’s not rocket science. We’ve just seen, despite the national emergency – or maybe because of it – a full-scale working model of how effectively the railway can be run.
A Yorkshire-based SME (small to medium enterprise) has been awarded a major contract working on High Speed Two (HS2), generating new jobs
Railway technology company 3Squared is working with one of HS2’s direct contractors, Skanska Costain Strabag JV (SCS JV), which is delivering the tunnelling programme for the route between London Euston and the M25.
The three-year contract will see the Sheffield company supplying its RailSmart software alongside some bespoke modules to form a supply chain management system, giving visibility of the complex freight supply chain and providing live performance, cost management information and operational control data in real-time.
As HS2 now has the go ahead to start building its new high-speed railway, the Main Works Civils Contractors (MWCCs) are leading the transition from scheme design and preparatory work to full detailed design and construction, and this progress has unlocked a huge amounts of new contract opportunities for the construction sector.
3Squared is now working on one of an estimated 400,000 supply chain contract opportunities that are being created for UK businesses and will support thousands of jobs on site and many more around the country.
This work package has meant that 3Squared will have expanded its workforce in 2020, creating thirteen new jobs at its head office in Sheffield, three of which were staff that have been employed following work placements or apprenticeships. It has also enabled 3Squared to further strengthen its relationship with local academia as it takes on 5 placement students who are all on their final degree year with Sheffield Hallam University.
HS2’s commercial and supply chain director, David Poole, said: “HS2 will play a key role in the UK’s economic recovery following the pandemic, and this contract award is just one of many that is helping create and sustain jobs around the country.
“Not only can HS2 support SMEs and regional economies near Phase One of the railway between the West Midlands and London, but it is also playing a pivotal role in the Government’s wider ‘levelling up’ agenda.”
RBS1 is the Rugby, Birmingham, Stafford line, often referred to as the Birmingham loop. The West Coast main line (WCML) starts at London Euston, heading north. At Rugby, it splits. One route goes up the Trent Valley, with stations at Nuneaton, Tamworth and Lichfield, before reaching Stafford and Crewe.
The other goes via Coventry, Birmingham International, Birmingham New Street and Wolverhampton, before it too reaches Stafford. That’s the Birmingham Loop.
On route to Birmingham New Street, the two-tracked, electrified line lies in a cutting, which passes through Brandon approximately 86 miles from London.
Brandon is probably better known for its Grade 2 listed viaduct, built in 1836 and designed by Robert Stephenson as part of the London and Birmingham Railway. However, it is the cutting, a couple of miles away which is the subject of this article.
You may recall that, at the beginning of February this year, the UK was exposed to a series of storms, in particular to Storm Ciara, a powerful, extratropical cyclone, which formed the first of a pair of rain and wind storms that pounded our shores. The storms were less than a week apart, the second one being Storm Dennis.
A number of people were killed and the rainfall levels were unprecedented, both during these storms and in previous months. The rainfall, which became a critical factor in exposing any earthwork instability within the railway network, was accompanied by winds that were recorded at 97mph, helping to make overall conditions extremely hazardous.
Impact of climate change
It is worth noting that the Summer of 2019, was recorded as the twelfth warmest on record, which meant that Network Rail’s geotechnical specialists were working with track engineers to manage the risks created by dry ground conditions.
Then the following six months were dominated by wet conditions and, by the autumn, the ground was saturated across much of the UK. The South East led the trend and this gradually migrated northwards to the Midlands. September was particularly wet and rainfall was recorded as 127 per cent of the UK average. In fact, only November saw a rainfall figure of lower than average (97 per cent).
CO2 levels are beginning to have a significant impact on our infrastructure and everyday life.
Because of the storms, the stability of the cutting at Brandon was causing concern. Network Rail has a call-out contract in place with contractors J Murphy & Sons, an organisation that has developed a reputation as the preferred contractor for earthworks as they are well equipped to respond to such a concern, with their own heavy plant and skilled operators in place throughout the country. Also, with depots strategically located in the north, south and midlands, rapid mobilisation within hours of a call is quite possible.
Action following storm Ciara
So, it was as a result of this unprecedented level of rainfall that Murphy received a phone call from Network Rail on 7 February, whilst storm Ciara was still in progress. Murphy was invited to attend a site meeting, at Limestone Hall Lane in Brandon, Coventry on the RBS1 line to examine a bank slip which had occurred on the Up Side of the cutting over a length approximately 200 metres.
Network Rail explained that it was in the process of arranging an emergency possession and isolation for the following night, to enable Murphy to remove the failed slip material and eventually stabilise the cutting by installing concrete blocks to retain any further slippage. Murphy’s representative at this emergency meeting was its project manager Christopher Reynolds, who is based in the regional offices at Stafford.
Christopher explained to Rail Engineer that, at the meeting, Murphy was also instructed to have a competent person/watchman positioned at this location around the clock until stability of the embankment could be resolved. Fortunately, Murphy has site staff on a call-out rota, ready to respond within hours to such an incident.
So, consequently, a watchman was positioned in a safe place in the cutting, armed with contact details for Network Rail control if circumstances were to change. Tower lights were put in position to illuminate the whole cutting, to enable the watch man to identify quickly any earthwork movement and respond accordingly.
To support this approach, Network Rail had imposed a Temporary Speed Restriction on both lines of 20mph (freight) and 50mph (passenger) throughout the cutting.
The team that was gathered to tackle this problem included Network Rail senior asset engineer Luke Swain and Murphy works manager Cathal McCann. They liaised with the Network Rail properties team to organise a land agreement with the farmer/landowner to ensure that access to the top of the cutting was agreed, to allow the large 32-tonne excavators and other long reach earth moving machines that would be required to carry out the work to reach the site.
Protect the horses
This access was critical, and Murphy was instructed to install 150 metres of wooden post-and-rail fencing to segregate the farmer’s horses from the planned work area.
Once this was completed, Murphy was then able to bring in large plant, including 32-tonne earth-moving equipment and a 60-tonne long-reach machine, to start work on the cutting. This all had to happen in a short space of time and Christopher explained that the farmer was very accommodating and helpful throughout the work, even though he was having to deal with circumstances that were totally unexpected.
Whilst the delicate and critical access negotiation was underway, Murphy’s team proceeded to establish the extent of the problem and to produce a design that would offer long-term stability for the cutting. However, whilst its engineers were on site, the bad weather continued over the following days and it was discovered that more of the cutting had failed and several pre-existing tension cracks were deteriorating, due to the continuing inclement weather. Slips 2,3 and 4 were now emerging.
Fortunately, Murphy was able to respond to this significant deterioration and new plans for additional resources were quickly put into action. Also, as Network Rail’s Luke Swain pointed out, the additional possessions that would be needed were quickly supported by the passenger and freight train operators. Joint plans, involving a huge amount of additional work, emerged from all parties that were agreed, enabling the route to remain open during this troublesome period.
Additional large excavators ranging from 13 to 67 tonnes were brought in along with additional road-rail equipment. Fortunately, the majority of the plant was owned by Murphy itself, and this was quickly dispatched from its plant depots at Golborne (Wigan), Hemel Hempstead and Cannock.
To keep everything happening in a safe and controlled manner, Murphy site manager Paul Tarbuck was the ever-present leader on site. He was working six or seven days every week to ensure that everything ran smoothly and that plant, materials and a skilled workforce were available on site and ready to work. The weather was improving, so what could go wrong?
The unleashing of a global pandemic, perhaps?
COVID-19 was not a problem at the time of the initial call-out, but it soon imposed itself on the work – and the world. However, because the contractors were using heavy plant and machines operated by individuals working alone, they were able to comply with the social distancing measures that were being imposed.
All machine movements were being overseen by banksmen, equipped with two-way radio systems, thus enabling compliance with the emerging government standards for the pandemic. As a further measure, Murphy also decided to introduce additional canteens, drying rooms and toilets to comply with social spacing and to have all site accommodation cleaned on a daily basis by experienced contracted cleaners.
Consecutive Saturday nights were utilised following the initial callout but, as the torrential rain continued and the situation deteriorated, three more slips were identified. All parties agreed that it was no longer possible to contain the situation solely with weekend working and that they would need to attend site under midweek possessions to install concrete blocks through the entire length of the cutting – approximately 200 metres.
Network Rail also planned to bring in a large freight train with empty wagons that could remove nearly a 1,000 tonnes in one night, which meant that the speed restrictions could be lifted and the permanent regrade works could commence.
Only viable design
The services of international designers BryneLooby, with headquarters in Dublin, were procured by Murphy and a design was signed off and agreed to regrade the full length of the Up side cutting and install a Redi-Rock wall at the toe of the cutting. Christopher explained that other options were considered, but these were soon put aside as this was the only viable option, given the current circumstances.
The cost of the works will be in the order £4.5 million. Fortunately, the weather has now improved considerably and the works are progressing well. Stone is being delivered from the quarries as requested and, at the time of writing this article, about 30 per cent of the planned work is complete with final completion due in August 2020.
In addition to the emergency work, Murphy is currently supporting Network Rail’s efforts in assessing the stability of the remainder of the cutting. This includes the installation of monitoring equipment and facilitating detailed inspections by Network Rail’s geotechnical engineers.
As Luke Swain noted, throughout this challenging period, Murphy has not only provided a critical role as the on-call earthworks contractor at Brandon Cutting, it has also managed this large complex site in conjunction with a series of other landslips that were triggered across the region by the winter weather conditions. A crucial element of the supply chain which keeps the railway safe and operational for passengers and freight, Murphy will have a significant part to play in delivering Network Rail’s ambitious geotechnical renewals plan on the North West and Central region.
Given all that is happening in the world today, with COVID-19, lockdown and a global pandemic, it is easy to ignore the day-to-day emergencies, but they don’t just go away. Murphy has clearly thought through the different emergencies that could hijack the UK railway network. It has organised its engineering teams strategically and was ready to respond to whatever storm Ciara had to offer, helping Network Rail to maintain a pathway for trains to run on one of the most important routes in the railway network, emphasising the value of being prepared to respond to whatever emerges, be it virus or tempest!
When someone who has had over forty years in the railway industry says that a machine is probably one of the most versatile railway materials handlers available, it is time to take notice!
Tony Fazekas, business development manager for Rhomberg Sersa, started his railway career dealing with the very first stone-blowers and ballast cleaners and, in his time, has seen many ‘big yellow machines’ come – and go. His view of Rhomberg Sersa’s Universal Materials Handling machine (UMH) is that it is “the Swiss Army knife of railway machinery for delivering material to and from site”. The UMH is part of Rhomberg Sersa’s ‘Machine Group’.
What to say about a machine that just dumps stuff?
Over the past three issues of the Rail Engineer we have looked at the Rhomberg Sersa system and the machines involved. Observant readers may have noticed that two machines in the system – the ITC and the MFS+ – have been covered in some detail. (Rail Engineer volumes 181 and 182). The final machine, the UMH, appears at first to be a little difficult to write about. What is there to say about a machine that just dumps stuff?
Well, in fact, there’s quite a bit to tell, and a conversation with Tony is a quick way to find out – and to be corrected.
The UMH – Swiss Army Knife – does dump stuff, but it is the way in which it does the dumping that can inspire so many varied ways of planning a project.
A capacity of up to 400m³/hr
To recap, the UMH is a rail-mounted, materials-handling machine. Unlike its companion machines the ITC and the MFS+, it does not have retractable caterpillar tracks. It is usually marshalled at the end of a rake of MFS wagons (the ones with a conveyor all the way along for loading and unloading aggregates and other material) – although it is compatible with many other items of rolling stock. It can travel at 60mph and has a RA1 route availability. It appears to be a completely conventional wagon, kitted out with several systems of conveyor belts.
New or spent ballast is fed into the UMH from the conveyors of linear wagons at the rear of the machine, initially onto the lower handling conveyor. The UMH is thus directionally sensitive – which is another way of saying that it has to be marshalled the right way round within a train and the whole train has to be the right way round as well!
From the initial handling conveyor, the material is directed to one of three other conveyor systems. The upper conveyor can swing sideways – out to 90° to the machine, an arc of 180°. It has a reach of up to 5.6 metres either side of the centre line of the track that the machine is standing on and has a capacity of up to 400m³/hour (about 800 tonnes/hour). This conveyor can be used to feed materials into wagons on adjacent lines, to deliver bottom ballast for spreading by dozers or for the rapid distribution of material for civils works such as bank slips.
The other two conveyor belts are on arms, one each side of the UMH and located towards the base of the machine. These can handle up to 200m³/hour (about 400 tonnes/hour) and are used for the precise placement of bottom ballast, top stone and shoulders, as well as drainage-trench and landslip materials. These arms can swing out independently – up to 65° from the machine’s centreline – and they also have a reach of 5.6 metres from the centre of the track.
There is also a gravity system that can deliver accurate quantities of stone for maintenance runs or for top-up around the shoulders.
So far, mention has been made of ‘materials’. These can include both new or spent ballast, along with other coarse materials used in off-track projects. If the MFS and MFS+ vehicles can handle it then so can the UMH – very quickly and accurately.
Although confined to a railway track – it does not have caterpillars like the aforementioned MFS+ – the UMH needs not be a static piece of plant. On the contrary, it can spread materials whilst on the move. With an engineering supervisor coordinating the specialist operators throughout the train, the whole system can be used at a crawling pace to spread stone very precisely over long distances.
The role of Europe
Part of Tony’s career involved travelling round Europe to explore how machines that had been developed and used over there could be brought across to the UK. Engineers in Europe have been using MFS+ vehicles, ITC machines and UMH machines for around twenty years.
Is there a natural translation of techniques? Well, it has to be acknowledged that the UK structure gauge proves to be a challenge on many occasions. Almost all of the kit from Europe has to be specially built or specially adapted, both to fit into the UK’s relatively constraining envelope and to meet today’s rigorous safety requirements, which is why all of the Rhomberg Sersa machines are fitted with dust-suppression systems.
Nevertheless, Rhomberg Sersa has invested in three types of specialist kit. There is the ITC, a derivative from the mining industry, used to excavate at the ‘coal face’ end of a job. There is the MFS+, a track and tracked machine that adds enormous flexibility to single line renewals planning, and the UMH for getting rid of ‘stuff’ or bringing ‘stuff’ to site – quickly.
The roll call
Rhomberg Sersa has one ITC machine, two MFS+ machines and three UMH machines. With the exception of the ITC, these are all planned through the national NROL (Network Rail Online Logistics) system, so that a client can rely on everything that is needed for a project turning up – and turning up the right way round.
This series of Rail Engineer articles has identified the advantages of the machines in the Rhomberg Sersa Machine Group. They all have their specific basic uses, but it is up to UK engineers to learn how these ‘normal’ tasks can be varied. This certainly applies to the UMH machine. It has a basic job – which is to dump stuff – but there are many ways in which its flexible methods of dumping can be used.
The key to innovative thinking
Tony took pains to describe how materials for landslip remedial works can be speeded up with innovative planning, how the number of items of plant can be reduced and the number of staff at risk around these machines can be minimised when material is delivered in large quantities and delivered precisely.
Railway plant doesn’t have to be used only on track projects. Graded materials can back-fill drainage trenches or other construction without the disturbance that can be caused by conventional plant.
The UMH really is the Swiss Army Knife of railway engineering. If someone who has seen forty years of railway engineering says so, then take notice!
Rail regulator the Office of Rail and Road (ORR) has published its 2019-20 annual assessment of Network Rail and has found that the infrastructure owner beat its target for efficiency savings last year.
In the first year of the new control period 6 (CP6), Network Rail saved more than £385 million as it looks to deliver £3.5 billion of efficiency savings over the five-year period.
However, ORR claims that this followed its early intervention in holding Network Rail to account and to improve planning after concerns were raised that Network Rail might not deliver the required volumes of work and efficiency improvements needed in CP6.
Passenger and freight performance also varied by region over the last year, with opportunities for Network Rail to learn from its better performing regions to improve performance nationwide. For example, passenger train performance has been good in the company’s Southern and Wales & Western regions, but below target in others, with poorest performance in the North West & Central region.
Freight performance was below target in three of the company’s five regions. ORR has separately investigated and reported on poor train performance in the North West & Central region and confirmed that Network Rail has now developed suitable improvement plans.
The company made progress in developing longer-term plans to improve performance; for example, improving the skills of operational staff. It also delivered its planned works to renew the railway in 2019-20. This is a good start to its five-year plan for keeping the rail network in good condition.
John Larkinson, chief executive of ORR, said: “We are very pleased that Network Rail has listened to and acted early on our concerns about making efficiencies, meaning that for the first time in many years it is delivering more efficiently than planned. It also delivered its planned volumes of work, to help keep the network in good condition. This efficient delivery is good news for its customers and funders.
“But performance – in terms of delays to passengers and freight – was uneven and just not good enough in some parts of the network. We will continue to hold Network Rail to account for its performance as services return to a more steady-state.
“Working with the industry, Network Rail is looking at what lessons can be learnt from the impact of Covid-19 on how it operates and maintains the railway. This is important work, which has the potential to drive further improvements over time.”
South Western Railway’s (SWR) first Class 701 train has arrived at Wimbledon depot, marking a significant milestone in the £1 billion transformation of suburban travel.
The 10-car train, known as ‘Train 6’, will become the focus of training programmes and dynamic testing to ensure the entire fleet is passenger-ready ahead of its introduction later this year.
Neil Drury, SWR’s Engineering Director, said:
“We’re delighted Wimbledon depot has received its first class 701 train. There will be many significant developments in this programme – this is one of them.
“Train 6 allows us to prepare our drivers, maintenance staff and other colleagues for a generational step-change in service performance, and ensure that the important components which define the experience of travelling on these new trains are ready before the fleet’s eventual introduction.”
Having Train 6 based at Wimbledon will allow drivers, maintenance and other depot staff to begin their training and develop new skills in preparation for the next generation of trains. Wimbledon depot will eventually become the new maintenance home for the entire Class 701 fleet.
All the current fleet operating on the suburban network – Class 455, 456, 458 and 707 trains – will be replaced over a two-year period when the new trains are introduced.
The train will also play a significant part in SWR’s programme for real-world network testing on passenger routes, which will take place from August. Modern onboard features allowing passengers to stay connected and travel comfortably – including air conditioning, Wi-Fi, at-seat charging points, travel information systems and fully accessible toilets – as well as technology which significantly boosts reliability and performance for passengers travelling every day on the network, will be put through its paces.
SWR’s Class 701 fleet consists of 90 new trains, representing a massive investment in modern, quicker and reliable services for passengers. Aided by the latest technology, the fleet will help more passengers arrive on time in the morning and evening peak periods on one of Europe’s busiest rail networks.
The track layout for the various junctions at Guildford, serving routes in several directions, were in need of scheduled renewal as a consequence of a level of underinvestment over a number of years. The switch and crossing work (S&C), in particular, was approaching life expiry and was displaying the inevitable increasing cost of maintenance. Several other work items in the surrounding area also needed addressing.
The Joint Alliance of Network Rail’s Wessex route and South Western Railway examined various alternatives for carrying out all this work. A series of long weekend possessions, of which 16 were estimated to be required, would have caused disruption to normal rail services for an extended period and would have been costly in its stop-start approach, with temporary reinstatements to ensure continuity of facilities after each weekend’s work.
Much better, decided Network Rail, to go for an extended blockade over and beyond the Easter weekend to get all the work done in one fell swoop. This would be done at a time when there would be less demand for the commuter services especially, as many workers would be taking time off for Easter and the school holiday.
Of course, completely unforeseen at the planning stage, the effects of the COVID-19 crisis and lockdown meant that there were almost no travellers. As it turned out, almost any dates could equally well have been chosen for the works!
The blockade overall was of ten days duration, but with a small component of it given back to traffic after four days. Apart from the renewal of all the S&C and some associated plain line, enabling the removal of five temporary speed restrictions – one of which was hardly temporary as it had been in force since 2016 – advantage was taken of the blockade to renew conductor rail, upgrade 41 track circuits, carry out some improvement works at Guildford station, renew wheel timbers on an underbridge and stabilise cutting slopes at a tunnel portal, along with several other miscellaneous works.
The overall blockade was taken from 00:01 on the morning of Good Friday 10 April until 04:00 on Monday 20 April. The Cobham lines were reopened to traffic at 04:00 on Tuesday 14 April, enabling a limited train service to run from Platform 1 of Guildford station to London Waterloo. This service was not greatly used in practice, no doubt due, in large measure, to the coronavirus restrictions.
For the remainder of the blockade, the possession was defined in a series of seven ‘Parts’, each one being a slight modification of the overall geographical area needed for specific work items or signalling testing, but in essence creating a working area over all five routes radiating from Guildford – to Cobham, Dorking, Haslemere, Reading and Woking.
The work did not involve any remodelling of the layout. Apart from the removal of a redundant headshunt at Guildford station, the track replacement was entirely like for like.
All of the new S&C concrete panels were manufactured by VAE & Partners, preassembled at that company’s Doncaster works, then broken down into 101 modules for transport to site at Guildford by road transport, provided by Walker Haulage and Lawsons Haulage. All of the modules were delivered in advance and stacked at lineside on both sides of the running lines.
The lifting and installation of the S&C modules during the blockade was carried out using two Kirow rail cranes, with the assistance of twelve road-rail vehicles (RRVs). The overall layout comprised fourteen S&C units. The removal of the old and the replacement of the new took place over a 4½ day period, from 16:30 on 10 April through until 02:00 on 15 April.
In addition to the S&C renewal, 1,500 metres of plain line was renewed and some heavy maintenance work carried out intermittently throughout the blockade. Also, 1,200 metres of conductor rail was renewed.
Craig Lightheart, blockade director for Network Rail, told Rail Engineer that the work progressed well and in accordance with the programme with only two exceptions – both regarding engineering trains.
18 engineering trains had been planned in for the delivery and removal of materials. One of these trains was for the delivery of new conductor rail. Unfortunately, because of social distancing rules required for virus protection, this train was prohibited from running. Therefore, the only conductor rail renewal that could be carried out used material that was already on site prior to the blockade.
The other, more significant problem, was that another engineering train, consisting of empty wagons for spoil loading, derailed at Hoo Junction in Kent on its way to site. This required the project team to juggle and repurpose some of the other trains to fill that gap.
41 track circuits were upgraded to EBI type, without change to the signalling design – again simply a like for like renewal. However, nine new location cases were installed as part of the rewiring scheme for the new track circuits.
Slope stabilisation at Sand Tunnel
Instability of the cutting slopes at the south portal of Sand Tunnel had led to a precautionary speed restriction since Christmas 2019. The Easter blockade provided the ideal opportunity to rectify this problem.
The local geology here is such that the exposed slopes, consisting of friable sand, were eroding – slips of loose material were occurring that risked blocking the running lines. The problem existed on both sides of the line but was more significant on the Up side.
The solution adopted was to regrade the slopes and install soil nailing with deep rock anchors to hold mesh down over the slopes.
Permission was obtained from the University of Law, on the Up side of the line, to use its grounds as a temporary access for the slope works. From there, machinery could work from the top of the cutting slope and a scaffolding stairway was installed for staff access to and from track level. The soil nailing was carried out by abseiling with the assistance of RRVs.
During the regrading of the slope on the Up side, an archaeological discovery of significant interest to local historians was made – a sandstone cave made up of several sections ranging from 0.3 metres to about 0.7 metres high. The cave may once have been much larger, but only this small piece survived the digging of the railway cutting through the hill in the early 1840s.
Initial findings by a specialist archaeological contractor suggest that it was a later medieval shrine or hermitage associated with the early 14th century chapel of St Catherine, the ruins of which are situated on the hill nearby. It may even have earlier origins as a site of cult activity, due to its pre-14th century name of Drakehill – ‘Hill of the Dragon’.
Mark Killick, Network Rail Wessex route director, said: “This is an unexpected and fascinating discovery that helps to visualise and understand the rich history of the area. A full and detailed record of the cave has been made and every effort will be made to preserve elements where possible during the regrading of the delicate and vulnerable sandstone cutting.”
Taking advantage of the 10-day blockade, Network Rail cleared its workbank in the area. This included:
Upgrading point heaters;
Rationalising hook switches;
Removing several large trees;
Commissioning a new transformer in an equipment room;
Resurfacing Guildford station footbridge;
Painting parts of the station buildings;
Replacing wheel timbers on the River Wey underbridge on the line to Haslemere.
Implications of coronavirus COVID-19 outbreak
Obviously, all the planning and resourcing for the actual work and the blockade, including bus replacement services and other alternative arrangements for rail travellers, had been completed long before it would be known that the world would be hit by the virus outbreak. Nevertheless, it was deemed important to stick with the Easter blockade plan, if at all possible.
In the last two or three weeks leading up to Easter, the Joint Alliance team had to review the implications from the COVID-19 outbreak and determine what changes needed to be made to enable the work to go ahead and yet still be in compliance with the government restrictions and precautionary arrangements.
Mark Killick explained what these changes were and related how it had all worked in practice throughout the blockade. He prepared a briefing video to be shown to all staff who would be working on the blockade, explaining the importance of the work still going ahead and why it could be defined as “essential” activity.
It was necessary to change or modify some of the planned activities to ensure that they could be carried out while observing the social distancing rules. Extra supervision would be provided to keep an eye on the social distancing working in practice and to take action immediately to remind staff if they forgot temporarily. There were even “social distancing champions” appointed, who would step in and stop an activity if necessary, then ask for a “take five” before recommencing work.
Back-up staff were incorporated into the planning, in case of anyone falling ill with the virus. In particular, certain specialist and critical staff for whom, in the event of becoming ill, might not be easily replaced, were mandatorily isolated in the days leading up to the blockade. A local hotel was able to remain open to accommodate staff who would have otherwise had excessive travelling distances and the hotel also provided food throughout for those staff.
Two-metre spacings were marked out for signing in procedures, hand gel and good hand washing facilities were provided on site. One example of thorough application of social distancing was at the Sand Tunnel worksite, where access to track level via the scaffold stairway meant that, if someone was descending, a person going up would have to wait to avoid passing at close-quarters.
Staff were encouraged to declare any encounter with the virus, for example, if there was any hint of infection within their own household. In fact, one such instance did occur, and the staff member concerned had to cease working on the blockade for the remainder of its duration.
On a worksite of this size and complexity, a number of contractors and specialist subcontractors were employed.
The track work was undertaken by Network Rail’s own Southern capital delivery track team, working with Colas Rail. On the various shifts, between 50 and 70 staff were on site throughout the S&C renewal works.
Sonic Rail Services and VolkerRail jointly carried out the upgrading of the track circuits, having up to 70 staff employed. Sonic provided the electrical feeds and the systems isolating the track circuits from the DC electric track equipment and VolkerRail provided the track circuits.
Cleshar Contract Services renewed the conductor rail with 12 staff. Osborne, Network Rail’s framework contractor, carried out the work at Sand Tunnel with 20 staff, and the resurfacing of the station footbridge. Directly employed Network Rail works delivery staff carried out the station painting and the wheel timbers for the River Wey underbridge was resourced with 15 staff from the same group.
Kier commissioned the new transformer. RRVs were supplied by Quattro for the S&C work and by Readypower for the conductor rail work.
When rail services are able to return to normal ridership, regular travellers from and through Guildford should begin to notice improved ride quality and reliability with the removal of speed restrictions and the updating of the signalling system.
But they will have hardly been inconvenienced or noticed that the area was given a discreet and well worthwhile £10 million investment, and all despite the virus!
Over the late May bank holiday and the following week, South Rail Systems Alliance (Colas Rail, Network Rail and AECOM) engineers replaced just under one mile (1,400 metres) of single-line track between Fareham and Botley on the Eastleigh-Fareham line, which forms part of the route from London to Portsmouth via Basingstoke.
The track was life-expired and, with a reduced number of trains running due to the Covid-19 crisis, this was an ideal opportunity to do the work. It was also school half term, so the small number of passengers who were using the line was further reduced.
Those passengers who did wish to travel were bussed between Eastleigh and Fareham, but those buses often only had single-figure passengers on them, vindicating Network Rail’s choice of timing.
The line was to be closed for a week, from Saturday 23 May until Saturday 30th.
As the track to be renewed was a single-track railway – it had been reduced from double to single track in 1973 – the normal practice of having supplies and equipment on the adjacent track was not possible. The line would have to be completely removed, dug out, new ballast placed and then new track laid. This would require the use of an NTC (new track construction) machine, which can lay sleepers ahead of itself, feed the rails into place and clip it up, ready for the machine itself to use that track as it moved forward.
In preparing for the work, Covid-19 had to be taken into account. All workers were instructed on the importance of distancing. High Motive, which provided a 24-hour service for duplex communications, back-to-back radios and RPE (respiratory powered equipment), as well as the MyZone proximity warning system for RRV (road-rail vehicle) exclusion zones, had sterilisation units on site so that equipment could be cleaned between shifts.
Work began in the early hours of Saturday 23 May. Much of the first day was taken up with cutting the old track into panels and lifting those out, with sleepers still attached, to be piled up alongside the line for later removal by train once the new track had been laid.
By the Saturday evening the old track was out and two new rails were being laid alongside the excavated trackbed, ready for the NTC machine when it started to lay track. The individual lengths of rail were welded together in continuous lengths.
The route included both track in the open and in Tapnage tunnel, (122 yards – 111 metres). Although the tunnel would require lighting, it was too short to need forced ventilation, although workers needed to be even more aware of the dangers of ballast dust, as well as having to keep two metres apart due to Covid-19!
Balfour Beatty’s NTC machine started work in the early hours of Sunday 24 May. At the front of the machine, two small ‘caterpillar’ tracks support a conveyor gantry that brings concrete (in this case) sleepers from the body of the machine and lays them in place, 600mm apart. It can place 10 sleepers per minute, although, with breaks and adjustments, it tends to lay around 1.4km (1,530 yards) per day – coincidentally, the same length as this track renewal.
Sleepers are supplied from a rake of special flatbed wagons pulled by and behind the NTC, with semi-automated ‘pickers’ running on rails along the edges of the flatbed wagons, bringing pallets of sleepers to the NTC and loading them into its hopper.
Once the sleepers are placed, the rail lying alongside the track is guided by a series of rollers, located on the NTC itself, into position and laid between the preinstalled clips. The rail is then clipped up before the wheels of the NTC machine run over the newly laid track.
The whole process is continuous and the entire length of new track, including through Tapnage tunnel, was completed in one 24-hour session.
Once the track was in place, the top layer of ballast was placed over it – the bottom ballast supports the track while the top ballast, above the level of the base of the sleepers, retains it in place.
One of Balfour Beatty’s tampers then took its first run over the new track. This process compacts and consolidates the ballast and also positions the track so that it is straight and level. Over the next two days, four more tamping runs would be carried out, each one improving the quality of the track so it would be in the best possible condition once the railway was handed back.
Over the same period of time, the rails themselves were stressed and trial running took place. Then it was just a question of tidying up, removing the old track panels and any other waste material, and handing the whole section back to the operator for Saturday morning.
What if there was a tried and tested solution to speed up trackside drainage times by a factor of 10, simultaneously reducing installation costs and improving site safety by halving the depth of trenches and the amount of crushed stone required? This method has been adopted by the highways industry for over 20 years, but fellow major linear asset engineers in the rail industry are yet to realise the same advantages.
This winter’s record rainfall and widespread flooding brought the issue of trackside drainage into sharp focus. Large sections of the network were inundated, flooding tracks and causing numerous embankment slips.
The scale of disruption highlights the importance of effective drainage systems. They must be able to resist high static and dynamic loads and be fully maintainable over a design life in excess of 60 years to provide the best whole-life cost.
As most drainage systems in the UK are installed during remediation, where time is limited, speed of installation is also a very significant factor.
Traditional cess drains
Current trackside drainage is reliant on cess drains, consisting of cut trenches, filled with crushed stone, below the sleeper level, either side of the track.
Excavating traditional cess trenches for drainage pipes and lining the sides of the trench with geotextile, prior to backfilling with crushed stone, is a relatively expensive and laborious process. Trenches deeper than 1.5 metres must be shored for support, prolonging the time that ‘boots are on the ballast’. Then there is the cost of disposing of the arisings and procuring new stone.
In addition, crushed stone is not a particularly efficient drainage material, since it interlocks when compacted, leaving very little void space for water flow.
The realisation that it is the void space within a layer of crushed stone that achieves the drainage flow led to the development and specification of Fin drains or Fildrains, polymeric cores that have a high void ratio.
ABG Fildrains are a preformed drainage layer comprising a high-strength, lightweight HDPE (high-density polyethylene) cuspated core, laminated with geotextile. Fildrain has a flow capacity many times that of traditional crushed stone, owing to the unique open structure created by the dimpled core profile, allowing unhindered water flow.
The cuspated core of Fildrain at just 7mm thick – when tested under simulated site conditions – achieves an in-plane flow capacity of 1.0 l/m/s at a hydraulic gradient of 1. This is eight times that of a 500mm layer of drainage stone. It is the reduction in layer thickness, and the narrower trench widths required, that enables the geocomposite drain to achieve project time and cost savings, reducing closure times and the number of trackside deliveries required.
Fildrain has many applications in railway cuttings, cess and embankment drainage and is BBA approved, meeting requirements for load resistance, maintenance and fast installation. It is simply installed into narrow trenches, with the excavated soil replaced as the backfill and then topped with a thin layer of crushed stone. Fildrain is supplied in a range of heights to suit each application and for easy connection to existing drainage systems.