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!