There are many intriguing local names that occur on the railway map, adding local character and interest to our national railway network. Stoat’s Nest is such a location. Writes Colin Carr

Passengers who use the Brighton main line between London Victoria, Gatwick Airport and the south coast might not know that, when they pass through Purley toward Redhill, they will travel through Stoat’s Nest. However, a number of passengers who didn’t know about Stoat’s Nest before Christmas will almost certainly be aware of its location now. Why? Because they were advised by Network Rail of significant changes to train services over the recent Christmas and New Year period.

Over the Christmas period, three significant infrastructure upgrades were carried out by Network Rail. These included a new platform and associated track and signalling work at Gatwick Airport, new signalling between London Victoria station and Battersea and a major replacement of switches and crossings between Redhill and Purley at Stoat’s Nest junction.

The renewal work at Stoat’s Nest was necessary because the existing layout was reaching the end of its useful life and if the renewal work had not taken place, speed restrictions would have been required. This would have impacted on Network Rail’s ability to provide an efficient service, so it was crucial that this work took place.

Infrastructure upgrades

The programme of work for Stoat’s Nest had been developed and meticulously planned by Network Rail over the last four years working closely with their suppliers and the Train Operating Companies who would be affected: Southern, First Capital Connect and First Great Western on both the main lines and associated branch lines. Tim Robinson, Network Rail’s Route Managing Director for the Sussex route, said: “These are three significant infrastructure upgrades which have been carefully planned to take place at the same time to keep disruption to a minimum. The result will be a more reliable network and more flexibility for trains calling at Gatwick, which continues to attract more passengers travelling there by train.”

The work at Stoat’s Nest included the renewal of 16 sets of switches and crossings located within a one-mile stretch of a four track section of railway between Purley and Redhill. Clearly, this is a crucial part of the infrastructure for the Network Rail signallers who operate this part of the railway network and they would want to know that all is in good working order for the return of normal services in the New Year.

Inclement weather

The principal contractor for the work was Balfour Beatty Rail with Archie Tait the contract director responsible for delivering this work on time and in good working order. In discussion with The Rail Engineer, Archie said that there were four identified routes for the engineering trains to access the site. He then explained that the job was nearly cancelled because the heavens opened hours before the start of the possession, two of the routes were flooded and there was a land slip on a third route. A decision had to be made whether they should continue, risking a possible overrun of up to four days.

Archie also added that as part of the planning process, Network Rail and Balfour Beatty had set up a command and control centre, which he described as a ‘War Room’, for monitoring progress. This would interface also with the Sussex Route control centre, thus enabling all options to be considered and amendments to the plan introduced and implemented with everyone’s agreement.

Core Relay night shot DSC_0090 [online]

Fortunately, all the S&C components were delivered to site before Christmas and work had been completed to construct the components into modular S&C units. They used adjacent sidings to carry out this work and Balfour Beatty Rail employed its Kirow crane to place the units, the largest lift being a set of G switches.

Sound engineering principles

Given the very difficult circumstances resulting from the inclement weather and the pressure to not overrun the possession, there must have been huge temptation to cut a few corners to claw back time. However, Archie and his team were adamant that they were not going to compromise on quality. As a consequence, great care was taken to dig out the old formation and creating correct formation cross levels before placing a well consolidated ballast base ready to receive the S&C components. By adopting this approach, Archie said that, by 27 December, there was a growing confidence that it would be possible to hand back on time by sticking to the plan and agreed contingency and mitigations.

A total of 112 lifts were carried out during the possession. More than one thousand workers were inducted throughout the possession and they worked twenty-six thousand hours. Archie expressed his thanks for the invaluable leadership received from his senior contracts manager, Amar Patel, as well as Mark Veness, project manager. Atkins Rail provided the signalling support for the project and a whole host of suppliers added invaluable support to the project. On the Monday 13 January, all the associated stressing and welding was completed and the four lines returned to the planned temporary speed restriction.

A team effort

We must not forget Network Rail’s National Delivery Service (NDS) which, with the cooperation of the route controllers, managed to redirect the engineering trains, re-roster their drivers and ensure that all the resources and materials were delivered to site. This must have been a herculean task given the time of year, the extensive flooding and the very tight timescales involved.

Steve Featherstone, track programme director for Network Rail, has suggested that this work must be an early candidate for ‘Project of
the Year’. It will certainly be hard to beat. It is difficult to imagine a worse set of circumstances for a delivery team to face. Four years in the planning and, if postponed, it would probably take another four years to gain access to do the work again. So the team had to balance the risk of overrunning by four days, and the negative effect that would have on passengers and in the media, against the nightmare of having to maintain the old and life-expired infrastructure for another four years.

Clearly, the expertise available and the confidence of the Balfour Beatty Rail team to deliver, knowing that they had the full support of the command and control centre, was significant. The attention to sound and proven engineering principles, ensuring that the ballast formation was constructed properly without compromising quality, required a significant amount of professional expertise. The result is a credit to those involved and will be appreciated by those who inherit and maintain this element of the infrastructure in future years.