Borders Railway: The construction story so far

Transfer of responsibility

Network Rail signed a project transfer agreement with the Scottish Government in November 2012, following 11 months of detailed planning and negotiations between the two organisations. The agreement committed Network Rail to complete the project by summer 2015, and we are on target to deliver this.

Advance work

Advance work to make the sites safe and ready for civil engineering works commenced in January 2013. This involved the removal of trees and vegetation along the route, fencing work to secure the working areas, and the construction of access points to the railway corridor.

Demolitions were also necessary as there were a number of houses which had been built on the route after the Waverley Line was closed down, or whose proximity to the old railway line were now incompatible with modern safety standards.

Advance work also involved a programme of ground investigations, using mobile drilling rigs, to establish the type of ground and rock along the route of the railway. This activity was supplemented by a range of engineering and environmental surveys to provide detailed information to support the development of the construction plan. Finally the team also began the painstaking process of identifying and diverting or protecting water and gas supplies and other utilities.

The project was split into three sections (North, Central and South) with a headquarters in Newtongrange and subsidiary section offices in Monktonhall, Fountainhall and Galashiels.

Earthworks

Starting in April 2013, around 1.5 million tonnes of spoil has been excavated along the whole route. The main focus for earthworks was in the most northerly section where the new railway will take a different route from that of the Waverley Line. As a result, an entirely new rail alignment was required to be formed.

Mining remediation

Another significant part of the preparatory works, mining remediation, took place throughout the first half of 2013 at various sites along the line, but with particular emphasis on Monktonhall, Newtongrange and Gorebridge. Mining remediation work involves stabilising the ground where the railway would be crossing old mine works, and in this part of Scotland that proved to be a significant undertaking.

While the project had access to many historical records, many mines in the area were exceptionally old and there was no comprehensive account of their location or scale. Drilling rigs were brought onto the sites to identify the location of underground voids and cavities which were then filled with grout. By April 2013 over 4,000 tonnes of grout had been pumped into old mines, and over 300km of drilling had taken place.

Structures

One of the biggest physical barriers to returning trains to Midlothian and the Scottish Borders was always going to be the A720 City Bypass, which runs south of Edinburgh and connects the city to the A1. It is used by approximately 80,000 vehicles each day.

By spring 2013 those motorists began to see evidence of a diversionary section of road which was being created alongside the route of their daily commute. The temporary diversion began operating in September 2013 and allowed an overbridge to be constructed through this stretch of road. A 450 tonne crane hoisted 48 22 tonne wall panels and 24 66 tonne roof panels into place. By June 2014 this significant obstacle was finally overcome, and the team has returned the A720 back to its former alignment. A road bridge now carries all of that traffic on the dual carriageway over the new railway line.

The longest bridge to be built from scratch was installed over Hardengreen Roundabout near Eskbank. Work to the bridge, spanning 71.m, was carried out over two weekends in February 2014. The installation saw a 1,200 tonne crane used to hoist the bridge’s four beams into place, each weighing 107 tonnes. A 30-strong construction team worked around the clock during the road closures to install the bridge beams and create the new bridge deck.

But the project has been determined to use as many of the Waverley Line structures as possible. With over 140 structures along the route, early investigative work was critical. Engineers examined all of the old Waverley Line bridges to ensure that they can be reused by a modern railway. Some were not suitable for modern use: the old deck of the Bowland railway bridge was demolished, for example; and the footbridge, which adjoined the two platforms at the former Eskbank station, was donated to the Waverley Route Heritage Association. At its new home in Whitrope it will be restored by a team of volunteers for eventual reuse on the heritage Border Union Railway.

However, other structures were in surprisingly good condition. The Lothianbridge Viaduct is one of the largest structures along the new route. Although it was over 160 years old, had transported many tonnes of passengers and freight, and then lay dormant for almost 50 years, it was still surprisingly sound and required very little restoration for its age. 

Two tunnels on the line needed to be refurbished so they were safe to be used by the new railway. Bearing in mind their age, the Torwoodlee and Bowshank tunnels were also in relatively good condition. Only around one tenth of the old brickwork needed to be removed or replaced. The rest of the brickwork was pointed, and strengthened where required, and should serve the line for many years to come. Construction teams achieved this by drilling through the brickwork, then pumping concrete into the voids behind to make sure it was secure. In the 200m-long Bowshank Tunnel where we have used slab-track as an alternative to traditional ballast, the team also needed to lower the tunnel floor by 400mm in order to accommodate passive provision for future electrification.

Protecting the local environment

With such a large project there was always going to be an impact on local flora and fauna. At one stage we had to divert the Gala Water river which runs alongside the railway line in the southern section. As a result the project team has worked hard to ensure they have done all that they can to help protect local wildlife that lives along the new line of route. It was work of this nature which led to the Borders Railway project team celebrating after receiving an ‘excellent’ CEEQUAL award rating in recognition of its outstanding environmental design credentials.

Track laying

Track laying marks the point in the project when peak construction comes to an end, and the railway corridor begins to take shape.

Deliveries of key materials begun months ago: ballast and railway sleepers were stockpiled along the route ready to be laid.

From June 2014, our teams have been installing drainage, creating attenuation ponds, preparing and compacting the ground, and laying ballast and sleepers. The rail installation machine with its specialist team from the Netherlands, began work on 6 October 2014 and we anticipate it will be finished by the end of 2014.

The coming months will also see engineering trains including ballast delivery trains, tampers and automated finishing machines running up and down the line completing the track installation.

The Borders Railway will have seven sets of points, at the ends of the passing loops, and at Tweedbank station. The points were transported from the manufacturer in sections, and reassembled on-site prior to the long rails being installed.

Now that the track laying is underway, work can begin on the railway’s stations. The station platforms are already taking shape and car parks will be built at six of the new stations.   However there are many more works which need to be undertaken at the stations before they are completed and handed over to the train operating company including signalling and telecoms and the installation of station furniture such as CCTV and lighting.

Completion

Construction will be completed in June 2015 after which time driver training will commence along the route. Passenger services will then begin operating on 6 September 2015. This will be a historic moment for all those members of the community living along the line who have been watching our progress over the past few years, and who can see the railway really taking shape.

For the project team, the most rewarding part is seeing the railway coming to life, and the prospect of trains coming back to an area where there haven’t been any for many years.

References

1. At 2012 prices
2. At the time of providing this article, October 2014.

Biography

Hugh Wark is the Project Director for the Borders Railway and has led its design, procurement and construction since Network Rail became involved in 2011. He is a Chartered Civil Engineer and has spent his entire career in railways. Hugh was previously in charge of the Airdrie–Bathgate Rail Link Project and the West Coast Route Modernisation in Scotland.