IN Brief:
- An 18-day closure compressed engineering work that could have required six months of weekend possessions.
- Contractors installed 29 bridge beams, more than 200 overhead line foundations, and 20 steel structures.
- The work advances a £311.5m programme to electrify 118km of railway and introduce battery-electric trains.
Network Rail has completed an intensive 18-day programme of bridge, signalling and electrification works in Fife, bringing together construction activities that could otherwise have required six months of weekend railway closures. Sections of the Fife Circle were closed between 10 and 27 October while engineers carried out major structural alterations and prepared the route for overhead electrical equipment.
The works form part of the Scottish Government’s £311.5m investment to electrify 118km of railway and introduce battery-electric trains. The October possession concentrated on bridge reconstruction, foundations for overhead line equipment, signalling changes and associated infrastructure, with teams working around the clock to complete interdependent activities before train services resumed.
At Bennochy Road in Kirkcaldy, Muriespot near Coaltown of Balgonie, and Main Street in Thornton, contractors demolished three railway bridges and began rebuilding them at greater heights. The reconstructed structures will provide the clearances needed for overhead electrical conductors and their supporting equipment. A total of 29 concrete beams were installed during the closure, although work on the bridges will continue beyond the completed railway possession.
Bridge clearances are a fundamental constraint when electrifying an existing railway. Structures originally built for diesel-operated routes can leave insufficient space between the track and the underside of a bridge for overhead conductors, electrical clearances and associated equipment. Raising a bridge allows the railway to retain its established alignment while accommodating the additional infrastructure above the trains. The revised structure must also provide the required road or pedestrian connection across the railway.
The bridge replacements were coordinated with the installation of more than 200 foundations and 20 steel structures for the overhead line system. Four additional masts were installed on the Leven line. These foundations and supports will carry equipment that positions the electrical conductors relative to the tracks, with their locations determined by the railway geometry, structural loading requirements and available space beside the running lines.
Overhead line supports must accommodate forces arising from the conductor arrangement, tensioning and operating conditions. Their foundations transfer those loads into the ground, requiring suitable design for the conditions encountered at each location. Installing the supporting infrastructure during a major possession reduces the need for separate future access periods, although conductor installation, electrical integration and testing remain distinct stages of the wider programme.
Alongside the structural works, engineers replaced 26 pieces of older signalling equipment around Burntisland and completed further upgrades between North Queensferry and Kirkcaldy. Signalling systems control and protect train movements, making their alteration part of the process of preparing the route for changes to its physical and electrical infrastructure. Equipment installation and commissioning must be coordinated with the track layout and the systems already used to operate the railway.
The same possession enabled modifications to the platforms at Cardenden station and the clearance of more than 209,000 square metres of vegetation beside the tracks. Platform changes must maintain the required relationship between the track, platform edge and passenger access arrangements. Vegetation clearance provides working space for installation and improves access around railway assets, particularly where overhead electrical equipment and supporting structures will be positioned close to the existing route.
Bringing these activities together required coordination between civil engineering, railway systems and electrification teams. Bridge demolition and beam installation depend on lifting equipment, controlled working areas and access to the railway corridor. Foundation installation and signalling alterations place different demands on the same restricted environment, while materials, equipment and construction personnel must enter and leave sites through established access points.
The extended closure allowed contractors to organise successive operations without repeatedly returning the railway to passenger service between short working periods. Some activities could proceed in parallel, while others depended on earlier work being completed before the next construction operation began. The programme continued through Storm Boelo and other difficult weather conditions, adding further constraints to the management of lifting, access and work beside exposed railway infrastructure.
Network Rail’s comparison with six months of weekend closures refers to the volume of engineering activity completed during the possession. It does not represent a six-month reduction in the overall electrification programme. Bridge reconstruction, additional overhead equipment and the remaining electrical systems work will continue as the railway is prepared for the introduction of battery-electric trains.
Michael McArthur, project manager at Network Rail Scotland, said: “Having the railway closed gave us the chance to do several big jobs at once rather than returning over a series of weekends.”
Battery-electric trains are intended to use overhead power where electrification is available and stored electrical energy over sections without continuous wiring. Their operation will depend on the completed electrical infrastructure, the characteristics of the rolling stock and the arrangements for supplying and managing traction power. The construction programme therefore involves both fixed railway alterations and the eventual integration of the new trains into passenger services.
That wider integration also requires the completed railway to support ordinary maintenance and safe operation. Bridges, overhead equipment, signalling systems and platforms must function together, with the installed infrastructure satisfying the applicable clearances, operating requirements and testing procedures before the new traction arrangements can enter service.
The October possession has left three bridge reconstruction projects advanced, supporting structures installed at more than 200 locations and substantial signalling and vegetation works completed. Further bridge construction and electrical installation will follow, using the infrastructure prepared during the closure to advance the 118km Fife electrification programme.
