Watch: world’s oldest railway viaduct gets face-lift

Work is underway to improve passenger and freight journeys between Manchester and Liverpool over the world’s first railway viaduct. Network Rail is investing £3.8M to overhaul Sankey viaduct in Newton-le-Willows which opened in 1830.

Although not as well-known, long or iconic as Ribblehead in North Yorkshire, Sankey is hugely significant as the first major railway viaduct in the world, and birthplace of the modern railway. Also known as ‘Nine Arches’ viaduct, it was designed by railway pioneer George Stephenson to bridge the 160m gap over the Sankey valley and built between 1828-1830. When it opened it connected Manchester and Liverpool to form the world’s first intercity passenger route with a regular timetable as we’d recognise today.

Watch the video, below:

The 193-year-old landmark is now having important maintenance ahead of its 200th anniversary in 2030 to secure its future for decades to come. Over the next four months a team of 25 engineers and scaffolding specialists will:

• Erect scaffolding towers along the span for painstaking repairs to take place
• Repoint mortar using specialist heritage mixes to match the existing materials
• Carry out extensive brickwork repairs
• Paint historic metalwork in heritage colours
• Install strengthening anchors to secure any cracks
• Remove overgrown weeds and plants
• Clean graffiti from the top of the stonework
• Fit three new pairs of pattress plates – metalwork which secures the structure

The viaduct was given Grade I listed status in 1966, and because of that free-standing scaffolding is being used so as not to interfere with the historic structure.

Laser scanners and drones have been used to map the Victorian viaduct as part of the major restoration project. A LiDAR survey was carried out by contractor Commendium in conjunction with heritage consultancy firm Wardell Armstrong. Drone flights also took place as part of the survey taking high-definition photographs of the Grade I listed structure.

Watch the LiDAR scan of the structure, below...

The data gathered was used to build up the 3D computer model by Network Rail’s specialist computer aided design (CAD) team. This detailed digital recreation will help engineers make repairs now and closely monitor areas needing any further attention in the future. The restoration work is expected to take Network Rail four months to complete.

How LiDAR technology works

Dozens of separate scans are taken from locations underneath and on top of the viaduct. In a LiDAR system, light is emitted from a rapidly firing laser like a strobe light. This light travels to the ground and reflects off objects. The reflected light returns to the LiDAR sensor where it is recorded. This data is then used to build up the 3D computer model.

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