Redbridge Viaduct in the Scottish Borders has the first phase of repair work completed!

Network Rail has successfully finished the first part of repair work to Redbridge Viaduct as part of an ongoing project to maintain safety and reliability on the railway.

The red stone, five arched, listed viaduct has had an investment of  £2.4m which will protect against future erosion by completing scour protection and masonry repairs. 

Scour protection is where the existing riverbed around the impacted base of the bridge pier is removed and then a scour ‘mattress' is installed and filled with concrete. This process helps to protect the base from damage by fast-flowing water.

The first phase of the project involved the installation of 600 square meters of scour mattress and 400 tonnes of permanent rock shield, along with 150 cubic meters of poured concrete.

To make this impressive work possible a portable dam system under the bridge was installed which allowed the team a safe working area and reduced river flow. Before the dam was installed the team worked closely with the River Tweed Commission to protect fish by relocating them to another part of the river before the water was drained to create the dry working area. This process will be repeated at each pier as the project progresses.

The beautiful structure was built in 1849 by North British Railway as part of the Edinburgh to Carlisle mainline. The viaduct crosses the River Tweed on the Borders Railway line and is situated between Tweedbank and Galashiels. The Edinburgh to Carlisle mainline closed in 1969 but was reopened again as a passenger line in September 2015 as part of the Borders Railway project. The repair work started in April 2021 and is expected to be finished by October 2021.

Christina Thomson, Network Rail's project manager for the work said: “The team has delivered the first of three phases of work to Redbridge Viaduct; essential maintenance that protects the piers of the viaduct from scour erosion and in turn, helps maintain the railway infrastructure.

“We've worked collaboratively with Scottish Borders Council throughout and with the River Tweed Commission and our environmental and marine engineering specialists to ensure our activity has minimal impact to the river's existing habitat – and will continue to do so throughout the rest of the project.

“The viaduct is an historic Victorian structure that continues to play an important role in carrying passenger trains on the Borders Railway route. When work is complete in October, we won't need to undertake repairs on this scale for many years to come.”