Network Rail is replacing 1,200 wooden sleepers on the Tay bridge – one third of total quantity – in a £500,000 programme that will continue until September.
Scotland’s Tay bridge, the longest railway structure in Britain, stretches for 2.75 miles across the Firth of Tay. It was built between 1883 and 1887 and consists of 80 metallic spans, constructed of wrought iron, and 44 masonry arches on the approaches to the north and south.
A recent programme to refurbish the bridge, repair metalwork and repaint it took 20 years. Local repairs and re-painting of its approach spans started in 1996 while strengthening repairs took place between 2000 and 2004. Grit blasting and repainting began in 2006 – with a total of 245,000 square metres of wrought iron and steel repainted. The work was completed in August 2017.
The £75 million restoration of the Category A-listed bridge won Network Rail and contractor Taziker a National Railway Heritage Award.
With the structure of the bridge now secure, attention has turned to the track across the bridge and. more specifically, the sleepers that support the rails.
Work is underway to replace more than 1,200 wooden sleepers on the bridge to extend the life of the track. One in three sleepers, including baseplates and the Pandrol clips that fasten the rails to the sleepers, are being replaced and ballast below renewed and re-packed.
Some of the sleepers’ baseplates date back to the early 1960s and the timber sleepers are now at the end of their natural life, having been exposed to the elements and the salty air in this coastal location.
In all, around 60 tonnes of sleepers will be installed, and an equivalent amount of redundant material and spoil removed, from the bridge during this £500,000 project. Logistics is always a challenge on a long bridge, or in a tunnel for that matter, as materials have to be brought in and removed along the railway as they are needed – there is no room to store anything alongside the tracks, even temporarily.
Replacing only one sleeper in three strikes a balance between maintaining the track to ensure it is fit for the volume of traffic travelling over the bridge and avoiding disruption to passenger services on the busy East Coast main line. This way, work can take place at night so as to keep trains running during the day.
The work is being planned and coordinated by Network Rail’s own works delivery team as it is, effectively, a maintenance job. Vital Rail Services is supplying the labour and Specialist Engineering Services (SES) the plant and road-rail vehicles (RRVs).
Network Rail’s works delivery manager Grant Ritchie explained: “We work every night to keep the railway open and running efficiently for key workers and essential journeys. Projects like this will benefit even more passengers when lock-down is lifted and we begin to move towards a new kind of normal.
“Any project on an historic and iconic structure like the Tay Bridge is always a pleasure but it presents its own problems due to its unique design and location. Being open to the elements over the Firth of Tay is unpredictable in itself, even when the work is during the summer months.
“Working in a confined location, such as on a bridge, also presents a logistical challenge in normal times but we now have the additional element of ensuring physical distancing, where possible. To do this we are following best advice, using additional protective equipment and learning new ways of working that will help keep everyone safe and let us get the job done.”