The Department for Transport has confirmed £37.4 million of funding for Network Rail to realise its plans to build a 209-metre-long extension of the rockfall shelter north of Parsons Tunnel between Dawlish and Holcombe.
England’s railway link to the West Country is vulnerable to adverse weather conditions and infrastructure failure, as was shown in February 2014 when a storm destroyed the railway at Dawlish, cutting Cornwall and western Devon off from the rest of the UK.
When the Great Western Railway built its line to the West, it chose the coastal route, south of Dartmoor. This forced it to run along a narrow corridor between the sea and South Devon’s hills and cliffs.
There was a second route to Cornwall. The London and South Western Railway built its line around the north side of Dartmoor. From Exeter, the line went through Okehampton and Tavistock before finally approaching Plymouth from the west.
However, this route was closed in the Beeching era. The track was lifted between Meldon and Bere Alston and, although limited passenger services continued to Okehampton, and freight from Meldon quarry, this ceased in 2019.
The government has now announced a £40.5 million project to restore and rebuild the line to Okehampton. While very welcome, this move has renewed calls for the rest of the line to be reopened, reinstating the second route to the west.
In the meantime, the GWR South Devon line is the only route available. Work to strengthen the sea wall at Dawlish is well documented, but that is not the railway’s only problem. Further west, towards Holcombe, the railway lies at the foot of some high cliffs that, from time to time, shed rocks and boulders onto the railway below, potentially closing the line.
A century ago, Parsons tunnel was extended eastwards, the artificial tunnel protecting the railway from the worst of the rockfall.
Now Network Rail is planning to extend this rockfall shelter for a further 209 metres towards Dawlish, although the new shelter will have open sides and so be more of a ‘roof’ than an artificial tunnel.
Network Rail is out to tender for both the design and construction of the new rockfall shelter. Construction is expected to start in August and should take around a year to complete.
Ewen Morrison, senior programme manager for Network Rail’s South West Rail Resilience Programme, said: “We are delighted to have received the support of the government to build this important rockfall shelter, which will help protect the railway in Devon for the next 100 years.
“This coastal stretch of railway is beautiful but also faces a number of vulnerabilities either side of the railway; rough sea conditions on one side can cause flooding whilst steep cliffs on the other side make the railway at risk of rock falls and landslides.
“We’re looking forward to getting started and are excited by the engineering challenge of building such a critical structure in such an inaccessible location whilst minimising the impact on train services.”
Councillor Andrea Davis, chairman of the Peninsula Rail Task Force (PRTF), said: “The line at Dawlish is a vital link between the Peninsula and the rest of the UK and the rockfall shelter is an important element in ensuring people can continue to travel across the peninsula safely and reliably.
“Network Rail has made fantastic progress on the South West Rail Resilience Programme, in spite of substantial challenges in recent months. Completion of all phases of this programme will ensure the long-term resilience of the line, which is vital to the economic success of the region.
“However, there is still work to be done and the PRTF looks forward to working with government to build upon efforts to level up the region, securing a rail infrastructure across the Peninsula that is resilient, reliable and improves connectivity and capacity for years to come.”
Preparatory work is due to begin at the top of the cliffs overlooking this stretch of railway on 22 March 2021, when Network Rail engineers will begin cutting back some of the vegetation and installing safety netting to secure the shrubbery on the cliffs and reduce any falling debris. This work will be closely monitored to ensure the least disruption for wildlife habitats and biodiversity.
The construction of the rockfall shelter at this location poses a number of engineering challenges, due to the limited access with the track sandwiched between high cliffs on one side and the sea on the other, as well as ensuring this work doesn’t result in lengthy closures of this critical rail artery to the south west.
The open-sided rockfall shelter will be constructed from 6.2-metre-long precast concrete wall panels and roof beams, covered by a cushioning material that will absorb the impact of any rockfalls as well as promote vegetation growth. This design will also ensure it is buildable in this hard-to-access location and that the appearance of the new structure is appropriate to its setting.