Bridges

Parsons Tunnel Rockfall Shelter, located on the picturesque Devon coastline in Southwest England, was constructed to enhance the resilience of a historic railway stretch between Dawlish and Teignmouth. This shelter protects a 110-meter section of track beneath an unstable cliff at the existing Parsons Tunnel northern portal. Due to previous rockfalls and landslips causing significant damage and disruption to the railway network, a risk assessment was undertaken and determined that a rockfall shelter was the most suitable mitigation measure at this location.

The gallery-style rockfall shelter, similar to those in alpine regions, features a concrete deck supported by columns on the seaward side and a continuous wall on the cliff side. The deck is covered with a thick sand blanket to distribute the impact of large rocks falling from the cliff above.

Given the site's challenging access, the design team collaborated closely with the contractor to develop a construction methodology using a travelling gantry crane. This crane straddled the operational railway and the structure's envelope, allowing the shelter to be built using predominately precast elements. These components were delivered by rail and placed using the crane during routine track closures. The crane could also operate while the railway was active, providing access to the entire site without the usual limitations associated with rail infrastructure projects.

The shelter has been well received by the public and has become a notable feature of this historic and famous stretch of British railway.