2024
St Athran, Vale of Glamorgan
Network Rail
GTS Group
N/A
Vale of Glamorgan Railway Rockfall Protection and Slope Stabilisation
Installation of Steelgrid HR
Completed Installation of Steelgrid
Detailed section of SteelGrid HR
Railway embankment with Steelgrid HR
Railway embankment with Steelgrid HR
Challenge
The Vale of Glamorgan Railway, originally constructed in 1897, was developed to connect collieries in the Llynfi, Garw and Ogmore valleys to Barry docks. While the line historically supported both freight and passenger services, passenger operations ceased in 1964 before being successfully reintroduced in 2005, improving access to Cardiff Airport via Rhoose and serving Llantwit Major.
As part of Network Rail’s ongoing commitment to railway infrastructure resilience and safety, a major upgrade programme was carried out during the spring and summer of 2024. A critical focus of this project was the section of railway between Llantwit Major and Ewenny, where embankment stability issues posed a significant operational risk.
Over time, vegetation growth and natural weathering had contributed to the formation of unstable rock masses along the rail embankments. These conditions increased the likelihood of landslips and rockfall events, which could disrupt rail services, damage infrastructure, and compromise passenger safety. To mitigate these risks, a robust slope stabilisation solution was required.
The project called for full devegetation of the embankments, followed by the installation of a high-performance stabilised rockfall netting system. In line with CIRIA C775 guidelines for the design, installation and management of rockfall protection systems, the solution needed to provide long-term stability by combining surface containment with anchored reinforcement to secure loose material and prevent slope failure.
Solution
To deliver an effective and durable rockfall protection system, Network Rail designers selected Maccaferri’s Steelgrid® HR30 P. This advanced stabilised netting solution was chosen for its high tensile strength, superior stiffness, and low deformation properties, making it ideal for critical infrastructure applications such as railway corridors.
Steelgrid® HR30 P is an innovative composite mesh system that combines double-twist hexagonal steel wire mesh with integrated high tensile steel cables. These cables are woven directly into the mesh during manufacturing, creating a high-performance structure capable of withstanding dynamic loads from falling rock and debris.
The unique manufacturing process produces a composite mesh with both full and half-hexagonal apertures, optimising load distribution and enhancing mechanical performance. The steel cables remain largely straight within the mesh, enabling immediate load resistance with minimal strain. This eliminates the need for pre-tensioning during installation, improving efficiency and ensuring consistent performance from the outset.
Compared to traditional double-twist rockfall netting, Steelgrid® HR30 P offers significantly improved performance characteristics. It delivers lower elongation, typically between 5–7%, compared to 16–23% for conventional systems. Additionally, its punching resistance is 20–40% higher, resulting in reduced deformation under load and improved slope containment. These benefits make it particularly suitable for stabilised netting applications where minimal displacement is essential to protect adjacent railway infrastructure.
The system is supplied as a complete installation kit, including specially designed anchor plates with clawed corners that securely engage with the mesh’s high tensile steel cables. This ensures tight surface contact between the netting and the slope, a key requirement for effective stabilised netting systems. The inclusion of high-performance HR Grips and HR Links further supports a fully integrated, system-based installation approach in accordance with CIRIA C775 best practice.
Durability and longevity are central to the Steelgrid® HR30 P solution. The steel components are protected with a Class A Zn-Al 5% GalMac® galvanised coating, combined with a Polimac® polymer layer for enhanced corrosion resistance. This dual protection system delivers a BBA-certified design life of over 120 years, even in aggressive environmental conditions.
By implementing Steelgrid® HR30 P, the Vale of Glamorgan Railway benefits from a long-term, low-maintenance rockfall mitigation system that enhances slope stability, protects critical rail infrastructure, and ensures safe, reliable operation for decades to come.
Used Products
