Enhancing One of the UK's Most Iconic Landscape
The Snowdonia VIP (Visual Impact Provision) Tunnel is a landmark infrastructure project for National Grid in the UK, designed to significantly reduce the visual impact of electricity transmission infrastructure within the spectacular Snowdonia National Park.
National Grid appointed HOCHTIEF as the principal contractor for the scheme, with Shay Murtagh Precast selected to design, manufacture and supply the precast tunnel lining segments that form the structural backbone of the underground tunnel.
Once complete, the project will enable the removal of 10 electricity pylons and approximately 3km of overhead transmission lines that currently cross the Dwyryd Estuary, restoring uninterrupted views across one of the UK's most treasured natural landscapes.
Delivering critical energy infrastructure within a protected national park required a solution that balanced engineering excellence with environmental responsibility.
The tunnel lining segments needed to:
- Meet stringent structural and durability requirements.
- Be manufactured to exceptionally tight tolerances.
- Support efficient tunnel boring machine (TBM) installation.
- Withstand a challenging underground environment while delivering a long design life.
- Be produced to demanding programme requirements to support project delivery.
Drawing on decades of experience delivering precast solutions for major tunnelling projects across Europe and the UK, Shay Murtagh Precast partnered closely with HOCHTIEF to manufacture high-quality precast tunnel lining segments.
Manufactured in a controlled factory environment, every segment was produced using rigorous quality assurance procedures to ensure consistent dimensional accuracy, durability and performance.
Our off-site manufacturing approach delivered:
- High precision precast tunnel lining segments.
- Consistent quality and dimensional accuracy.
- Efficient production to meet programme milestones.
- Reduced on-site construction time.
- Reliable long-term performance in demanding underground conditions.
Supporting Sustainable Infrastructure
The Snowdonia VIP Tunnel demonstrates how modern engineering can deliver essential infrastructure while protecting environmentally sensitive locations.
By moving electricity transmission infrastructure underground, the project will:
- Remove 10 existing pylons.
- Eliminate approximately 3km of overhead power lines.
- Enhance the visual landscape of Snowdonia National Park.
- Protect the natural character of the Dwyryd Estuary.
- Improve the experience for residents and visitors alike.
The project highlights the important role precast concrete solutions play in delivering sustainable, resilient infrastructure with minimal environmental impact.
Project Partners
Client: National Grid (UK)
Main Contractor: HOCHTIEF
Precast Tunnel Lining Supplier: Shay Murtagh Precast
Delivering Infrastructure That Respects the Environment
We are proud to contribute to infrastructure projects that combine engineering innovation with environmental stewardship.
The Snowdonia VIP Tunnel showcases how precision-engineered precast solutions can help deliver complex tunnelling projects while preserving the landscapes that matter most.
