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We are developing proposals for a modern rail industry testing facility in south Wales.

Part of:
First published:
13 July 2018
Last updated:


Project status: planning
Region/county: south Wales
Start date: end 2017
End date: 2023/2024
Cost: approximately £150 million
Partners: Neath Port Talbot Council and Powys Council.

What we are doing

We are developing proposals for a rail testing complex. This will allow rolling stock and infrastructure testing. The site is located at the Nant Helen surface mine and Onllwyn coal washery at the head of the Dulais and Tawe Valleys. 

Proposals for the Nant Helen surface mine site include:

  • electrified high-speed outer rail testing track (6.9km) with testing speeds of up to 110mph
  • electrified low-speed inner rail testing track (4.5km) with testing speeds of up to 40mph
  • dual platform station environment 

Proposals for the Onllwyn washery site include:

  • research, development, education and training/conference centre 
  • an operations and control centre/office 
  • staff facilities
  • rolling stock storage/sidings
  • rolling stock maintenance facility 
  • 25kv overhead line equipment (OLE) infrastructure

Infrastructure will be made up of:

  • access routes, 
  • staff car parking
  • drainage 
  • lighting 
  • mobile and land-based communications ‘hyper-connectivity’ 
  • CCTV 
  • perimeter/security fencing which may include sound controlas required) 
  • Neath and Brecon branch line connection and signalling upgrade.

Why we are doing it

We want to deliver a world class train testing facility in the UK. We are confident this will be a significant attraction to investors. This will provide a vital service to UK and international train manufacturers, network operators, the wider industry and the supply chain. For decades to come it will:

  • fast-track improved services for passengers and freight operators
  • deliver significant efficiencies for the rail industry and the delivery of major projects
  • accelerate the throughput of innovation and support Wales and UK exports
  • provide high quality jobs and training opportunities locally.

Current progress

We have entered into a Joint Venture Agreement (JVA) with Neath Port Talbot and Powys local authorities. In partnership we have developed a site masterplan. Working with industry partners we have developed a detailed business plan. This will allow us to take the project forward. 

UK government confirmed its support and a funding commitment to help deliver the project in the March 2021 budget.

Celtic Energy’s planning application for earthworks was approved in summer 2020. The land can be adapted for future use including rail testing and storage.

An outline planning application has been submitted for the project.

How we are consulting


Public consultation: summer 2019 and autumn 2020
Planning application submission: spring 2021
Planning approval: summer 2021
Site preparation / construction: 2021 to 2023
Accreditation / validation: 2021 to 2023
Phase 1 operational: 2023
Fully operational: 2025

Next steps

A planning application has been submitted.