A joint venture between Siemens Mobility and Costain is set to be awarded a major contract to deliver high-voltage (HV) power supply systems for HS2, the high-speed rail project connecting London to the West Midlands.

The contract covers the entire 225km route and represents a significant milestone in the development of the UK's largest infrastructure project.

The joint venture will oversee the design, manufacture, supply, installation, testing, commissioning, and maintenance of HV power systems along the route. As part of the Rail Systems Alliance structure, the partnership will collaborate with industry stakeholders to ensure the efficient delivery of the railway.


The initial design and build phase will be followed by a separate seven-year maintenance contract. The overall value of the HV power systems contract is estimated at around £300 million, with the maintenance agreement contributing an additional £32 million. There is potential for contract extensions beyond the initial term.

The Siemens Mobility and Costain partnership will leverage its expertise in project management, digital coordination, systems integration, equipment manufacturing, and supply chain collaboration. The work will include the construction of traction and non-traction substations to power stations, shafts, portals, depots, and other railway systems along the route.

Both companies bring experience from high-profile infrastructure projects such as the Elizabeth line and the East Coast Main Line Power Supply Upgrade.

In line with HS2's sustainability goals, the high-voltage power will be sourced from the national grid, enabling trains to run on zero-carbon energy from the first day of operation. This aligns with the project's commitment to reducing carbon emissions and promoting environmental sustainability.