Project team (left to right): Neil Perrins, Stepnell Project Manager; Judith Barker, South East Midlands Local Enterprise Partnership programme and assurance manager; Dr Rob Lewis OBE, Managing Director of Aero Research Partners and TotalSim; Lucinda Young, South East Midlands Local Enterprise Partnership Programme Support Officer

Work has begun at the Catesby tunnel project which aims to transform a disused Victorian railway tunnel in Northamptonshire into a hi-tech vehicle testing facility.

Construction and civil engineering specialists from West Midlands-based Stepnell have now completed the retaining structures which will enable the development of the main building at the new Catesby Aero Research Facility (CARF).

Brackley-based Aero Research Partners are behind the project to create a technologically advanced facility for aerodynamic testing set to attract car industry and motorsports customers from around the world. The remodelling of the 2.7km long 1897-built tunnel into a smooth asphalt road will deliver a unique, highly-controlled test environment allowing vehicles to reach speeds of over 100mph and enabling accurate assessment of vehicle performance, aerodynamics, noise, emissions, and cooling.

The soil-nailing rig in action

During the widening of the railway cutting, the Stepnell team used two soil-nailing rigs to reinforce the ground and build retaining walls. The soil-nailing process involved the insertion of up to 14-metre long hollow steel nails into the sloping ground with grout injected at pressure through the nails before mesh and fixing plates were then attached to the bar ends to keep the slope face stable. The team is now working on the next phase of the project involving construction of the CARF building outside the south tunnel entrance.

Stepnell project manager Neil Perrins says: “Our team is making excellent progress on this challenging and complex construction and civil engineering project. The next phase will see us install new drainage to improve or replace the existing drainage, as well as build the two-storey steel framed CARF building within the footprint provided by the retaining structures we have created.”

The other partners working on the scheme are Roger Coy Partnership (architects); Lockhart Garratt (landscape design); David Smith Associates (civil engineers) and David Symonds Associates (civil and structural engineers). The project is going ahead with support from Daventry District Council.

After sitting disused and derelict since 1966, the Victorian Catesby railway tunnel in Northamptonshire in the UK is to receive a new lease of life as an aerodynamic vehicle-testing centre. Built in 1897, the 2.7km long tunnel was on the route of the former Great Central Main Line that was closed in 1966.

New plans for rail tunnel after 50 years derelict

The transformation project will see the remodelling of the perfectly straight tunnel into a smooth asphalt roadway, with lighting, end closures and other substantial upgrades. Designed by the Roger Coy Partnership and carried out by the construction and civil engineering firm Stepnell of the West Midlands, the transformed tunnel and the adjoining 4.5 acre science park of offices, workshops and research laboratories will be used for testing automotive and race car development.

The Catesby Aero Research Facility project is commissioned for Brackley-based Aero Research Partners (ARP) and is being funded by a £4.2 million award from the UK Government Local Growth Fund through the South East Midlands Local Enterprise Partnership.

“The original tunnel is in remarkable condition given the low levels of maintenance since its decommissioning in the 1960s,” said Richard Wakeford, Director of Stepnell. Early works will be construction of the access roads to the site and to the disused rail tunnel.

“We now have planning permission and much of the required budget secured, with investors ready to join the project early in 2018 to advance the construction work towards an expected opening date of the centre by late 2019,” said Dr Rob Lewis OBE, Managing Director of ARP. “The facility will give the UK an aerodynamic research centre for hire and we intend to explore also academic collaborations and to engage with schools and inspire children into the world of science, technology, engineering and maths.” The research facility is expected to employ about 50 staff.