Engineers working on the construction of HS2 have completed the major part of the work on three major structures on the southern approach to the HS2 Interchange Station at Solihull in the West Midlands.

The three viaducts are at Balsall Common, Marsh Farm and across the River Blythe and during the next few weeks, engineers from Balfour Beatty VINCI, HS2’s construction partner, will install the final parapets on the largest of the three viaducts, the River Blythe Viaduct.

Marsh Farm Viaduct was the first of the three to be completed, followed earlier this year by the main structure of Balsall Common Viaduct, and all its 304 parapets will be installed by next spring.

The River Blythe Viaduct is the nearest viaduct to Interchange Station, about 1½ miles away.

Because of the viaduct’s size, proximity to communities, or location within sensitive areas, the River Blythe and Balsall Common viaducts were significant structures, and local communities were involved in their design.

The River Blythe Viaduct also crosses a Site of Special Scientific Interest (SSSI), and this was taken into consideration when the viaduct was built.

The deck was designed to reduce the volume of concrete and enhance its aesthetic appeal, and local communities suggested that, on one side of the structure, there should be larger, polished parapets; they were also consulted on subsequent tree planting to blend the viaduct into the landscape.

Although it is structurally complete, engineers still need to install acoustic barriers and complete the waterproofing.

Marsh Farm Viaduct is the smallest of the three structures and 2½ miles south of the River Blythe and Balsall Common viaducts.

It is just five metres above ground level, and is currently used as a road for haulage lorries constructing the adjacent embankments and cuttings.

Ultimately, Marsh Farm Viaduct will carry HS2 over Bayleys Brook and surrounding marshland.

Balsall Common Viaduct is eight metres high and 430 metres long northeast of the existing Network Rail line. It crosses the Heart of England Way footpath and the associated floodplain.

After a public consultation, the design of its parapets was chosen to have a polished finish to reflect the sky and surrounding vegetation.

The consultation also suggested the viaduct should feature a unique weave motif as a reference to the area’s history of producing textiles.

“Our engineering teams are making fantastic progress on the Interchange Station approach, and it’s a significant achievement that all three viaducts in the Solihull borough are now structurally complete. The design and landscaping solutions were of utmost importance to local residents, and we worked extremely hard to get that right.”

Doug Barnett, Senior Project Manager, HS2 Ltd