Balfour Beatty to dual A9 Tomatin to Moy stretch of road across challenging peat areas

The Scottish Government announced last week that it intends to award Balfour Beatty Civil Engineering the £184.7M main works contract to upgrade the 9.6km section of the A9 between Tomatin and Moy to dual carriageway.

Balfour Beatty was one of three companies shortlisted for the contract in November of last year, as the result of a second round of procurement. The other shortlisted contractors were John Graham Construction and Sacyr.

While Transport Scotland’s technical advisor – Atkins Réalis WSP Joint Venture – prepared the specimen design for the project, the detailed design will be carried out by Balfour Beatty and its designer Mott MacDonald.

A multi-phase programme of ground investigations (GI) was carried out to support the design work.

A Transport Scotland spokesperson told GE that the GI has “shown the superficial deposit beneath the project footprint to include peat, river terrace deposits, alluvial deposits and glacial deposits, overlying bedrock”.

“The investigations have also shown bedrock – comprising gneiss, semi pelite, microdiorite, psammite and microgranite – encountered at various depths across the site,” they added.

“Locally made ground deposits and engineering fill were also proven at locations at or adjacent to historic development, including the existing road corridor.”

The results of the GI phases have been issued to the British Geological Survey for inclusion in its database.

When asked about the main ground engineering and earthworks elements on the scheme, the spokesperson said: “The scheme alignment for the specimen design was developed to achieve an earthworks balance across the site. One of the challenges of achieving this was the management of the extensive peat deposits that will be encountered.”

More information on these aspects of the project will be shared once the contract is officially awarded.

Transport Scotland carried out £22.5M worth of advance works ahead of the main works contract procurement.

In addition to the ground investigations, this has included the replacement of Lynebeg underbridge on the Highland Main Line railway, and the establishment of an ecological pond to support translocation of a rare fly species ahead of the dualling works. The advance works also covered upgraded active travel and public transport infrastructure, archaeological investigations and outreach work with local schools.