Work on the complex sub and superstructure packages on The City of London Corporation's Salisbury Square Development has begun.

Keltbray, a leading specialist construction engineering and infrastructure services provider, was awarded the £73m contract for this stage of the scheme, following its successful completion of the £10m demolition and enabling works at the site.

The work is being carried out on behalf of the principal contractor, Mace.

Darren James, Keltbray's chief executive officer, said the contract was a significant step forward for Keltbray, "extending our service offering further along the value chain, where clients are recognising the value in our integrated approach to self-delivery”.

Vince Corrigan, chief operating officer, added the contract award marked "another important milestone" in the firm's ‘onekeltbray’ strategy and provided a "fantastic opportunity to demonstrate our ability to deliver projects of this scale and complexity using our inhouse engineering expertise”.

Keltbray will use sustainable circular economy techniques to minimise waste and reduce the overall environmental impact of the scheme.

Michael O’Hagan, managing director of Keltbray’s built environment division, said: “With the redevelopment set to take a further three years, we recognise the desire for a highly sustainable build with carbon reduction and the circular economy are key drivers.  

"Therefore, where possible, we have developed a methodology to complete the works in the most sustainable manner.”

The work will include the installation of over 500 king post piles, secant piles, contig piles and bearing piles, construction of a new basement slab, core base and box, as well as four new cores.

The formation of a reinforced concrete superstructure for the court building is also part of the scheme.

To retain key elements of the heritage structure, a ‘listed building’ soft strip using ‘cut and carve’ techniques will be undertaken.

The Salisbury Square Development will principally deliver a new, purpose-built 18-courtroom legal facility called the City of London Law Courts and an industry leading City of London police headquarters equipped to combat amongst other things, fraud and economic crime across the UK.

Keltbray was founded in 1976 and is privately owned, directly employs more than 2,000 people, and is a key delivery partner to prestigious public and private sector customers.