Coastal Countdown

With a tight tidal window, work to upgrade the coastal defence in Blackpool required precision timing and careful product specification to deliver the project on time and on budget

For more than 100 years an old sea wall provided Blackpool with protection from coastal erosion and flood alleviation. But constant bombardment from winter storms, sand and salt had taken its toll, leaving much of the defensive structure in need of replacement.

Now, a new sea-defence scheme, led by Blackpool Council and delivered by Birse Civils, is the town’s biggest-ever civil engineering project. The four-year contract has seen the old structures replaced with 65,000m3 of in-situ concrete and 44,000m3 of precast concrete, all supplied by Tarmac.

The final section of work, near Blackpool’s North Pier, was a challenging 12-month project. Tarmac worked with Birse Civils to supply precast concrete and Topforce – a specialist high-strength, fibre-reinforced concrete which is poured in situ and removes the need to use steel mesh.

Tidal window

Saving time was a key driver in Birse Civils’ specification decisions. ‘Every day we were working against nature’s clock and only had a 6h tidal window in which to operate,’ said Anthony Burgess, regional engineering manager at Birse Civils. ‘Using Tarmac Topforce delivered both cost and time savings, because using mesh fabric typically requires significant on-site preparation time. The product provided us with a viable material that could reach structural strength early on, while also giving us sufficient workability for the site teams.’

For a job this complex, high technical standards and rigorous product testing were vital, both at Tarmac’s concrete batching plant and on site. This ensured that the product offered the optimum strength and workability that the contractor team required.

Delivering first-rate technical support was an important element of Tarmac’s support. ‘You don’t just choose a product in a brochure for schemes like this; it needs to be adapted to meet the requirements of the job and the conditions you are working in,’ explained Mr Burgess. ‘Because we were carrying out part of this work in extreme winter temperatures, Tarmac provided us with a high level of technical expertise, and their team were able to change the concrete mix designs on the product to ensure it met our specifications of use.’

Right on time

Ensuring precise logistics and delivery times was also a key element of project delivery. ‘Preparatory works were undertaken before the concrete arrived on site because the tidal restrictions make it crucial that  the product is delivered on time and at the right quality,’ said Mr Burgess. ‘If a load doesn’t arrive, the work has to be done again, which has significant time and cost implications. Tarmac were able to meet this challenge and ensure that our site schedule was not affected.’