A record-breaking achievement

Team members working at Hinkley Point C have been celebrating ‘J0’; the project’s biggest achievement yet.

Jalon Zero (J0) is a French term meaning ‘moment in time’. It is significant because it marks the moment when the foundation, or ‘Common Raft’, for Hinkley Point C’s first reactor is complete. From this point on, work will begin above ground on the permanent reactor buildings.

The last of the five concrete pours that took place in June completed J0 and was the UK’s biggest-ever pour, beating the record held by The Shard in London. It took 72 continuous hours to pour more than 9,000m3 of concrete.

Peter Abel, Chief Materials Engineer with Bylor, leads the teams responsible for producing and placing concrete at Hinkley Point C. He said: “J0 has been very motivating for everyone. Three years ago, pouring 200m3 was a big thing. We’ve worked hard since then, and now, we’ve achieved the biggest structural pour in the UK.”

Whatever their role, everyone working at Hinkley Point C and throughout the supply chain has made a contribution to J0.

The journey to J0

It took a total of five large concrete pours to complete the common raft and reach J0. But before any concrete could be poured, a huge amount of pre-work was required – involving many smaller milestones, thousands of people and hundreds of companies. More than 300 engineers worked on the design, which included 244 reinforcement drawings. Preparations for the concrete pours included de-watering, deep excavation of 5.6 million m3 of rock, construction of a pre-stressing gallery under the common raft, and placing more than 4,000 tonnes of reinforced bar (rebar).