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The world’s largest crane, “Big Carl” lifts the 245-tonne dome onto the second reactor building

Big Carl lifts the dome onto Hinkley Point C’s second reactor

By Hinkley Point C media team | Posted July 17, 2025
  • Major milestone highlights the efficiency gains of “Build and Repeat”
  • Pictures and video show the spectacular operation  

“Big Carl”, the world’s largest crane, has successfully placed the 245-tonne dome onto Hinkley Point C’s second reactor building, marking a major step forward for the power station’s identical second unit.

The 14-metre-tall dome closes the 44-metre-high reactor building, allowing its fit-out to accelerate. Images of the spectacular operation can be downloaded here - and the video can be downloaded here.

Work on Unit 2 was stopped during the pandemic, but teams are catching up on lost time.  Their progress is helped by innovation and experience from Unit 1, which means Unit 2 takes 20-30% less time to build. The twin nuclear reactors will provide reliable zero-carbon electricity for more than six million homes, boosting Britain’s energy security for decades to come.  

Build and Repeat

Although the second dome was lifted 18 months after the first, Unit 2 is further ahead, compared to the same moment for Unit 1.   Prefabrication in factories on and off-site is driving gains in productivity, safety and quality, with giant steel structures and complete rooms now being lifted in, making Hinkley Point C a “Large Modular Reactor”.

  • On Unit 2’s civil construction, 30% fewer people achieved 40% more work than on Unit 1 with prefabrication of structures now approaching 60%
  • More equipment has been fitted and 300 tonnes of internal steel installed, versus just 10 at the same stage for Unit 1
  • Innovation allowed the massive concrete cylinder around the reactor to be built 40% more quickly
  • More examples of replication benefits can be found here

Hinkley Point C is the first nuclear plant to be built in Britain for 30 years, restarting a supply chain and industry after a long pause. The figures highlight the benefits of building a series of identical plants. Innovation and experience gained at Hinkley Point C will benefit Sizewell C from the start.

Stuart Crooks, CEO of Hinkley Point C, said:

Restarting the industry has been hard, but the second of our two identical units shows the big benefits of repeating an identical design.

Build and Repeat is the best way to build new nuclear with time savings already at 20-30%. All  our experience and innovation will benefit Sizewell C from the start.

 

Energy Minister Michael Shanks said:

Hinkley Point C will deliver the next generation of clean, homegrown nuclear power, creating high quality jobs and growth in Somerset and across its supply chains.

The government is ending years of delays to usher in a golden age of new nuclear, with funding for Sizewell C and SMRs, protecting family finances and boosting our energy security.

Downloads

The world’s largest crane, “Big Carl” lifts the 245-tonne dome onto the second reactor building
The world’s largest crane, “Big Carl” lifts the 24...
At 47-meters in diameter, it is wider than the dome of St Paul’s Cathedral
At 47-meters in diameter, it is wider than the dom...
The steel dome is 14-metres tall, weighs 245-tonnes and is made up of 900 welds
The steel dome is 14-metres tall, weighs 245-tonne...

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