Saracens’ new rugby stadium in Barnet had to built in 38 weeks. Precast concrete and careful planning made sure the ground was ready for the start of the 2013 season.
- Stadium experience
- Benefits of using precast concrete
- Precision engineering
- Organising the supply chain
When Watford FC decided to activate a break clause in its groundsharing agreement with Saracens, the rugby club was forced to begin searching for a new home.
They found it at Barnet Copthall Stadium, renamed after its £20m revamp to become the 10,000-seater Allianz Park.
Eric Wright was main contractor on the redevelopment, which used a large amount of precast concrete throughout.
“We won the contract thanks to a previous relationship with the developer,” says Eric Wright operations director Jonathon Raynor.
“There was quite a fast turnaround on the project and there was a trust there that we could deliver to that timescale.”
The build programme was 38 weeks long, with Eric Wright beginning on site in May 2012 and handing over in February 2013 prior to Saracens’ first home game of the season.
“We had done some work on stadia before but not a huge amount,” Mr Raynor says. “Where we are experienced is in other kinds of sports facilities, such as swimming pools and athletics tracks. We also worked on Manchester United’s training complex at Carrington.”
“The speed of the programme was the biggest challenge and there were so many different elements that we had to engage all our subcontractors very early on”
Jonathon Raynor, Eric Wright
Experience of similar projects also helped secure the job for Bison Manufacturing, the firm that produced the precast concrete products used on the project.
“We were specified by the structural steel subcontractor Billington because we had worked with them on a number of other stadium projects,” says Bison commercial manager Mike Nelson.
Bison’s work on other large stadia included Manchester United’s Old Trafford, Wembley Stadium and a number of other Premier League grounds.
“I think that’s one of the big reasons Bison was picked: the quality of their products’ finish and their quick delivery times,” Mr Raynor adds.
Benefits of using precast concrete
Bison designed, manufactured and delivered a total of 485 precast concrete units for the project. This included 278 terrace units plus vomitory walls, solid slabs, step blocks, stairflights and precision gable walls.
The components are cast in steel moulds using self-compacting concrete. One of the main reasons precast concrete was specified was for the high quality of the finish.
“Precast concrete reduces the need for wet trades because there are no bricklayers on site, which means there is less labour and so a lower health and safety risk”
Mike Nelson, Bison Manufacturing
“It’s the first time Saracens have owned their own home and their chief executive Ed Griffiths was very passionate about making sure it looked as good as possible for the fans,” Mr Raynor explains.
The team was able to exert better quality control by manufacturing the products offsite.
“They are created within a controlled factory setting so we can make sure each individual component is of the correct size and quality for the job,” Mr Nelson says.
The use of precast concrete also provided additional benefits for health and safety and to the build programme.
“It reduces the need for wet trades because there are no bricklayers on site, which means there is less labour and so a lower health and safety risk,” Mr Nelson explains.
With wet trades absent, weather delays were not a concern during one of the worst winters in recent years, saving time and money.
“The steel frame and the precast concrete elements were built from the centre of the stands outwards,” Mr Raynor says. “This allowed us to have two gangs working at once.”
The gable walls were the most technically difficult concrete aspect of the project, requiring precision from Bison to avoid delays.
“There was no opportunity to fail because the ground had to be ready for the first home game”
Jonathon Raynor, Eric Wright
“In this case, they formed a parallelogram structure that required absolute precision engineering,” Mr Raynor says. “You have to get the setting out of the moulds exactly right, making sure you have a nice straight line so that everything lines up and it’s also easy on the eye.”
The walls had a maximum span of 5,000 mm, heights of 997 mm and 150 mm depths. Components were continually measured throughout the process to ensure they were meeting the exact design dimensions.
“We had to really plan and be very, very organised on this project,” Mr Raynor says. “There was no opportunity to fail because the ground had to be ready for the first home game.
“We installed precast lift shafts for the first time on this project and were able to install three of them in just two days – a very quick turnaround.”
Organising the supply chain
This organisation flowed right through the supply chain and was not just limited to the precast concrete components.
“The speed of the programme was the biggest challenge and there were so many different elements to the stadium that we had to engage all our subcontractors very early on,” Mr Raynor says.
“The stadium is used as an athletics facility by the community on weekdays before turning into a rugby stadium at the weekend, and there are all of the hospitality requirements as well – so we had to make sure we got the stadium right for everyone involved.”
The quality of the stadium’s finish was very well received by Saracens and its supporters, with the ground opening in time for the start of the 2013 season.
“Mr Griffiths had a real vision for how he wanted this stadium to be, for both the club and its fans,” Mr Raynor adds.
“I know it’s a bit of a cliché, but everybody on the team bought into that vision and produced a great stadium. We ended up using as much precast concrete as we could because of the benefits it brought.”