A 290-tonne particle accelerator and 6 m-thick radiation walls are just two of the obstacles for Interserve on the UK’s first proton beam therapy facility
Project: Proton Beam Therapy Centre
Client: The Christie NHS Foundation Trust
Contract value: £90m
Main contractor: Interserve
Structural engineer: Arup
Concrete subcontractor: Heyrod
Start date: August 2015
Completion date: April 2018
When Interserve was confirmed as the preferred bidder on Manchester’s new Proton Beam Therapy Centre in July 2015, it took on the challenge of delivering something that had never before been built in the UK.
The centre will be the first facility of its kind in this country when it opens in August 2018, bringing with it life-changing and life-saving cancer treatments.
The enormity of the job, on a tight site immediately adjacent to an active cancer treatment centre, is not lost on the Interserve construction team, which is having to tackle a host of technical obstacles to deliver the project.
To produce proton beams, very specialist equipment is needed. In this case, it is a cyclotron, a compact particle accelerator that uses electromagnetic waves to deliver the treatment.
The cyclotron uses these waves to accelerate the particles, which are then fired down a beam line using magnets at two-thirds the speed of light to four separate gantries, which house the treatment equipment.
These gantries, housed in three-storey-high compartments in a radiation-protected area, rotate 360 degrees around the patient to deliver the radiation therapy to the patient lying inside.
The huge size of the gantries and of the cyclotron – which weighs 290 tonnes – are among the largest challenges for the project, but Interserve contracts manager Colin Dowell explains that the team undertook extensive research to understand exactly what was needed.
“We wanted to embed ourselves into this technology,” he says.
“We decided to invest in learning about it ourselves, rather than outsource, so we can control it, rather than relying on bolt-ons.”
Proton Beam Therapy Centre Interserve A6707
The team travelled globally to see similar projects, including to Poland and the US, and met with experts with previous experience of delivering proton beam therapy schemes.
“What we also needed to understand was how this was delivered, and we had the opportunity with [structural engineer] Arup to see a live project in Poland,” Mr Dowell adds.
“We decided to invest in learning about it ourselves, rather than outsource, so we can control it”
Colin Dowell, Interserve
“We had a number of visits to this site where we met with the structural engineer who lived and breathed this project; he knew everything there was to know about protons, the structures and the M&E – they were absolutely key visits for us.”
Architect HKS had also worked on similar proton beam projects worldwide, including the Boca Raton Cancer Centre in the US and the National Taiwan University Proton Beam Therapy Centre.
With vital knowledge and an extensive team in place, Interserve could now tackle the more challenging aspects of the building’s construction. Concrete was chief among these.
Radiation protection is of paramount importance while building any facility of this type, and Mr Dowell explains that the team has been meticulous to make sure it deliver sthe safest facility possible.
“Two things that can stop this radiation escaping are water and concrete,” he says. “Obviously we can’t build a big goldfish bowl, so we have to build concrete – and a lot of it.”
Proton Beam Therapy Centre Interserve 6986
In total, Interserve will pour 20,000 cu m of concrete, and will place 17,000 tonnes of steel reinforcement within it. The walls around the cyclotron, the main source of radiation, are up to 6 m thick.
The danger for the team was that absolutely no thermal cracking of the concrete could occur that would risk radiation escaping.
To tackle the huge scale and technical requirements, Mr Dowell says the team spent “a long time” looking at different mix designs.
“It’s important to have a low water content from the point of view of the exothermic reaction, but equally, we needed to be able to pump it as well,” he says. “What we found is, what we can pump doesn’t actually give us what we need, so we’ve had to change the mix.”
“We can’t build a big goldfish bowl, so we have to build concrete, and a lot of it”
Colin Dowell, Interserve
The team, alongside concrete contractor Heyrod, came up with a mix using reduced cement content and a high coarse aggregate, which had high tensile strength and low thermal expansion.
Traditional C28/35 concrete was selected with a density of 2,359 kg per sq m, incorporating 70 per cent ground-granulated blast furnace slag that cures more slowly and at a lower temperature than other types of cement, eliminating the danger of thermal cracking.
Interserve and Heyrod then tested this mix by building a sample wall that was 8 m long, 3 m thick and 5 m tall.
Open Doors 2016_Interserve_Proton Beam Therapy Centre Manchester.
Behind the hoardings
Construction News visited the site during Open Doors 2016 week.
Read the full report and view a gallery of pictures from the site visit – Interserve opens up UK’s first proton beam therapy centre
“We threw in every imaginable conduit and duct you could think of, just to make sure we covered all the bases, to see how the concrete would react,” Mr Dowell says.
Every piece of concrete must also lock together securely to prevent radiation leakage.
Interserve used a ‘toggle joint’ process – pre-formed linkages that lock two adjacent concrete pieces together to ensure that they cannot pull apart during the curing process – which will make sure no radiation can escape.
The team will undertake 107 concrete pours over the course of the scheme, all using a Level 2 BIM model. According to Interserve, the project will also be the first time that BIM has been used to model radiation protection in the UK.
Proton Beam Therapy Centre Interserve 7263
The radiation protection model was used to provide a simulation of the neutron scattering from the proton beam equipment, while these simulations also showed the team the ideal mass and location of the concrete pours.
Mr Dowell says these modelling processes were crucial for both the contractor and the client. “It’s essential for the end-user as well, being able to take them through the model. It’s ‘sleeves-rolled-up BIM’, not just ‘fancy BIM’ – we want to take the client through a virtual model of the clinical space and how it will look.”
The relationship with the Christie NHS Foundation Trust has been strong from the start, he adds, after the client chose to involve the main contractor early in the procurement process.
“We’re using ‘sleeves rolled up BIM’, not just ‘fancy BIM’”
Colin Dowell, Interserve
Interserve had also previously worked with the client under the P21+ Framework.
“As the Christie involved us early, we’ve been able to support them all along the process,” he says. “We were able to support the Christie along the equipment supplier selection process as they had three potential vendors they were looking at, at the time.”
Varian Medical Systems was chosen as the preferred firm to supply the technical equipment for the job, including the 290-tonne cyclotron, from a list of three potential bidders.
“We had to respond to the requirements of those three vendors to then feed back to the Christie to say, ‘With that vendor you need to do this, with that vendor you need to do that’, and our price is coupled with their price to give the client the overall picture,” Mr Dowell adds.
Super heavy lifting
Early engagement has also helped the team to plan what will be one of the largest technical challenges of the project: lifting the cyclotron and the other medical equipment into place.
The massive weight of the equipment means that Interserve cannot simply lift it into the building using traditional techniques.
Proton Beam Therapy Centre Interserve A6822
Aside from the cyclotron, each gantry weighs around 180 tonnes while some of the large magnets needed for proton acceleration weigh as much as 15 tonnes.
To tackle this, the team had early dialogue with the vendor’s rigging team to see how the machinery could be positioned using specialist techniques, and saw this process in action during a visit to a proton beam therapy site in Poland.
“We’ve thought about the project in a different way; the clinical side is just as important as the technical side”
Colin Dowell, Interserve
Mr Dowell says that the equipment has to be lifted in through the roof, after which the team will lift 4 m-thick concrete planks into place using the same heavy-duty rigging to make sure no radiation can escape.
Interserve will have to achieve all of this on what is an incredibly tight site.
The proton beam therapy facility sits only 3 m away from the Christie’s treatment centre, completed by Interserve in 2014, and immediately behind there is an education centre and auditorium, as well as a block of flats right on the doorstep.
What is proton beam therapy?
The new facility will be the first of two UK proton beam therapy centres, with Bouygues currently constructing the second in London.
The Christie facility, based in Didsbury, south Manchester, will be the first to open, after the Department of Health approved the business case for the scheme in February 2015.
Proton beam therapy is a new type of cancer treatment that is both more effective and safer than traditional X-ray radiation therapy, as it uses specialist equipment that allows treatment to be applied directly to smaller area which minimises damage to healthy tissue.
Traditional X-ray radiotherapy means that healthy tissues around the target area can be damaged, and there are further risks of patients developing cancer in later life due to their treatment – particularly so in paediatrics.
The location is “completely different” to other proton beam centres around the world, Mr Dowell says.
“We’re not in the middle of a field somewhere, which is where they tend to get built in America; in the middle of nowhere with plenty of room where it’s nice and flat, and no issues with logistics,” he adds.
“We’re in the middle of Manchester, right in the heart of the Christie – that’s a big challenge.”
All the medical equipment will be lifted into place in summer 2017, with the facility set to treat what will be the UK’s first proton beam therapy patient in August the following year.
Mr Dowell says that the team is “immensely proud” to be working on what will be a life-changing scheme for cancer patients – something that has stayed with Interserve throughout the construction process.
He recounts how, on a visit to New Jersey, the team met one of the world’s leading proton beam therapy oncologists, Dr Eugene Hug.
“He told us, ‘The technology does what it does, and the technical side looks after itself – the patient’s journey is the most important part’,” Mr Dowell recalls.
“That really changed our mindset and made us think about the project in a different way – the clinical side is just as important as the technical side.”
It’s not often that construction teams can say that what they are building will save lives. But once the immensely challenging build of the Proton Beam Therapy Centre is complete, that is exactly what it will do.