John Swaffield, CIBSE's new president

John Swaffield’s bag of tools, as he describes his mathematical methods, have seen action on projects as diverse as the Hong Kong outbreak of the potentially deadly SARS virus and Concorde’s fuel system. Yet, says the next CIBSE president, investigation of the former used the same principles as the latter.

The SARS (severe acute respiratory syndrome) case, involving drainage in a Hong Kong apartment block, was a particularly satisfying application of theory, so it’s fitting that Swaffield intends to campaign on water issues and urban drainage in his year as president.

In 2003, SARS spread swiftly through the Amoy Gardens apartments, affecting 321 people and causing panic across the estate. Its symptoms include fever, chills, headaches and diarrhoea, and its source was finally tracked to a man who had visited the block. But how did so many people contract SARS from him?

It took a building services engineering team, not a medical one, to establish the facts and come up with a solution. When sick people on upper floors used a toilet, a mist of diarrhoea particles and water was flushed through the down-pipes. Water should have prevented blow-back in open floor traps in bathrooms below, but because it had dried up the traps allowed contaminated air to be pulled in by the electric air vents.

Swaffield and his team at the School of the Built Environment at Heriot Watt University, who had been asked to investigate by the Hong Kong government, concluded that a sheath trap, a rubberised seal that opens in one direction only, could have stopped contaminated air spreading. The work showed the importance of sound engineering research in approaching the natural and built environment, a task made increasingly complex by climate change and the issues arising from it, especially in terms of water conservation.

“We proved with mathematical models that what people thought was actually true, that bathroom fans could draw contaminated air through the dry floor traps,” Swaffield says. He visited Amoy for the first time last November. “It was very satisfying to see your work had some practical application,” he says. “We felt that the outbreak was such a dangerous thing and could happen so easily anywhere.

“If I have a bee in my bonnet it’s about having solid engineering solutions. Our advantage as CIBSE members is that intellectually we understand the science that drives the planet. We can also turn this understanding into engineering solutions.”

Swaffield left his native Aberystwyth at 18 to study fluid mechanics in the aeronautical school at Bristol University in the early 1960s, just as computer analysis was becoming available. After his PhD he joined the British Aircraft Corporation at its factory in Filton, Bristol, to run the Concorde full-scale fuel system test rig. “It was a full-scale model of Concorde,” he explains. “We had to be able to tilt it 50º, which meant a 30-foot hole in the floor to accommodate the tail section. We could depressurise tanks to simulate altitude and pump fuel out at rates similar to flying Heathrow to Washington. There were 30 people in the group. It was a huge toy to give someone at my age [26], really, really exciting.”

For the SARS investigation he went back to his original pressure surge work on Concorde’s fuel system to devise a test for determining where potentially hazardous open traps are in a building. “Pressure surges when one plane refuels another in flight are exactly the same as when you cut off air-flow in building drainage systems. So you simulate it in the same way.”

Whether it’s carbon sequestration, tidal barrages or nuclear energy, Swaffield believes big engineering solutions are just as valid for the planet’s future as windmills on roofs. But the debate must be rooted in sound engineering thought, no matter what discipline a person hails from.

“Aeronautical engineering at Bristol University in the 1960s was very much engineering science with maths. So I got a bag of tools, mathematical methods, and I have been able to use them throughout my career,” he says. “It’s allowed me to apply myself to a range of issues, from Concorde fuel systems to why an eight-year-old girl in Brooklyn nearly lost an arm due to a water hammer in the family’s toilet.”

Swaffield realised he had this “bag of tools” early in his career. When he joined Southbank Polytechnic in 1972 he had to teach fluid mechanics to first- and second-year students in the Institute of Environmental Engineering. “It was great fun, the students, the staff, and I found the school’s subject absolutely fascinating.”

He went on to Brunel University to set up a new department, and in 1985 moved to Heriot Watt University where he has been ever since. But he understands the need to ensure research is rooted in practical applications. During his year as president, Swaffield hopes CIBSE can be more of an interface between practising engineers and those in academia – research funding usually depends on demonstrating that you can generate support from industry. “That is where CIBSE can act as a broker. It can connect people wishing to do research with people in industry who, whether they realise it or not, could benefit from it. When that research is finished, then CIBSE has a direct route into using it to enhance design guidance for its consultant members.”

Climate change, with particular reference to water, offers a major opportunity for research. But he denies there will be a CO2 versus H2O debate in the services sector. “Carbon as a concept has been a brilliant media success. That one word has allowed people to understand climate change. But OK, you also should know that there are water issues.”

Swaffield believes water conservation will increasingly be an issue for communities, even for those with too much of it. “A third of the drinkable water we use is flushed down the toilet. So if you are being rational about water conservation, your first target is the WC.”

The wider subject for services engineers is sustainable urban drainage – how a large, complex commercial building, can effect less stress on sewerage and drainage systems. “Sustainable urban drainage means time-delay runoff of water through holding tanks, on-site ponds, syphonic rainwater systems and green roofs. Building services engineers will increasingly work with the flow outside a building although still within its periphery.” It’s a public health aspect, and CIBSE already encompasses the Society of Public Health Engineers.

The increasing diversity of issues tackled by services engineers has led some CIBSE members to call for a name change. But Swaffield feels this is a distraction from what the institution is essentially about – engineering. “It is not a coincidence that it’s still called Chartered Institution of Building Services Engineers. It’s the engineering ethos that is most important.”

Rumblings by groups thinking of leaving to set up their own body have been heard in the past year. Swaffield doesn’t believe this is the way forward. He says CIBSE’s strength is its ability to include other professional groups. He would be disappointed to see SoPHE and the Society of Light and Lighting set up shop on their own. “The institution should be acknowledged by all its parts that it is a good forum where you can come, present your views, support it and help take forward your speciality.”

He would like to see a water group created within CIBSE. “The Institution of Civil Engineers and the Chartered Institute of Water and Environmental Management tend to look at these issues outside a building’s boundary, such as large-scale civil systems. Inside a building the rainwater, stresses, recycling, harvesting are all within the remit of CIBSE.”

Swaffield retires from Heriot Watt in September but is likely to keep up his research links. “I’ll be able to do all those things I enjoy as opposed to running a 130-strong department,” he says. It will also mean he has more time to drive his CIBSE agenda forward.