Designing for Fire

On 25 July 2006, a derelict flat in Dalmarnock caught fire. The blaze started in the lounge and spread to the surrounding rooms before it was extinguished by the fire services. The fire was no accident.

Neither was it a crime. It was a scientific experiment, jointly funded by BBC2’s science programme Horizon and the Engineering and Physical Sciences Research Council (EPSRC). It was designed to make future buildings safer.

The World Trade Center disaster in September 2001 focused attention on the danger of fire in tall buildings. “Tall buildings are often explicitly designed to withstand high winds and earthquakes but fires have not been as well considered,” says Martin Gillie of the School of Engineering and Electronics, University of Edinburgh.

When a fire breaks out, structural materials expand as they are heated. This leads to high forces that cause walls and floors to bow and warp. Most buildings are not designed to withstand these additional forces and may collapse. If a structure can remain upright, it buys valuable time for people to escape and also allows the fire service and other emergency workers to operate more safely. But the behaviour of structural materials, especially concrete, in a fire is an area of uncertainty. This latest experiment takes a step towards remedying that lack of knowledge.

“If we understand how structural materials behave during a fire, we can design new buildings with that in mind and make them safer,” says Gillie.

In parallel with Gillie’s work, another team of researchers from the same department, this time led by Professor Jose Torero, monitored the sensor data in real-time and used it to slow down the spread of the fire by ordering automatic windows to open and close. In the early stages of a fire, opening windows can cool the fire, slowing it down. In the later stages, shutting windows can help starve it of oxygen.

“We slowed the spread of the fire for about ten minutes,” says Torero. Then the fire reached a hallway where the team had no control and the fire brigade stepped in.

The team are working as part of the national FireGrid project to develop an artificial intelligence (AI) that will process the sensor information and actively fight the spread of a fire in future buildings. AI is essential because the job of interpreting the data, even from this small experiment, was overwhelming. “I reached information overload very quickly,” says Torero.

He hopes to run a second set of experiments towards the end of the year. During these, the job of deciding which windows to open and which to close will be done, for the first time, solely by a computer.