Missiles could help firefighters put out high-rise blazes

China has developed missiles that can be fired at high-rise buildings to put out blazes.

The projectiles, which are filled with a fire-extinguishing agent, can hit targets up to 50 floors high and go through glass up to 19 millimeters thick when launched from several hundred meters away.

The system has been developed by China Aerospace Science and Industry Corp, a major producer of missile systems for the Chinese military.

Each missile can put out a fire of up to 60 cubic meters, the company said, adding that it uses aerospace technologies and boasts high mobility, maneuverability and the ability to operate hundreds of meters from the scene of the fire.

Infrared and laser sensors on the missile launch vehicle detect and calculate the location and height of the blaze, while the ballistic computer calculates the necessary trajectory.

Qiu Xuyang, the system's chief designer, said developers attached importance to the system's operational safety and guarantee that the missile will not miss its target.

"In case the missile accidentally deviates from the predetermined course, the onboard control system will guide it to the ground," he said.

There are more than 350 skyscrapers (buildings higher than 152 meters) in China, and the number is expected to increase rapidly.

Extinguishing fires in skyscrapers poses a tough challenge to fire departments worldwide, said Luo Qifeng, deputy director of the Shanghai Institute of Disaster Prevention and Relief, adding that such fires usually cause casualties.

"There are a lot of pipes, shafts and stairwells in a high-rise building that will greatly speed up the spread of the fire by what is called the 'stack effect'," he said. He said the complex layout of electrical wiring and the large quantity of electrical equipment in such buildings also helps to drive fires.

Normally, it is difficult to put out fires on the upper floors of a skyscraper because most fire trucks are unable to reach great heights. This means firefighters often have to enter a burning building to extinguish it.

Kang Qingchun, a professor specializing in fire control at the Chinese People's Armed Police Force Academy, said even special equipment, such as hydraulic platforms capable of reaching over 100 meters, can only be used under certain conditions.

"For example, you can't use a hydraulic platform in strong wind because it will sway strongly," he said, adding that fire suppression equipment inside high-rise buildings is the most reliable method of extinguishing blazes.

He suggested that the developers of the fire-extinguishing missile system should conduct more research to improve the product before putting it on the market.

"They must figure out how to determine whether there are people in the room and how to detonate the 'warhead' and release the extinguishing agent at the right point."

zhaolei@chinadaily.com.cn

(China Daily 10/25/2013 page5)