The Tunlan colliery had some of the world's most sophisticated technology and expensive equipment to prevent gas explosions, but hardware alone is not enough to save lives, say some mainland mine-safety experts. Every minute nearly 300 cubic metres of methane, a colourless, odourless and highly flammable gas, was released in the Tunlan mine shafts, said Li Shaochen, deputy director of the Beijing Institute of Mine Safety Technology, who has visited the site. Mr Li said that compared with most other mainland coal mines, the rate of gas build-up was alarmingly high - enough to fill Beijing's National Aquatics Centre or 'Water Cube' in two days. Methane built up quickly and when concentrations reached 5 per cent, just a fraction of the energy needed to light a match could ignite the gas, Mr Li said. 'To be fair, the management of the Tunlan mine knew they were digging into what seemed like an active volcano and had invested a lot of money in some of the most advanced technology and equipment to avoid explosions.' Mr Li said modern mining methods could effectively prevent a blast, and at the Tunlan site, miners were required to wear uniforms that prevented sparks from friction. Huge excavation machinery weighing hundreds of tonnes was carefully designed, manufactured and tested to make sure it did not create sparks during operation. But Mr Li said the most expensive and difficult challenge was extracting methane. Many tunnels were too deep and long to allow the methane, and other harmful gases, to escape quickly. He said Tunlan had an innovative methane drainage system that used water to convey the gases through specially designed pipelines and pumps. Another expert at the China Coal Research Institute, who had also visited Tunlan's underground facility many times, agreed. 'Most victims suffocated with a costly life-support system strapped to their waist that went unused. If they had received any serious training and knew that the first thing to do after an explosion was to put on the mask, most of them would have survived.'