Even world's best technology cannot by itself prevent pit gas explosions, experts say

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.