Tunnelling can be a very dangerous enterprise and accidents occur all too frequently in mines all over the world. One such recent event occurred in a mine in Northern Mexico, but unlike the happy ending in Chile, it appears that hopes have faded for the nine men still trapped underground in the San Juan de Sabinas Mine near the border of Eagle Pass, Texas.
Five men were killed instantly in the initial explosion that rocked the mine, but a further nine miners were thought to be trapped underground and potentially still alive. A rescue team used shovels, picks, and even their hands, to try and reach the trapped men 197 feet below ground while about sixty relatives maintained an overnight vigil outside as they waited for news.
Five bodies were found in the first piles of rubble, but despite the state of the collapsed mine shaft, the relatives were still hopeful that the men deeper underground could still be alive. Unfortunately, the local authorities were forced to suspend rescue efforts when a gas build up occurred.
Experts believe the main blast that caused the tragic mine shaft collapse was as a result of methane gas (it was a similar chain of events that led to another catastrophic blast in February 2006 at the Pasta de Conchas coal mine not too far away). This latest gas explosion was so powerful that a teenage boy working above ground on a conveyor belt was badly injured with an arm torn off in the blast. As a result, experts say it is highly unlikely that anybody underground survived the blast.
The rescue team hope to be able to dig down and recover the bodies of all nine miners, but they admit that the task will take time and a great deal of work.
A new report into the Chilean mine collapse has produced evidence that safety failings were responsible for the disaster that saw thirty three men trapped in an underground mine shaft for more than two months.
Following the catastrophic rock fall at the San Jose mine in the Atacama Desert in Chile last August, the miners were trapped deep underground for seventy two days while rescuers tunnelled down through solid rock in an attempt to reach them. At the time of the Chilean mine disaster, the only concern of the rescuers and the watching world was whether the thirty three miners would ever be pulled free from their underground prison, but investigators have since been examining the circumstances of the mine collapse in an attempt to discover who was at fault.
Thankfully for the men and their families, the story had a happy ending and all 33 men survived the disaster, but the report into the Chilean mine collapse has now pointed the finger of blame firmly in the direction of the mine’s owners and the Chilean government has been completely exonerated of any wrongdoing.
According to the commission appointed by the Chilean Congress to look into the causes of the disaster, the owners of the mine were more interested in making money than safety issues. Adequate safety procedures had not been put in place, despite being a requirement by the authorities. The report also apportions some of the blame on the Chilean mining regulator for not making regular mine inspections. As a result, the commission recommends that the mining regulator be completely reorganised.
Families of most of the rescued Chilean miners have since lodged a claim for £17 million against the mine owners and the Chilean mining regulator. Whether the claim is successful remains to be seen.
A contract was signed at the end of December between Rio Tinto and Aker Wirth for the delivery and testing of a new Tunnel Boring System that has been designed as part of Rio Tinto’s Mine of the Future programme. Rio Tinto is hoping that the programme helps to introduce safer processes into the tunnelling and underground mining industry.
The new TBM has been designed to use innovative technology known as the Mobile Tunnel Miner concept and is based on Aker Wirth’s many years of experience in the field of hard rock tunnelling and mining. It uses ideas first developed and tested more than ten years ago and aims to combine the flexibility of a roadheader operation with the robustness of a TBM.
A statement issued by representatives of Aker Wirth stated that the machine ”…is capable of meeting the challenges set out by Rio Tinto to improve the safety and speed of tunnel construction in underground mining.” The CEO of Aker Wirth, Christoph Kleuters, added, “We are proud to have this opportunity to partner with Rio Tinto and be part of an important development that may change the face of underground mining.”
The TBM will be tested in Australia, at the Northparkes copper mine. Operational trials of the new tunnel boring machine are expected to be complete by the end of 2012.
It is hoped that the trials will help to significantly improve the face of modern mining and tunnelling. Commenting on the trials, Rio Tinto Head of Innovation, John McGagh said, “This significant new investment offers the possibility for a step-change improvement over conventional drill and blast practices. Depending on rock conditions, this system should provide a capability to excavate at more than double the rate of conventional methods.”