Engineers were preparing to free the 33 miners trapped deep underground in Chile as NCE went to press.
Codelco general manager underground mining Fidel Báez said that all risks were under control. “In my opinion we have no risks.
“A trial proved they are all under control. It is just a normal winching operation for the mining industry,” said Báez.
The rescue attempt – set to begin at midnight local time on 12 October follows a series of successful test runs where the 500mm wide and 1.9m tall capsule was lowered down the 622m shaft.
On Monday, the empty capsule was winched to a location just 10m from where the miners have been sheltering for the past two months. The operation was a resounding success with Chile mining minister Laurence Golborne claiming “it didn’t even raise any dust”.
“It is just a normal winching operation for the mining industry”
Shaft drilling was completed late last week after 33 days of operations using a Schramm T-130 rig – known as Plan B drill.
Two other drills – Plan A and Plan B – were also on site but suffered major setbacks after repeatedly veering off course.
After inspection of the completed 700mm diameter shaft, it was found that only the top 58m needed steel reinforcement, with the rest of the excavation bored through high quality, competent rock.
Báez said cameras and scanning equipment had confirmed that no fractures were found through the 622m depth.
The steel casing was installed on Monday before the capsule test runs took place.
It should take about an hour for the rescue capsule to make a round trip, although only 15 minutes of that would be spent in the capsule according to Báez. Codelco predicts all miners will be freed within 48 hours.
- 5 August: 33 miners are trapped underground when part of the San Jose mine collapses.
- 7 August: A second collapse blocks access to the lower parts of the mine, hampering rescue efforts.
- 22 August: Rescue workers hear tapping on a drill that has reached a depth of 622m. The miners are confirmed to be alive.
- 30 August: Rescuers decide the best way to free the miners is to drill three shafts and winch them to safety. The holes, named Plan A, Plan B and Plan C, are dug at the same time to try to rescue the men as quickly as possible.
- 26 September: The first of three rescue capsules built to lift out the men arrives at the mine.
- 9 October: The miners celebrate as a drilling rig breaks through into their underground chamber. It is decided that only the first 55m of the shaft need to be reinforced.
- 11 October: A test rescue capsule is successfully sent nearly all the way down to where the miners are trapped.
- 12 October: Evacuation begins.