NEW Zealand rescuers have released CCTV footage of an underground blast which trapped 29 miners last week, showing a powerful and sustained explosion.
The security video, which was shown to the miners' relatives and the media on Tuesday, showed white powder shooting out of the shaft's entrance for some 52 seconds before subsiding, as the camera shook.
Meanwhile a replacement robot has arrived at the site of the disaster, where the 29 men - including two Australians - have been trapped for five days.
The New Zealand Defence Force robot was flown from Wellington to the Pike River Coal mine on Tuesday afternoon, after a similar military machine broke down 500 metres into its 2.5-kilometre mission to find the trapped men.
A helicopter delivered the second robot to the remote, horizontal mine at about 3pm (1pm AEDT) on Tuesday, a spokesman for NZ Minister of Defence Wayne Mapp, told AAP.
"Any (call on the) use ... of it has to be made by police and rescue officials," the spokesman said.
"If and when it would be used, it's completely up to rescue authorities."
Grey District Mayor Tony Kokshoorn told AAP that water from within the mine had damaged the first robot and admitted he was "frustrated" that the mishap had occurred.
"There was a lot of anger because people couldn't understand why water would get in to it when they knew water was coming off (the mine)," Mr Kokshoorn told AAP at the Council Chambers on Tuesday afternoon.
"Why would you run a robot in without having ... some protection?"
However, the police officer in charge of the mine blast rescue, Superintendent Gary Knowles would not confirm the robot had suffered water damage.
"It stalled and we can no longer use it," he said at a packed media conference on Tuesday morning.
When AAP asked Mr Kokshoorn about the discrepancy he said: "Well I'm sorry but that's what they said to us".
Meanwhile, an Air New Zealand plane was on its way to Perth to collect another robot from the West Australian Water Corporation, a spokesman for WA Water Minister Graham Jacobs told AAP.
The machine - designed to travel along pipes - was described as a "robust, skid-steered remotely operated vehicle, equipped with cameras, lights, communications and gas testing equipment".
Another robot is also expected to be brought in from the US.
The machines were essential in making progress in the mining disaster, Mr Kokshoorn said.
"The robot will actually find the miners and the robot will actually say if they're ok or not," he said.
"So, there will be some finalisation to this one way or another.
"When you can see where they are, if they're dead or alive, at least at that point we can actually move to another stage."
Tuesday's setback had made for tense times between officials and the miners' anxious relatives.
"A couple of days ago everyone was rowing the boat together but there's a lot of strain there now, you can sense it," Mr Kokshoorn said.
"There's a credibility factor comes in to it, it makes people angry especially when they know every day is crucial."
Earlier, NZ police conceded a strong possibility the missing men may have perished during or in the aftermath of a methane explosion in the mine last Friday.
"This is a very serious situation and the longer it goes on, hopes fade, and we have to be realistic," the police officer in charge of the operation, Superintendent Gary Knowles, said on Tuesday.
There has been no communication with the miners since the explosion, which trapped them in four different locations underground.
On Monday, plans were made to drill a 162-metre hole in to the horizontal, mountain-side mine, allowing more gas samples to be taken and analysed.
But after hitting hard rock overnight, drilling was stalled.
Pike River CEO Peter Whittall now hopes rescuers will be able to drill through the last 20 metres on Tuesday afternoon, and he said crews were looking for other potential drill sites.
Rescue teams still can't enter the mine due to toxic gas levels, Supt Knowles said.
"According to experts, the levels of toxicity remains too unstable to send rescue teams in," he said.
Frustrated father, Lawrie Drew, whose 21-year-old son, Zen, is trapped in the mine, told a small group of reporters: "Drilling is slow, we've just got to sit and wait".
Friends and relatives left a morning meeting weeping and hugging one another after hearing news that a robot sent in to the mine at daybreak had broken down.
A 2.7-kilometre track was hacked through the dense forest at Paparoa National Park, and on Tuesday a fibre-optic cable would be laid, allowing officials to see what's happening at the top of the mine and to monitor gas levels.
Seismic equipment was attached at the mouth of the tunnel, Superintendent Knowles said.
"This will not record voices but this will give us an indication of what's happening, he said.
"If we do hear something that gives an indication they're alive we'll react to that."
NZ Mines Rescue manager Trevor Watts said another 18 people had been deployed from NSW Mines Rescue this week, joining the hundreds of staff working around-the-clock to save the 29 men.
The families of the two Australians trapped in the mine, Joshua Ufer, 25, and Willy Joynson, 49, arrived in Greymouth - the nearest centre to the mine - this week.
Mr Joynson's sister, Leanne, told AAP the family did not want to talk to the media until they had "settled in".
Attempts to contact Mr Ufer's family since their arrival in the mining town have been unsuccessful.
WA robot off to NZ mine
THE West Australian government is sending a robot to New Zealand to assist in the rescue operation for 29 miners, including two Australians, trapped underground at the Pike River coal mine.
An aircraft from New Zealand was expected to pick up the WA Water Corporation robot from Perth on Tuesday, a spokesman for WA Water Minister Graham Jacobs told AAP.
Early on Tuesday, a robot sent into the South Island mine broke down and rescue officials reported it could not be used again.
The WA Water Corporation robot was employed to travel along pipes, the water minister's spokesman said.
It is a "robust, skid-steered remotely operated vehicle, equipped with cameras, lights, communications and gas testing equipment".
The robot is controlled via a fibre-optic cable and has a range of up to 6km.
Technical staff at the state-owned Water Corporation Inspection Services had offered their time without pay to prepare the system if required.
Failed robot a 'kick in the guts'
THE Defence Force robot was "the bright spot" for West Coast residents waiting on the rescue of 29 trapped miners and news it broke down this morning was "a kick in the guts", the Grey District Mayor says.
Relatives of the miners were told this morning that the robot sent into the Pike River mine was not waterproofed and malfunctioned when water fell onto it.
Mayor Tony Kokshoorn told nzherald.co.nz news a robot was going into the mine had been a rare piece of positive news.
"We were hanging our hat on that. When the robot packed up and when they said they couldn't retrieve it I started losing hope at that point," he said.
"I'm only a lay person, my first thoughts were why didn't it have a bit of gladwrap over it.
"I thought this robot is going to go in and tell us the condition of the miners. But when they said the water had got in it was just demoralising."
Mr Kokshoorn said it was crucial to get another robot into the mine to assess the situation while toxic gases prevented rescuers from entering.
"If they can locate the miners with a robot and if those miners are alive, I think at that point in time it will be time to take some risks."
Tasman Area Police Commander Superintendent Gary Knowles told a media conference the robot was sent into the mine at 6am and he was informed at 8am it had broken down.
Reporters were told the robot had only got 550m into the mine when it malfunctioned.
"We will be speaking to the Defence Force this morning to establish whether it [the robot] got any visuals. Anything of a visual nature would only show us a clear tunnel because there was no men in that area."
Mr Knowles said rescuers were trying to get more advanced robots from Western Australia and America to deploy underground.
He said authorities were "pulling all strings" and the Royal New Zealand Air Force would fly in the Australian robot on a Hercules aircraft.
Mr Kokshoorn said he had spoken on the Australian breakfast show Sunrise where he appealed for Prime Minister Julia Gillard to "just please put it (the robot) on an airforce jet and bring it over to us".
"I've no doubt they (the Australian Government) will have pulled out every stop for us."
'Kick in the guts'
Earlier, Mr Kokshoorn said the breakdown of the robot had angered family members and made them question the rescue efforts at Pike River.
Hearing the high-tech defence force robot had short circuited after water from the ceiling dripped on it was a "kick in the guts" for them, he said.
"We were hanging our hopes on the robot because it can get around anywhere in the mine and tell you where our miners are and how they are. Without rescuers it was the next best thing.
"We walked in there and it was a kick in the guts. It's history. Imagine how that went down."
"People really started to be questioning of the procedures. There's a certain amount of anger coming up now. It was very emotional for everyone including myself."
Frustration turned to anger when family members after they were told a replacement robot was being flown in from the United States, he said.
"They asked why didn't they have a backup on their way already. Hell, it's desperate. It's so frustrating."
He implored families and the wider community not to give up hope of getting the miners out alive.
News of 29 Chinese miners rescued from a coal mine yesterday had buoyed some spirits, he says.
"We've got to take heart from those kinds of things."
The trapped miners:
Conrad Adams, 43 (Greymouth), Malcolm Campbell, 25 (Greymouth - Scottish), Glen Cruse, 35 (Cobden), Allan Dixon, 59 (Rununga), Zen Drew, 21 (Greymouth), Christopher Duggan, 31 (Greymouth), Joseph Dunbar, 17 (Greymouth), John Hale, 45 (Ruatapu), Daniel Herk, 36 (Rununga), David Hoggart, 33 (Foxton), Richard Holling, 41 (Blackball), Andrew Hurren, 32 (Greymouth), Jacobus 'Koos' Jonker, 47 (Coben - South African), William Joynson, 49 (Dunollie - Australian), Riki Keane, 28 (Greymouth), Terry Kitchin, 41 (Runanga), Samuel McKie, 26 (Greymouth), Francis Marden, 42 (Runanga), Michael Monk, 23 (Greymouth), Stuart Mudge, 31 (Rununga), Kane Nieper, 33 (Greymouth), Peter O'Neill, 55 (Rununga), Milton Osborne, 54 (Ngahere), Brendon Palmer, 27 (Cobden), Benjamin Rockhouse, 21 (Greymouth), Peter Rodger, 40 (Greymouth - British), Blair Sims, 28 (Greymouth), Joshua Ufer 25 (Australia), Keith Valli, 62 (Winton).
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