Once filled, the automated train will snake through a series of narrow tunnels, emerge from a rocky outcropping, then loop past St-Jean's window and dump its payload for sorting.

Vale SA, the Brazilian company that owns the mine near this nickel-rich Canadian town, has spent nearly $50 million in two years to install and test the "rail-veyor." The company believes the transport system will revolutionize how it builds and extracts new mineral deposits.

The equipment is made locally by Rail-Veyor Technologies Global Inc. It is one of many mining technologies that developers hope will allow future production to be run almost entirely by people safely above ground.

Such advances may prove crucial as easy-to-exploit deposits run dry and miners drill deeper in more remote places to supply China, India and other emerging economies. The technology could make mining cheaper and safer, avoiding the need to dig wide tunnels and hire large numbers of expensive, skilled workers.

"As we go deeper, if we continue to apply existing thinking and existing technologies, it's a death spiral" for company profits, said Alex Henderson, who heads Vale's technology team in Sudbury.

"We need to begin to look at a step-change in mining rather than just incrementally improving our existing processes."

The rail-veyor is one such step-change. At the test site, it has halved the time to build a mine, and Vale expects a 150 percent boost in production rates before year end.

In Australia, Rio Tinto Ltd, one of the world's largest miners and an automation pioneer, is rolling out a fleet of self-driving trucks and trains at its iron ore operations. Vale, BHP Billiton and Chile's Codelco are in hot pursuit.

Gold miner AngloGold Ashanti is eyeing automation in South Africa, where miners spend hours each shift traveling up and down shafts and ounces of gold are left behind in support pillars each year.

Organized labor has made its peace with the automation drive, although there were some concerns that robots would displace humans.

"We're ok with automation, it's part of the changing times and it's a good thing for productivity," said Myles Sullivan of the United Steelworkers Canada, whose workers ended a year-long strike at Vale over bonuses and wages in 2010.

700 STORIES UNDERGROUND

New challenges in mining are driving technological changes. Large, accessible deposits have all but disappeared. Resources of tomorrow are in far-flung corners of the globe or hundreds of meters beneath the surface.

Add a shortage of skilled labor - expected to worsen as the baby-boom generation retires - and mining costs have surged.

While soaring demand means higher metal prices, rising costs are crimping profits. Canada's S&P/TSX Mining share index has fallen more than 38 percent since the beginning of 2011.

Experts say mining companies must change how they operate.

Making that shift is not easy for an industry steeped in tradition, especially when change doesn't come cheap. Rio Tinto is spending more than $500 million on train automation alone.

"This is a very conservative industry that has been very productive over the last 30 years doing it the way they're doing it now," said Douglas Morrison, chief executive of the Centre for Excellence in Mining Innovation (CEMI), an industry-funded research center in Sudbury.

"But is the old way going to work for us into the future? I think probably not, so we need to make some changes."

After decades of production, the nickel mines around Sudbury are getting deeper and deeper. At Vale's Creighton mine, the No. 8 shaft drops nearly 8,000 feet into the ground - equivalent of a 700-story condo tower.

At that depth it is very hot, around 50 degrees Celsius (120 Fahrenheit), so tunnels must be pumped full of cooled air to make temperatures manageable for people and heavy machinery.

"The bigger issue is when we get much deeper we start to generate our own earthquakes - very small earthquakes - these are called 'rock bursts,'" said Morrison.

Smaller tunnels and new ways of digging can hopefully reduce the danger of these rock bursts, which create a safety concern and slow development.

Rio Tinto is working with CEMI on automated tunnel borers, currently used to build subway and sewer tunnels. By cutting through the rock instead of blasting, Rio aims to quadruple its underground advance rates to 20 meters a day.

But while automated tunnel borers will build shafts and tunnels more quickly, massive mining equipment still handicaps the industry, which is where Vale's rail-veyor comes in.

A train hauling 50 tonnes of ore uses a far smaller tunnel than a truck with the same load. By taking the massive trucks and scooptrams - large vehicles with shovels on the front - out of the equation, Vale can build more compact and stable tunnels.

The rail-veyor, built on tracks that zig-zag down to the deposit, actually eliminates the need for expensive shafts and may eventually move people and equipment, along with ore.

Vale's Henderson believes the technology - which the company plans to roll out in five upcoming projects - is a game-changer that will help usher in a new era of mining.

"Just as the scooptram was the key enabler for the mechanized era, is the rail-veyor a key enabler for the next?" he said.

MAN VS MACHINE

What that "next era" will look like is still up for debate. Some innovators believe robots will do most of the labor in mines of the future, as in automobile assembly plants. This would ease likely shortages in skilled labor in many countries.

Over the next decade Canada's mining sector will need more than 100,000 skilled new hires to sustain even modest growth, according to the Mining Industry Human Resources Council.

In Australia, the labor crunch is already so intense that truck drivers can make upwards of $100,000 a year, with turnover rates at some mines still near 40 percent.

"One of the biggest problems that the mining industry faces worldwide is trained personnel. We can't get them," said John Meech, director of CERM3, a mining research center at the University of British Columbia in Vancouver.

"One of the ways we are going to have to deal with that is to automate the systems so that the human becomes the supervisor, rather than the direct means of control."

It is a concept already used at remote open-pit mines in Australia, where Rio's new fleet of driverless trucks can be run from a control room hundreds of miles away.

Canada's Nautilus Minerals Inc is using automated rovers to explore the ocean bed for mineral deposits that underwater robots will eventually mine.

In addition to boosting productivity, the advances will enhance safety. As labor leader Sullivan says, "so long as there's underground mining, there will be women and men working underground."

Safety is the focus at a converted schoolyard just outside Sudbury, where a duo of mine rescue robots roll through a makeshift obstacle course. Their thick tires grind over logs and through mud pits.

Designed by Canada's Penguin Automated Systems Inc, the equipment is being tested by Codelco at its Andina copper mine in Chile, doing dangerous jobs like checking stability after blasting and surveying tunnels at risk of flooding.

"Our mining industry is not quite there yet in Canada and it needs to get there to be competitive with the rest of the world," said Penguin Chief Executive Greg Baiden. "It comes back to the culture. Who wants to do it? Who wants to be first?"

(Additional reporting by Bhaswati Mukhopadhyay in Bangalore; Editing by Frank McGurty, Janet Guttsman and David Gregorio)

• A Permanent Economic Emergency