As jobs disappeared, the villages and towns that grew up around mines were drained of cash. The legacy lives on into the 21st century.
"You can find dead-end valleys an hour's drive from cities, there are so few jobs, long-term unemployment, and high levels of economic inactivity," said Chris Williams, professor of Welsh history at Swansea University.
"These communities are shadows of their former selves."
Davies, whose family ties to the area and to the job are strong, is keen to employ as many local men as possible.
"It's sad what we witnessed," he said. "Things that happened then are still fresh."
Nearby Tower Colliery is running out of coal to mine, and will soon be closing. Some 300 jobs will go, but Energybuild could take on up to 100 of those, Davies reckons.
It's not only coal mining that investors are looking at again. Record prices for industrial metals may make Anglesey Mining's
At Aberpergwm, Davies is hoping Britain's need for energy security will continue to drive demand for Welsh coal. "Strategically, what have we got? Oil and gas are running out, but we have got coal," he said.
Britain became a net importer of fuel in 2004, and last year domestic energy production lagged consumption by more than 20 percent, according to government figures.
And while Britain has ready-made infrastructure and labour, it is less amenable to new projects than developing countries in Africa and South America, which are doing all they can to attract investment in mining.
And at a time when environmental concerns about coal are high, there are no tax breaks or other government incentives on the table for Welsh coal mining, said Peter Hain, Minister for Wales in the British government.
"The future's got to be clean," Hain said. "I don't think there's a great appetite for coal mining that's not driven by power stations that are clean."
