'There wasn't a last day.'

The Penrhyn Strike of the early 1900s greatly affected the whole of the north Wales slate market. Compared with the situation before the Strike, for three whole years this huge quarry supplied the world with very few slates. Many companies who had been keen buyers of Welsh slates turned to other suppliers during this time and never returned. The Second World War further affected the slate industry as the demand for building slates fell considerably, and many of the quarrymen enlisted in the army. Although there was a spurt of post-war building activity, the north Wales slate industry never really returned to the level of productivity it had enjoyed at the turn of the century. During the 1950s it became obvious that the quarry was more or less worked out, and although there were attempts to find good rock and to diversify, Dinorwig Quarry closed without warning in August 1969.

The quarry's equipment and fittings were put up for auction and many of the items you can see in the Museum today were only saved from the auctioneer's hammer by the sterling efforts of a few former workers. According to Hugh Richard Jones. 'They'd already sold some things, and what frightened me most was to see them up on the big [water] wheel…they were going to burn it as scrap. I got the chance to stop them doing that, and talked to the receiver and the auctioneer, and they closed the whole lot up and got the 'vultures' out of there. That's what we called them, those scrap merchants — 'vultures' because they would take the whole lot. Whatever they saw, they'd take it, store it then burn it.'

'It had slackened an awful lot. But nobody thought it would close down that suddenly.'

The Museum was opened to the public in 1972 with Hugh Richard Jones, former chief engineer, as manager.

Many of Dinorwic’s former quarrymen and engineers were employed to present and interpret their craft, and a collection of significant examples of equipment was begun, often collected from other slate quarries in Wales. This is still the policy today: we’re proud of the opportunity to use knowledgeable staff, who understand the wider context of the amazing history of the slate industry.

And that industry still exists. About 350 people are currently employed in Wales’ slate quarries, with a large number working for McAlpine in Penrhyn Quarry, Bethesda and in numerous smaller quarries belonging to the same company around Blaenau Ffestiniog and the Nantlle Valley. The historical J.W. Greaves company still works in Llechwedd Quarry, Blaenau Ffestiniog; and the Wincilate company is responsible for the only working underground slate mine, Tal-y-Llyn Quarry. The foundation of the industry is still producing roofing slates, but Welsh slate is also used for architectural purposes, for example the Cwt-y-Bugail slate in the Museum’s shop and café, and for many other uses for instance foundations for roads.