Timeline: Some Important Dates
500 million years ago: the creation of slate
1300s Cilgwyn Quarry, Nantlle, is in production
1700s
1787 Dinorwig Quarry is established
1790 Port Penrhyn is developed for export business
1800s
1801 Penrhyn Tramway opens
1818 Welsh Slate Company’s quarry opens in Blaenau Ffestiniog
1820 Construction of Porthmadog harbour
1830 Penybryn Quarry, Nantlle, is the first user of chain inclines
1848 steam locomotives are first used on the Padarn Railway
1874 North Wales Quarrymen’s Union is established
1874 steam locomotives are introduced at Port Penrhyn
1881 Ffestiniog parish has over 11,000 inhabitants
1890 hydro-electricity is first used at Llechwedd Quarry
1900s
1900–3 The Penrhyn strike, one of the longest in British labour history
1918 Minimum wage is agreed by quarry owners and union officials
1920s Crushing mills are erected at Penrhyn Quarry, to grind slate waste used in road construction
1940s Slate waste is used to make building blocks
1964 The Alfred McAlpine company purchase Penrhyn Quarry
1969 Closure of Dinorwic Quarry, establishment of museum
1972 Llechwedd Slate Caverns open to the public
1999 A large shipment of slates from Penrhyn Quarry is sent to Australia, for storm repairs
