Silverdale colliery, Newcastle (1830-1998). Silverdale opened in 1830, to provide coal for the Silverdale Ironworks. A mechanisation programme began in 1950 when £20 million was invested. Construction of a new mine and two drifts from the surface, each of 4,000 yards, to extract 50 million tonnes in the Keele – Hanchurch area. A new coal preparation plant was also built. It was the last mine to close in the area in December 1998.