Landore Siemens Steelworks was opened as an experimental plant in the converted buildings of the Landore Silver and Spelter Works (NPRN 301167) in 1867-69. The site was developed by William Siemens (1823-1883), who German by birth, came to Britain in 1843 and subsequently developed the open-hearth method of steel production. By 1870 Landore Siemens Steelworks was producing steel rails.

In 1871 a second works was opened to the east of the River Tawe, with two blast furnaces and extensive mills. By 1873 it was one of the four largest steelworks in the world, although it closed in 1888. Siemens steel was used to construct warships at Pembroke Dock and the Forth Bridge. The Mannesmann Tube Company converted large areas of the mills into production lines for seamless steel tubes. The blast furnaces and steel making plant were taken over by the Swansea Hematite Company in 1899. The site operated as a foundry until 1980 although tube production ceased in 1961.

Source:
"A Guide to the Industrial Archaeology of the Swansea Region", Stephen Hughes and Paul Reynolds, Association for Industrial Archaeology, 2nd Edition, 1989

RCAHMW, 8 September 2011.