Preserved Koepe extraction tower of the Pozo Rotilio, a listed industrial monument within the Zona Minera de Riotinto-Nerva, Huelva.
The Malacate Pozo Rotilio is a steel and iron winding tower standing in the municipality of Nerva, Huelva, within the historic Riotinto-Nerva mining basin. It was constructed by the Compañía Española de Minas de Río Tinto between 1970 and 1975 to serve the Pozo Rotilio, a shaft sunk from 1966 to extract ore from the Masa San Antonio deposit on the eastern edge of the Riotinto anticlinal. The Koepe-type extraction tower — one of only two of this type surviving in the Iberian Pyrite Belt — stands 18 metres high, 12 metres long, and 8 metres wide, above a shaft of 400 metres depth.
Ore extraction proved economically unviable owing to the complexity of the deposit, and all activity at the shaft was halted in 1980. The structure was restored in 1998 by the Fundación Río Tinto and is now protected as patrimonio etnológico within the Zona Minera de Riotinto-Nerva, listed in the Catálogo General del Patrimonio Histórico Andaluz since 2005. The shaft and tower take their name from Rotilio Martínez Barreiro, director of the Minas de Riotinto from 1954 to 1970, who died in a rail accident in 1978.
The Riotinto-Nerva mining basin has one of the longest documented records of mineral extraction in the Iberian Peninsula, with organised exploitation traceable to the Roman period. Modern industrial exploitation was transformed from the 1870s under the British Rio Tinto Company Limited, which introduced open-cast methods, built a narrow-gauge railway to the port of Huelva, and developed the Corta Atalaya and other open workings that defined the basin's twentieth-century character. By the mid-twentieth century the basin's principal extraction company was the Compañía Española de Minas de Río Tinto (CEMRT), which operated across the municipalities of Minas de Riotinto, Nerva, and El Campillo.
Between 1960 and 1962, exploration by the CEMRT identified a previously unknown sulphide deposit at Nerva — the Masa San Antonio — on the eastern side of the Riotinto anticlinal. This discovery prompted the decision to develop a dedicated underground shaft to exploit it. Work on the Pozo Rotilio began in 1966, the shaft being driven to a depth of 400 metres.
Between 1970 and 1975 a steel and iron malacate — a winding or extraction tower — was constructed above the shaft. It was of the Koepe type, a friction-wheel single-rope extraction system, and at the time of its construction represented one of very few examples of this technology in the Iberian Pyrite Belt, of which only two now survive. The tower measured 18 metres in height, 12 metres in length, and 8 metres in width.
The shaft was named after Rotilio Martínez Barreiro, who had served as director of the Minas de Riotinto from 1954 to 1970 and subsequently as a councillor of Rio Tinto Patiño. Martínez Barreiro died on 15 December 1978 in the TALGO train accident at Manzanares, Ciudad Real. Once the shaft installations were complete, it became apparent that the Masa San Antonio ore was metallurgically complex and difficult to process economically.
Operations at the Pozo Rotilio were suspended in 1975 according to some sources, and all activity was definitively halted in 1980. No production of commercial significance was achieved. The shaft subsequently stood disused.
In 1998 the Fundación Río Tinto undertook a restoration of the malacate structure, stabilising and conserving the tower. The Pozo Rotilio was included in the Zona Minera de Riotinto-Nerva, the heritage-protected zone encompassing the Riotinto basin. From 2005 the malacate was formally indexed in the Catálogo General del Patrimonio Histórico Andaluz by the Instituto Andaluz del Patrimonio Histórico as patrimonio etnológico, alongside other surviving mining infrastructure of the basin including the malacates of Pozo Alfredo and Masa Planes.
The Zona Minera de Riotinto-Nerva was in the process of formal Bien de Interés Cultural designation with the categoría of Sitio Histórico in 2005. The malacate continues to be preserved in situ at Nerva and is promoted as part of the industrial heritage of the Riotinto basin.