El Entrego, San Martín del Rey Aurelio
Entrego mine, owned by Nespral and Co. until HUNOSA absorbed it in 1969, is the first vertical shaft coal mine in the Central Valley of Asturias, and it was dug between 1905 and 1909.
Up until that point coal was obtained by mountain mining, but the chance of reaching reserves in the valleys underground would prove more fruitful, even if it required much larger investments, which the companies were willing to do at a time of booming regional, national and international markets.
The history of Entrego mine mirrors that of every other Asturian mine – timid, slow, yet ever forward. This one, the very first vertical shaft in the valleys, was operated by means of a wooden headframe and a simple winch until 1926. In that year some aligners were added to the headframe, which was replaced in the Forties with an iron latticework frame which housed a modern steam-powered extraction engine, replaced with an electrical one a decade later.
A new welded structure headframe was built shortly afterwards. When deeper levels were reached a new Koepe pulley extraction engine supplied by GHH and Siemens was used – one of the earliest in Asturias.
The mine was completed in 1958 with the addition of a small coal washing plant that was renovated in the Sixties. Indeed, innovation was a trademark of El Entrego: later came a new powerhouse, new machinery – such as Worthingthon and Ingersoll compressors, essential for pneumatic drilling – the first BARTZ electric locomotive, the first pneumatic loading docks.
And so, Entrego mine entered mining history due to its early vertical opening, yet this has obscured the vital advances and experiences that originated in a familiar, almost domestic little big operation in the mining heartland of Asturias.