Abandoned Asturian coal shaft retaining its steel headframe and pithead buildings at San Frechoso, Olloniego, south of Oviedo.
Pozo San José is a former deep coal shaft located in the parroquia of San Frechoso, within the parish of Olloniego in the concejo of Oviedo, Asturias. Coal extraction in the Olloniego area began in the mid-nineteenth century under foreign operators including the Compañía Anglo-Asturiana and later La Espada, which registered concessions from 1842. Subsequent consolidation brought the concessions under Compañía General Minera and then Carboneras de Olloniego, which merged in 1918 with Hulleras de Veguín to form Hulleras de Veguín y Olloniego.
Sinking works on the vertical shaft that would become Pozo San José began at San Frechoso around 1951 and were completed in 1958, reaching ten working levels and a depth of 650 metres. The shaft concentrated all extraction following the closure of subsidiary workings and was absorbed into HUNOSA in 1968. Production ceased in 1972 and the shaft was reactivated by HUNOSA in 1982 before final closure on 11 January 1993.
The headframe, winding house, and medical building survive on site, though all are reported in poor condition.
The coal-bearing lands of Olloniego were first commercially prospected in the mid-nineteenth century, when the former concejo of Tudela — integrated into the concejo of Oviedo in 1857 — attracted a wave of mining registrations. Among the early operators was the Compañía Anglo-Asturiana, which worked the Tudela concejo lands, and La Espada, which registered several mines in Olloniego from 1842 onwards and constructed a small coking furnace. The complex ownership and concession geography of this early period makes the succession of operators difficult to trace precisely, but by the early twentieth century the Olloniego concessions had passed to the French-registered Compañía General Minera and subsequently to Carboneras de Olloniego.
In 1917 the properties were acquired by the Sociedad Hullera de Veguín, and in May 1918 this body merged with the Olloniego interests to form the Sociedad Hulleras de Veguín y Olloniego. The new company, whose shareholders included the Masaveu family — principally interested in coal as fuel for their cement works at Veguín — undertook a systematic development of the Olloniego area. This included the construction of organised mountain mining headings, inclined planes, a modern coal-washing plant at La Servanda, and loading docks connected to the railway network. A narrow-gauge railway of 600-millimetre gauge connected the bocaminas with the main installations and with the RENFE terminal at Olloniego; this line was replaced in June 1962 by an aerial ropeway.
After the Spanish Civil War, Hulleras de Veguín y Olloniego acquired additional workings in the Caudal basin and the Aller district. The company continued to operate a group of mountain mines in the San Frechoso area into the 1950s. Around 1951 the company began sinking a new vertical shaft at San Frechoso, which received the name San José. The sinking was completed in 1958, giving a shaft of ten working levels reaching a depth of 650 metres. The headframe was a steel lattice structure. The shaft was equipped with an extraction winding installation and served a coal face extending over a strike length of 2,500 metres, exploiting seams numbered 5, 6, 10, 17, and 18.
On 1 July 1968, Hulleras de Veguín y Olloniego was absorbed into the state company HUNOSA. Under HUNOSA, Pozo San José became the focus of all extraction in the Olloniego group following the closure of the Mina Vicentina workings in November 1968. From its commissioning in 1958 until a first closure in 1972, the shaft produced a total of four and a half million tonnes of coal. HUNOSA reactivated the shaft in 1982, and extraction continued until final closure on 11 January 1993, ending over a century and a half of mining in the Nalón valley tributary at Olloniego.
At the time of closure, works on a second shaft designated Pozo nº 2 were already under way but were halted with approximately 140 million pesetas already invested. The surface complex at San Frechoso comprised the headframe, winding house, medical building, and workers' housing. In 2012 a brace member of the headframe was cut and removed by thieves; HUNOSA subsequently replaced the stolen element. The headframe, winding house, and medical building remain standing but are reported in a markedly deteriorated state, and the site has not been converted to museum or heritage use.