Tower Colliery (Welsh: Glofa Twr) was the oldest continuously working deep-coal mine in the United Kingdom, and possibly the world, and the last mine of its kind to remain in the South Wales Valleys. With coal located so close to the surface, it was known by locals to be possible to drift mine coal from Hirwaun common. This activity increased from 1805, until in 1864 the first drift named Tower was started, named after the nearby Crawshay's Tower, a folly built in 1848 and named for Richard Crawshay.
In 1941, a new shaft was sunk to a depth of 160 metres. From 1943 until closure, this shaft was used as the main ventilation shaft and for the transport of men. In 1958 Tower No. 3 was driven to meet the No. 4 colliery workings, and was used as the main intake; airway, conveying coal to the surface and transporting materials into the mine working areas.
Post the 1984/5 UK Miner's strike, the Conservative government authorised British Coal to close the majority of the UK's deep mines on economic grounds, nominally including Tower. But from 30 June 1986, with new underground roads having been driven, all coal from Mardy Colliery was also raised at Tower, the two mines effectively working as one coalfield system. Mardy closed as an access shaft on 21 December 1990.
In October 1993 the red flag was raised on Hirwaun common as a symbol of unity between workers of Tower Colliery during a march to commemorate the Merthyr Rising in 1831, and highlight the plight of their own pit.. In 1994, the constituency MP, Ann Clwyd staged a sit-in in the mine to protest its closure, accompanied by the late Glyndwr 'Glyn' Roberts (Senior) of Penywaun.
British Coal closed Tower Colliery on 22 April 1994, on the grounds that it would be uneconomic in current market conditions to continue production.
Led by local NUM Branch Secretary Tyrone O'Sullivan, 239 miners joined TEBO (Tower Employees Buy-Out), with each pledging £8,000 from their redundancy payouts to buy back Tower. Against stiff central government resistance to the possibility of reopening the mine as a coal production unit, a price of £2 million was eventually agreed. With their bid accepted, the miners marched back to the pit on 2 January 1995, with a balloon inflated for each worker. On 3 January 1995 the Colliery re-opened under the ownership of the workforce buy out company Goitre Tower Anthracite. Philip Weekes, the renowned Welsh mining engineer, was a key advisor to the buy-out team and became (unpaid) Chairman.
Although the mine remained financially viable and continued to provide employment to the workers, by the time of the buyout the only seam worked at Tower was the Seven Feet/Five Feet, a combined seam of several leaves which offered 1.3m of anthracite in a mined section of 1.65m. Working directly under the shaft of the former Glyncorrwg Colliery's (Nr, Maesteg) nine feet workings, the four faces worked in the western section of the lease were considered uneconomic by British Coal.
As the worked seam reduced in capacity, the management team considered three possibilities to extended the length of mine production:
