17 Tir John Power Station

17. Tir John Power Station (photos: tower demolition, interior) – 26 September 2015

In 1881 London’s Savoy Theatre became Britain’s first public building to have electricity, whereas in Swansea electric light was used in 1886 in J.S. Brown’s Oxford Street premises.  Initially private companies as well as municipal councils provided electric power: Swansea Corporation’s power station was built from 1899 to 1901 in the Strand near the North Dock, and operated a general supply from December 1900.  But its 23-megawatt output struggled to meet the growth in demand for the new source of energy: by 1924 the need for a new power station was being discussed. 

James William Burr was Swansea Borough’s electrical engineer from 1914 to 1939, and he oversaw the largest engineering project in Wales - the building of Tir John power station.  The Strand power station closed in 1936 - to widespread relief having discharged smoke and grit over a wide area.

Tir John North electric generating station was built on the east side of Kilvey Hill on the edge of Crymlyn Bog between 1931 and 1935.  Unemployment relief schemes were utilised, as with building Cefn Coed psychiatric hospital, and the Main Drainage scheme.  Tir John cost £1.4 million to build, from the outset was connected to the National Grid, and operated from 1935 to 1976.  At the time it was the largest power station in Britain, being revolutionary in its use as fuel of anthracite duff.  This was a waste product from the washing of mined coal at colliery pit heads, supplied at a fixed price of four shillings per ton for 25 years, which made it the cheapest rate for fuel ever supplied to a British power station.  Once the 25 years had expired, the price increased in 1960 to 35 shillings per ton. 

Tir John was opened on Thursday 20 June 1935 by Labour MP and future Home Secretary Herbert Morrison, followed by an evening gala dinner at Swansea’s recently completed Guildhall.  The Evening Post issued a commemorative supplement for the occasion.

Tir John eventually had three 89m high brick chimneys, though by the start of the Second World War two were only partly built, being completed afterwards.  The final brick of each chimney was fitted by the wife of the foreman in charge; she was hoisted to the top of the chimney, and had her name inscribed on the brick she laid.  The third chimney was completed in 1947.

By agreement with the Great Western Railway Company, seawater for cooling Tir John was drawn from the King's Dock through an 820m (over half a mile) underground inlet tunnel.  After passing through the power station’s condensers the seawater was returned to the larger Queen’s Dock by a 1,180m long discharge tunnel; each tunnel was concrete-lined and about 3m in diameter.  The water flow was 6 million gallons per hour, with warmer water being returned to the Queen’s Dock, thereby raising its water temperature.  Every two years Tir John had to be closed for a week while the build-up of mussels – an estimated 50 tons - was removed from the inlet tunnel. 

Although one bomb fell into Crymlyn Bog, Tir John escaped war damage.  Throughout the 1950s the power station employed as many as 420 people, but in 1967 it was converted to oil burning, with a direct pipeline from the nearby Llandarcy Oil Refinery, built in 1921.  Ironically a few years later the OPEC oil embargo led to the substantial escalation of oil prices which made it uneconomic – so Tir John closed in March 1976. 

The three chimneys were blown up in June 1980, and following demolition the area became a landfill site.  Tir John’s capacity when opened was 40-megawatt, later increased to 155-megawatt, while Baglan Bay power station, built from 2000 to 2004, uses natural gas and has a 525-megawatt capacity.  That shows the extent that provision of energy has progressed, but in its time Swansea’s Tir John power station was innovative.                                                    (With thanks to Mr A.R. Walker)