The two shafts for this pit were sunk by Watts, Ward & Co. (who later merged with the London and South Wales Colliery Company) in 1875.
Situated several hundreds of yards northwest of the Risca Black Vein Colliery and on the opposite side of the valley to the Rockvein Colliery, near the junction of the Ebbw and Sirhowy Valleys.
Coal was first produce at Risca Colliery in June 1878.
Later it came under the ownership of the United National Collieries then the Ocean Coal Company.
On July 15th 1880 at 1.30am a gas explosion ripped through the mine killing 120 men and boys. The force of the blast was so great that it badly damaged the ventilation fan, thereby delaying the rescue effort.
Prior to the explosion deputies would use the “Davy” safety lamp when carrying out their inspections of the mine, but the colliers preferred the use of the older “Clanny” lamp because it gave out a better light. Years before Sir Humphrey Davy had strong doubts over the safety of this lamp because the gauge was unprotected against strong air currents. His opinions were later proved correct and the use of the Clanny lamp in the mines was banned.
This disaster brought the total number of miners killed by gas explosions alone; between the Risca collieries and the neighbouring Prince of Wales colliery to 591.
In 1882 an underground explosion killed another four men, the only men underground at the time, all the collieries 60 ponies also died.
They were; Charles Dixon, Overman, of Risca, Francis Evans, Fireman, of Cross Keys, John Gittings, Fireman, of Pontymister and Evan Morgan, Labourer, originally from Llanidloes.