Much of the growth of Llay village is connected with the development of coal mines, particularly the Llay Main Colliery. It was first established by the industrialist Sir Arthur Markham in 1913, but the sinking of the shafts was interrupted by the First World War and by Markham’s death in 1916. The shafts were eventually completed in 1921, and coal production started in 1923.
Both shafts were 18 foot (5.5m) diameter and No1 was sunk to a winding depth of 1000 yards (916m) whereas No2 was only 775 yards (709m).
The colliery had a reputation as a well-run, modern pit with a relatively satisfied workforce, and by the 1930s was employing more than 3,000 men, 450 families being installed in new housing schemes in Llay.
In 1924 an explosion occurred killing 9 men and boys, the full report can be found here.
The plans below have been prepared by Lee Reynolds and used here with his permission.
Composite plan of all seams
