Kay's Slope

Overview

A Blaenavon Company slope colliery that formed the intake for Milfraen's workings, absorbed Milfraen in 1933 and Garn Slope in its returns. It became part of the NCB's Blaenavon super-pit and was merged with Garn in 1958.

History

Kay's Slope was a slope colliery of the Blaenavon iron and coal companies near Blaenavon. In 1894 it employed 350 on the Three Quarters, Big and Elled seams, rising to 649 in 1910. In 1908 it was returned with Garn and Milfraen, the three employing 957 underground. Kay's Slope was the intake for its own workings and for those of Milfraen Pit, whose shaft was the upcast for both. In 1929 the Milfraen and Kay's combine employed 1,189 and raised 10,150 tons a week. Kay's workings were lit by naked lights, Milfraen's by locked safety lamps.

Milfraen was merged into Kay's Slope in 1933. With Garn Slope it employed 936 that year and 1,027 in 1940. In 1945 the Blaenavon Company's Big Pit, Kay's and Garn Slopes raised 600,000 tons. After nationalisation the National Coal Board planned to work all the Blaenavon collieries as one super-pit, with the men going down Big Pit. Kay's Slope employed 341 in 1947, when it raised 90,000 tons, and was merged with Garn in 1958.

Geology

South Wales Coal Measures: the Three Quarters, Big Vein and Elled, with the Black Vein worked through Milfraen from 1926.

Workings

A slope (inclined drift) serving as the intake airway for its own workings and Milfraen's, ventilated through the Milfraen upcast by a Schiele fan; connected underground with Garn Slope.

Closure

Merged with Garn Colliery in 1958 within the NCB's Blaenavon group; Garn itself was merged with Big Pit in 1961.

What remains

Unknown.

Redevelopment

Unknown.

Related mines

• Big Pit — Part of the NCB's Blaenavon super-pit with Big Pit.
• Garn Colliery, Blaenavon — Connected underground; merged in 1958.
• Milfraen Colliery — Worked as one mine; Kay's Slope the intake, Milfraen the upcast; merged 1933.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• Employed 350 in 1894 and 649 in 1910 on the Three Quarters, Big and Elled. ¹
• Kay's Slope was the intake for its own and Milfraen's workings, Milfraen's shaft being the upcast for both. ²
• Milfraen was merged into Kay's Slope in 1933. ²
• Garn Colliery was merged with Kay's Slope in 1958. ³
• In 1947 it employed 341 and raised 90,000 tons. ¹

Photographs & further reading

Sources

1. (primary) Kay's Slope — Durham Mining Museum
2. (secondary) Milfraen Colliery — Northern Mine Research Society
3. (secondary) Garn Pit, Blaenavon - Welsh Coal Mines — Welsh Coal Mines

Record created: 1 October 2026 · Last researched: 2 October 2026