Steve Gardham: However I can't find any uses of 'Main' in the Yorkshire pit context. Are you sure it doesn't say 'Mine'?

There were many "Main" shafts or collieries in Yorkshire:

- Markham Main
- Maltby Main
- Dinnington Main
- Edlington Main

to name just a few, and others further north in Durham etc such as:

- Tyne Main
- Bewick Main

A lot of collieries had Main seams or shafts, even if there was no "Main" in the colliery name. It was a very common appellation in northern coalfields.

I strongly suspect he was referring to the main seam at South Kirkby colliery, which was running at the time of McGinn's visit to a "Yorkshire mine in 1962"...South Kirkby's quite close to Huddersfield.