Interests of persons other than colliery concerns or class A subsidiaries thereof, being persons whose business includes the operation of things mentioned in this paragraph, in railways, aerial ropeways, wharves, harbours, staithes, and other fixed and movable property, used exclusively or mainly for colliery transport activities for the purposes of a particular colliery concern or of a class A subsidiary of such a concern, or of both such a concern and such a subsidiary thereof.