ABSTRACT
With the introduction at the beginning of this century of ‘scraper’ and, later, ‘belt’ conveyors, it became possible to extend the length of the working face. In North West Durham these straight long-walls are conventionally 80–100 yds in length. As distinct from the honeycomb of short faces contained in a bord and pillar flat, a longwall district has one continuous face, connected by end gates to a trunk road. A single unit longwall has a main roadway or ‘gate’ to the face, known as the mothergate, and a secondary road at the opposite end of the face, known as the tailgate. If the district is laid out as a double unit to obtain greater concentration, there are two faces, one on either side of the mothergate, each having its own tailgate and making up a panel of 160–200 yds overall. Each face is serviced by a conveyor, which loads the coal down one of the gates—the central one in a double unit—whence it is transported by another conveyor to the trunk road, where tubs or further conveyors take over.
