heapstead
The elevated framework of wood or iron at bank, to the top of which the pit is continued above the surface, to provide the necessary height to pass the coals over the skreens into the wagons.
heapstead: the pit's wooden tower for sorting coal
A heapstead is a tall wooden or iron framework erected at the pithead, rising above ground level to create the vertical drop needed for coal to fall through screening and sorting equipment before loading into wagons or carts. It extends the working height of the shaft collar upward, solving a practical problem: gravity-fed separation requires distance.
The structure sits directly above the pit mouth and typically stands 20 to 40 feet tall, depending on the screen arrangement and wagon size below. Coal brought to the surface by the winding engine reaches the top of the heapstead, where it enters the screening mechanism, cascades through riddles or bars of varying mesh sizes, and drops into separate grades, with waste falling to the outer edges and better coal directed toward loading chutes.
Materials and Function
Early heapsteads were timber frames, bolted together from heavy squared beams, with platforms and railings for workers who fed coal into the screens and cleared blockages. Later installations used wrought iron or cast iron columns to reduce fire risk and improve durability, though the principle remained unchanged. The frame had to withstand vibration from screening equipment, uneven loading from lumps of coal, and the wear of decades of operation.
The heapstead is essential to the coal processing chain: without it, coal would be difficult to screen and grade efficiently at the surface, forcing expensive re-handling or acceptance of mixed quality output. Its height also kept muddy or fine coal dust away from wagons and workers closer to ground level, though this created hazardous working conditions aloft for screen tenders and coal trimmers.
The term appears chiefly in British and European mining vocabulary; American operations used similar structures but often called them pit frames, breaker towers, or coal towers. As coal mining declined and modern screening became automated and lower-profile, the traditional heapstead largely vanished from active collieries, though examples survive as industrial heritage structures.