Summary
An area of iron mining pre-dating the Industrial Revolution represented by at least 60 shaft mounds surviving as substantial earthworks, these overlying medieval earthwork remains thought to relate to the well documented grange of Byland Abbey.
Reasons for Designation
The iron mining shaft mounds and medieval earthworks south of Bentley Grange Farm, are scheduled for the following principal reasons:
* Period, survival: as one of the best preserved mining landscapes nationally that pre-dates the Industrial Revolution;
* Documentation: although the shaft mounds may be mainly C16, the monument is thought to include earthworks related to the well documented medieval monastic grange;
* Diversity, potential: for the range of different forms of shaft mounds providing the potential for a greater understanding of early mining technology, the spoil heaps are also thought to overlie and preserve remains of medieval buildings.
History
Medieval documents indicate that the Cistercian Abbey of Byland in North Yorkshire had established a grange and an iron forge at Bentley by the late C12, with a subsequent reference in circa 1226 to “stones for burning at the grange of Bentley” taken to indicate the smelting of iron ore in addition to forging. Byland also held land or other rights at Emley, Denby and West Bretton. Although a document dated to circa 1197-1215 mentions a chapel, dedicated to St Werbergh, there are no other documentary indications that there was a pre-existing settlement at Bentley Grange. In the late C13, a licence was granted to construct a mill dam on Bank Wood Beck; although this has been assumed to have been for a corn mill, it may have been to power bellows for a forge or furnace. The site of this mill is not known for certain, although it has been suggested that it was some 0.5km north-west of Bentley Grange Farm, outside the area of scheduling. By the mid-C15 iron working appears to have ceased at the grange which was by then being leased out as agricultural land. When Byland Abbey was dissolved in 1538, the assets of Bentley Grange were recorded as being enclosed pastures. In the late C16, within the wider area, it is known that the Tankersley ironstone bed was mined by the Wentworth family. In the 1950s, much of the surrounding area, beyond the surviving earthworks and area of the scheduled monument, was opencast mined for coal, the land then being reinstated for agriculture.
In 1953, J.K.St Joseph took aerial photographs of the substantial and extensive earthworks of mining remains at Bentley Grange and made a connection with the documentary references to medieval iron working, concluding that the shaft mounds were medieval bell pits for iron ore. Earthwork survey by S Moorhouse and A Wilmot in 1985 showed that the shaft mounds were complex in form with many having clear platform working areas associated and respected by the individual shafts. Because of the complexity in form of the shaft mounds and the sharpness of the earthworks, Moorhouse and Wilmot suggested that the remains were more likely to be the result of mining promoted by the Wentworths in the C16 rather than being to supply the C13 monastic iron forges of Bentley Grange. The survey also clearly demonstrated that the mounds overlay earlier ridge and furrow, possibly even two separate phases of ridge and furrow, being evidence of medieval arable agriculture, this in turn overlying even earlier building platforms and small terraced enclosures orientated to face down the slope to the south-east. These earliest earthworks are interpreted as being medieval, either the remains of the monastic grange, or an undocumented settlement related to the grange.
Monastic granges were land holdings owned and run by monastic communities, the granges being independent of the secular manorial system of communal agriculture and servile labour. Pioneered by the Cistercian order, but soon imitated by other orders, most were agricultural, designed to provide food for consumption within the parent monastic house itself, and also to provide surpluses for sale for profit. Some granges were worked by resident lay-brothers (secular workers) of the order but others were staffed by non-resident labourers. The majority of granges practised a mixed economy but some were specialist in their function. Six types of grange are known: agrarian farms, bercaries (sheep farms), vaccaries (cattle ranches), horse studs, fisheries and industrial complexes. A monastery might have more than one grange and the wealthiest houses had many. Frequently a grange was established on lands immediately adjacent to the monastery, this being known as the home grange. Other granges, however, could be found wherever the monastic house held lands. On occasion these could be located at some considerable distance from the parent monastery, especially those that were in effect run as commercial enterprises. Because the land tenure of monastic houses was comparatively stable and as organisations they could more easily plan for the longer term, industrial monastic granges are thought to have been very significant in the development of medieval industries, particularly iron working.
Shaft mound mining landscapes are characteristic of early mining for seam deposits such as coal and iron ore, with examples typically dating from the medieval period up until the C17, although in some marginal areas this form of exploitation continued into the early C20. In its simplest form, large numbers of pits or shafts were dug down to shallow seams, the bottoms then worked outwards to the limits of ventilation and stability to form a bell-shape, the spoil deposited as a ring at the top of the shaft – the classic bell pit. However most areas of shaft mounds are now thought to have been interconnected underground, the seam typically worked by the pillar and stall method, the large numbers of shafts sunk to provide ventilation and to provide access as the workings extended. It is thought that with this type of working, individual shafts were often specialised: shafts with a simple ring of spoil being airshafts; those with access ramps up onto flat-topped spoil heaps being winding shafts for raising material, typically with a platform for a horse gin either concentric with the shaft or off-set to the side; those without ramps, but with levelled platforms, thought to represent ladder shafts for access. Some shafts with gin-circles may have also been used for pumping water out of the mine workings.
Details
PRINCIPAL ELEMENTS: iron mining shaft mounds surviving as upstanding earthworks, medieval ridge and furrow overlying earthwork remains of building platforms and small enclosures, along with associated buried remains and deposits.
DESCRIPTION: the shaft mounds are not randomly scattered, but form a rough grid pattern, the shafts being typically about 50m apart. The smallest mounds are about 25m in diameter and appear to be simple rings of spoil around a central depression marking the position of the shaft. Most are larger, typically around 40m in diameter, up to 2-3m high, and have definite flattened tops, mostly with a central shaft, but sometimes with the shaft off-set to one side. A number of the mounds have access ramps, platforms interpreted as gin circles and other earthwork features. About five shaft mounds, concentrated in the western part of the area of assessment, south of Woodhouse Lane, are particularly large, more irregular and complex in shape with earthworks suggestive of horse gins set to the side of the shaft along with earthworks of other features. There are at least 50 shaft mounds surviving as upstanding earthworks south of Woodhouse Lane. To the north of the lane there are a further 10 shaft mounds surviving as clear upstanding earthworks, although generally more spread and eroded than those to the south of the lane, in addition the western part of this area is thought to include the buried remains associated with up to three or four infilled shafts. These shaft mounds are considered to pre-date the Industrial Revolution, probably the C16, although a medieval date cannot be completely discounted.
Overlain by the shaft mounds, most clearly observed south of Woodhouse Lane, there are the upstanding earthworks of medieval ridge and furrow arranged in two blocks: that to the east being orientated north-east to south-west, with the second block to the west being orientated more east-west. This ridge and furrow also appears to be of two phases with a lower profile ridge and furrow pattern overlying a higher profile pattern. The ridge and furrow also appears to at least partially overlie a set of earlier earthworks including a number of small rectangular enclosures around 30m across, terraced into the hillside. Close to Woodhouse Lane there are a number of smaller building platforms, typically 10m across, some of which clearly extend under the spoil of later shaft mounds. All of these medieval earthworks are considered to be related to the monastic grange.
AREA OF SCHEDULING: this includes all of the shaft mounds that survive as upstanding earthworks. The area of scheduling is divided into three areas by Woodhouse Lane and the driveway to Bentley Grange Farm. The largest area, that to the south of Woodhouse Lane, is defined by existing field boundaries. To the north of Woodhouse Lane, the area to the west of the driveway to the farm is also defined by modern fence lines except to the north-west where the boundary is as mapped, drawn to follow the edge of arable cultivation at the time of the site inspection. The area to the east of the driveway is drawn to fencelines to the south and west, the stream to the east and a straight line on the north side drawn 5m beyond the bases of the larger two shaft mounds.
EXCLUSIONS: fences, gates, stiles and water troughs are all excluded from the scheduling, however the ground beneath these features is included.
