Little Clifton open heap coke producing bases and associated slag heap, 220m north of Oldfield Bridge

Reasons for Designation

Coal has been mined in England since Roman times, and between 8,000 and 10,000 coal industry sites of all dates up to the collieries of post-war nationalisation are estimated to survive in England. Three hundred and four coal industry sites, representing approximately 3% of the estimated national archaeological resource for the industry, have been identified as being of national importance. This selection, compiled and assessed through a comprehensive survey of the coal industry, is designed to represent the industry's chronological depth, technological breadth and regional diversity. Coking is the process by which coal is heated or part burnt to remove volatile impurities and leave lumps of carbon known as coke. Originally this was conducted in open heaps, sometimes arranged on stone bases, but from the mid- 18th century purpose built ovens were employed. By the mid-19th century two main forms of coking oven had developed, the beehive and long oven, which are thought to have been operationally similar, differing only in shape. Coke ovens were typically built as long banks with many tens of ovens arranged in single or back to back rows, although stand alone ovens and short banks are also known. They typically survive as stone or brick structures, but earth- covered examples also exist. Later examples may also include remains of associated chimneys, condensers and tanks used to collect by-products. Coke ovens are most frequently found directly associated with coal mining sites, although they also occur at ironworks or next to transport features such as canal basins. Coal occurs in significant deposits throughout large parts of England and this has given rise to a variety of coalfields extending from the north of England to the Kent coast. Each region has its own history of exploitation, and characteristic sites range from the small, compact collieries of north Somerset to the large, intensive units of the north east. All surviving pre- 1815 ovens are considered to be of national importance and merit protection, as do all surviving examples of later non-beehive ovens. The survival of beehive ovens is more common nationally and a selection of the better preserved examples demonstrating the range of organisational layouts and regional spread is considered to merit protection.

Little Clifton coke bases are the sole surviving example of 18th century open heap coke producing bases. They now lie buried and undisturbed and along with the nearby furnace slag heap will retain important technological information on 18th century open heap coking and iron smelting.

Details

The monument includes the buried remains of three intact stone-built open heap coke bases which were used to produce coke for a nearby 18th century iron furnace, together with remains of the furnace slag heap. It is located on level ground between the River Marron and a steep bank 220m north of Oldfield Bridge. Little Clifton Furnace was the first coke-fired iron furnace in Cumbria, commencing operations in 1723 and producing cast iron until its closure in 1781. Locally mined coal was used to heat the iron ore for smelting but before it could be used the coal had to be cleaned. This cleaning operation converted the coal into coke and the process employed here at Little Clifton was described by Gabriel Jars in 1765, who noted that round areas about 3.5m in diameter were filled with large pieces of coal to form a cone- shaped pile some 1.5m high. The coal was arranged in such a manner as to allow air to circulate through the pile, then lighted coal was placed into the top of the pile and the whole covered with layers of straw, earth and coal dust. Two workers were employed to oversee the whole operation and once the coal had been converted to coke it was taken to the furnace to be used in the iron smelting process. Remains of these three coke bases were visible until the 1980s when they were covered over by earth during landscaping; they now lie buried and undisturbed. A short distance to the north is an irregularly-shaped flat-topped mound of furnace slag up to 2.5m high. This represents the waste product from the iron smelting process. A number of features are excluded from the scheduling; these are all fenceposts, gateposts, a telegraph pole and the timber posts which support the horse jumps; the ground beneath all these features, however, is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.

Legacy

The contents of this record have been generated from a legacy data system.

Legacy System number:

27814

Legacy System:

RSM

Sources

Books and journals
Jars, G, Voyages Metallurgiques, (1765), 235-7
Marshall, J, Davis-Shiel, M, Industrial Archaeology of the Lake Counties, (1977), 250-1

Other
SMR No. 5653, Cumbria SMR, Little Clifton, (1987)

End of official list entry

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