Backwell Environment Trust

...10+ years of conservation, protection, improvement...

The Lime Kiln

Location

Walk downhill from the Jubilee Stone (towards the Church Town entrance to the reserve) for about 100 metres. The Lime Kiln is situated on your left hand side, about 20 metres along a side path edged with stones & logs.

Restoration

The restoration of Jubilee Stone Wood's limekiln began in 2006. By the end of the first year we had removed approximately 1.5 tonnes of rubble to expose more of the structure.

 

The kiln itself has been found to be in remarkably good condition - probably protected from the elements by the enormous rubble pile in front of it. The picture below shows the kiln as it was at the end of 2009 (after the removal of approximately 5 tonnes of rubble) when we were at last uncovering the full extent of the structure.

Limekiln

Historical Context

The Lime Kiln in Jubilee Stone Wood was constructed sometime between 1843 and 1884 to convert limestone (calcium carbonate) to ‘quicklime’ or ‘lime’ (calcium oxide). This material had many uses ranging from the production of lime mortar and lime wash for buildings to its use in agriculture as a soil improver. 

Towards the end of the 19th century, improvements in transport enabled larger industrial kilns to mass-produce lime at comparatively lower prices whilst the use of cement in the construction industry was becoming increasingly popular.

Historical evidence from old maps indicates that Jubilee Stone Wood’s lime kiln fell into disuse sometime between 1884 and 1902. The adjacent structure probably collapsed soon after the kiln was abandoned which has clearly helped to preserve the kiln in the excellent condition we find it today. 

The manufacture of quicklime was a time-consuming, dangerous and labour-intensive process. Sufficient limestone and fuel (probably coal and/or wood) would have to be collected and transported, loaded into the kiln and set alight. The limestone was then heated in the kiln at temperatures of up to 1000ºC for around 3 to 4 days. The raw materials needed for the process were all available locally. Wood (or charcoal) could be easily sourced from nearby woodlands and coal could be hauled up Cheston Combe from the pits around Nailsea.

Limestone was almost certainly mined from the surrounding area and the woodland has several large, square shaped pits where limestone has clearly been extracted.

Construction

The kiln has been built from locally extracted, shaped limestone blocks and has been deliberately set into the sloping hillside. This arrangement has the advantages of saving on construction costs whilst also assisting in its ease of operation by being able to load from the top and unload from the bottom. It also ensured the kiln was aligned with the prevailing south-westerly winds which would have helped fan the fire and speed up the conversion process.

The internal bowl of the kiln would undoubtedly have been lined with Pennant sandstone extracted from around Nailsea. Whenever kilns were constructed from limestone blocks it was always necessary to physically separate the limestone used in the main body of the kiln with the fuel otherwise it too would be converted to quicklime during the lengthy firing process.

Direcly in front of the kiln are the remains of an open-sided rectangular enclosure which may have served as a storage area for the kiln’s labourers or alternatively used as a sheltered loading point for the extracted quicklime.

 

© 2017 Backwell Environment Trust