Monument Type(s):

• Hoffman Kiln (Late 19th century - 1899 AD to 1899 AD)
• LIME KILN (Late 19th century - 1899 AD to 1899 AD)

Summary

The Hoffman kiln is exceptionally well preserved and is of particular importance, not least because it retains its chimney (PRN 03815). It was constructed c 1899. It had 14 chambers which were stacked with limestone transported by tramways which ran along both sides of the kiln. The kiln is protected by Grade II Listing and by Scheduling.

Related records

Associated Finds: None recorded

Associated Events

• ESA4761 - 1993 Test Pits at the Hoffman Kiln, Llanymynech by SCCAS
• ESA5650 - 2004 assessment in connection with the Llanymynech Heritage Area Development Project by CPAT
• ESA6151 - 2006 Excavation at the Hoffman Kiln, Llanymynech, Shropshire by SCCAS
• ESA6163 - 2001 Archaeological Survey at Llanymynech heritage area, Shropshire, by Archenfield Archaeology Ltd
• ESA6202 - 2007 WBs at the Hoffman Kiln, Llanymynech, Shropshire by SCCAS
• ESA6235 - 2007 Excavation at the Hoffman Kiln, Llanymynech, by SCCAS
• ESA6318 - 2008 WB at Llanymynech Limeworks heritage area by SCCAS
• ESA7340 - 2001-2002 Development study of the Llanymynech Heritage Area by Graham Barrow Research and Consulting
• ESA7341 - 2004 Survey of series of buildings at Llanymynech Limeworks Heritage Area by Tim Ratcliffe Associates

Description

Kiln, now disused. 1899. Massive oval-shaped earth-covered mound over red brick kiln with 2 tunnel vaults. These are entered through 14 round headed arches with smaller round-headed kilns to south on east side and to north on west side. Air vents to vaults. Associated with Hoffman Chimney (PRN 03815) immediately to south. <1>

In order to facilitate the preparation of specifications for repairs to the Hoffman Kiln, Llanymynech, a number of test pits were archaeologically excavated through the deposits on top of the roof of the kiln in 1993. The arched roof was constructed of a single skin of bricks, and was seen to be in a basically sound condition. A capping layer of fired clay was recorded over much of the brickwork on the western and eastern sides of the kiln. <9>

The Hoffman kiln is exceptionally well preserved and is of particular importance, not least because it retains its chimney. The kiln is (unusually) constructed of brick rather than limestone, with battered walls, measuring 44.8m by 17.5m overall externally, with a height of around 3.4m. There is some disagreement regarding the date of construction, although this seems to have been generally accepted as being around 1899. Certainly, the kiln was not recorded by the Ordnance Survey in 1874, but was in existence by 1900, and continued in use until 1914. The Llanymynech kiln had 14 chambers which were stacked with limestone transported by tramways which ran along both sides of the kiln. The coal was brought onto the roof of the kiln by a tramway on an embankment to the north, with a bridge over the ground level limestone-carrying tramway passing around the north end of the kiln. The whole structure was covered with a corrugated iron roof, the iron stanchions for which are still visible along the base of the kiln walls. ->

-> This design of kiln was developed in Germany by Friedrich Hoffman, who first patented the design in 1857 for the firing of bricks. The design was later modified for the firing of lime. The key characteristic of the design was that it allowed more continuous operation of the kiln by containing a tunnel divided into a series of chambers separated by temporary dampers. Each chamber had a main entrance, which would have been sealed by bricks when it was firing, as well as a ground level air intake and a flue connecting to a central flue along the length of the kiln which led to the chimney. The Llanymynech kiln had 14 chambers, of which at any one time one would be empty, one being filled, five pre-heating, two firing, four cooling and one being emptied. The kiln at Llanymynech is a relatively small example of the type, and would probably have been less efficient than larger ones. ->

-> The Hoffman kiln had been cleared of vegetation and was surveyed in some detail as part of this project. The report, however, recommends clearance of the overburden in the interior under archaeological supervision, and detailed building recording in association with reconsolidation. <10>

In September 2006, Shropshire Archaeology Service led a community archaeology project at the Hoffman Kiln, Llanymynech, Shropshire on behalf of the Llanymynech Limeworks Heritage Project. Five trenches were excavated around the kiln. The fourteen volunteers uncovered remains of former yards, evidence of repeated firing within the kiln, tramways beside the kiln, and parts of the structure of a steel roof that once covered the kiln. Further understanding was also gained of the operations of venting and draft control at the kiln. <11> [see also <12>]

In 2007 a series of watching briefs were carried out in and around the area of the Hoffman kiln, Llanymynech. The stubby brick chimneys around the vents/coal charging holes in the kiln roof were observed as well as a series of soil deposits similar to those observed during the excavation of trial pits in 1993 [ESA 4761]. Repairs to brickwork showed that the kiln was double skinned, with separate spaces between the outer wall and inner arched wall being filled with loam. Inside the kiln a layer of burnt lime was exposed, though no trace of any floor surface was seen. The top of the charging ramp was cleared and exposed parts of the old track bed of cinders and limestone chippings and uncovered a couple of in-situ sleepers. The retaining wall lying along the sides and at the northern end of the Hoffman kiln were of very rough drystone construction and composed a mixture of limestone rubble and vitrified bricks, the latter presumably had been used to block the openings during firing. Around 3m of the northern end of this wall was removed to accommodate public access to the site. During the removal of topsoil on the east side of the kiln two concrete turntable bases were exposed. The southern base had had all its ironwork removed, but still retained the impressions of the cartwheel base-plate. The northern base still retained its iron “cartwheel” base-plate within the concrete and fixing runner bearings.->

-> In September 2007 four trenches were excavated around the Hoffman kiln in advance of the installation of drains along both sides of the kiln. Trench A revealed the former yard surface and track bed, complete with impressions left by tramlines and sleepers. A large pit was also revealed indicating the position of a former turntable including the remains of the timber turntable. Trench B re-exposed the northern turntable base seen earlier in the year [ESA 6202]. A former yard surface was exposed between the base and the kiln, though no trace of the former tramlines remained. A hollow in the centre of the area may have marked the former location of a turntable base. Trench C revealed another concrete turntable base 0.40m below the surface beneath a layer of disturbed and compacted topsoil with brick rubble. Only the cartwheel impression of the base of the original iron turntable survived, with no ironwork present. No evidence of former yards or tracks were seen between the base and the kiln. Trench D exposed a further turntable base. Most of the cast iron cartwheel base plate survived intact, together with three runner wheels and some of the sides of the turntable. The concrete pad this was set in was of irregular shape, but impressions of sleepers survived in the concrete at the E and W sides and grooves for the tramlines on the E side of the pad. <12>

In 2001 an historical, archaeological and landscape 'tier two' survey of Llanymynech and the surrounding environs and included land that had previously been used for limestone quarrying and a large area of mixed woodland. The development of the site was assessed from the pre-industrial landscape, to the development of the fields, kilns, tramways, canals, railways, plantations other industrial and economic infrastructures. <13>

Further to the work carried out in 2006-2007 (see <12>), a series of watching briefs were carried out during the installation of interpretative sculptures at the site during 2008. Two small trenches were excavated adjacent to the Hoffman Kiln, to a maximum depth of 0.40m below ground level. They revealed small areas of late 19th/early 20th century yard surface associated with the kiln. <14>

Photographed during aerial photographic survey in 2009. <15><16><17>

In 2001, a condition survey was undertaken of the kiln, as part of a development study of the Llanymynech Heritage Area. This included inspection of the roof structure of the kiln. <18>

A series of large scale drawings were made of the Hoffman kiln prior to consolidation as part of the development of the limeworks heritage area, and in association with plans to protect the site with a metal roof superstructure. <19>

Mentioned in the scheduling document, from 2006. Immediately north east of these [draw] kilns [PRN 19380] is the large brick built Hoffmann Kiln with its massive 140 foot high brick chimney. The kiln measures 44.8m long by 17.5m wide, stands up to 3.4m high and has 14 chambers which were loaded with limestone through the ground level arches. The interior of the kiln takes the form of two parallel vaulted tunnels built side by side, connected by curved tunnels at either end. The coal to fire the kiln was dropped in through a series of small openings in the roof. The entire structure was covered by a freestanding corrugated iron roof which no longer survives, although at least one stanchion does. The Hoffmann kiln was built around 1898 and would have significantly increased the efficiency of the lime burning operation at Llanymynech. The kiln was finally abandoned when lime burning operations ceased in 1914. <20>

Sources

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