Llanymynech Heritage Area
CPAT has made a detailed measured survey of the Llanymynech Heritage Area on the Powys-Shropshire border. The structural remains of the lime industry at Llanymynech make this a site of national importance, added to which there is also a major prehistoric hillfort atop Llanymynech Hill and the course of Offa’s Dyke around its western margins.
Right: Aerial view of Llanymynech Hill. CPAT photo 92-C-1051
The Heritage Area lies on the northern side of the village, extending from the canal to the main road from Oswestry to Welshpool. The survey area also included the area of the Llanymynech Rocks Nature Reserve at the foot of Llanymynech Hill, together with the line of two tramway-inclines connecting the quarry with the canal and railway. The work was undertaken on behalf of Oswestry Borough Council in connection with proposals to improve visitor access and interpretation.
The general area around Llanymynech is one of considerable historical importance, containing a number of monuments of national significance ranging in date from prehistory to the early 20th century.
Llanymynech Hill is occupied by an impressive Iron Age, or possibly Late Bronze Age hillfort, the ramparts enclosing an area of 57ha, making it one of the largest in Britain. Archaeological investigation on the hillfort has so far been rather limited. In 1981 a section through the ramparts was recorded during construction work. This revealed the stone rampart and ditch of the inner defences, together with metalworking debris in the interior of the rampart dating to the 4th century BC to the 1st century AD. A number of small-scale archaeological evaluations within the hillfort in recent years have revealed further evidence of occupation and metalworking, including part of an Iron Age roundhouse beneath the 13th green of the Golf Club, which occupies much of the hillfort.
The area to the west of Llanymynech also contains a number of other prehistoric sites, including the remains of several Bronze Age burial mounds and evidence for prehistoric land divisions, known as pit alignments.
The area has a long history of copper and lead mining dating back to at least the Roman period, and a hoard of 33 coins dating between 30 BC and 161 AD was found in the Ogof, on top of Llanymynech Hill. It has also been suggested that the hillfort may have been the location for the last stand of Caractacus against the Romans in AD 49.
The general area also includes a number of Iron Age, or Romano British defended enclosures or farmsteads, including a multiple-ditched enclosure just to the south of the canal.
It has been suggested that the western defences of the hillfort may have been adopted as part of Offa’s Dyke, the 8th-9th century linear earthwork which defined the boundary of the kingdom of Mercia. The precise course of the dyke through Llanymynech is unknown although further to the south, around Four Crosses, it survives as an impressive earthwork.
Left: Aerial view of Llanymynech Heritage Area with the canal to the right, the Hoffman Kiln in the centre and the line of the railway in between. CPAT photo 03-C-791
The Ellesmere Canal
The waterway now known as the Montgomery Canal was built in stages between 1794 and 1821, and runs from the Shropshire Union Canal at Frankton Locks to Newtown. The canal, which reached Llanymynech by at least 1786, originally consisted of four distinct schemes which have only been linked together in name under modern ownership. Three of the schemes were specifically constructed to carry and distribute lime for agricultural purposes from the Llanymynech Quarries. By 1840-41 there were 92 limekilns along a 26 mile stretch of the canal and a peak carriage of 56,501 tons of limestone per annum was achieved.
In addition to limestone, the canal was also used to transport lead from the Tanat Valley mines of Cwm Orog, Craig y Mwyn and South Llangynog, as well as slate from the Llangynog area, which had previously used a river port on the Vyrnwy at Carreghofa.
The canal wharf at Llanymynech developed in association with the tramway system. Originally, limestone would have been transported from the quarries to the canal by horse and cart, presumably being loaded onto boats moored along the northern side of the canal, close to the turnpike road, or a side road to the east. By 1806 the first tramway was constructed, associated with a small triangular canal wharf, with a second, larger wharf, lying to the east of the road. A third, longer wharf, was added further to the west sometime between 1813 and 1858.
The Cambrian Railway Llanfyllin Branch opened in 1863, taking much of the lime trade from the canal, the wharf probably being disused by around 1900, although quarrying and lime burning continued until 1914.
Right: The stable block, built around 1870 to replace an earlier building which had burnt down. CPAT photo 1603-123
In 1845 the Shrewsbury Oswestry and Chester Junction Railway was formed with the intention of constructing a line from the Shrewsbury to Chester railway at Gobowen, through Oswestry to Llanymynech. The line was only completed as far as Oswestry, in December 1848, by which time the company had been amalgamated with the North Wales Mineral Railway to form the Shrewsbury and Chester Railway, itself later absorbed into the Great Western Railway in 1854. Meanwhile, the London and North Western Railway had acquired the Montgomeryshire Canal Company and its tramroads and backed a scheme proposed by the Shropshire Union Railway and Canal Company to convert the canal into a railway. In 1855 the Oswestry and Newtown Railway was incorporated, with the line completed to Pool Quay by 1860 and to Newtown the following year.
The Llanfyllin Branch of the Cambrian Railways was constructed by Mr Savin and his brother-in-law, Mr Ward, and opened on 10 April 1863. A stipulation of the Act of Parliament allowing the construction was that the line was not to interfere with existing tramways by crossing them on the level which thus necessitated two bridges to carry the railway over them. At Llanymynech, a north-end bay platform catered for the Llanfyllin trains which, in order to surmount the canal, used the long ‘Rock Siding’ to a shunting neck, reversing on or off the branch. After several false starts and changes in company, a railway was eventually constructed from Shrewsbury to Llanymynech, and on through Llanyblodwell to the limestone quarries at Nantmawr. The single-track line, which bypassed the Cambrian line, was known as the Potteries, Shrewsbury and North Wales Railway, and was opened in August 1866. Through traffic on the Rock Siding ended in January 1896, although it continued to serve the limekilns until their closure in 1914. After this the siding was used to store redundant wagons until the track was removed in 1939, the Llanfyllin Branch line itself finally closing in 1965.
The Development of the lime industry at Llanymynech
The use of lime as a fertiliser may date back to the medieval period and lime putty mortars were used by the Romans and more extensively from the Norman Conquest. It is not known when the burning of limestone commenced at Llanymynech, although earliest reference is a map of Chirk Castle Estate in 1753 which depicts what appear to be three banks of triple kilns within the area of the quarry workings. The site of the kilns is not known, although they are likely to lie beneath extensive late 19th century spoil tips. In 1754 the Reverend Richard Pococke noted ‘a great number of lime kilns’ at Llanymynech, whilst travelling from Oswestry to Welshpool.
Although the raw limestone was clearly in abundant supply at Llanymynech, what made the area of particular significance was the relative proximity of coal from the Oswestry, Chirk and Ruabon coalfield. The southern end of the coalfield, between Trefonen and Morda, is only 6km from Llanymynech. The kilns at Llanymynech date from the main period of activity towards the end of the 19th century. By the end of the 19th century the use of lime in the construction industry was in decline with increased competition from Portland cement, which was both stronger and more water resistant, and this was undoubtedly a major factor in the eventual closure of the lime works in 1914.
Left: The development of the tramway system during the 19th century
The development of the lime industry is most clearly illustrated by the various cartographic sources and these have been used to produce an illustration of the phasing, based on the evidence from mapping in 1807, 1863, 1874 and 1900.
Prior to the opening of the Ellesmere Canal in 1796 the quarrying and burning of limestone, although an important industry, was undertaken on a relatively small scale. The new markets which could be supplied by the canal led to a rapid expansion of the lime industry at Llanymynech. The main problem faced by the quarry companies was the transportation of limestone from the quarry to the canal 80m below and 0.7km distant. Initially, transport was provided by horse and cart although this situation was clearly unable to cope with the increased demand for limestone. As a result, a tramway and incline was constructed in 1806 to carry limestone from the western quarry workings to a new wharf on the canal. The incline had a double track with a drum house at the top and a cross-over at the bottom where the lines joined a single track tramway leading to the canal wharf where it divided, with a branch running either side of the wharf.
There appear to have been limekilns within the quarry from at least 1753 and although kilns are shown there in 1806 it is unlikely that the lime would have been transported by canal due to its volatile nature. Instead, quicklime would probably still have been transported by horse and cart with only limestone taken by canal.
Right: Mr Roberts, a foreman at the quarry, breaking rocks on the canal wharf
A second tramway was constructed further to the east between 1807 and 1837. This was to become the main transport route which, with later modifications, remained in operation until the closure of the quarry in 1914.
Limestone from the quarries was transported along the tramways to the canal wharves, where it was stored before being manually broken into smaller pieces for shipment by canal barge.
Each of the inclines had a drum house (also known as a brake house or Gin wheel), at the top which controlled the decent of laden wagons. A system of tramways developed within the quarry to transport quarried stone to the head of the inclines and also to remove spoil to the tipping area. These internal tramways would have been subject to frequent modifications as the quarry face receded and new areas were worked, the sections of track being easily lifted and relaid as and where necessary.
The tramways carried wagons to the head of the inclines and from the bottom to the canal. The inclines at Llanymynech are of a type known as self-acting balance or gravity inclines, whereby the decent of a full wagon raised an empty one to the top. A drum house at the top contained a large drum which rotated on an axle supported by the structure’s substantial stone walls. A single haulage cable ran the length of the incline, being wound around the drum at the top. A loaded wagon was attached to the cable at the top end and an empty wagon at the bottom. The decent of the laden wagon under gravity thus raised the empty wagon to the top. The speed of decent was controlled by a braking mechanism, comprising a broad metal band around the drum which, through the action of levers, was tightened to produce a braking effect. The easternmost drum house appears to have been operated remotely, so that the operator stood at the top of the incline, with a clear view down, the braking mechanism being connected to a lever by a series of rods running in a culvert alongside the tracks.
Left: The ivy-clad ruins of the drumhouse at the head of the eastern incline. CPAT photo 1603-40
The opening of the Cambrian Railways Llanfyllin Branch in 1863 had a dramatic affect on the lime industry at Llanymynech. Although the canal continued to be used for transporting lime, the railway afforded a much faster means of transport with links to a much wider network, thus introducing new potential markets. The tramway system which had developed to serve the canal was largely retained and modified to utilise the new means of transport. By 1863 the earliest tramway had been abandoned below the incline, with a new connecting track having been constructed to join the two tramways immediately west of the road, and a double line running beneath the road to a cross-over. To the south the western line ran in a curve before heading to the western canal wharf, while an eastern line took a more direct route to the eastern wharf. A building is shown in the position of the presumed stables, as depicted the shape suggest that this was a different structure to that which survives.
Right: Ordnance Survey 1st edition map of 1874
By 1874 the tramways, although presumably rather earlier, the western tramway had been augmented by the addition of a siding along the south side of the main railway, while further tramways had been constructed to serve the canal wharves. At the quarry workings the western tramway system remained in use, although the incline appears to have been down-graded to a single track with passing loop. The eastern tramway system has what must be an incline, although without a brake house, leading south from the quarry face, with a siding joining from nearby limekilns. A series of lines lead south-west from the eastern workings and limekilns to join the incline above the mid-point. As in 1863, both systems join near the road crossing, with a weighing station beyond.
The two large kilns to the west of the Hoffman kiln are both draw kilns, designed to be run in a continuous operation. Cartographic evidence suggests that they were built in association with the railway after 1874 and abandoned by 1900. A detailed survey of the upper part of the kilns was not possible due to safety fencing restricting access. Both kilns are constructed of roughly dressed limestone blocks, the smaller eastern kiln seeming to be the earlier of the two, measuring c. 11.5m east-west by 15.5m north-south and up to 6m high, with a single central pot. The western kiln also has a single central pot, approximately 2.7m across, the kiln measuring c. 14.6m by 16.8m at ground level, rising to 8.5m above the stone revetment wall following the north side of the Rock Siding. A coal hoist was located on a platform on the western side of the kiln, fragments of which can still be identified. The supports for a small cabin on top of the kiln can still be seen projecting from the front wall. The front of the kiln was protected by a canopy and projecting corbels below the draw hole suggest a raised floor for unloading the lime directly into railway wagons.
Left: The two large draw kilns with the Hoffman kiln chimney in the background. CPAT photo 1603-164
Both kilns appear to be straightforward single-draw kilns which would have been loaded from the top with alternating layers of coal and limestone. The charging ramp for the earlier is not now evident, having been subsumed within the bank of the much larger ramp for the later kiln.
A brick-floored building to the west of the kilns has a series of concrete machine bases within it, and this may be the site of a stone crusher. If so, it may have been constructed in association with the larger kiln, utilising the hoist to raise the limestone to the charging platform.
Right: Ordnance Survey 2nd edition map of 1900
The last major development at Llanymynech was the construction of the Hoffman kiln sometime around 1900. The Ordnance Survey second edition, revised in 1900, shows the kiln along with significant changes to the transport system, including additional tramways and main line railway sidings serving the kiln. At the quarry, the western workings and the associated tramway system had been abandoned, while the eastern system was altered to include a double-track incline, with a new series of feeder tramways along the quarry face.
The Hoffman Kiln
The Hoffman kiln is exceptionally well preserved and is of particular importance as it retains its chimney. The kiln is constructed of brick with battered walls, measuring 44.8m x 17.5m overall externally, with a height of around 3.4m. The square brick chimney stands on a plinth 3.7m across, and rises to a height of around 42.5m. 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.
Left: An impression of the Hoffman kiln in its heyday
This design of kiln was developed in Germany by Friedrich Hoffman, who first patented the design in 1857 for the firing of bricks. The earliest Hoffman kilns were circular, later developing into larger, elliptical or rectangular structures. An English patent was taken out by Humphrey Chamberlain in 1868, with the first kiln built in Nottingham in that year. The design was later modified for the burning of lime and a number of such kilns were constructed in the late 19th century, including the well-preserved example at Langcliffe near Settle in North Yorkshire, as well as two kilns at Minera, near Wrexham.
The significance of the Hoffman kiln is that it allowed for more extensive continuous operation, with the kiln comprising a continuous tunnel which was divided into a series of chambers separated by temporary paper dampers. The Llanymynech kiln had 14 chambers, such that at any one time one would be empty, one was being filled, five were pre-heating, two were firing, four were cooling, and one was being emptied. The main entrance to the chambers was sealed bricks during firing, the inner side becoming vitrified with use. When not in use the bricks were stacked close by and a number of these stacks remain at the foot of the embankment to the west of the kiln. Other vitrified bricks may be found built into the revetment for some of the embankments north of the kiln, suggesting that these were constructed after the Hoffman kiln. Alongside the main entrances each chamber has a semi-circular air intake at ground level, with a corresponding flue beneath the floor which connects to a central flue along the length of the kiln, leading to the chimney. Each intake has above it a row of bricks projecting from the external wall
Right: The Hoffman kiln today. CPAT photo 1603-9
Limestone was brought to the kiln on tramways which ran at ground level on either side of the kiln. To fire the kiln the limestone was carefully stacked in each chamber in succession, with vertical shafts or ‘pillars’ being left immediately beneath a series of ‘feed holes’ in the arched tunnel roof. Small piece of coal were fed through these holes to be burned in the hot air passing through the tunnel. The combustion gases circulate from one chamber to the next until they are drawn into the central flue leading to the chimney. Once the lime in one chamber is sufficiently burned, the flue is closed and coal is fed into the next chamber, which has its flue opened, and thus the fire moves around 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 corrugated iron roof, the iron stantions for which are still visible along the base of the kiln walls.
The recent survey work at Llanymynech is only the start of what promises to be an exciting programme of restoration and interpretation. Plans are currently being developed by Oswestry Borough Council to consolidate the main structures and provide greatly improved visitor access, with the creation of new footpaths and interpretation panels. In additional, proposals by British Waterways to reopen the Llanymynech section of the canal could lead to the restoration of the canal wharf, helping to revitalise another part of Llanymynech's history.
Further information about Llanymynech's heritage follow these links to web sites for the
Llanymynech Community Project and
Llanymynech's Hoffman Lime Kiln.