Soap Vein Pit Head Structure
Within the area of temporary overburden dump (OB2) the archaeological investigation centred on three specific areas; the excavation of a supposed early-Industrial ironstone pithead (NPRN 85558), the excavation of the early-Industrial Soap Vein Dam (NPRN 85525) and the evaluation of a large triangular-shaped area to the north of the Soap Vein Pond (NPRN 85525)
The early-Industrial pithead (Soap Vein Pithead) is first shown on the 1841 tithe map and is illustrated as ‘old’ at that time. Later cartographic evidence (OS 1st, 2nd, 3rd and 4th editions) illustrates the pithead as a pond. Careful machine trenching was carried out in the area immediately north of the supposed pithead. A shallow layer of topsoil was removed to reveal a substantial complex of buildings and structures. The focus of the investigation was careful excavation by hand, which exposed a large building and three structures; the latter included a circular chimney, engine platform and a structure probably associated with winding activities.
The large building (10.5m x 4.2m) was divided into two contiguous sections, one which backed onto the chimney (Plate 3) and one containing a large rectangular sump. The walls had survived to several courses and were constructed of roughly coursed sandstone blocks. The sump (c4m x 2m x 1m in depth) (Plate 4) contained two large cast-iron plates in the base and a large drain supported by a cast-iron lintel. The drain was found to follow a stone arched culvert south for some 30m where it emptied onto the common moorland. The northern section of the building is clearly associated with the chimney and may have housed a boiler, however, little survived of this section and its poor condition was further compounded by a modern test trench found to lie directly through the building. Conversely, the chimney was well preserved and stood to 1.2m along its northern half and had a diameter of 3.4m. The chimney base was constructed of large (0.5m x 0.6m) flat blocks of sandstone and appears to have been demolished
shortly before abandonment. Indeed, rubble found in a linear direction to the southwest across the site may indicate that it was toppled in that direction.
The central section of the site, immediately to the west of the large building, was taken up by a large segmented structure (10.85m x 2m) of roughly coursed sandstone blocks believed to be the base for a Cornish beam engine. The western edge of the platform contained several short recesses (0.34m wide x 0.68m long) identical to similar features found in a structure to the extreme west of the site (Plate 5). The western linear structure (8.7m x 1.21m) was constructed of the same roughly coursed sandstone blocks; it contained six of these short recesses and the whole feature helped to enclose a large open area (8.3m x 2.8m) with the engine platform. The position of this area immediately to the north of the pithead is thought to represent the location for the winding machinery, driven by the beam engine, with the short recesses designated machine anchoring positions.
The exposed Soap Vein Pithead shaft boasted a rectangular opening (c6m x 4m) of roughly coursed sandstone blocks, which altered at 1m in depth to an oval shaft of coursed sandstone slabs. The shaft was not bottomed and excavations ceased at 3m in depth. A full photographic survey complemented by GPS/EDM was carried out on the shaft.
Given the cartographic and excavated evidence it is highly likely that the Soap Vein Pithead is a very early industrial concern and may even be one of the earliest industrial features to have survived at Ffos-y-fran.
The Soap Vein Dam (Plate 6), part of the DFDS, was sectioned by machine and then hand cleaned to reveal a complex composition to the bank. Initially, an earthen bund was placed directly onto the original ground surface to mark out the position of the dam. Immediately in front of this a clay bund was excavated through the underlying peat horizon, presumably to prevent water seepage under the dam bank. A large earthwork bank was then thrown up over both features. The composition of the bank included many small individual tip-lines and turf horizons indicative of a hand-built bank and the clearance of the reservoir area immediately to the north of the dam. Herringbone stone cladding was then added to the north side (reservoir) of the earthwork bank. Compacted fine silts were then found between the stones, presumably carried by the reservoir water, creating a water-tight finish to the dam.
Finds
A number of interesting finds were discovered during the excavation of the Soap Vein Pithead structures. A substantial quantity of post-medieval ceramics, which includes blue printed transfer ware, common red wares associated with cooking vessels, a few sherds of North Devon Gravel Tempered-ware and many 18th-19th century clay pipes. Some interesting metal work has also been found associated with mining including three large coal-face chisels c750mm and one short chisel. Six cast-iron trapezoidal boilerplates have also been found and it is possible that these formed part of the boiler that powered the suggested beam-engine. Metal work associated with a tramroad was discovered, which includes one cast-iron tramroad rail-pin and one timber tramroad sleeper.