This List entry does not comprise part of an Asset Grouping. Asset Groupings are not part of the official record but are added later for information.

The monument includes a late-C18 and C19 hammer and grist mill complex and ropeworks together with an associated water management system.

The late C18-C19 mill complex, ropeworks and associated water management system are scheduled for the following principal reasons:

* Survival: the upstanding remains of the various mills and ropery survive well as consolidated ruins and clearly show the sequence and differences in character of the various components of this industrial complex;

* Potential: significant buried remains will survive relating to the range of technological processes that occurred at the site and to the operation of the related water management system;

* Group value: they represent one of the most coherent surviving groups of industrial structures associated with the internationally-renowned Harvey's Foundry, retaining elements that date to the initial establishment of the company.

The Hayle Estuary has been a focus for settlement and maritime trade since prehistoric times. From at least the mid 18th century it developed into one of Cornwall's main industrial ports, serving surrounding mines and becoming home to Copperhouse Foundry and Harvey’s Foundry. Internationally renowned for the scale of their work and the breadth of their engineering expertise, these rival companies were largely responsible for the expansion of Hayle during the C19.

Harvey's Foundry was established at the head of Penpol Creek, an area later known as `Foundry', in 1779. Initially serving local mine needs, it became one of the world's leading suppliers of industrial pumping engines in the early C19, a role shared with the rival Copperhouse Foundry located in the north-east part of the town. Fierce competition over access to quays produced the `South Quay' built by Harvey's in 1819, aggravating the natural problems of estuarine silting. These problems were resolved by impounding Copperhouse Pool and, from 1834, creating the wholly artificial Carnsew Pool as tidally-filled sluicing pools whose waters were directed to the canal, quays and harbour mouth. This complex system maintained the port facility that gave the foundries their national and international role besides serving their regional hinterland. Accompanying this industrial growth, the foundry companies operated as general merchants, developing the necessary storage, cartage and stabling facilities and further stimulating use of the port.

The former industrial complex to the east of Millpond Avenue includes the remains of hammer mills, a grist (grain) mill, and a ropeworks. The initial development of the site dates from circa 1780 and it developed through the C19 as an industrial focus growing from the establishment of John Harvey's iron foundry at the head of Penpol Creek in 1779. The site finally ceased operation in the early C20, having spanned the full duration of Harvey's engineering production. Part of the original water management at the site includes a leat that possibly originally powered a metal-boring mill in the north-east part of the site which was later replaced by or converted to a grist (corn) mill; and a reservoir or millpond which John Harvey gained permission to impound in 1780 and which powered hammer mills at the site. The leat allowed the Penpol Stream to bypass the millpond or reservoir as required; it was recut to its present course in 1795 following a dispute over rights to the land it originally crossed. The earliest mill at the site may have originally been a boring mill but by at least 1827 it was grinding corn, which was in demand to feed the many horses that provided Harvey's land transport needs. Milling was one of the major industries in Hayle from the early C19 due to the demand for supplying horses and men with feed. It expanded into a major commercial concern, with flour production and export, baking and retailing all becoming more important throughout the C19 and into the mid-20. In 1851, in a division of Harvey's property, the grist mill complex was sold to J H Trevithick & Son. It was extended during the C19. Milling ceased in the 1890s when a mint humbug factory took over part of the building. A ropery was established at the site in 1796. Rope making was one of the first of Harvey's diversified activities after establishing his foundry and especially used in mines and for ships' rigging and cordage. The ropeworks closed in 1916, demand for its products having declined with the collapse of Cornish mining and the replacement of hemp rope with wire for maritime uses.

PRINCIPAL ELEMENTS A former industrial complex which includes the earthworks, standing and buried remains of hammer mills, a grist mill, ropeworks, store, reservoir and leat. It was established in the late C18, and was expanded and altered in the C19. The site is situated in a slight valley extending south from Penpol Creek, and to the east of Millpond Avenue.

DETAILS In the north-east part of the site are the ruins of a building which map evidence confirms as the earliest mill at the site. Rectangular in plan, the grist mill was converted to steam power in about 1830 and was extended southward by about 1832. By the end of the C19, photographs show the mill rising five storeys high to a shallow pitched roof. In 1940 the mill was reduced to first-floor level, reputedly to prevent the tall building from being used as a landmark to guide German bombing raids. The surviving north end and east side walls of the mill are faced externally by granite block masonry and internally by granite rubble, with dressed granite quoins and lintels. Large brick arches pierce each ground-floor wall, with an original window above the north wall arch. A ground-floor doorway and first-floor window in the east wall are now blocked.

Extending west and south-west from the grist mill are remains of Harvey's C19 hammer mills. Early-C19 map evidence indicates that they occupied most of the area between the grist mill and the millpond, with an extended frontage to the millpond which provided the power. An 1864 plan adds detail, showing three elongated roofed ranges adjoining side by side, ending along Foundry Hill to the north but extending south to different lengths, the central range being the shortest. The western range has a rounded projection with a dormer roof extending into the edge of the millpond and is considered to have housed sluices controlling the distribution and force of water to the mill. Early-C20 photographs, taken about the time of the mill's closure, show the western range and its projection as a single-storey building with a shallow-pitched slate roof; a later aerial photograph, prior to 1940, shows that the hammer mills were roofless by this date. The hammer mills survive with their north, west and southern walls standing to single-storey height, of granite rubble masonry with dressed granite quoins and lintels. The north wall, extending west from the grist mill, shows at least three construction phases, corresponding with the ends of the three ranges: the gable end of each range has two window openings with blocked doorways beneath, and the west range has a large brick-arched opening. Against the internal north-east corner of the west range is a masonry chimney stack base with its brick lining projecting above. The mill's west wall, facing the millpond, has closely-spaced window openings, all truncated just below lintel level; the rounded projection into the edge of the millpond is entered by a doorway in its rear wall, set back slightly within the mill, and has a small window facing towards the millpond. The mill's south wall again combines several construction phases, with a window near its west end and the base of a first floor opening at the east.

The ropeworks is situated to the south of the hammer mills. The ropewalk extended SSE, straight along the narrow strip between the millpond and the leat, eventually reaching about 210m long at its maximum extent by the 1840s. Of this, the northern 158m survives, lacking its roof. The ropewalk interior, about 5m wide, is defined to the west by a substantial rubble wall, now slightly reduced, with frequent external buttresses. Along the wall, small rectangular sockets with iron linings are considered to have held spars used in stretching the rope. The eastern side of the ropewalk has a very low wall and was largely open-sided to assist ventilation, the roof being held on supports which no longer survive. East of the ropewalk's northern end are two large, wall-lined flat-bottomed pits; one of these, circular with a rectangular extension to the south, is identified as housing a former steam-powered rope-spooler. The 1870's mapping shows a roofed building over the pits, of which some walling survives, with another ropery building to the south which stands to gable height. At the north-eastern end of the ropeworks is a mid- to late-C19 building that is marked on a plan of the 1880s as a store. It survives to first-floor height and is roughly square in plan, subdivided into several rooms, one containing a chimney base and another, a small hearth. The frontage to the lane has three broad brick-arched openings appropriate for wagon-loading.

The reservoir, known as the millpond, remains largely waterfilled, though partly silted at the south end. It measures about 200m NNW-SSE by up to 55m wide; its slender northern third is sub-divided as an inner pool by a bank. On the east it is defined by a strip of raised ground, broad on the north but narrow further south, separating the millpond from a leat which allowed the Penpol stream to bypass the millpond as required. The leat, part of the Harvey's original water management at the site, powered the wheel of a metal-boring mill.

All modern fences and railings, the pedestrian barriers under the entrance arches, modern path surfaces and kerbing, signs and notices, seating, electricity supply cables, control and fuse boxes, telephone pole, cables and guys, lamp posts, modern drains and covers, playground equipment, modern statuary and artwork, litter bins, life-belt and housing, and the modern culverts along the millpond edge are all excluded from the scheduling. The ground beneath all these features is, however, included.