Moons Hill Quarry is the only in Somerset currently working Pyroxene-Andesite, a hard rock formed in the Silurian period which is suitable for road-making. The presence of this rock was discovered in the mid-1860s by Somerset geologist Charles Moore, who had believed for some time that the Mendip Hills had been uplifted and thought that only volcanic action could account for this. He searched for evidence to prove his theory and found it while walking down a lane at East End, Stoke St Michael. Moore recognised that the hardness of the rock made it an ideal material for use as roadstone and suggested a trial excavation be made at Moons Hill. He also suggested to the local authority at Bath that the stone should be used in making its roads, but without success.
It is not known when quarrying began at Moons Hill, but the first reference comes in July 1877 when the Western Daily Press reported that the surveyor of Chippenham asked for permission to order 200 tons of Cranmore stone, 100 of Westbury stone from the Vobster Quarry of the Westbury Iron Company and 100 tons from “Moon’s Quarry”. On 1October 1880 William George Roberts leased the quarry from the Knatchbull family for 21 years, paying a sleeping rent of £25, a surface rent of £4, and a royalty of 2d. In 1889 Roberts died, and in April 1890 the Bristol accountancy firm of Tribe, Clarke & Co. advertised the business for sale by private treaty. The advert pointed out that the lease still had 11½ years to run, mentioned that there was a manager’s house on the property, and stated that the purchaser would have the option to buy the stock, stores, engine, stone breaker, and railway wagons. Unfortunately, this glowing description was not enough to ensure that the lot made its reserve price and Tribe, Clarke & Co. continued to run the quarry, employing eight men on site.
In 1897 the Knatchbull family made a second attempt to sell the quarry, but without success. In September 1898 John Wainwright and his partners John Purnell Luff and John Laver approached Knatchbull and offered to work the quarry. A lease was signed on 15 September leased the quarry, and John Wainwright and his partners operated Moons Hill as tenants of the Knatchbull family for almost a year, but on 18 August 1899 felt sufficiently confident to buy the quarry by private treaty for £1,000. Following the purchase of the freehold they began to invest in the development of the quarry, and over the next five years installed new plant and increased the workforce to 25 men.
At ther beginning of the 20th century Wainwright erected new screens and bins, these being housed in a large wooden structure which comprised compartments for six sizes of screened stone, surmounted by a rotary screen fed by an H. R. Marsden elevator.
By then there were two quarries on the site – the original north quarry, and a larger one immediately to the south. It is not certain why a second quarry was started, rather than enlarging the first, but the most likely explanation is that an area of particularly hard rock was encountered, which was easier to go round than through.
In 1904 Moons Hill Quarry was connected to Cranmore Station having made an agreement with Mendip Granite & Asphalte to use that company's 2ft gauge tramway, which was extended north from Waterlip Quarry to serve a newly opened basalt quarry (Sunnyhill Quarry) to the west of Moons Hill Quarry. However, after a few months Wainwright ceased to use the tramway, and instead relied on steam lorries and traction engines to haul the stone by road.
In 1934 Wainwright merged its limestone quarries (Downside, Ham Wood, and Vobster) into newly created Roads Reconstruction (1934) Ltd. It retained Moons Hill Quarry and in 1936 erected a new Stothert & Pitt tarmacadam plant.
In 1946 it purchased a Gyrasphere crusher for the secondary plant at a cost of £1,379. Gyratory crushers were better able to deal with the hard Moons Hill basalt than the hammer mills used in many local limestone quarries, and continue to be employed to this day. Wainwright also bought cement mixers and slab machines for the quarry’s concrete manufacturing works, the company still advertising its basaltic slab paving as a speciality at this time.
In 1948 Wainwright applied for permission to continue working Moons Hill Quarry under the Town and Country Planning (General Interim Development) Order of 1946. The company was granted Interim Development Order consent unconditionally in respect of 65 acres, which by the late 1960s would increase to around 93 acres through conditional planning permissions for extensions to the workings and tipping of waste.
In 1950 the board resolved to install a new primary crusher to feed the quarry’s two secondary plants. The machine chosen was a 36 x 24 jaw crusher with a 25-ton feed hopper and electrically operated feeder with grizzly waste extractor. The new plant was to be designed and supplied by Pegsons and J. & F. Pool of Hayle, Cornwall, at an estimated cost of £20,172.
In 1963 a new primary crusher was installed to the east of the previous one, and deeper in the quarry. In December 1964 it was decided to build a new secondary plant this coming into operation in February 1966. The new unit replaced the quarry's old No. 1 and No. 2 plants and was designed for higher throughput and to produce the smaller sizes by then in most demand. In 1972 a Parker “Starmix” coating plant was erected at Moons Hill to replaces the existing Stothert & Pitt equipment.
In February 1979 extraction began across the road at Sunnyhill Quarry, 70 years after its closure by Mendip Granite & Asphalt. In the early 1980s the company worked the Old Red Sandstone on first the north side of the quarry and then on the south side. This was not a success and was discontinued after a number of years. In 1986 the company bought neighbouring Stoke Quarry giving the company a monopoly of basalt production in the Mendips for the first time in half a century.
A new primary crusher was erected at Moons Hill in 1987, and in the early 1990s the screen house was refurbished. In 2000 the company's offices were moved from the company's former Downside Quarry to a new building at Moons Hill.
In 2005 the decision was taken to erect a Benninghoven coating plant capable of producing a wide range of high-specification coated materials, including modern thin surfacings. The TBA240U model chosen has a 4,000 kg mixer and can produce 240 tonnes per hour across the full spectrum of the modern day asphalt range. It also has the added flexibility of a 360 tonne multi-product hot storage facility. It was decided to locate the new plant in the former Sunnyhill Quarry, and work began in the spring of 2005. The levelling and preparation of the 4.6-acre site involved the removal of 300,000 tonnes of material. The plant was to be heated by natural gas, a new supply being installed at a cost of £290,000, this including the laying of 1.7 km pipeline to the quarry. Construction work began in May 2005 and the plant was commissioned in 2006.
Wainwrights most recent investment at Moons Hill has been the erection of a new £3.5 million processing plant - commissioned in 2014 - to replace the one erected in 1963.