MSO7702 - Colton Pits, Nettlecombe (Monument)

Ancient iron mining was known about before 1853 and in 1865 an adit on the East side of the hill was opened. After driving 130 foot ancient workings were intercepted over 100 feet below the surface. In these were found an oak shovel, some broken earthenware, a pickaxe and a turf dam - the dam appearing to be one of a series by which means water was baled from level to level out of the mine. These were probably 18th century relics as a 100 foot deep mine would have been unusual before then. (The adit may be represented by 'Shaft disused' published at ST 0535 3484 on 1:10 000 1976 Ordnance Survey map [1]). Between 1872 and 1874 a second adit was driven East from Galloping Bottom and another drift of 150 feet was sunk to connect with it. However, the ore seems to have been poor and all work stopped about 1876. The mine was reopened in 1880 with a drift extending to 195 feet with 5 levels. Output necessitated an extra siding at the Brendon Hill depot to receive the ore which was brought by horse and cart. The mine was closed 1883. The mine had a portable engine. The mine was reopened 1907 by the Somerset Mineral Syndicate and a 2 foot gauge light railway, with an incline, was built to carry ore to Brendon Hill. Closed 1910s. Colton Pits was worked during the latter part of the 19th century by the Ebbw Vale Company. [2] Linear depressions seen on the aerial photographs are likely to be the old tramways. [4-5] The ironstone mining area covers a large area of ground on the northern escarpment of the Brendon Hills, and is centred at ST 052 348. A spur of land, defined by Galloping Bottom to the west and an un-named stream to the east, is covered with the remains of extraction pits for ironstone. These may date from the medieval period or earlier and compare in form and extent with those preserved on the Blackdown Hills, for example at North Hill Common. [6] The 19th Century ironstone mines consist of West Colton Adit, on the eastern side of Galloping Bottom, and East Colton Adit, on the side of the un-named tributary stream. West Colton Adit is depicted on the 1st edition OS 25" map as an adit and large spoil dump (ST 0503 3512). East Colton Adit is also depicted on the 1st edition map, and is named "Colton Pit (Disused)". A shaft is shown at ST 0535 3482 and also marked on the 1st edition are two large spoil dumps to the east of this shaft. [7] Both the 19th Century mining remains and the earlier extraction pits are now under dense coniferous plantation. The remains are, however, visible on air photographs of 1947 and 1964, and are the subject of a large scale transcription by the APU. [8-9] The 19th Century remains overlie earlier circular extraction pits . A combination of ground survey, aerial photographic plotting and cartographic methods mapped the locations of the East Adit and West Adit, together with associated spoil heaps. The East adit was opened in 1865 and despite hitting "ancient workings" located good ore. A drift was sunk to connect with it. The West adit and drift were sunk between 1872-4 but the mines had closed by 1877. Work resumed around 1880 when the east drift was deepened and the west adit extended to meet it. The mines closed again in 1883. They were reopened in 1907 when both west and east adits were cleared. The mines were connected to the West Somerset Mineral Line by a narrow gauge tramway along the road. The company was declared insolvent in 1910. The exact location of the east adit could not be located on the ground but it probably lies just to the west of a large spoil dump. Two drifts appear to be associated with the east adit. One remains as a deep shaft surrounded by a fence. The other lay between the two large spoil dumps (from the OS map) but was overgrown at the time of survey. The East adit was sunk in 1865. In 1907 an underground steam pump was installed with a boilerhouse on the surface. A deep rectangular hollow in the side of the hill marks the mouth of the west adit with a long narrow spoil dump to the North-East. An open level area to the south is presumably where the ore bins stood before transfer to the railway trucks. The associated drift is a deep vertical shaft, surrounded by a fence. There are no obvious traces of the boiler house. The pits lie in three main areas. The largest runs across the spur for 370 metres northwest to southeast and is 100 metres wide. A narrow band of pits 30 to 40 metres wide runs for 200 metres northnortheast to southsouthwest downslope from the main pit. A further block of pits lies on the western edge of the spur. The pits are fairly uniform, roughly 8 metres in diameter and between 0.8 and 1.5 metres deep. Many of the pits have an associated spoil heap, usually downslope of the pit. The site shows of having been worked over a period of time, with pits being dug into some of the spoil heaps. Silting at the bottom of some of the pits suggest that they are of considerable antiquity. There are some deep linear trenches (caused by pits located close together to exploit a particular ore). If the pits are of considerable antiquity then preliminary ore processing could have occurred close to the extration area. The area of ironstone extraction has been surveyed by EH at a scale of 1:1000 at the request of the ENPA archaeologist. [10-11] The site is in private ownership. [12] The pre-19th Century extractive pits are clearly visible as earthworks on aerial photographs of the 1940s, 1960s and 2000s. They have been transcribed at a scale of 1:2500 as part of the Exmoor National Park National Mapping Programme Survey. At the surface the pits are roughly circular in shape and measure over 5 metres in diameter. They are closely spaced, with less than 1 metre separating many of the pits. Large dumps of spoil surround many of the pits. The 1960s aerial photographs reveal that the earthworks have been impacted by landscaping in advance of plantation planting. It is possible the circular earthworks are later prehistoric in date. [13-16] Colton mine shaft centred at circa ST 05353484. The shaft is open to a depth of circa 60 metres and fenced off.The west adit is centred at circa ST 05043511. The entrance is blocked but water still flows from the feature. Colton mine west shaft, centred on circa ST 05113493. The shaft is open to a depth of approximately 46 metres and fenced off. [19] This record was enhanced as part of the National Record of the Historic Environment to Exmoor National Park Historic Environment Record data transfer project. [20] The site is mentioned in a publication on the industrial archaeology of Somerset. [21]