The Nettlebridge Valley

Limited parking is available on many roadside verges. Refreshments are available in most of the villages.

The Somerset Coalfield stretches from the Mendips north to Pensford and Timsbury, and is centered around the town of Radstock. It was in this coalfield that William ‘Strata’ Smith, the so-called Father of English Geology, first put together his ideas on stratigraphy based on observations at Mearns Colliery near Clutton.

The localities described in this chapter deal with the southernmost part of the coalfield adjacent to the Mendip Hills, focusing on the Nettlebridge Valley. Lying just north of the Carboniferous Limestone outcrop, this area contains a wealth of interesting geology, industrial archaeology and wildlife, and several nature reserves. The contrast between the damp soils of the Nettlebridge Valley and the limestone plateau to the south is quite marked.

The Nettlebridge Valley has incised through a cap of Dolomitic Conglomerate, to expose the upper Carboniferous Coal Measures. The Coal Measures, a thick sequence of grey mudstone and sandstone with thin coal seams, are highly contorted and faulted as a result of folding at the end of the Carboniferous. In places the rocks are vertical or even overturned, which has made coal mining in the area very difficult. Because of the thin near-vertical seams, the miners employed techniques more akin to Cornish tin mines than traditional methods used elsewhere.

Coal was probably worked in Roman times (the Fosse Way passes through the middle of the coalfield) but mining began in earnest in the 1600s. The early pits exploited surface outcrops, but by the 1790s, shafts up to 150 m deep were being sunk. The arrival of the railways in the mid to late 1800s caused some expansion, but most of the mines served local markets and could not compete with other coalfields.

The decline began in the early 1900s, but it was after nationalisation in 1947 that the decline really set in. The narrow seams made production expensive, and many smaller pits were closed. The larger pits survived into the 1960s when reduced national demand together with competition from more economical coalfields led to the closure of the last remaining pit in 1973.

The legacy of coal mining can be seen throughout the area. Some of the best-preserved remains occur in the Benter area. Near Upper Benter, the remains of Moorewood Colliery [42] [ST 64211 49505] can be seen in the valley floor. Sunk in 1860, the shaft was constructed in the anticipation of a rail link to the Somerset and Dorset railway. However, this never materialised and the pit experienced problems with flooding, closing in 1873. It was reopened in 1909, when a tramway was built up an incline [43] [ST 63878 49922] and along what is now Coal Pit Lane to the railway at Old Down. However, the mine was never really profitable and following flooding in 1931, it was closed in 1932. More miningremains exist at T’other Side of the Hill [44] [ST 63817 49187] where six substantial spoil heaps mark the position of former shafts.

On the hillside to the north is the site of Strap Pit [45] [ST 64801 49541]. Begun in 1863, by 1874 this shaft was sunk to a depth of 560 m, the deepest in Somerset. However, as at Moorewood Colliery, the lack of a railhead meant it was never profitable and it closed in 1879. It was reopened in 1953 by the National Coal Board and connected to the nearby New Rock Colliery, where upon it became known as Mendip Colliery, but it too made a loss and was closed by 1969. Little remains today.

In the valley between Benter and Nettlebridge is an extensive area of earthworks associated with early coal mining [46] [ST 64716 48748]. This area adjacent to the Fosse Way may have been worked in Roman times, and certainly before 1700.

Numerous mining remains occur in Harridge Wood. This area is a nature reserve maintained by the Somerset Wildlife Trust. Several shafts and bell pits occur around [ST 654 482]. About 500 m to the south-west, the southern side of the wood is developed on the steep dip slope of the Quartzitic Sandstone. A small quarry was dug here in the late 19th century. The quarry, spoil heaps and tramways survive. Nearby are the remains of an old mill and the footpath leading up to Ashwick Grove. More mining remains occur in the separate eastern part of Harridge Wood [47] [ST 658 483]. At least 52 bell pits (small shafts sunk along the surface outcrop of a coal seam) probably dating from medieval times lie scattered through the wood, together with a number of deeper shafts and 16 adits (horizontal mines for access and drainage). The remains of a number of water leats probably constructed to power water pumps for the coal mines can also be seen.

Aside from the industrial archaeology, Harridge Wood is thought to be very old. In the mid-20th century, much of the old broad-leaved woodland was cleared and planted with conifers and poplars. Old low pollards of ash, pedunculate oak and, unusually, alder remain, known locally as ‘stoggles’. Old hazel coppice is also a dominant feature in places.

Where the wood retains its semi-natural character, there is a very rich woodland flora. The distribution of species closely reflects underlying variation in geology, soil wetness and pH. Much of the wood overlies clay slopes, dissected by streams. Ferns are a distinctive feature of the woodland floor, with many different species found. Large ‘shuttlecocks’ of lady fern, male fern and broad buckler-fern are abundant in very wet places. Drier ground supports a profusion of ancient woodland herbs, commonly bluebell, pignut and dog’s-mercury.

The area is particularly good for bats, including rare greater and lesser horseshoe bats, which roost in caves and buildings nearby. Daubenton’s bats forage along rivers and streams, particularly in the western arm of the wood. Bird- life in Harridge Wood is also very diverse, and includes green woodpecker, goldcrest, nuthatch and dipper.

The nearby Edford Wood [48] [ST 66449 48452] is also a nature reserve, but access is limited to the footpath. This is an ancient semi- natural woodland, with clay-rich soils, supporting a very interesting and attractive woodland flora. In the past, many of the trees and hazel bushes have been coppiced, allowing a rich ground flora to develop on the woodland floor. Wetter woodland along the banks of the Mells stream is characterised by a canopy of alder, with tussocks of tufted hair-grass below. Monk’s-hood is an unusual native, growing in wetter areas with water avens and ramsons. Dog’s-mercury carpets higher ground under an ash canopy, in association with many of the ancient woodland herbs that are characteristic of old Mendip woodlands. Notable plants include toothwort, a curious plant that parasitises hazel and other trees, wood vetch, Solomon’s-seal and early purple orchid.

Like Harridge Wood, many bell pits and spoil heaps, relicts of pre-18th century mining activity, have been recorded in the southern part of Edford Wood [49] at [ST 661 482] along with two later 18th century mine shafts.

To the north of Edford Wood is the western end of the Dorset and Somerset Canal [50] [ST 66588 48799]. This canal was intended to connect the Somerset coalfields with the woollen mills of Frome, and to link with a proposed Bristol to Poole canal. In the end, only about 13 km of canal was cut. A footpath now runs along its course. At Edford [51] [ST 66848 48822], the remains of a canal bridge with coping stones of Inferior Oolite can be seen. The path can be followed past Ham to Coleford, where the canal crossed a valley by a two-arched viaduct [52] [ST 68493 48697], known locally as the Hucky Duck and on to Vobster.

For more detailed information about coal mining in Somerset, a trip to the Radstock Museum, located in the Market Hall in the centre of the town, is well recommended.

Figures

(Figure 52) Aerial photograph of the Nettlebridge Valley area.

(Figure 53) Mendip Colliery, 1962, with the winding gear still intact. Courtesy John Cornwell collection.

(Figure 54) Map of the old coal mines, canals and tramways in the Nettlebridge Valley.

(Figure 55) Hummocky ground left behind after old surface coal workings, Benter.

(Figure 56) Ramsons, a common woodland plant. © Sharon Pilkington.

(Figure 57) Bluebells and stoggle in Harridge Wood. © Sharon Pilkington.

(Figure 58) Disused canal bridge, Edford.