Saltom Pit

Saltom Pit 1731

Coal has been mined in Britain since at least the Roman period, although the scale of workings was very small until the mid-16th century. Up to that date, coal was extracted largely from outcrops – places where the coal seams appeared on the surface. Sometimes the seams were followed vertically downwards, which resulted in ‘bell-pits’ – shafts that bell out at the base to exploit a small area of the seam.

Coal output in England increased considerably from the second half of the 16th century, largely as a result of a growing shortage in the national stock of wood. Coal was increasingly being used in the home, but new technological developments were also creating more uses for coal as an industrial fuel. The development of coal-fuelled glassmaking in the early 17th century, the introduction of reverberatory smelting of non-ferrous metals in the late 17th century, limeburning, saltmaking, the preparation of alum, and the use of coke-fuelled iron furnaces in the 18th century all stimulated the demand for coal.

These developments created an increasing cycle of consumption. The growing industrial demand meant that miners needed to tap larger and, more importantly, deeper seams. One of the great problems facing miners was the flooding that was encountered at great depths. A solution to this was provided by the invention of the steam engine, which was used to pump water from the mines. However, the steam engine was rapidly adapted to serve other industries, and by the late 18th century, for instance, it was being employed to drive the new textile mills. This in turn greatly increased the demand for more coal.

New methods of coal mining had to be introduced to satisfy this ever-increasing demand for the ‘black gold’. During the 18th century Cumberland and Tyneside emerged as important coal mining areas, where new techniques were developed.

Coal mining was certainly the earliest industry to have a major effect on the economy and landscape of West Cumberland. The coalfield within the region is small, the most important section extending in length some 14 miles from Whitehaven to Maryport with a breadth of some 4-6 miles from the coast inland. This coastal position was to be a great advantage, as sea transport could be used for longer distance trade. The Irish market was particularly important, as Ireland produced no coal itself. During the early 18th century, coal from Sir James Lowther’s mines near Whitehaven was the most common in Dublin, but during the 1720s an increased share was being supplied from his competitor’s mines in the Workington area. Lowther saw this as a major threat to his business, and in order to maintain his share of the market he wanted to increase production from his pits. His choices were mining deeper, or further inland. Lowther chose a combination of the two, by proposing mining to a lower level, and winning coal from under the sea.

The main problem facing Lowther in achieving these ambitions was technology. He sent his steward of the estate, Carlisle Spedding, to Newcastle, to learn about the improvements in coal mining being developed there. Spedding gained work as a hewer in several collieries under a fictitious name, until he was burnt in an explosion and his true identity was revealed. After his return in the 1720s, Spedding sunk an exploratory bore at Saltom, on the Cumbrian coast near Whitehaven, and found the Main Band at a depth of 80 fathoms. He proposed to sink a pit just above the high-water mark and erect a powerful pumping engine, ‘which would drain hundreds of acres under the land, and an unknown, but enormous extent under the sea’. Work began in 1729, and by 1731 the pit had reached a depth of 456ft.

The sinking of Saltom Pit was a huge undertaking, described by Spedding himself as ‘perhaps the boldest thing that was ever undertaken’. It represented the first attempt at undersea mining in England, and was the deepest undersea mine ever, at that time.

A major problem with deep mines was the very real risk of underground gases exploding, particularly methane or ‘firedamp’. Although firedamp had been encountered in earlier shallow workings, the sinking of Saltom Pit brought the miners sharply into contact with its dangers. When the shaft had reached a depth of 252ft, a large pocket of firedamp was encountered. Like a true entrepreneur, Spedding’s response was to have the gas piped to the top of the pit and offered for sale for the illumination of Whitehaven! More importantly, he experimented with the gas and its characteristics, and shortly afterwards invented the ‘Steel Mill’ lighting device (a forerunner of the celebrated Davy Lamp). Essentially, this was a piece of flint that was pressed against a small wheel, and produced a shower of sparks when the wheel was rotated. Spedding had discovered that momentary sparks were less likely to ignite firedamp than the flame given off from the only alternative lighting system of the time – candles.

The most effective way of protecting against explosions, however, was an adequate system of ventilation. The problem of ventilation was especially significant at Saltom; not only was there a greater amount of firedamp at this depth, but also the traditional practice of a separate upcast flue could not be used under the sea. In order to solve the problem, Spedding split the shaft into two with timber boarding and designed a system of ‘coursing the air’ to allow the passage of air throughout the workings. It worked by a system of boarding and doorways (usually operated by boys) which forced an air-current to sweep through every part of the mine between its entrance at the downcast and its exit at the upcast pit. The oval-shaped shaft, which was introduced by Spedding at Saltom Pit, made this much more effective.

This design also made the pumping of water and the winding of coal to the top of the pit easier. A Newcomen-type atmospheric steam engine was used to pump the water, whilst the winding of baskets of coal from the pit bottom was originally done using a horse gin.This was replaced later by a steam-powered beam engine, which stood in a purpose-built engine house. The engine house still stands on a shelf of bedrock some 6m above the high-water mark of Saltom Bay. The structure is roofless, but otherwise almost intact and contains housing for a winding engine and winding gear. The layout of the building is unusual, possibly unique amongst surviving examples, not least because the engine was completely enclosed within the structure and the beam of the engine appears to have been supported within the framework of the engine itself, rather than on a huge cross-beam or cross-wall.

The engine house still standing on a shelf of bedrock some 6m above the high-water mark of Saltom Bay (above)A Newcomen-type atmospheric steam engine

Once extracted from the mine, the coal was transported to ships. For this purpose, Spedding built one of the earliest examples of a tracked waggonway. At the same time, Lowther built a small pier and staith in Saltom Bay, to allow ships to approach the pit. He hoped to increase profit by exporting from the site, rather than moving the coal to Whitehaven by cart. The new quay was completed in 1732, but it proved hazardous, and colliery accounts record shipments there only in November 1735 and June 1736. By 1738 the pier had been almost abandoned.Potentially the most important factor of all, however, was that Saltom Pit demonstrated the feasibility of extracting profitably the vast quantities of coal underlying the Solway Firth, which put the Cumbrian coalfield at the forefront of mining technology. This paved the way for further mining under the Irish Sea, firstly at William Pit (sunk 1804-12), then at Wellington Pit (sunk 1840), and more recently, Haig Pit (sunk 1907). Saltom Pit was abandoned in 1848, but today it is a Scheduled Ancient Monument (SM 27801) and is the best known surviving example of a predominantly 18th century nucleated colliery layout. On account of this, English Heritage proposed recently that a programme of conservation work should be undertaken for the upstanding remains of Saltom Pit. OA North was commissioned to undertake a survey of the site as part of the conservation work. The survey showed that the site was made up of many inter-related components. Although the area to the north of the shaft, itself capped, has been obscured or destroyed by tipping or land slippage, many of the components of the colliery identified by the documentary study were in fact found. Evidence of the shaft, horse gin, stable, winding engine house, boiler house and chimney, cottages, cartroads and retaining walls, all survives in situ, and has immense value for archaeologists as a group of buildings that originally functioned together in such a nucleated complex. The footings of the unsuccessful pier built in 1732 were also discovered.