Pleasley Forge

 

Well thanks to hours of tedious library searching that nearly cost me the will to live, I think I have solved the mystery of Pleasley Forge. Although the records are very scant, I have attempted to piece together the history behind Pleasley Vale's first commercial enterprise. Firstly, I dug up records of Hollins' initial site appraisal in 1784, which was conducted to assess the suitability for his new venture. The items of most interest to the partners were listed on the particulars sent to them by the owner of the Manor, Thornhill, whom had owned the estate for 40 years. The particulars were 40 years old even then and described 'Iron Forges' called Pleasley Forges together with a mill dam. The actual inspection revealed machinery inside the forges that could be utilised for their own purpose. Later documents revealed they initialy leased 15 acres of land including the 'Forge Meadow', the 'Forge Dam', Upper Forge, out buildings and a water corn mill inclusive of wheels, machinery and works. It transpired that of the two forges existing when Thornhill bought the Manor, only the Upper Forge now remained but the lease identified 'the land whereon the building called Pleasley Old or Nether Forge lately stood'. The oldest detailed map of the area is Chapman's 1774 map of Nottinghamshire and clearly shows the forge on the Meden in the position where the Upper Mill now stands.

The site of Pleasley Forge shown on Chapman's 1774 map above.

The forge has been replaced by Hollins' Upper Mill on this Sanderson 1835 map above. Note the much larger mill pond and the road rebuilt around it making the hairpin corner where the security lodge is today.

 

Firstly, at this point, it will be useful to write a short history of iron ore smelting and its development that will help put in context the activities of the Pleasley Forge. The earliest wrought iron (not to be confused with the modern term wrought iron work) is known as 'charcoal iron' made by the 'direct reduction' process, which was smelted by heating iron ore (iron oxide + rock) with charcoal in small furnaces called 'bloomeries'. The charcoal (carbon) reduced the iron oxide to iron, giving off carbon monoxide in the process but retained most of the impurities or 'slag'. In particular, iron silicate remained in the iron.

After smelting, the 'blooms' of iron were forged by heating to red hot and then beating them out into long bars. Each bar was then cut into shorter lengths, bundled together and reforged. The process could be repeated many times. With each forging, more of the slag was removed, and the fine residues left behind became integrally incorporated with the iron, together forming the distinctive fibrous microstructure which gives wrought iron its tensile strength. The iron produced in the finery could be of excellent quality, but it was a laborious process, subsequently, was graded according to its end use. The markets were blacksmiths, whitesmiths, locksmiths, edge-tool makers, gunsmiths and bottom of the pile, nailers, which was by far the largest market.

c1400 A smelting revolution occurred when blast furnaces were introduced, enabling production to increase significantly by the invention of the chemical removal of impurities. This resulted in a cheaper, higher quality pig iron. The iron ore was first smelted with charcoal in the blast furnace much as before, producing cast 'pig' iron but then in a second stage the iron was further refined by 'decarburization', the removal of carbon, before being forged. The carbon content of iron determines its end use; too much and its hard & brittle without the ability to be 'worked'.

In the late 16th century, water-powered rolling mills such as the Pleasley Forge were introduced to mechanise the forging process. The red-hot bars were passed between two heavy water-mill powered rollers, becoming longer and thinner each time. Further improvements in production included the introduction of heavy water-mill driven hammers set on a fulcrum to beat the semi-molten metal bloom to remove slag.

By the mid-1700's, there arose a need for higher quality iron and this was served by the tecnnique known as 'Puddling'. This method of charcoal pig iron refining made a significant contribution to the industrial revolution. Puddling is a technique, perfected by Henry Cort in 1784 for making pure iron from pig iron. Bars of charcoal iron were heated in a furnace by an indirect coal fire. Molten iron was then cast into ingots (pigs) and stacked in a pile on the Puddling hearth. Here it was heated and "puddled" to remove impurities (the "puddlers" stirred the liquid). Impurities burned off and the puddled iron formed pasty balls. Puddled iron was then transferred to the shingling hammer, (a gigantic power hammer which was capable of earth-shattering blows) which formed the iron into a billet. This was then rolled, cut up into lengths, re-stacked and the whole process repeated over again. The more times the process was repeated, the better was the quality of the finished wrought iron.

By the mid 18th century, coal was becoming more readily available and cheaper. Coke production (a carbon substance produced by heating coal to a very high temperature in the absence of air) was also increasing, presenting an opportunity to solve the charcoal supply issues caused by deforestation.

By the mid-19th century, wrought iron was considered relatively expensive. Cast iron, although weak in tension, became mass-produced and was therefore much cheaper. For most decorative purposes, cast iron provided a more cost-effective solution and for structural applications, cast iron replaced wrought iron wherever loads were carried in compression, such as columns, but wrought iron continued to be used in tension, for example in the roof of a conservatory. Then in 1856, Henry Bessemer invented the Bessemer Converter, which enabled steel to be produced more cheaply than ever before. Unlike wrought iron, steel contains no slag and it has a higher carbon content than puddled iron. As a result it is harder and even better in tension. By the late 19th century wrought iron was in decline.

Now we have all that out of the way we can continue with the story of the Pleasley Forge!