Darkhill Reports

It had initially been intended for English Heritage to schedule the Darkhill Ironworks in 1979 but so many things went wrong in the administration of the dig on site at that time that English heritage washed its hand of the whole undertaking.
By 2002 when most of those involved had retired English Heritage looked at the prospect again. I submitted a report to them, as did the Forestry Commission England on whose land the site lies. 
The outcome is that the site of the Darkhill Ironworks and the Titanic Steel Works are now both scheduled ancient monuments by English Heritage.

The report I submitted at the time is available (in three parts) for download or viewing at the bottom of this page after the National Monument schedule seen here below.
Keith Webb  Webb722@btinternet.com

Below is a copy of the National Monument File No. 28878.

Department for Culture, Media and Sport Batch Number:   11337

                                                            FILE REFERENCE; AA80644/1






MONUMENT; Dark Hill iron works and brickworks complex and Bear 220m south and 200m south east of Yew Tree Cottage














The monument includes the standing and buried remains of an iron works, brickworks, part of a tramway and a ‘Bear’ lying on the southern slope of Dark Hill in the Forest of Dean.  It lies in two areas of protection.  The standing remains of the walls of the ironworks and brick works have been consolidated and stand to between 1m and 4m high.


The works were owned by both David Mushet, a figure important in the dedvelopment of both iron and steel working technology, and his son Robert, who carried on the work of his father.  David Mushet first arrived in the area in 1809 when he moved to Coleford, managing the iron works at Whitecliff [the subject of a separate scheduling]  about 2km to the north west of Dark Hill.  Titanic Steel Works, built later by Robert Mushet  lies 250m to the north west  and is the subject of a separate scheduling (SM28879). The brickworks were established some time before 1818 and were owned by David Mushet  in 1841. After David’s death in  1847 the furnaces at the smithy in the brickworks were used by Robert for experimental work on new metals to discover their properties. Robert Mushet carried out much of his secret experimental work near his home, but larger scale experimentation was done at the furnaces by the Smithy.  The lessons learned here were put into practice when the nearby “Titanic Steel and Iron Co. Ltd.” Works were built in 1862.  In his will dated to April 1847 David Mushet left the brickworks to three trustees.  In July of the same year the premises were advertised for sale, and when it was sold again in 1857 it was in need of repair Later the site of the brickworks became a Colour Works for processing ochre which is the yellow or brown hydrated oxide of iron (ferric oxide).  “Colour” or “oxide” is suitable for pigment.

David Mushet built his first iron working furnace at Dark Hill in late 1818 or 1819.  It is thought that the iron works at Dark Hill were developed mainly as an experimental site, although small-scale production appears to have been carried out. In 1845 David Mushet conveyed Dark Hill iron works to his three sons and in November of that year, the Dark Hill Iron Co. styled “Robert Mushet and Co.” was formed, with Robert Forester Mushet, David’s youngest son, as the sole manager.  In June of 1847 David Mushet senior died and in July of that year Dark Hill Iron Works was auctioned, but not sold.  In September of 1847 there was a deed of dissolution of agreement under conveyance of 1845, and the furnace was probably never again in blast.

No contemporary plan has been found, and therefore the interpretation of successive uses to which different buildings were given is based on expert opinion.

The complex of tramway, brickworks and ironworks lie on a series of terraces above one another on the hillside. At the north end of the complex , on the high ground above the brickworks is the Milkwall  branch of the Severn and Wye  tramroad, some of the stone tram road blocks of which are still visible.  In 1819 instructions were given to extend the branch tram road to serve the new furnace at Dark Hill, thus a second branch of the tram road from the west enters the site above the furnaces and below the brickworks area. Just below the upper tram road is the brickworks which lie above the ironworks on the slope.  At the north west corner of the brickworks is a kiln, with another at the north east corner, shown by its semicircular brick floor.  These are linked by a long building which served  as the brick drying sheds, some 45m long and 7m wide. This building had brick pillars under the floor  enabling heat from stoves to circulate around the stacked bricks allowing them to dry. To the south of the drying sheds, on the west side,  is an edge mill room, measuring 10 sq. m, which contains an edge runner  millstone,  2m in diameter, lying on its side. In its original upright position it would have been rotated around a trough by a pony harnessed to a beam. At the centre of the room is a posthole lined with five wedge-shaped packing stones, although originally there were six, which ark the point of the central pivot post around which the millstone was rotated The millstone is thought to have been used for crushing dried clay to powder, or alternatively may have been used to crush ore for the iron work

At the same level as the edge mill room of the brickworks is the Smith’s Shop which is quite extensive, measuring 15m x 7m, and two large blacksmiths hearths, with four brick-lined crucibles. The Smith’s Shop building is thought to be the site of Robert Mushet’s spiegal experiments of 1847. In September of 1847 Robert entered into partnership with Thomas Daykin Clare and formed the small experimental steelworks called “R. Mushet and Co.” Forest Steel Works, with premises which lay a few hundred yards to the north west of Dark Hill’ was probably situated within the brickworks site. The kiln base on the east side of the Smith’s Shop is thought to be the site of the 1856 Bessemer Furnace, with which Robert, and his then partner, S.H. Blackwell of Dudley, revolutionized the method of steel production by the addition of Spiegel to adjust the carbon content  of the metal.  Spiegel is pig iron which contains high concentrations of manganese and carbon, which, when added to steel adjusts its final composition.

Downslope from the Smith’s Shop is the loading area, and the charge preparation area for the iron works, below which is the charge incline. The loading and unloading area is an artificially raised platform, some 65m long and 22m wide, held by a massive retaining wall along its south side 4m high. On top of the wall above the furnace complex is the charge preparation area, which is made up of the weigh batching room and the coking area. Iron ore and other materials would be barrowed out to the blast furnace, which lay directly downslope from the charge preparation area, via a charging bridge The furnace, measuring 5m by 3m lies within a walled enclosure measuring 6 sq. m internally.  On the west, within an enclosure measuring 7l5 x 4m is the site of the hot air blast furnace dating to 1845-6 and on the east is a boiler room. A brick arch still stands behind the blast furnace area. On the east side of the furnace, beyond the boiler room, are the remains of the area thought to have contained the steam powered beam blowing engine for the furnace. The engine house is 10m by 5m, and sub-divided internally. In front of the arch, at the lowest level, is a horseshoe shaped hearth, which was never fired.

At the very southern end of the site is the railway embankment, built in 1874, which covers the area where the “Puddling” sheds stood. The embankment stands to abut 5m high and it is thought that it also covers the remains of an earlier part of the iron works including the sand floor and the casting house of the 1819 furnace site.

Approximately 150m to the north east of the iron works is a mass of solidified impurities known as a “Bear” which consists of the scum which is removed from the metal before it is tapped. The Bear is about 1m wide by about 2m long and 0.1m thick, surrounded by large stones, about 1m diameter, which had hidden it until some of the stones had rolled down the slope. It is thought that the Bear had been deliberately hidden to conceal the secret of the contents of the blast furnace.

A number of accidents occurred at the iron works; most notably in August 1846 when a steam engine exploded causing five deaths and seven injuries. The site was abandoned, probably around 1862 when Robert built the Titanic Steel Works nearby. Following the building of the Severn and Wye Valley railway embankment across the south east corner of the iron works in 1874 the site lay undisturbed until partial excavation in 1977. The excavation was carried out under the MSC Job creation scheme, although supervised by an archaeologist. Finds from the site included mainly hammers, some bottles and two small crucibles.

The post and wire fence, which surrounds the site, is excluded from the scheduling, although the ground beneath it is included.


Iron has been produced in England from at least 500 BC.  The iron industry spurred on by a succession of technological developments, has played a major part in the history of the country, its production and overall importance peaking with the Industrial Revolution. Iron ores occur in a variety of forms across England, giving rise to several different extraction techniques, including open casting, seam-based mining similar to coal mining, and underground quarrying, and resulting in a range of different structures and features at extraction sites. Ore was originally smelted into iron in small relatively low-temperature furnaces known as bloomeries.  These were replaced from the 16th century by blast furnaces which were larger and operated at a higher temperature to produce molten metal for cast iron.  Cast iron is brittle and to convert it into malleable wrought iron or steel it needs to be re-melted. This was originally conducted in an open hearth in a finery forge, but technological developments, especially with steel production, gave rise to more sophisticated types of furnaces. A comprehensive survey of the iron and steel industry has been conducted to identify a sample of sites of national importance that represent the industry’s chronological range, technological breadth and regional diversity.

Despite having been partially excavated, the brickworks and iron works at Dark Hill survive well. The site is associated with the Mushet family who were amongst the foremost pioneers in the development of iron and steel technology in England in the century. Their achievements include the first commercially produced refined iron from a blast furnace without the use of a refining furnace, and the production of the first steel rail for railways. A number of locations at the Dark Hill site are associated with specific developments in the industry. Kilns at the brickworks site were used for small-scale experiental work on new materials, and it was also the site of a Bessemer furnace in which, by the addition of Spiegel and the adjustment of the carbon content, Mushet revolutionized the method of steel production. In addition, the site displays the elements of a complete 19th century iron works including a tramway track for the movement of goods. An example of the production of the works is found in the ‘Bear’ which lies some distance away from the main site, and which is thought to be the fused residue of the contents of the blast furnace after one of Mushet’s experiments.

The site will retain archaeological information and environmental evidence relating to the industrial activity on site, and will preserve a record of the long series of experimental operations that took place under the Mushet’s from 1819 to 1862.

David Mushet at one time owned the brickworks, and the site is integral to the events which formed the sequence of development of the iron works  and Robert Mushet’s Forest Steelworks The brickworks site preserves the layout and processes of a 19th century example of this type of industry and the tram road, which abuts the site, completes the contemporary industrial landscape. As a site which is open to the public, it is also a valuable educational amenity.




The site of the monument is shown on the attached map extract.



On behalf of the Secretary of State for Culture, Media and Sport under batch no: 11337.


The report I submitted at the time is available (in three parts) for download or viewing at the bottom of this page.

Keith Webb,
Aug 11, 2010, 7:53 AM
Keith Webb,
Aug 11, 2010, 7:54 AM
Keith Webb,
Aug 11, 2010, 7:54 AM