Devon colliery pumping engine house, Alloa, Clackmannanshire

Description

The building is the beam engine pumping house of the former Devon Colliery, built in 1864 by Neilson & Company of Glasgow. It is built of ashlar red sandstone with a hipped, grey slate roof, and is rectangular in plan. The cast iron pumping beam and cast iron girders of the pumping engine machinery survive in situ, with the beam passing through a large arched opening in the south wall. The beam is inscribed with a record of its origin, reading "No.189 / Neilson & Co. / Glasgow / 1864". Additional arched openings in the north, west and east walls house a variety of arched metal framed multi-pane windows, along with an arched doorway in the east wall providing access. Internally, a framework of cast iron beams provides support for the pumping beam, and a narrow turnpike stair in the northeast corner provides access to the upper areas. Two mezzanine floors have subsequently been inserted into the space to provide office accommodation during the conversion of the building.

Legal exclusions

In accordance with Section 1 (4A) of the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997 the following are excluded from the listing: late 20th century office interiors.

Historical development

The Devon Colliery beam engine house was first constructed in 1864, with the pumps fully installed and operational by 1879, when the colliery was reopened. The pump engine remained the primary means of water extraction for the colliery until a series of electric pumps and a steam turbine pump were installed to replace it in 1932, although the beam engine continued in occasional use to supplement the new pumps until the 1950s.

Statement of Interest

Beam engine house, excluding late 20th century office interiors, former Devon Colliery, Fishcross meets the criteria of special architectural or historic interest for the following reasons:

It is part of a very small surviving collection of remains relating to the formerly extensive coal mining industry within Scotland.

It is one of only two surviving historic beam engine houses within Scotland.

For its technological innovation: the Cornish-type pumping engine was an important advance in the development of steam power and the technology used in deep mining work.

The building itself is little altered and still houses the beam of the pumping engine and retains much of its original 19th century character as a result.

In accordance with Section 1 (4A) of the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997 the following are excluded from the listing: late 20th century office interiors.

Architectural interest

Design

The beam engine house is designed as a functional building of rectangular plan form. Both the exterior and the interior design is reflective of this, with minimal decorative or architectural features and a tall open internal space primarily to provide sufficient space for the machinery of the beam engine itself, extending out through the south wall. This plan form is typical for a 19th century beam engine house and is not of special interest in listing terms.

The materials used in the construction of the engine house have also been selected for their functionality rather than aesthetic or design principles, with the use of dressed stone and cast iron providing a physically solid structure to support the industrial machinery housed within.

The Devon Colliery beam engine house has been designed around its function, with substantial stone walls and cast iron girders to support the heavy machinery of the pumping engine itself. Surviving in situ is the cast iron beam, housed in the upper part of the building and extending through a purpose-built archway mounting in the south wall.

The development of the 'Cornish' type beam engine, so called because of its origin in the tin mining region of Cornwall, was a significant technological advancement on earlier versions of the technology such as the Newcomen engine or the Boulton-Watt engine. The Newcomen atmospheric engine, first built by Thomas Newcomen in 1712, used atmospheric pressure to generate energy. It worked by pumping steam into a piston chamber, where the steam was cooled, forcing it back into water and creating a vacuum as a result. Atmospheric pressure would then force the piston into the vacuum. By connecting the piston to a rocking beam, itself then connected to pump shaft, the force generated could be used to pump water out of underground workings. The Newcomen design was further enhanced by James Watt in the latter half of the 18th century with the addition of separate steam condensers and other elements, significantly improving the efficiency of the pumping engine, although still restricted by the use of atmospheric pressure on the piston.

Following the expiry of Watt's patent on steam engines in 1800, a sudden and rapid process of developments in steam technology began. This included the creation of the 'Cornish'-type beam engine, which utilised high pressure steam in place of atmospheric pressure to push the piston into the vacuum. This immediately raised the force on the piston from a maximum of around 15lbs per square inch to 40-50lbs per square inch, and consequently allowed for significantly more efficient and deeper water pumping from the mines.

This improved quality of pumping engine was essential for Devon Colliery, as the depth of its coal seams and associated issues of water ingress had resulted in the closure of the first phase of mining operations in 1854. The more powerful pump allowed the colliery to reopen in 1879, and it was of sufficient quality and power that it was not replaced until 1932, when a combination of five electric pumps and one steam turbine pump were installed to replace it. Even after this the beam engine remained in occasional use to support the new pumps until the 1950s.

Neilson and Company was established as Mitchell and Neilson in Glasgow in 1836, becoming Neilson and Company in 1855. Initially manufacturing maritime and stationary engines, the company began producing steam locomotives in 1843 and within a few years was primarily engaged in this work. The 1864 date of this particular beam engine therefore makes it a late example of a stationary engine built by the company at a time when almost all of its production had shifted to railway locomotive manufacture.

Setting

The building now sits within an area of rolling arable land to the north of Alloa, with the Ochils rising prominently to the north, with no real indication from its modern setting of the building's historic context. Historic Ordnance Survey mapping show the beam engine lay at the heart of a heavily industrialised landscape. This includes the other buildings of the main Devon Colliery itself, along with the later Devon No. 3 pit nearby, with its adjacent brickworks and briquetting plant. To the north of the main colliery was the site of the Devon Ironworks, closed shortly after the end of the first phase of mining at the site, but still extant at the time the pumping engine was built, although the site was subsequently cleared and replaced by an extensive quarrying operation involving the Devon and Bankhead quarries and a gravel pit. Following the final closure of the industries in the area it was entirely cleared and landscaped, leaving the beam engine house as the sole surviving element of the former industrial complex.

As the historic context of the site has been entirely lost, the modern setting of the building is of no specific interest in listing terms.

Historic interest

Age and rarity

The building is a very rare example of 'Cornish'-type beam engine, with only one other known example surviving within Scotland, built in 1874 at Prestongrange (LB17534). Although there are no other examples of this particular variant of beam engine pumping technology, examples of some other variants do survive, including the water powered beam engine at Wanlockhead (SM90310), earlier examples at Thornton Colliery (LB42992) and Kilmux Colliery (SM7769) and the engine house within the complex at Preston Island (SM5079).

The building is also rare as a surviving element of Scotland's former coal mining industry. Although formerly an extensive and highly visible part of Scottish industry, the closure and subsequent clearance of almost all of the industry has left very little visible trace by comparison. Of the surviving sites connected to the coal mining industry, by far the most complete is the former Lady Victoria Colliery (LB14604), now home to the Scottish National Mining Museum. Other sites where remains survive include a medieval mine at Birsley Brae (SM3352), the winding gear head frame of the former Mary Colliery (SM9016), the pithead buildings and waste bing at the former Lochend Colliery (SM9680) and the waste bings at the former Avonhead Colliery (SM9675).

Social historical interest

Coal mining was formerly one of the most significant and substantial industries within Scotland. Coal mining is believed to have been introduced to Scotland by the Cistercian order at Newbattle Abbey, founded in the 12th century. During the 18th and 19th century it was one of the key driving forces of the Industrial Revolution within Scotland and was vital to the period's transformative impacts on manufacturing, transportation and industry. During the 19th century, Devon Colliery was one of four collieries in Clackmannanshire, owned by the Alloa Coal Company. At its peak in the early 20th century, the Scottish coal industry employed around 150,000 people, and even by the time of nationalisation in 1947 the industry employed almost 80,000 people across more than 300 mines. Around this time (1948), Devon colliery had 488 employees and an annual output of 237,500 tons of coal. However, the number of operating mines within Scotland was drastically reduced through the 1950s and 1960s, and closures continued through the later 20th century. Devon Colliery itself closed in 1960. By the turn of the millennium, Longannet was the only remaining deep mine within Scotland, closing following flooding in 2002, leaving only some open cast mining operations in operation. The loss of the coal mining industry caused significant socio-economic impacts on large parts of Scotland, and in many cases the effects of these are still being felt today. As one of only a small number of surviving buildings of this industry, the beam engine house at the former Devon Colliery is an important and tangible link to Scotland's industrial past.

Association with people or events of national importance

There is no association with a person or event of national importance.

External Links

Historic Environment Scotland Listing

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