Mining

Taking the lead on lead (Pb)!

Historic England writes on the history of the lead industry in the UK.

Approximately 10,000 lead industry sites are estimated to survive in England, spanning nearly three millennia of mining history from the later Bronze Age (c.1000 BC) until the present day, though before the Roman period it is likely to have been on a small scale.

Two hundred and fifty one (251) lead industry sites, representing approximately 2.5% of the estimated national archaeological resource for the industry, have been identified as being of national importance.

This selection of nationally important monuments, compiled and assessed through a comprehensive survey of the lead industry, is designed to represent the industry’s chronological depth, technological breadth and regional diversity.

Nucleated lead mines are a prominent type of field monument produced by lead mining; they consist of a range of features grouped around the adits and/or shafts of a mine. The simplest examples contain merely a shaft or adit with associated spoil tip, but more complex and (in general) later examples may include remains of engine houses for pumping and/or winding from shafts, housing, lodging shops and offices, powder houses for storing gunpowder, power transmission features such as wheel pits, dams and leats. The majority of nucleated lead mines also included ore works, where the mixture of ore and waste rock extracted from the ground was separated (‘dressed’) to form a smeltable concentrate.

The range of processes used can be summarised as:

  • picking out of clean lumps of ore and waste;
  • breaking down of lumps to smaller sizes (either by manual hammering or mechanical crushing);
  • sorting of broken material by size;
  • separation of gravel-sized material by shaking on a sieve in a tub of water (‘jigging’); and
  • separation of finer material by washing away the lighter waste in a current of water (‘buddling’).

The field remains of ore works vary widely and include the remains of crushing devices, separating structures and tanks, tips of distinctive waste from the various processes, together with associated water supply and power installations, such as wheel pits and, more rarely, steam engine houses.

The majority of nucleated lead mines with ore works are of 18th to 20th century date, earlier mining being normally by rake or hush and including scattered ore dressing features (a ‘hush’ is a gully or ravine partly excavated by use of a controlled torrent of water to reveal or exploit a vein of mineral ore).

Nucleated lead mines often illustrate the great advances in industrial technology associated with the period known as the Industrial Revolution and, sometimes, also inform an understanding of the great changes in social conditions which accompanied it.

Because of the greatly increased scale of working associated with nucleated mining such features can be a major component of many upland landscapes. It is estimated that several thousand sites exist, the majority being small mines of limited importance, although the important early remains of many larger mines have often been greatly modified or destroyed by continued working or by modern reworking.

A sample of the better preserved sites, illustrating the regional, chronological and technological range of the class, is considered to merit protection.

Barytes is a vein mineral normally found in association with lead deposits, particularly in the North Pennines. The dominant period of extraction was in the late 19th and 20th centuries and a high proportion of its extraction has come from former lead mines, either by renewed underground workings or re-processing dumps, barytes having been discarded as gangue or waste rock.

The processing of barytes was relatively simple and involved crushing, jigging, drying and grinding at a mill into a powder.

The chief uses of barytes have been as a cheap, inert white filler in the manufacture of paper and paint and more recently it has been used as the basis for barium chemicals.

And now you know!

 

See the entry on the Historic England website – HERE!

 

31st January 2017Comments Off,
Dreams of Steam leave you Beaming

Where did it all begin? This is an overview of the birth of the beam engine…..

Thomas Savery, a Devonian military engineer and inventor turned his attention to the problem of pumping water from the lucrative Cornish mines – we’re talking 1690s here! He successfully patented an atmospheric steam engine, which in truth closely followed the principles of a machine published by Edward Somerset way back in 1662 – such is life!

Savery’s early steam engine was mainly based on the compartmentalisation of steam by shutting off taps in order to create a partial vacuum. This was created by the condensing steam in a closed space that included the surface water deep in the mine via pipes. The suck of the vacuum dragged the water up into the pipes at the bottom of the mine and then another tap was shut off to retain it there. The tap to the outlet pipe was then opened to release the water. Needless to say, it was inefficient! It was also the only solution at the time to deal with flooding mines! Annoyingly, it could only raise water about 30ft, so mines needed a whole series of Savery pumps.

Savery’s pumps were employed ‘successfully’ for many years to maintain water supplies in various locations in London, including Hampton Court!

Amazingly, his original patent was extended by an Act of Parliament and it covered all types of steam engines that pumped water! Although Savery died in 1715, royalties from this somewhat lucky patent continued to be paid into his estate until 1733.

So, the genius that is Thomas Newcomen (also born in Devon) was forced to go into business with Savery when he invented the world’s first practical steam pumping engine. He improved Savery’s pumping engine by replacing the steam reservoir with a cylinder and moveable piston in 1710 – see? Genius!

The piston was actually originally invented by a French engineer called Denis Papin in 1690. The piston was forced up inside the cylinder by the pressure of the steam and sucked down by the vacuum created by water-cooled condensed steam. Newcomen attached the the top end of the piston to a rocking beam via a chain. The other end of said beam was attached to a pump deep in the mine underwater. The up and down movement of the beam caused the water in the mine to be drawn into the pump and forced to the surface.

Water could now be raised 150 feet! Newcomen’s Common Engines were built in large numers, with some remaining in commercial use for over 150 years!

Newcomen’s beam engines were a major leap in  technology and were soon being used to drain deep mines throughout Britain and Europe, so he should have been rich right? Wrong, that Savery patent denied him any financial success from the major contribution to deep lode mining. Newcomen died in 1729, just 4 years before Savery’s patent expired.

And there was the Hornblowers!

The Hornblowers were a Cornish family and pioneers in steam power in the 18th and early 19th century. Joseph Hornblower (1696-1762) worked as an installer of Newcomen beam engines in Cornish mines in the early 1700s.

Joseph’s eldest son, Jonathan Hornblower (1717-1780) was also a Newcomen engine master, building and installing them in the tin mines. Joseph’s youngest son, Josiah Hornblower (1729-1809) also followed the family trade and indeed became a mining master. He travelled to North America in the 1750s to advise on copper mining and built with British parts, what some say was the first steam engine on American soil!

Before I mention the next generation, we must address a certain Mr. James Watt.

James Watt was born in 1736 in  Greenock, a long way from the Southwest! But in 1754 he travelled to London to study instrument making.

Watt returned to Glasgow to work, repairing astronomical instrumentation and eventually opened a workshop manufacturing musical instruments, toys and various equipment and it was here that he first got his hands on a broken model of a Newcomen steam pumping engine. While repairing it he noticed the engine’s inadequacies and importantly, it’s inefficient use of steam. Watt developed the solution, the separate condenser and in 1765 he was able to demonstrate his breakthrough.

Funding the first full-size prototype was incredibly expensive, so this is where Matthew Boulton from the major Soho Foundry in Birmingham and his fat wallet enters the scene. Their partnership was a success and their first Boulton and Watt steam engine was complete in 1775.

With Savery’s patent long since expired, Watt was able to patent his ideas and financially benefit from it.

The Boulton and Watt engines made a 75% saving on coal in raising the steam, so the mine owners lapped them up. Importantly though, Boulton and Watt charged an additional license fee to the owners based on the coal saving made.

The company continued to develop their ideas by introducing double acting pistons, rotative motion, centrifugal governors and parallel motion to connect between piston and beam.

Watt died a very wealthy man in 1819 and the company continued to produce his engines.

And now we can introduce the Hornblower grandchildren.

Jabez Carter Hornblower (1744-1814) was Jonathan’s eldest son. He too became a Newcomen engine installer and went on to work for Boulton and Watt, building Watt’s engines too. He set up business with John Mabberley and built a new steam engine, but BOOOM, the might power of Watt’s patent saw it torn apart and poor old Jabez ended up in a debtor’s prison!

And finally, Jonathan Hornblower Jnr (1753-1815), youngest son of Jonathan Snr. He invented a compound steam engine in 1781, but his work was also successfully stopped by James Watt, who claimed it was his intellectual property.

Incidentally, the compound engine was successfully revived later on by the mighty Arthur Woolf!

There are several major contributors to the development of the early steam technology, but two more men need to be mentioned – William Murdoch and Richard Trevithick – they took the beam engines and gave us high pressure steam.

Another Scottish Engineer, William Murdoch was born in 1754 in Ayrshire. He initially worked as a millwright with his father, but made a bee-line for James Watt in 1777. In fact he walked 300 miles wearing a hand-turned wooden hat, which impressed Matthew Boulton so much that he was immediately employed.

He had an amazing career with Boulton and Watt and started there as a pattern maker. He was soon sent down to Cornwall to oversee the installation and repair of the engines in the Cornish mines. He became a master at tweaking the engines to increase their performance and so increased the revenues to the firm based on their dubious efficiency tax! Needless to say, Boulton and Watt loved him!

While keeping an eye on the ground for patent infringements for the firm, he had many original ideas of his own, which subsequently became the property of the firm. A major achievement was that of the sun and planet gear that achieved rotary motion by turning a drive-shaft.

Murdoch also invented the pneumatic despatch system and a door bell run on compressed air, iron cement, gas lighting and the use of steam to propel boats, but he was quite delighted by his steam carriage. It was a self-propelled steam road carriage – the first in Britain!

His employers weren’t in favour of this high-pressure steam and would not support him, so it was left to his neighbour – a Mr. Richard Trevithick to develop the steam road vehicle, but that’s another story!

So where can you see a surviving beam engine?

At the time of writing, there are 37 beam engines to be discovered on the GooseyGoo Industrial Explorer map. Just select beam engine in the By Category section on the map search and hit search.

Elsecar

Rather nice suggestions include:

The Levant Beam Engine

The engine at Strumpshaw Hall Steam Museum

Stretham Fenland Pumping Station

The original Newcomen engine in Dartmouth

The fantastic Elsecar Beam Engine

Markfield Beam Engine

East Pool Mine

Crossness Sewage Pumping Station

Coldharbour Woollen Mill

Claymills Pumping Station

Abbey Mills Pumping Station

Crofton Beam Engines

Goldstone Pumping Station

20th September 2016No comments, , Steam Engines
Telling stories – the one that got away

In 1975 my brother and I took a holiday in Cornwall.

Not for a week on the beach at Newquay like most of the other men of our age, instead we elected to look at and photograph the legacy of the Cornish Tin Mining era.

We were into the hip cliché Industrial Archaeology

My brother had done the background planning, he had read a lot about Cornish mining, and was able to recognise most of the iconic engine houses in and around Camborne and Redruth. I was the up and coming budget photographer. To develop and print a roll of 36 exposure colour film in those days cost around £5.50; a week’s wages for me as a construction apprentice was £17.00.

East Pool Beam Engine © Morturn.

We had a tent and a sleeping bag each, no camp bed or mat, and we spent an incredible week living on fish and chips. I was shooting in black and white, Ilford FP4, and would develop the films when home in our mum’s bathroom. She loved us to death – honestly!

Before we even set-up camp, we came across East Pool and Agar Mine at Taylors shaft. In those days you bought a ticket at East Pool Whim that gave entrance to the Cornish Engine house at Taylor’s shaft.

It was there we met John Bolt, a retired Cornish miner – a shaftsman. John was working as a volunteer for the National Trust, and would open the engine house on a daily basis. John seemed at first a little bit tired of the visitors. Static Cornish Beam engines and retired Cornish miners don’t say a lot to the casual visitor, they invite you to bring something to the party first – it’s a test!

John Bolt.jpg

However we did bring something to the party, our thirst for knowledge, the need to know about an industry that shaped the face of the country, we passed the test and the stories started and did not stop for a week!

John had worked in the Cornish Tin Mines all his life, when he retired he ran a chicken farm nearby, but John’s identity was that of a Cornish tin miner. Over the week in Cornwall, we would pop in and see John every day, where he would tell us remarkable stories of his life underground, right up until the mine eventually changed over to electric pumps in 1954.
Taylors Shaft030

John was a shaftsman who maintained the Taylor’s pumping shaft at East Pool Mine – all 1,700 feet to the sump at the bottom. He told us that on occasions, he had also driven the 90” Cornish beam engine, and could have been one of the last people to see it working. The normal Cornish beam engine driver was a young chap who can been seen at work on a BP archive film, John knew him well.

John told us all about the layout of the pump rods, plunger and lift pumps, clack valves and the 5 other underground balance beams. It would take him an hour or so to climb up the ladders to the surface. The Cornish engine has a beam weighing around 52 tons, yet when the command to ‘blow poles’ was given, the driver “could move that beam a quarter of an inch” John would tell us.

John told me the story of a miner who had become trapped by his hand, and after couple of days still could not be freed. A doctor was bought down the mine, to anaesthetise the guy. As John held him steady the doctor cut his hand off; John said “in about three seconds”. John said the guy was back at work a week or so later, and happened to come across his own hand after some blasting. The guy just casually picked up the hand, looked at it and said “look, a perfectly good hand, nowt wrong with it”. The guy put the hand in his pocket and took it home with him!

East Pool Beam Engine. © morturn

I made a further visit to East Pool and Agar mine the following year, and again was entertained by John Bolt. He was a guy I thought would be around forever, so in 1977 I did another trip to Cornwall, only to find John’s green Reliant car was not outside the engine house.

I enquired inside to a well-spoken BBC accented middle aged gentleman, who casualty informed me John had died in his sleep over the Christmas holiday. As you can imagine, I was gutted. My feeling arose not only from the news of John’s death, but because this loss was presented to me by this other person, as just the passing of another doddery old man. He clearly stereotyped John as someone well past their sell by date who had passed away, and had made way for a new up and coming intellectual who was really going to give the visitor experience a proper job well done.

He was not in the same race. He did not have the capacity to see that the world had lost a giant of a man whose depth of practical hands on knowledge reached back several generations and brought the past alive.

John’s name, along with a few others, is etched into the glass window on the first floor of the engine house – the one overlooking the entrance door. John’s name is right in the place he loved to be, in a Cornish tin mine engine house entertaining the visitors with his remarkable stories…. Well only the ones who were able to pass his special test!

I wish I had made a tape recording of John’s stories, but the retroscope has yet to be invented, so now, I am the keeper of John’s memories, and need to tell the stories myself…. I must devise a test!

You can tell me facts and I will learn, you can tell me the truth and I will believe you, but if you tell me a story it will remain in my heart forever.

19th February 20163 Comments, , ,
Bideford Blaaaack!

Quite remarkably, there is a small area of anthracite (or culm) in Bideford! It was worked for 200 years from the 1760s until the early 1960s and sports a piratey name – Bideford Black!

There are 2 seams identified in the local area; a northern and southern seam. One was mined up at East-the Water and down at Greencliff near Cornbrough the mining activity tapped into both seams at an intersection point.

The seams stretch unseen from Hartland and Abbotsham on the coast in a southeasterly direction beneath Bideford and inland as far as Umberleigh. There were various coal yards in the town and a Biddiblack processing plant in Chapel Park.

Inclined shafts and adits in Cleave Wood, extending east for 400 to 800 metres, have been recorded, but in the name of progress, the housing situation has encroached and in 2015 the site was up for sale with planning permission for an irreversible urban sprawl. The Bideford coal industry ended in 1969 with the closure of the last mine at Chapel Park, east of Bideford.

Miners with a tub of raw culm at Chapel Park Mine, North DevonThe northern seam is thought to have formed due to a substantial log jam in an ancient river system! Evidence for this is the composition of the coal (cellulose debris with no plant spores)  characteristic of vitronite and because it presents as a series of lens shapes (such as you’d find with a culmination of logs in an Oxbow lake).

It was used occasionally as a fuel, but only for use in steam engines and lime-burning, well-away from domestic areas, because it gave off sulphurous and noxious fumes. The majority of the winnings supplied a local paint company because of its lovely black colour! (Anyone who recalls the Fast Show sketch, may pause for a reminiscent chuckle at this point!)

The southern seam (known as the Paint Seam) is a carbonaceous shale called carbargillite and was also no good as a domestic fuel, but found multiple uses as a dye in paints, antioxidant for iron clad ships and mascara!

The only other recorded coal in Devon is the Oligocene brown (lignite) coal in the china clay basins at Petrockstowe and Teigngrace, Bovey Tracey over towards the eastern coast.

Remember this juicy knowledge nugget, because nobody will believe you! Bideford Black – a colliery oasis.

 

Sources:

http://bidefordblack.blogspot.co.uk

Chris Popham’s report on Dr Chris Cornford’s AGM talk on Coal Mining in Devon (Feb 2015)

Images:

Miners with a tub of raw culm at Chapel Park Mine, North Devon

Mines Road sign in Bideford, North Devon

27th August 2015No commentsCoal