The Process of Brick Making

A description of how bricks were manufactured during the late Victorian era

Jubilee trucks
Peter Gillard collection

Kiln Fired Bricks

There are two methods of producing bricks the first is the traditional kiln fired method. Dried bricks, commonly known as Green Bricks are stacked in an enclosed area called a “Kiln” and baked or fired. Kiln firing is an age-old method that has been refined over time from a simple mud enclosure to a variety of brick built kilns. The “Bottle or Beehive kiln” so called due to its shape was one of the most commonly used for firing clay products of all kinds. This firing process requires a constant feed of combustible material to maintain a temperature sufficient to complete the firing process. The kiln size also limits the number of bricks that can be fired at one time.

Clamp Fired Bricks

In the second method of brick making the dried bricks are arranged in a “Clamp” for firing, the “Stock Brick” is produced by this method. It is thought that the method used to produce this type of brick originated in the village of Stock, near Chelmsford in Essex. Unfortunately no specific documentary evidence is available to prove this but it is known that a number of small brickwork’s existed in and around Stock in 1588 and it is thought that the formula was discovered by one of these brick manufacturers. The description of the Yellow Stock brick has been passed down thus; “a yellow coloured brick with a mauvy streak, formed by the admixture of ashes with the clay before firing”.

Differences between types of brick

Bricks, other than the Stock, are made from the local clay or “Brick-Earth” and have a finished colour that reflects the colour of the local clay. This can vary from the very red clay found in Devonshire that produces a very red brick to the other extreme the so-called White Brick that is common in Cambridgeshire. This white or pale yellow colour is due the high chalk content of the local brick-earth. The Stock brick contains one extra ingredient; a combustible material in the form of ash is added to the clay and chalk mixture. The common form of Stock brick is the “Yellow Stock” which is produced by an admixture of 64% clay, 11% chalk and 25% combustible material. The less common “Red Stock” is made from 75% clay and 25% combustible material.

The process used for firing the Stock brick eliminates the need for a kiln and it is possible to produce more bricks from one firing. A Stock Clamp may contain between two hundred thousand and one million bricks. The fuel for igniting the Clamp is laid in the first few rows of bricks, when sufficient heat is generated the bricks themselves self-ignite, the fuel contained within the bricks maintains the firing process. The firing time will vary from two to six weeks depending on the weather; wind, rain and ambient temperature will have an effect on the duration. The method used to produce Stock bricks allowed small manufacturing operations to be set up and in production relatively quickly, without the time and expense of building kilns. The attraction of the Clamp firing process encouraged Victorian entrepreneurs to set up new brickfields to meet the demand for bricks, investors were found who were prepared to risk their money in such ventures. This was particularly the case during the latter part of the nineteenth century, when there still appeared to be a thriving market for Stock bricks for the continuing development of London and other urban centres.

The manufacture of the Stock brick tended to be close to inland waterways and the coast of Essex and Kent. Both Counties had abundant brick-earth and easy access to the other raw materials. Chalk was available locally in both Counties and the sand used to prevent the loam mixture sticking to the Brick Mound was available on the bed of the Thames just for the taking. The river Thames also provided a highway for the transportation of manufactured bricks to London, the main market for Stock bricks and other clay products.

The Brickfield

When an area of land was found that had sufficient brick-earth to warrant exploitation the topsoil was removed to reveal the clay layer. Inland brickfields were dominated by a large hole in the ground as more and more clay was removed.

Brick-earth was dug and conveyed by wheelbarrow or “Jubilee Truck” to Wash-Mills. The larger manufacturers made use of tramways to move the brick-earth, smaller sites that manufactured close to the brick-earth seam or lacked the financial resources, used manual labour. By removing the topsoil the brick-earth is exposed and can be simply removed by digging out to the depth of the seam. At South Benfleet and Hadleigh the land rises away from sea level very quickly so that the removal of the brick-earth was achieved by a method of stepped extractions or terracing as the labourers cut into the side of the hills. The result of this type of extraction was still just visible circa. 1930 at the former site of Marsh Brickfield.

Gathering and preparing the Raw Materials

The Autumn and Winter was used, in the main, for the extraction and preparation of the brick-earth and the stock piling of sand, coke, ash and chalk in readiness for Spring. The brick-making season commenced in early April but on occasions was delayed due to inclement weather conditions.

Brick-Earth

The term “Brick-Earth” is used to describe a particular type of clay based material that is used to make bricks; it is abundant in Southeast Essex and North Kent. Three categories of clay are present, “Head Brick-Earth, River Brick-Earth” and “Brick-Earth”. They are described as, “sandy or silty weathered clays generally of Quaternary age but also including Tertiary strata, particularly the Claygate Beds and the higher siltier part of London Clay”. The survey defines three types of brick-earth deposit that is available in Southeast Essex, “Within the district brick-earth’s occur in three principal situations: firstly overlying the chalky Boulder Clay on the plateau; secondly mantling slopes and valley floors; and thirdly overlying river terrace gravel”. The brick-earth had been deposited during the glacial periods and over the “former flood plains of rivers”. This is consistent with the location of many Stock brickfields, adjacent or close to Essex rivers, areas that would have been flood plains in the past.

An investigation by members of the British Brick Society to define “Brick-Earth” as compared to “Brick Clay” is also helpful in understanding why brick making is located along the Thames Valley. Brick-clay has a higher clay content and is more suited to pottery and tile making, due to its greater elasticity. Brick-earth, on the other hand, has a much lower clay content and is predominantly quartz and is described as:

“Brickearth, Loam used for making bricks. Especially in the Pleistocene of the Thames Valley and Eastern England. A sedimentary deposit related to the Loess of western and central Europe, consisting largely of quartz (SiO2) of a characteristic particle size range, 20-60 micrometers and perhaps up to 30% by weight of clay minerals. Of recent age, usually less than 20,000 years old. Used as found to make medieval bricks; from about 1700 mixed with combustible material to make Stock bricks”.

Chalk

There are deposits of chalk along both sides of the Thames estuary, often under the clay deposits. Chalk is available locally in Essex, particularly at Grays and Thurrock where a number of brickfields were also located. The “Globe Cement, Brick, Whiting and Chalk Co.” at Little Thurrock, is listed in Kelly’s Directory from 1878 till the early part of the twentieth century. The “Grays Chalk Quarries Co. Limited”, at Grays’s is similarly listed throughout this period. At Shoeburyness the brick-earth itself contains sufficient chalk to produce Stock bricks with just the addition of combustible material.

Combustible Material and Grading Bricks

Coke and breeze is a waste product of gasworks and coal fired electrical power stations, these two industries had a need to dispose of their waste. Coke and breeze was collected from Battersea power station, conveniently situated adjacent to the Thames. Barges also collected London’s households refuse from chutes at Battersea, Camberwell and Putney. The household refuse consisting of decaying organic matter, part burnt coal, bone, broken glass and pottery, it was sifted and sorted into fine and coarse material. The ash and smaller pieces of coke and breeze was mixed with the brick-earth to form the bricks. The coarse material was spread in several thick layers at the bottom of the Clamp and ignited with faggots and coal, when the temperature of these layers had risen sufficiently the fuel in the lower bricks of the Clamp would start to burn. Eventually the whole Clamp would burn firing the bricks; it would remain alight for between two to six weeks. The lower layers in the centre of the Clamp would over burn becoming distorted and fused. Conversely the bricks on the outside of the Clamp would only be lightly fired; the best brick came from the centre. The Clamp was dismantled after firing and the bricks sorted into five grades. The “First Grade” of brick was one of an even yellow colour and of a uniform shape and sized, this was used for facing work. The “Second Grade” was of a slightly paler yellow colour, but still often used for facing work if a cheap option was acceptable. The “Third Grade” was an orange coloured softer brick compared to the previous two grades. It was used for hidden work such as inside walls where the bricks would be plastered over. The “Fourth Grade”, known as “Roughs” was a hard but distorted brick used for garden walls. The fifth and final grade called “Burrs” was basically a reject, over burnt, black, distorted and often fused to other bricks, it was mainly used as hardcore in the footings of buildings. However Burrs are used for boundary walls of residential property, from research of Ordinance Survey maps it would appear to indicate this practice often took place close to the site of a nineteenth century brickfield; presumably they where cheap to purchase. This has proved a good pointer for locating nineteenth century brickfields.

Resources needed to produce stock bricks

The advertisement for the sale of the “Benfleet Brick and Tile Company Limited” provides an invaluable inventory of the resources needed to run a brickfield. The produce from site was the “Yellow Stock” brick, this is apparent from the list of raw materials available to a prospective purchaser. The advertisement mentions measure of weight called a “Chaldron, full name “Newcastle Chaldron”, this was a measure of about 1.25 Imperial Tons; it is a term that has fallen out of use. By some simple arithmetic it is possible to provide an indication of the number of Stock bricks that could be produced with the quantity of combustible material available at the site, assuming it was sorted for brickmaking:

Note: All weights are in Imperial measure

  • 1 Ton = 2240 pounds
  • 1 Chaldron = 1.25 tons or 2800 pounds
  • 1 Stock brick weighs approximately 5 pounds, (dry weight)
  • 1 Stock brick is made of 25% combustible material equivalent to 1.25 pounds per brick
  • The weight of 1 Chaldron, 2800 pounds, divided by the weight of combustible material contained per brick, 1.25 pounds, gives the number of bricks that can be produced by 1 Chaldron of combustible material, which is approximately 2,240 Stock bricks.
  • Therefore 900 Chaldrons of ash and breeze will produce approximately 2,016,000 Stock bricks
  • If a brick gang of six individuals can produce on average of 900 bricks per hour, for an eight and a half-hour day, the number of bricks produced per day is 7,650.
  • By dividing the number of bricks available from 900 Chaldrons by the day rate of production, (7,650) the approximate number of days work available for Stock production is 263.53 days.
  • Given that the working week was six days and the average number of days worked per month, April to October, was 26 days then 411 days of Stock production will provide approximately ten months work for one brickmaking gang consisting of six men.

Using this crude analysis it becomes clear that there was considerable material in hand to commence brickmaking for the 1882 season.

Moulding Sand

The generic terms used for mounding sand, in Essex and Kent is “Thames Sand” or “Leigh Sand”. The port of Leigh is situated on the Essex coast just a few miles from South Benfleet, towards the mouth of the estuary. The sand was readily available in abundance close to the shore, a barge crew had only to anchor over the Leigh sandbank and wait till the tide had ebbed; the barge would be left resting on the bank. The three-man crew then had the gruelling task of loading the hold with wet sand. The following tide would lift the barge off the sandbank and the crew sailed their craft and its cargo to a brickfield.

Site Tramways

An example of a site tramway can be seen in at the Salvation Army Brickfields where workers are extracting brick-earth, At South Benfleet, the Ordinance Survey of 1896 shows that a small site tramway was constructed for “Hill Brickworks”.

The Use of Horses in Brickfields

The story Black Beauty written by Anna Sewell, (1820-78) includes a section that provides one view of the life of a brickfield horse. Anna Sewell, like many Victorian writers, vented her feelings on the social ills of the nineteenth century. The following passage re-enforces her views on animal cruelty.

“The note was delivered and we were quietly returning till we came to the brickfield. Here we saw a cart heavily laden with bricks; the wheels stuck fast in the stiff mud of some deep ruts; and the Carter was shouting and flogging the two horses unmercifully. It was a sad sight. There were the two horses straining and struggling with all their might to drag the cart out, but they could not move it; the sweat streamed from their legs and flanks, their sides heaved, and every muscle was strained, whilst the man, fiercely pulled at the head of the forehorse, swore and lashed most brutally”.

Horses were used for much of the heavy work in the brickfield and at times the conditions were wet, muddy and cold. Ill-treatment may have been a regular pattern of life in some brickfields. Photographic evidence tends to show that individuals who were responsible for horses had affection for their charge. However Anna Sewell had undoubtedly witnessed or heard of cruelty to horses in this context for her to write so passionately about it.

 Horses continued to be used in the brickfields into the twentieth century. Photographs show them at work turning chalk and pug mills. There is some evidence that horses were used at the South Benfleet brickfields. The 1881 Census Returns lists two individuals who worked with horses, “Albert Gray” had the calling of “Brickfield Carter” and “Harold Hague” is listed as “Brickfield Carman”. The advertisement for the sale of the lease of Benfleet Brickfields includes, “seven valuable young horses, ten useful Brick Carts, twelve sets of harnesses”.

The Wash-Mill and Wash-Back

Brickworks consisted of a number of “Berths” or “Stools”. The term Stool was derived from the brick-moulders stool or table where bricks were made. The number of Stools was dependent on the width of the brick-earth seam being worked. Each berth had its own “Wash-Mill”; a circular brick lined pit over which a wooden framework was built from which harrows were mounted and extended into the pit. A horse was attached to the frame by a yoke and harness; it walked in circles rotating the harrows. Clay, Chalk and Water were introduced into the pit and the rotating harrows mixed the ingredients till they combined to a suitably pliable consistency. The partly prepared brick-earth was removed and stored in a pond called a “Wash-back”, ash was spread over each layer of admixture as it was added to the stockpile. When full water was poured into the Wash-Back to cover the preparation, it was left here until required for brickmaking. This initial preparation of brick-earth took place during the winter months,

The Pug-Mill

In due course the stockpiled brick-earth, chalk and ash admixture would be taken from the Wash-Back and feed into the “Pug-Mill”. A horse drawn Pug-Mill consisted of a conical shaped tub that was held together with iron bands, similar in construction to a wine of ale keg. A spindle carrying blades fitted inside the mill. A horse was attached to the mill by a yoke, as it walked in a circle two sets of blades worked through the admixture as it was feed into the top of the mill. “Cutting-knifes” continued the mixing process while “Force-knifes” pushed and forced the earth downwards and out of the “Ejection hole”. The now prepared brick-making loam was loaded on to a barrow and transported to the brick moulders table.

Brick Moulds

The 1886, Kelly’s Directory carries an advertisement for the manufacturer J. T. Bower, “Inventor & Patentee of Solid Corner Brick Moulds & Adjustable Bed Pates”; Bower’s Business address is Sittingbourne, Kent. Two types of mould are advertised, the “Fire Brick Mould” and the “Stock Brick Mould”. It would seem that Bower considered that a market existed in Essex to warrant advertising and supplying his wares in the County. Sittingbourne was at this time the location of one of the largest brick manufacturers in the region, Smeed-Dean. The fact that a Stock mould was being advertised in Essex would tend to suggest that the manufacture of the Stock bricks was common in the county. The mould comprised two parts; the “Stock-Board” which fixed to the table with metal pins on which the manufacturers identification mark inscribed; this would transfer to each wet brick. The other part was an oblong box shape that fitted snugly over the Stock-Board into which the pug was thrown. Many small manufacturers used unmarked hand-made wooden moulds with no identification mark.

The Moulders Table

The brick “Moulders Table or Stool” was a simple, but functional, wooden affair comprising a flat surface with an edge strip on three sides and an attached inclined page for off loading the bricks produced. A brick moulders only hand tool was the “Striker”, a small wooden board that was drawn across the mould to remove surplus pug. A brick moulder will often be seen holding a Striker as a mark of his trade in photographs of brickmaking gangs.

The Hack and Hack Barrow

The completed bricks were placed carefully on to the “Hack Barrow” and wheeled to the “Hack” and left to dry. The capacity of the Hack barrow varied from 26, 28 or 30 bricks, The “Hack” was an area of the brickfield set aside for drying bricks; it consisted of long open sided sheds where the bricks were laid out to dry. If it rained an alarm would sound as a warning to the workforce; they would rush to close the shed louvers to prevent the bricks becoming wet. Bricks were left to dry for a period of five to seven weeks.

The Brick Clamp

The “Clamp” was constructed on a sheltered, well-drained flat dry area of the brickfield. Ash and brick rubble was first spread on the ground as a barrier against rising damp. The bottom layer of the Clamp was formed by laying previously burnt bricks, known as “Wasters”, on edge in a diagonal pattern with a brick width space between them; this was known as “Skintling or Scintling”. The dried bricks were stacked in rows across the Wasters to form the Clamp; the bottom rows being interspersed with the combustible material, faggots and coarser ash. Once lit the combustible material would eventually produce sufficient heat to ignite the combustible material in the he brick’s. The tunnelled construction provided a passage for air to be continually drawn into Clamp aiding firing at a high temperature until the fuel in the bricks was spent; this could take between two to five weeks. When cool the finished bricks would be sorted and stacked ready for transportation.

 

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  • Such an interesting article, thank you. I’m trying to find a clay that will fire yellow in an electric kiln.

    By Helen (17/07/2019)

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