Brick Making in the Midlands

Introduction

For many hundreds of years, bricks have been the main building unit for building construction over large parts of the world. Before industrial methods were introduced, bricks were made in a laborious hand-made process. In Britain the clay was dug from pits during the summer and spread to expose it to frosts in the winter to break the lumps. In the spring water would be added and then mixed, often by trampling by oxen. Small quantities of the clay would be rolled in sand to form a clot that was then pressed into a mould on the moulding table with more sand being used to prevent the clay sticking to the mould. Excess material was removed by pushing a wet stick across the top of the mould, the surplus material being returned to the clot maker. The raw bricks would then be removed from the mould and spread over an area to allow the water to evaporate, a process that could take two weeks or more depending on the weather. For this reason, in Britain, brick making was often restricted to the summer period.

To fire the raw or ‘green' bricks, beehive kilns built with walls of previously fired bricks were filled with stacks of the raw bricks. Temporary walls were built inside the kiln so that when fires were lit in the fire holes around the sides of the kiln, the hot gases would rise up towards the domed top before being drawn down through the brick stacks by under floor ducting leading to a chimney. Initially the temperature was kept low for one to two days to drive off any remaining moisture from the bricks before being increased to about 1,000 degrees Centigrade to fuse the raw brick material into a fired brick. After that, the fire holes around the kiln would be bricked over and the kiln allowed to cool for up to another week before the fire holes were opened and the fired bricks removed.

In the first half of the 19th Century, industrial processes began to be used in the brick making industry, initially using steam power but later replaced by electrically powered machinery. The clay was obtained from pits or mines and transported to the processing works where it was crushed, sieved and blended with other ingredients in large drums with sufficient water to produce a semi-stiff product. This was then extruded into moulds and compressed to produce a raw brick slightly larger than the finished brick to allow for shrinkage during drying and firing. By fitting an imprint plate into the bottom of the mould, the required details could be imprinted onto the raw brick when it was compressed to the required thickness. The raw brick was then ejected from the mould and transported to a drying area before being transferred to the kiln for firing. Many coal mines required large quantities of bricks and established their own brick works to supply their needs. While mining for coal, seams of shale could be extracted and, after crushing and grinding to a fine state, be used as a clay substitute for brick making.

As the brick making industry increased, to fire the larger quantities of bricks being produced, beehive kilns were often replaced or supplemented by larger 'Hoffmann' rectangular kilns that had many sections that could be used in turn. The hot gases
from the burning zone were drawn over raw bricks in other sections to dry them before they were fired. Brick making could then become a continuous process instead of the batch process when beehive kilns were used.

Because of the weight of bricks, in early times bricks were often made on or close to the site where they were required. Transport by horse and cart was very limited by the weight that could be moved and it was only later when canals were constructed that bricks could be made ‘off-site' and transported to the building site. Later the railways and roads became more important for brick carriage but in the present age, almost all bricks are transported by road from the large brick makers. It is obvious that towns and cities, with many brick buildings, required enormous quantities of bricks for their construction. The main requirements were readily available supplies of the raw materials of clay and coal. This resulted in many brickworks being created in areas where large numbers of bricks were required in order to reduce transport costs. As an example, the Digbeth and Bordesley areas of Central Birmingham once contained many brickyards producing bricks with the readily available clay and coal brought by canal or rail from Midland mines.

All the bricks that are displayed in the Cart Shed at the mill during Open Days have some details imprinted in the brick, usually in the 'frog', a depression in the brick surface produced by the imprint plate. These details may include the makers name
or company, the location of manufacture or a trademark.

The remainder of this article gives examples of the information included in the imprint with photographs of example bricks and brief details of the brick manufacturers. All the displayed bricks were produced within an area limited to about 30 miles from the centre of Birmingham, extending into the Black Country and the western and eastern parts of the Midlands.

To continue reading this article you can download a pdf file below. Click the arrow to open the file and download it.