It is a common experience in our country that our thought-processes, and resulting technological developments, are greatly influenced by their counterparts in the developed world. And brick industry is no exception to this rule. Therefore, while attempting to predict the future of our brick industry, study of the European (particularly English and German) and American brick industries becomes inevitable. For this purpose, brief account of some important events, trends, trade practices, technological developments, etc. prevalent in the European and American brick industries during the last three centuries [ 1] is given below :

1) The Great Fire of London ( 1666 A.D. ) which devastated the city and resulted into the Rebuilding Act of 1667, really gave a shot in the arm of the then low-key English brick industry. The Act banned use of wood ( being highly combustible ) and recommended exclusive use of bricks and stones for reconstruction. This resulted into an unprecedented demand for bricks and made its use very popular ( and even a status symbol !) all over England.

2) Brickmaking was a seasonal operation then. The season began in April and ended in October. Brick earth was dug in the Autumn and piled up in heaps to 'weather', especially by the frost. In the Spring, the material was tempered, i.e. trodden or turned with spades to make it evenly plastic. Moulding was then done on a table using either sand or water as a release agent, and the surplus from the wooden mould was sliced with a stick or a cutting wire on a bow. The moulded bricks were carried to the drying ground (sometimes between two small boards called pallets ) in 'herringbone' pattern. When the first row was partly dry, a second was laid across it and when that was ready, a third and so on, until a height of ten courses was reached. This pile of drying bricks was known as a 'hack'. Straw covers were provided over the hacks to protect the drying bricks from rain and excessive solar heat. Drying used to take upto 6 weeks. The bricks were then fired in 'clamps' or 'scoves' or 'skotch kilns' using cinder, coal and/or wood as fuel. The clamp size varied anywhere between 20,000 and 100,000 and the firing took 2 to 6 weeks from cold to cold.

3) Red colour was aspired to by nearly everyone planning to construct a brick house or add a brick chimney to his timber house.

4) Horse-driven pugmill was the first labour-saving piece of equipment which emerged at the end of the 17th century. It was shaped like a barrel containing a vertical shaft with projecting blades and was used for blending of clays in wet state.

5) By the middle of the 18th century, popularity of red colour started declining. Comments such as "..... the colour is fiery and disagreeable to the eye; it is troublesome to look upon it; and in the summer, it has an appearance of heat which is very disagreeable; for this reason it ( red brick ) is most inappropriate in the country..." ** started appearing and use of red bricks became unfashionable. Thereafter, hues of pink, yellow-orange, yellow-brown, buff, green, blue, etc. started appearing in the market, which were generally described as 'grey'.

6) In 1784, Brick Tax was introduced in England to help partly meet the expenses of the American War of Independence. In the beginning, bricks of all sizes attracted the same tax and therefore, there was a tendency to produce as large a brick as possible, even upto a size of 12" x 6" x 3¼". However, the subsequent Act of 1803 put a double duty on bricks of volume more than 150 cubic inches - which made production of 10" x 5" x 3" size bricks a very attractive proposition. Finally in 1850, the Brick Tax was abolished altogether.

7) In America, until the end of the 18th Century, burnt bricks were imported from England, which was considered profitable ballast on vessels which had light cargoes. However, wood was the more common choice of locals and English colonists for building their houses and shacks (and this tradition continues even today ).

8) Open-faced brick buildings lost their charm in the beginning of the 19th century and stone-dressed or stuccoed ( i.e. rendered ) walling became the "in thing". This obviated the need for producing and / or using good quality burnt bricks along with sand-lime mortar, because, in the end, all brick faces were to be plastered over. However, as the quality of brickwork deteriorated, public opinion changed, and in the end, by about 1860, unrendered brickwork once again regained its lost popularity.

9) Till around the middle of the 19th Century, brickfields were mainly the concern of reformists and missionary clergymen because of the degenerate behavior that went on in them. Child labour, drunkenness, unhygienic working and living conditions and exploitation of all sorts was order of the day. Few other industries of the time could match the earthy and uncivilized 'image' of the then brick industry. The owners of brickfields were usually portrayed as 'brutish, troublesome, hard-drinking, rollicking, dirty-tongued' mortals and the moulders as 'ones who raised their families with the earnings of their wives and children and spent their own income entirely on drinking'. Work used to start at as early as 4.30 a.m. and continue till 8 p.m., although 6.00 a.m. to 6.00 p.m. was the more common practice. Labourers were paid by piece-rate and a moulder 'gang' could mould anywhere between 1,500 and 3,500 bricks in a day, depending upon its composition and strength. However, the quality of the then English brick was far superior to its American and German counterparts.

** Quoted from " Complete Body of Architecture," 1766, by Isaac Ware

10) The second-half of the 19th century saw the birth of numerous brickmaking machines and firing techniques, fuelled mainly by the ever -increasing demand for bricks and shortage of skilled labour. Britain's brick production doubled during the period 1850 and 1900 and the industry could operate year-round and provide steady employment. Initially, the mechanisation drive met with more commercial failures than successes. Also, machines were looked upon as job-stealers and several attempts of sabotage ( like dropping a steel spanner into a grinder or blowing-up a steam engine ) were reported. However, the initial aversion to mechanisation and fear of failure soon gave way to openness and finally, a preference for advanced / state-of-the-art technologies.

11) A list of major inventions during the 19th century is given below in chronological order [ 1, 2 & 3 ] :

1813 - Manually operated soft-mud moulding machine developed by Kinsley
(England )

1828 - Development of piston or box-type horizontal reciprocating
extruders

1840 - First tunnel kiln patented by Yordt in Flensburg ( Denmark )( However, the
kiln became techno-commercially viable only after 1947 )

1849 - Extruded hollow brick developed by Henry Roberts ( England )

1854 - Vertical extruder with die developed by Carl Schlickeysen ( Germany )

1856 - Annular continuous kiln developed by Friedrich Eduard Hoffmann, an Austrian by
birth, patented in Germany in 1858. It was circular in shape with a chimney in the
centre surrounded by a semi-circular vaulted channel divided into 12 chambers.

1860 - Semi-dry process for pressing shale dust developed at Accrington ( England )

1865 - Development of horizontal auger (or worm) extruder and mobile cutter, the latter
developed by Gebruder Sachsenberg (Germany )

1867 - First chamber dryer built at Mensing ( Germany ) ( However, the dryer
attained wider acceptance only after 1894, when the finger car was
invented by Keller in Germany )

1870 - Re-press for wire-cut bricks developed by Bennett and Sayer ( England )

1876 - Bull's trench kiln design patented by W.Bull, an Engineer ( England )

1927 - Habla kiln invented by Alois Habla (Germany)

Present Technology Status :

Technically, burnt clay bricks fall under the category of 'Heavy-Clay Products' forming a major part of the 'Ceramic Industry'. Heavy-clay products are those that are mainly made from a single clay or similar mineral with very little additions of other raw materials. They are principally used in structural work, hence they are often called 'Structural Clay Products'.

The first heavy-clay machinery in India was introduced at Jeppu ( near Mangalore ) in 1865 - around the same time it started gaining popularity in Europe. However, during the last 150 years or so, our Brick Industry has made very little real progress w.r.t. development and / or adoption of 'appropriate' technological solutions. This is despite the fact that -

(a) the roof tile production process - which is the torch-bearer of the heavy-clay technology in India - has taken firm roots in all parts of the country ( e.g. Calicut - Southern India, Balaghat - Central India, Morbi - Western India, Allahabad - Northern India, Raniganj - North-Eastern India and Samalkot - Eastern India ) and

(b) a number of dedicated Government R & D Institutions and Promotional Agencies are rendering yeoman service to the industry.

The present production of burnt clay bricks in India is estimated at about 120 billion bricks per year coming from at least 1,00,000 brickfields ( of which at least 40,000 are moving / fixed chimney / Hoffmann / High-draught kilns ) scattered all over the country. Although Ceramic Products like glazed tiles, crockery, sanitary ware, refractory bricks, etc. are being made with the most advanced / state-of the-art technologies, the state of the brickmaking technology in India is far from being satisfactory. The present work culture of our brick industry is no different than the one that existed in Europe during the mid-19th century, as mentioned earlier. Majority of the units still employ age-old hand-moulding, sun-drying and clamp, scove or moving chimney kiln burning methods. Use of roller crushers, extruders and Hoffmann kilns for brickmaking has remained restricted to the Mangalore-Calicut coastal belt only, while use of fixed chimney kilns and high-draught kilns is mainly prevalent in the Northern and North-Eastern and some Southern States.

There have been attempts in the recent past to set up oil and coal-fired tunnel kilns in Kannur and Erode districts of Kerala and Tamil Nadu, respectively. However, they are yet to report commercial successes. More recently, 13 Vertical Shaft Brick Kilns ( VSBKs ) have been designed, constructed and made operational at Datia, Tekanpur and Gwalior (M.P.), Mohuda and Asurmunda ( Orissa ), Palakkad ( Kerala ), Pune, Nimbut and Amravati
( Maharashtra ), Varansi and Bareily ( Uttar Pradesh ). By far, they appear to be the fastest, cleanest and most fuel-efficient kilns developed for firing upto 15,000 bricks per day. Of late, a few improved versions of fixed chimney / high-draught kilns (incorporating arrangements to increase the existing heat-transfer rates, decrease the heat losses and contain pollution more effectively ) have also been put to commercial tests.

Present Entrepreneur Psychology :

The present psyche of the Indian brick fraternity can be best described by the term 'mechanisation phobia'. The phobia is due to the techno-commercial failures of a large number of semi-mechanised / mechanised brick plants set up so far. The main reason for these failures has been the lack of insight on the part of entrepreneurs as well as machinery suppliers and technology providers as to 'what makes a brick plant click in the real world'. Most people mistake the brick industry for one, which involves mere mechanical operations, while in reality; it is a unique process industry. Therefore, an unbiased evaluation of technical feasibility (including raw material testing ) and economic viability ( including reliable market survey and proper selection & training of personnel ) of a project is a must for guaranteed commercial success.

On one hand, this fear psychosis, coupled with the high cost of capital in the country, is making the entrepreneurs extremely cautious towards mechanisation. While on the other, the recent 'Brick Regulation '96' of the Ministry of Environment & Forests is forcing them to convert their existing clamps / moving chimney kilns into cleaner and more fuel-efficient kilns. Also, factors like fast depletion of deposits of 'good' brickearth, ever increasing problems of labour management, decreasing profit margins, etc. are inducing entrepreneurs to consider immediate adoption of affordable, cost-effective, dependable and simple technologies.

Shape Of The Things To Come :

Since the early seventies, the world is becoming increasingly aware of the ill effects of smoke, acid rain, desertification, 'green-house phenomenon', extinction of rare species, disintegration of the ozone shield, etc. on our environment. This has lead to 'sustainable development' becoming the buzzword of the day. In line with this thinking, all long-term developments in our brick industry are expected to be influenced by the 'principle of sustainability' alone. 'Sustainable development' means 'development that meets the needs of the present without compromising with the ability of future generations to meet their own needs'. Even though we in India are equally concerned about (and feel responsible for) the well-being of our future generations and our planet, the omnipresent scarcity of resources and influence of the traditional thought is bound to limit our choices to solutions of 'appropriate technology' alone in the short run.

These short and long-term trends are described below in brief.

Short-term Trends ( 2000 to 2010 ) :

1) Seasonal operation to continue, by and large, upto 2005 followed by gradual replacement with all-the-year-round operation

2) Adoption of 'functionally useful' products and production systems without much concern for aesthetic / decorative considerations

3) Wide-spread use of clay preparation machinery, simple extruders, drying sheds and material handling equipment

4) Introduction of hot floor dryers and chamber dryers

5) Conversion of existing moving chimney kilns of more than 15,000 bricks per day capacity into fixed chimney / high draught / Hoffmann kilns

6) Conversion of existing open clamps and annular kilns of less than 15,000 bricks per day capacity into vertical shaft kilns

7) Continuous improvement in design and operation of fixed chimney, vertical shaft and high draught kilns ( including use of setting equipment/ fork-lifts / trolleys, etc. for loading / unloading )

8) Entry of open-cured semi-dry-pressed calcium silicate bricks (including flyash bricks ) and soil bricks

Long-term Trends ( 2011 - 2050 ) :

1) All-the-year-round operation

2) Strict compliance with environment regulations and quality standards

3) Product diversification (facia bricks, brick pavers, hollow blocks, split tiles, etc.)

4) Stiff competition to burnt clay bricks from calcium silicate bricks

5) Introduction and anchoring of stiff-extrusion and semi-dry pressing technologies

6) Wide-spread use of chamber and tunnel dryers

7) Introduction and anchoring of tunnel kiln and process automation systems

References :

[1] Woodforde John & Paul Routledge/Kegan, Bricks to Build a House, 1976
[2] Bender Willi, 'From Craftsmanship to Industry - The Development of Brick
-making Technology in the 19th Century', Tile & Brick International
( No.1,2,3 & 4 ), 1996
[3] Searle Alfred B., Modern Brickmaking, 1931