It is a calendering machine (mill) designed to bind mixed rubber (rubber plus added chemicals) and reinforcing fabric together into rubber sheets of different thicknesses. The sheets would then be vulcanised, by the application of heat and pressure. A usable product was then made which was neither sticky when hot nor brittle when cold. Some of the earliest products made using this calendaring process were waterproof capes and footwear for troops who fought in the Crimean War.

The spaces between the three big rollers could be adjusted so different thicknesses of rubber sheet could be made. Steam or water would be fed through the rollers to control the temperature of the process. The additional cogs on the outside of the large toothed gear wheel (on the left side as you look at it) provided the option of having differing roller speeds so that the rubber could be ‘scrubbed’ into the weave of the fabric’ and the product made more effective.

Stephen Moulton (1794-1880) was an Englishman living in New York who studied rubber technology with Charles Goodyear. He wanted to set up a rubber manufacturing plant in England under licence from Goodyear. After much hard work he succeeded, and chose to locate his factory in Bradford on Avon which was unusual in that it was in the west of England, far removed from the more usual centres of industrial activity. It was a disused woollen mill (Kingston Mill), nevertheless it had a wealth of advantages, coal from Somerset, the river Avon alongside the mill to supply power and washing water, together with the closely adjacent Kennet & Avon canal and the Great West Road to provide access to London. It was also cheap and contained within the 8 acre site a home, Kingston House (now The Hall), which would provide a family home. He had a financial backer and a plenty of unemployed people who were used to working in factories.

The Iron Duke, named after the Duke of Wellington, was the first such machine / mill in the UK and one of the first in the world. It was designed in the USA but built in the UK around 1848. The rollers were cast and machined at the Highfield Foundry in Bilston, Staffordshire; the huge cast iron frames were made by Bush & Co, Bristol, where castings for Brunel’s ships were made; Coalbrookdale in Shropshire forged the vertical wrought iron rods that hold the machine together; and other parts, possibly including the name board, were made by millwrights and iron founders in Bradford on Avon. When the Iron Duke ceased working after 120 years, it was taken to Bristol museum for storage in 1969/70. It represents over a century of Bradford on Avon’s industrial heritage.

Starting in 1848, the town was dominated by rubber manufacturing for nearly150 years. Stephen Moulton & Co began the industry, followed by an amalgamation with George Spencer & Co in London in 1891 to form George Spencer, Moulton & Co. Ltd. In 1956, the Avon India Rubber Co took over Spencer Moulton’s company and later became known as the Avon Rubber Company then Avon Industrial Polymers. Rubber manufacturing became difficult in the town in the 1990s so production was moved to other local towns from 1992. The company head office finally left the town in 2000.