Description:The Soho Foundry was established in 1795-6 as the first purpose built and integrated steam engine manufactory in the world. For the first time all the parts of a steam engine, including the very important cylinder, were cast or forged on one site, processed to fit accurately and then assembled to make a complete engine. A location on the Birmingham Canal a mile away from the Manufactory was essential in order to transport the finished engine more easily to customers.
The original plan of the Foundry was supplied by William Wilkinson after he had split with his brother, John in 1795. They had previously supplied most of the cylinders for Boulton and Watt engines. The collapse of the Wilkinson partnership forced the firm of Boulton and Watt to change its business radically and abandon the selling of a few specialist parts and licenses to customers to make the improved Watt engine. The expiry of James Watt’s patent in 1800 was also another major reason for the establishment of the Foundry. In their new buildings the firm could get ahead of any competitors who might make their type of engine from 1800.
James Watt Jnr, son of James Watt, modified William Wilkinson’s plan and laid out a main Foundry building, where the engine cylinders and other parts were cast. From here cylinders could be moved on the level into the Boring Mill adjacent, where they were accurately bored internally. The Boring Mill also contained lathes and drills for finishing engine parts.
By 1799 other buildings included the Smithy (for forged parts), the Carpenters Shop (for making patterns) and a Pattern Store. The Soho Foundry in the 1790s was tiny by current standards and even when it grew to about three times it original size by 1895, the modern Avery buildings on the site still dwarf it.