Uncovering Manchester’s industrial past (part 2) – bleach and dye works

The British cotton industry was centred on Manchester in the 19^th century. The invention of machines for spinning and weaving cotton in the 18^th century enabled the development of factories producing considerable quantities of fabric ready to be printed into the finished cloth for marketing both in Britain and overseas.

The cloth-finishing industries

By the early 19^th century there was a demand for bleached factory-produced cloth for dyeing and printing. The dramatic rise in the quantity of woven cloth being produced meant that cloth-finishing industries had to increase their industrial output. The cloth-finishing industries responded in various ways, one being through developing factory-based processes following the invention of bleaching powder (slaked lime impregnated with chlorine gas) for bleaching, which generated a ten-fold increase in the output of bleached cloth by the 1830s.

While there are many 19^th century mill buildings still in existence in Greater Manchester there are only a small number of bleach and dye works that survive. Archaeological excavations of the below-ground remains of late 18^th and early 19^th century bleach and dye works are a way of exploring the development and growth of the cloth-finishing industries.

Bleaching and dyeing in Salford

Bleaching and dyeing required access to water, which led to the Irwell Valley becoming a focus for cloth-finishing industries. Archaeological Research Services Ltd has recently investigated two bleach mills in Salford in advance of urban regeneration: the Crescent Bleach Works and the Poplar Grove Bleach and Dye Works, both of which were in use until the mid-20^th century. The archaeological excavations at both sites suggest that, once industrialisation using bleaching powder had been developed, there was little change in the bleaching and dyeing process itself, even with the introduction of synthetic dyes in the 1850s. However, the introduction of improved and larger-scale machinery and power sources enabled an increase in the scale of production in the 19^th century to be achieved, largely by modifying and expanding early mill complexes and building new factories.

Establishing a 19^th century bleach works

The Crescent Bleach Works in Salford was established on the site of an 18^th century water-powered corn mill. The structure housing the original water wheel was rebuilt and linked with a weir constructed on the River Irwell in 1793. This was used to power a complex of corn, logwood and cotton spinning mills. By 1811, the cotton spinning business was being converted into the bleach works, which included terracing and building new structures on the site. Part of the enlarged mill complex was powered by a steam engine.

The logwood mill probably produced dyes for the dye works situated further downstream. Most dyes were derived from plants, notably indigo, madder and logwood, until synthetic dyes were introduced in the 1850s. Logwood grinding activities ceased at the site by the early 1880s and the bleach works was extended to occupy the entire site.

While water power continued to be used, a succession of increasingly efficient steam engines culminated in the installment of a horizontal steam engine in the 1880s and 1890s (or a number of such engines) to power different parts of the factory. Chimneys associated with earlier engine houses, including an octagonal-shaped chimney, had been removed, with only a single chimney with a circular plan form being used by the 1890s.

Other features associated with the bleach works investigated at the site included a series of machine beds, a set of four stone-lined chemicing cisterns, four vats which used acid to remove impurities from the cloth, and wells which provided clean water for the steam engines and the bleaching process. Long ‘ribbons’ or ‘ropes’ of cloth sewn together were fed continuously into the rooms where different bleaching and washing processes took place. This happened via round holes fitted with ceramic “pot-eyes”, a number of which were recovered during the excavations.

An integrated 19^th century bleach and dye works

The Poplar Grove Bleach and Dye Works was built in the early 1800s, comprising two ranges of buildings separated by a yard or road. The presence of lime deposits indicated that the western range was devoted to the bleaching process, while dye residues on the floors indicated that the eastern range was the dye works. These dye residues included synthetic aniline purple and probably Paris green dyes that had been in use from the late 19^th century onwards. The building complex was accompanied by three reservoirs situated immediately to the north which would have supplied the factory with clean water for the bleaching and dyeing process. The footprint of the buildings appears to have remained largely unchanged, although there were additions and adaptations at various points in their life as new machinery was introduced. Numerous pot-eyes were found, along with several iron cogs, crown wheels and other pieces of metal machinery.

The bleach croft had a series of cellars, including three beds for Lancashire boilers and an adjacent steam engine bed. They had all gone out of use and been built over at the end of the 19^th century or beginning of the 20^th century. Meanwhile the dye shop had a dynamo installed, made by the Lancashire Dynamo and Motor Company in either 1912 or 1913, which represents the early introduction of electricity to the building complex.

> If you missed it, see part 1 of our series (the world’s first industrial city) here.

> See part 3 (iron works) here.