Curator Christian Redford (right) inspects the site. © Paul Box

Visitors to Isambard Kingdom Brunel’s steamship Great Britain in Bristol have been able to watch an archaeological dig unfold before them.

On October 22 they were able to glimpse the excavations of a tannery yard built on top of the site of the Great Western Steam Engine Factory, which is being investigated prior to work starting on the building of the Brunel Institute conservation and learning centre and new flats.

“We knew about the existence of the tannery yard, but it is interesting to witness the dig unfold and to be able to contribute to the Brunel archive – this will be one of the best recorded tannery yards in England,” said Phil Andrews, Senior Project Officer for Wessex Archaeology who are conducting the dig.

Underneath the tannery the archaeologists have located the floors used by Brunel’s workforce to build the engines for ss Great Britain in the 1840s. The dig aims to gather as much information as possible on the site’s use for the ss Great Britain Trust’s archives.

The Great Western Steam Engine Factory was the first ever purpose-built steam engine factory in the world. It was sold to the Great Western Tannery in 1852 and was later used as a timber yard, granary and warehouse, until it was destroyed in a World War Two bombing raid.

The Steam Engine Factory lies underneath the Great Western Tannery. © Paul Box

Where possible its surviving walls will be preserved and used in the new building development.

Christian Redford, curator at the ss Great Britain Trust, said: “While the revolutionary iron hull of the ss Great Britain was taking shape in the dry dock, her enormous engine and transmission gear were being constructed in the engine factory.”

“Nothing as large or powerful had been built before and the machinery in this building represented cutting edge technology. For example, we know that James Nasmyth invented the steam hammer to come into this building to work on steam ship engines.”

Excavations at the site will continue until the end of the year, with the new building work set to start in January 2008.

“With another two months of work to go, we are looking forward to seeing what else the archaeological team will discover, especially about the industrial processes that took place in the Great Western Steam Engine Factory,” added Christian.