Watching Brief

Date 6 November 2006 - 10 March 2007

Event ID 558875

Category Recording

Type Watching Brief

Permalink http://canmore.org.uk/event/558875

NS 3996 7453 A small excavation and assessment took place over four days at Dumbarton Castle during November 2006. The French Prison had been deteriorating badly and this was particularly evident in the badly cracked W wall of the E ground floor room and E wall of the small room at the base of the stairs.

To investigate these problems two trenches were opened - one to investigate the wall foundations in the E room, and the other to examine the base of the stairs. The excavations revealed an earlier floor level, probably dating to the first half of the 20th century, and also deposits associated with levelling for, and the construction of, the French Prison (1795). The N part of the trench in the E room was excavated as far as bedrock and it was

discovered that only the N wall as built directly onto bedrock, with the other walls built onto imported levelling material. This appeared to be the cause of the slumping and subsequent cracking of the walls.

These trenches showed evidence of the installation of a timber floor and confirmed the sloping or terraced nature of the bedrock, dropping steeply from N to S. Levelling material up to 1.5m deep was imported towards the S of the trench to form a platform for the late 18th-century building campaign.

A further visit comprising excavation and assessment took place outside the French Prison during February and March 2007. Trenches were excavated along the length of the S wall and W wall. The former was dug to a depth of 0.8m and revealed evidence of medieval industrial activity. The other trench was dug to a depth of 0.7m and revealed traces of a toilet block apparently demolished before 1928, on the basis of photographic evidence.

A Radley 2007

Funder: Historic Scotland

Kirkdale Archaeology