Archaeology Notes
Event ID 841016
Category Descriptive Accounts
Type Archaeology Notes
Permalink http://canmore.org.uk/event/841016
NS47SW 5.00 centred 39988 74485
(NS 4000 7446) Dumbarton Castle (NAT)
OS 6" map (1922)
NS47SW 5.01 NS c. 3998 7441 Chapel
NS47SW 5.02 NS 40010 74407 Governor's House
Dumbarton Castle. For historical and architectural description see Guide.
I MacIvor 1958
Apart from the fragmentary remains of the White and Wallace Towers, and the Portcullis Arch, all as described by MacIvor, the buildings and walls which now form the Castle, date from the 18th and 19th centuries.
Visited by OS (JLD) 29 November 1960
The principal objective of the work was to seek archaeological evidence which might be correlated with the well-known documentary evidence for Dumbarton (which some identify with Alcluith) as an important British stronghold in the Early Historic period. In particular, traces of possible early defences had been detected on the Beak, the larger of the two hills which comprise Castle Rock; and these traces were tested by excavation.
Four trenches were excavated on the Beak and the findings in each are summarized here.
Trench A examined a sharp slope on the W side of the hill, above an apparently rock-hewn passage-way. The discovery of a turf-stack containing a sherd of Antonine Samian gave high promise of an early defence; but the rubble foundation of the turf bank overlay green-glazed pottery. It seems likely that the structure was the flag-pole mound seen in Slezer's drawing of about 1693.
Trench B examined the flat top of the hill. The level ground was found to be a make-up of ash and cinders. This may perhaps be dated to the mid 16th century by two pieces of Charles I, but was deeply disturbed by rubbish pits of the 1939-45 war.
Trench C examined a bank on the E side of the hill, and showed that it was later than a layer of mason's chips from the mid 18th century magazine.
Trench D was sited on a quarried ledge on the Clyde-ward side of the hill. Modern debris was less abundant here, and there were tenuous traces of drystone and timber buildings. These could not be fully explored in the time available, and Trench D demands further exploration. Finds included two silver pennies of Edward I - Edward II, and a strap-handle from an 'E-ware' pitcher of Dunadd type.
it is clear that there are no visible traces of defences earlier than those of the medieval castle. (this does not exclude the possible existence of buried traces). Moreover, the demonstration that all the areas of level ground on the E hill are recent creations implies that this hill was originally rugged and craggy as the W one.
L C Alcock 1974
A second season of excavation explored rock-cut terraces on each of the twin summits. The W terraces yielded principally recent pottery and appeared to have been garden plots using earlier stone quarries. The E terrace had carried some form of timber buildings, but contained material swept off thesummit. This ranged back from building debris of 1939-45, and included fragments of mail; iron tools and arrowheads; a dispersed hoard of Edward I and II; a few sherds of Saintonge ware and much green-glazed; fragments of probable Merovingian glass; post-Roman import wares of class Bi, Bii and E; and a very little Roman pottery.
Outside the medieval and later curtain, on the E spur of the Rock, traces were found of a timber-and rubble rampart which had been burnt and partly vitrified. It is doubtful whether this had formed a continuous enceinte; and the purpose of the defence-work as explored had probably been to control access to the Rock across a tidal isthmus. This work may have been destroyed in AD 780 (when Annals of Ulster record the burning of Dumbarton) or after a Hiberno-Norse siege in AD 871-2. Finds apparently from the destruction of the rampart included a Norse lead weight decorated with a glass bangle fragment of Lagore type, and an iron sword pommel with Irish parallels. The rampart itself probably formed part of bede's civitas Brettonim munitissima (HEi, 1).
L C Alcock 1975
Excavations were carried out in 1974-5 at Dumbarton Castle, anciently known as Alt Clut or Clyde Rock. They revealed a timber and rubble defence of Early Historic date overlooking the isthmus which links the rock to the mainland. Finds include the northernmost examples of imported Mediterranean amphorae of the 6th century AD, and fragments from at least six glass vessels of germanic manufacture.
L Alcock and E A Alcock 1991.
NS 400 745 A watching brief was maintained during the excavation by Historic Scotland staff of a power cable trench in an area immediately E of the Governor's House, latterly a garden. Masonry dating from the earlier Gatehouse (demolished in advance of the 18th century artillery fortification) was revealed running E-W close to the E wall of the Governor's House (NS47SW 5.02).
Sponsor: Historic Scotland.
G Ewart 1995.
NS 4000 7446 A watching brief was undertaken in October 2000 during minor excavations at the powder magazine at Dumbarton Castle (NMRS NS47SW 5). No significant discoveries were made.
A further watching brief was undertaken in March 2001 while contractors excavated a series of trial pits in and around the French prison. The purpose of the trial pits was to investigate the subsidence presently afflicting the W wall of the building. The pits were dug at various strategic points in order to determine the nature of the underlying deposits, as well as checking the strength of the foundations.
In total, the evidence from the pits regarding the stability of the French prison masonry revealed that the long E wall of the building is built directly on bedrock while the W frontage sits on and within a soft fairly wet sludgy silt. The result of this positioning is an inevitable settlement of the W side of the structure.
Trial trenching was undertaken in May 2001 in an attempt to recover the line of an 18th-century sentry path believed to have existed along the inside face of the N curtain wall, where it runs between the Wallace Tower and the Argyll Battery. Remains of unmortared paving were found only at the W end of the wall; elsewhere the stones seem to have been removed. Various 17th to 20th-century midden deposits were found accumulated against the inner face of the curtain wall, while the wall itself was seen to sit on top of a lower wall, potentially an earlier perimeter.
Sponsor: Historic Scotland
G Ewart and A Dunn 2001
NS 400 744 A small cable trench was excavated in February 2002 adjacent to the W wall of the steps leading from the Governor's House to the Guardhouse. A small stump of an earlier wall was found protruding from under the present wall on the garden terrace below the Guardhouse. This was possibly the remains of an earlier approach to the entrance to the upper castle, leading from the probable site of the medieval Hall, to the W of the Governor's House, thus adding weight to the theory of this being the original location of the Hall.
Archive to be deposited in the NMRS.
Sponsor: HS
G Ewart and J Franklin 2002
NS 400 744 Three small pits were excavated in February 2003 to erect a gate in the gap between the Governor's House and the parapet wall of the King George Battery. Levelling layers were found, including building debris from various periods of construction, possibly relating to the laying of the path or the building of the King George Battery.
Archive to be deposited in the NMRS.
Sponsor: HS
G Ewart, D Stewart 2003
NS 400 744 Archaeological monitoring was undertaken in March 2004 during the excavation of foundation pads for a
handrail by the flight of stairs near the Governor's House, with a light gravel path covering the areas at the top and bottom of the steps. There were no finds of archaeological significance.
The need to erect scaffolding over the Inner Gateway and drawbridge required monitoring of clearance of turf and topsoil over bedrock on the E side of the gate. Nothing of archaeological interest was revealed.
Archive to be deposited in the NMRS.
Sponsor: HS.
A Radley 2004
Watching brief NS 4005 7440 A watching brief was undertaken in October 2004 during the clearing and removal of vegetation and soil in an area near the portcullis on the E side of the main stairway through the castle complex (NS47SW 5.00). This area consisted of a purpose-built platform just S of the E side of the portcullis. The platform measured c 5 x 2m, with a roughly metalled or cobbled surface, and no clear structural function beyond the reinforcement of the
rock face.
The shallow excavations required for the creation of new bicycle racks on the bowling green immediately within the castle compound was monitored. Nothing of archaeological interest was revealed.
NS 3999 7448 A number of artefacts were found by a visitor, and the area where they were reported to have been discovered was examined: on the surface to the W of the staircase leading from the guardhouse to the portcullis arch. The finds include a copper-alloy coin, green-glazed pottery, a piece of black glass or black glazed pottery, clay pipe stems, a small quantity of animal bone, and a number of sherds of white glazed and patterned pottery. These finds
were unstratified and are of limited archaeological interest.
Archive to be deposited in NMRS.
Sponsor: HS.
C Shaw 2005
Evaluation; watching brief NS 4000 7440 A short programme of clearance and evaluation was undertaken in January 2005. The site consisted of the walled-off area below King George's Battery on the S side of Dumbarton Castle rock, an irregular-shaped courtyard containing two adjoined buildings. It was hoped that original occupation surfaces might be
revealed; in particular, the cobbled W half of the site was expected to exhibit the footprints of lost structures. Following this initial work, a watching brief was undertaken while contractors cut a number of drain and foundation trenches.
This area appears to have been a Victorian addition, set against the old sea wall of a Georgian gun battery. All structures and features seen during these works therefore date from the mid- and late 19th century to the late 20th century. The basic structure is mostly intact, comprising the new sea wall, the two store sheds and the general levelling deposits. An original gateway positioned halfway down the compound had been demolished, probably to improve access to the end of the site. The cobbling at the W end of the site seemed to respect the line of the gateway and consequently was probably in place while the gateway was in use.
NS 3996 7453 A small excavation was undertaken in July 2005 around the French Prison, which lies just S of the Duke of York's Battery. The aim was to examine the foundations to assess the nature of the underlying material and assist in establishing suitable areas for engineering work.
Previous archaeological work had been carried out on the N and W sides of the building (DES 2001, 98) in the form of
small trial trenches with similar criteria. This was expanded upon, exploring additional sections of the building in order to ascertain the relationship between the building and the underlying bedrock. Stone-lined drains and other features were exposed and recorded, which appeared to pre-date the French Prison.
Archive to be deposited in NMRS.
Sponsor: HS.
D Stewart 2005.
