Publication Account
Date 2007
Event ID 586645
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/586645
NC02 1 CLACHTOLL ('An Dun 5') NC/0366 2784
This broch, possibly ground-galleried,in Assynt, Sutherland, stands on a low rocky knoll just above the flat rocks fringing the shore at the south end of the Bay of Stoer. It is in a fairly good state of preservation except towards the sea where a segment of the wall has vanished, presumably having been washed down the sloping rock of the foreshore (visited 10/9/84, 28/6/88,in August 2001 and July 2005).
Description
It is clear from the plan that this was a complete broch and not a D-shaped structure. The wall was somewhat thicker along the seaward side where the large segment has disappeared, a fact which is doubtless to be explained by the relatively smooth, sloping rock surface here. The base of the outer face must have descended as it crossed this rock and would have to have been built further out.
The interior of the broch is full of debris, the inner wallface standing up to 90cm (3ft) above the rubble and 90cm -1.2m above the top of the outer wallface, itself standing in places 1.8-2.1m (6-7ft) high. Some indication of how well this broch is preserved is gained from the height of the scarcement which is exposed at the two broken ends of the inner wallface – at 1 o’clock and 4 o’clock; elsewhere the ledge is hidden under rubble. The ledge at the latter position is at exactly the same height as the lintels covering the central part of the entrance (it is slightly lower at 1 o’clock). The schematic cross section shows how most of the wall is below this ledge but how parts of it are higher; this Level I of Clachtoll is well preserved and Level II above it is preserved up to 60-90cmin places. The highest part of the wall could be about 3.5m (11.4ft) above the rock. The internal diameter is about 9.6m (32ft) [2] and the central court has a radius (above the scarcement) of 4.78 +/- 0.08 m. Allowing for the width of the ledge the internal diameter at ground level should be about 10.2m (33.4ft).
The main entrance is on the north-east (not on the east [2]) and is blocked at its inner end; there is a massive triangular lintel over the outer end of the entrance which measures 1.35m (4.5ft) long, 1.17m (3ft 10in) high and 30cm (1ft) thick. The passage has evidently been further emptied of debris since 1909 and the chamber over the entrance is now clearly visible; its walls seem continuous so no upper gallery connected with it. The passage below can be seen through a gap in the lintels forming the floor of this chamber.
The door-frame is 1.50m (5ft) from the exterior and is formed of two recessed checks faced with upright slabs. Immediately inside these are a deep bar-hole on the right and a shallower bar socket opposite on the left; the drawbar was probably about 1.2m above the original floor of the passage. This passage, 1.0m wide at the outer end, widens to 1.20m (3ft 11in) after the checks, expanding further inwards to 1.26m (4ft 2in) at the opposed doors to the intra-mural spaces.
The right door leads to a guard cell which follows the curve of the wall for 3.95m (13ft) and has a partly corbelled roof; this is capped with lintels which rise up like steps from either end to the highest point in the middle, to a height of 1.83m (6ft) above the debris. The highest lintel has been removed to allow access into the cell, the doorway to the passage being at present impassable without crawling. The existence of the lintels riding over the domed roof of the cell implies that an upper gallery once ran over it. This guard cell has a very unusual feature in the form of a low doorway at its innermost end communicating with the central court; it must emerge well below the present level of the rubble there.
The left doorway leads from the entrance into a space which is hard to identify; a flash photograph taken with the camera held in the entrance suggests that it is part of a long gallery. In 1909 it was described as “small and low, and a hole in the back of it suggests a connection with something beyond” [2]. This “something beyond” appears, as noted, to be a ground level gallery. Further clockwise along the wallhead from this opening are several long stones aligned radially to the broch and tipped downwards and outwards; they should be the dislodged lintels of an upper, not a ground level, gallery since they are well above the exposed chamber over the main entrance.
At 8 o’clock is the top of a huge intra-mural domed cell capped with lintels; its curved end can be seen just clockwise from this point and in the opposite direction it doubtless narrows to the lower ground level gallery which connects with the left doorway in the entrance.
In 1909 the top of a stairway was said to be visible opposite the entrance, at 12 o’clock [2]. Further clearance has evidently taken place since then which shows that what the Commission saw was probably not a stairway but the remains of the lintelled roof of the passage leading to the stair, at 11.30 o’clock. A short length of the neatly built inner wallface of the gallery containing the stair stands above the rubble from about 12-1 o'clock, and immediately anti-clockwise of this are the lintels referred to. The stair must be still hidden below rubble and many steps of it are likely to be preserved.
The clearance has also revealed, just anti-clockwise from the gallery lintels referred to and at about 11 o'clock, the massive lintel of the doorway from the stair to the central court and, to the left (anti-clockwise), the almost blocked opening into what must be either the stair-foot guard cell or another length of ground level gallery and which still has its lintelled roof. An inspection of this last might reveal whether Clachtoll is a ground-galleried or a solid-based broch but it is inaccessible at present.
The stair door (its inner end is invisible under the rubble in the central court) appears to be about 1.2m (3.9ft) wide and the even longer sandstone lintel bridging its visible end has – not surprisingly – cracked in the middle. A cubical block of stone is now jammed between this slab at the crack and the earth and rubble debris some 20cm lower down. This may somehow have been inserted recently but it is possible that it may be the top of a pillar put in to hold up the fractured lintel while the broch was occupied in the Iron Age.
An outer defence is visible at the base of the knoll from the south-south-east round to east and consists of a single heavy stone wallface – built of massive blocks and boulders. Presumably it was intended to make the base of the rock knoll impassable. It only partly surrounds the broch on the landward side and is as little as 3m from it on the south; this distance increases to 7m on the east. Since the broch itself was built practically on the rocky foreshore it seems unlikely that this outer wall ever completely surrounded it, unless the sea was significantly further out two thousand years ago.
As it runs towards the north, and towards the line of the broch entrance, this wallface, as noted, lies further away from the broch and becomes a turf-covered stony bank about 2.4m (8ft) thick and walled on its inner face; no doubt this changed appearance is the result of dilapidation. An outer gate-way isin this 'bank', more or lessin line with the broch doorway, and is 1.8m (6ft) wide with some stone uprights flanking it. Two huge blocks form the outer end of each side. Another stone wall 90m (100yds) from the broch was thought by the Commission to be part of the outer defences, but Feachem considered it more likely to be a farm wall of a much later date [3].
A secondary external extension has been added to the broch entrance passage but the exact details are obscure because of the covering rubble. The extension curves outwards to the left or east for about 6.0m (20ft) but only the east side is visible beyond about 3.0m (10ft) out, and the upper part of this looks like modern re-building. There is a gap in this east wall about 1.8m (6ft) out and the masonry curves back towards the broch wall, forming a wedge-shaped block; it may be the south side of a doorway leading to outbuildings. A single lintel still spans that part of the secondary passage closest to the broch, which may well be an added, secondary door-frame, though any checks are invisible. Similar structures can be seen at many other brochs.
Structural analysis
Level I: although part of the ground level storey has disappeared much of the surviving wall contains galleries and chambers. These include the right-hand guard cell and, left of the entrance, a length of gallery which may expand into the high domed cell at 9 o’clock. Further round at 11 o’clock is the door to the stair with a gallery or cell running anti-clockwise from it for an unknown distance; the stair runs upwards in the opposite direction, and it is conceivable that the ground level gallery continued beyond this right round to the guard cell (although nothing is visible among the rubble at the end of the wall).
Level II: a fine ledge scarcement of Hebridean type runs round the interior at an unknown height above the primary floor and marks the beginning of the first floor storey. The scarcement at 4.30 o’clock is at exactly the same level as the top of the lintels covering the entrance so the innermost of the latter (hidden under rubble) doubtless forms part of the ledge. The chamber over the entrance is clear but no upper gallery joins it; it was thus entered only from its inner end. The rows of dislodged lintels in the southern and south-western arcs could well have fallen from the roof of the wrecked first floor gallery and the inner wallface of this is clearly preserved between 11 and 12.30 o’clock.
The two cells in Level I appear to project upwards into the Level II gallery. The guard cell has a roof of stepped lintels and the tall chamber at 8.30 o’clock has the apex of its roof above scarcement level, which is doubtless also the level of the lintels roofing the ground gallery.
Finds
A steatite cup or lamp was found in a recess in the wall of the guard cell to the right of the entrance “many years ago” by the Rev. J. M. Joass of Golspie who still had it in 1909 [2]. It is now in the Dunrobin Castle Museum (for some reason the author did not draw this cup when he saw it in 1989).
in 2005 the author found a battered fragment of what appears to be the lower stone of a discoid rotary quern of sandstone among the rubble on the wallhead on the southern side. As with the shattered upper quern-stone found at Dun Osdale (NG24 3) this fragment seems most likely to have been thrown into the wall core when the broch was built. In this case it would have been used in pre-broch times. The quern is now in the Ranger’s hut nearby.
Dimensions: theinternal diameter (now known to have been taken above the scarcement) was originally measured as 9.6m (32ft) [2]; a new surveyin 1988 found the radius of this to be 4.78 +/- 0.08m, giving a diameter of 9.56 m. The scarcement is about 30cm wide so the diameter of the central court at ground level should be about 8.96m. Most of the external diameter is about 18.0m (60ft) if the walls are 4.2m (14ft) thick as reported [3]; the wall proportion is therefore approximately 48.5%.
Sources: 1. NMRS site no. NC 02 NW 2: 2. RCAHMS 1911a, 2-3, no. 7: 3. Feachem 1976, 174: 4. Young 1962, 185 and Illus. V, no. 3: 5. Close-Brooks 1986, 150 (Illus.).
E W MacKie 2007
