Spittal - year 2
The second season at spittal quarry concentrated on putting the experimental data derived from 2004's work on the cairn elements into practice. The first step involved clearing away the remains of the previous seasons work and the erection of a second set of orthostats. This done a level platform was constructed from which to spring the corbelled chamber walls.

John Barber's work at 'Point of Cott' stalled cairn suggested that the lowest coarse of the corbelling in each bay of the chamber had been arranged to form a shallow horizontal arch with the front edge of each stone tilted up on small stone. The weight of the superstructure would force the small stones into the underlieing ground surface causing the arch-length to increase as it tended to flatten. This resulted in the corbel tending to wedge between the orthostats thus locking the whole structure together.

In the spittal reconstruction, the combined effect of the small tilting stones and the 'give' of the natural ground surface was simulated by the insertion of a strip of 50 mm square-section expanded polystyrene (see centre image below).

On completion the cairn was fully surveyed; this allowed any subsequent settling of the structure during the winter of 2005/2006 to be detected and evaluated.

The second project undertaken at Spittal during the 2005 season was the construction of two, half scale, adjacent segments of two different brochs. The segment built against the quarry face was an accurate reconstruction of The Broch of Gurness, Orkney. Keyed into this was a section of outer wall of Mousa Broch, Shetland which was known to vary in thickness.

The Gurness segment was destined to be demolished by destabilising the inner wall and analysing the mode of collapse of both the inner and outer walls; the outer wall being supported by the inner wall at higher levels.

The intention for the Mousa segment was to evaluate the deteriorating stability of the single wall as it increased in height. Neither segments was completed during the 2005 season; construction was to resume in 2006.

Broch project - Nybster year 2
A limited excavation was undertaken to address questions relating to particular structural features and to seek evidence date various elements of this complex monument. The floor deposits within the broch/roundhouse proved to be very thin; most of the material having been removed by Sir Francis Tress Barry the nineteenth century antiquarian.

Excavations also demonstrated that both sets of steps built into the forework/blockhouse were prehistoric rather than Tress Barry constructions. The monument appears to have been modified extensively in antiquity.

Battle Moss - year 3
The excavation of the small Bronze Age cairn, discovered in 2003, and close to the Battle Moss stone rows continued for a further season. The cairn, being excavated by Dr Kenneth Brophy of Glasgow University and Dr Amelia Pannett of Cardiff University will require a further season's work to complete, however the evidence to date suggests an initial phase of activity either quarrying or the formation of a scoop or pit. Some time later this feature was covered by a layer of soil containing charcoal, ash, cremated bone, pottery and flint fragments.

A central area was constructed which appears to have been surrounded by an earthen mound. It is not yet clear if the central area was filled-in or not at this time. At about this time the partial kerb was constructed in the north east quadrant; it probably never totally enclosed the central area.

The area between the outer kerb and the central area was filled with stones.

The final act was to cover the entire structure with a further thin layer of stone such that the central area and the outer kerb would have been completely hidden.

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