Watching Brief

Date 23 March 2011

Event ID 991782

Category Recording

Type Watching Brief

Permalink http://canmore.org.uk/event/991782

Under the terms of its PIC call-off contract with Historic Scotland, Kirkdale Archaeology was asked to monitor the initial stage of the insertion of a series of fin drains within the Antonine Ditch at Rough Castle. This followed a test trenching exercise in February 2011 which raised the possibility that artefacts could be recovered during the current drain trenching exercise. The purpose of the monitoring was to establish whether it was feasible or practical to carry out a full archaeological watching brief based on the conditions and methodology being employed during the cutting of the drains. The existing drainage system consisted of a central drain comprising a pipe covered in pebbles and wrapped in a Gore-Tex terram. The terram was effectively preventing water from entering the drain and this was causing water to stand in the ditch. To solve the problem a series of fin drains was cut diagonally from the base of the S ditch slope, deepening towards the central drain. When the fin drain met the central drain, the Gore-Tex terram was cut back to expose the pebble fill within. The fin drain was then filled with washed pebbles (without finings to prevent clogging) so that water could now percolate down the fin drain, into the central channel and away.

The trenches were manually de-turfed and excavated by a mini-digger. Of the eleven trenches marked out on the W side of the ditch, the first four were monitored until it became apparent that a watching brief during this stage would yield no more information than had been noted during the test trenching in February. The nature of the machine scrape meant that relatively large volumes of spoil were removed quickly, making the chances of recovering any artefacts extremely unlikely. This, coupled with the fact that the ground had been disturbed during drainage installation work in the 1960s, as well as during more recent drainage works, suggested that an archaeological watching brief was not required. The initial trenches were cut and monitored on 23rd March 2011.

Kirkdale Archaeology 23 March 2011; OASIS-ID kirkdale1-171809