Recording Inchnacardoch Bridge

Laser scanning underway beneath Inchnacardoch BridgeInchnacardoch Bridge is situated on the military road running west from Fort Augustus, through Inchnacardoch Forest into Glen Moriston. It is one of a number of bridges along a military road constructed between 1748 and 1753 under the direction of Major William Caulfield to link the garrison at Fort Augustus to the Bernera barracks at Glenelg, around 70km to the west. The road follows a former drove route from Skye which was metalled to make it suitable for troops, carts and artillery. The road fell into disrepair after 1784, when maintenance ceased with the end of the Jacobite threat. Some sections of the road where upgraded by Thomas Telford during the Parliamentary Road building programme in 1808-1811 and these form part of the modern road network.

Much of the construction of the military road network was undertaken by troops stationed at the various garrisons spread across the Highlands. These troops undertook the straightforward elements of the construction programme, mainly the building of the roads themselves. The more complicated constructions such as the bridges and were contracted out to experienced civil engineers and builders. Much of the road network was constructed to a standard design with a foundation trench being filled with increasingly fine grades of stone from broken boulders at the base to fine gravels forming a top surface to the road. The road was typically flanked by drains on the uphill and downhill sides with open cross drains in the early days of the construction programme; these were later replaced with buried culverts.

In 2017, Inchnacardoch Bridge was cleared of heather and scrub and laser scanned by AOC’s survey team on behalf of Forestry Commission Scotland (FCS). This archaeological recording will both enhance the Highland Historic Environment Record and inform ongoing condition monitoring. The bridge still carries a popular footpath and is monitored by FCS’s civil engineers.

Above, right: survey underway beneath the bridge © FCS 2018
Below: orthoimage of the bridge from the north, coloured by intensity © FCS by AOC Archaeology Group

Ortho image of the bridge viewed from the north, coloured by intensity