Archaeology Notes

Event ID 743506

Category Descriptive Accounts

Type Archaeology Notes

Permalink http://canmore.org.uk/event/743506

NH23SW 1.00 22255 31286

Dam [NAT] (at NH 2221 3129)

OS 1:10,000 map, 1971.

NH23SW 1.01 NH 22990 32112 Cozac Quarry

Location formerly cited as NH c. 219 316 to NH c. 223 310

For associated reservoir (Loch Mullardoch), see NH13SW 6.

For monument (cairn, at NH 21638 31548), presumably associated with the construction of this dam and reservoir, see NH23SW 6.

For associated supply tunnel (to Loch Beinn A' Mheadhoin: NH c. 223 314 to NH c. 248 265), see NH23SW 7.00.

For associated Mullardoch Generating Station (NH 22259 30960), see NH23SW 7.01.

The North of Scotland Hydro-electric Board's plan for Constructional Scheme No. 7 (Mullardoch-Fasnakyle-Affric) was published in Fenruary 1946; there were no objections on fishery or amenity grounds. Labour camps were established at Cannich and Cozac (near Mullardoch).

The Mullardoch Dam (at the E end of Loch Mullardoch) was destined to be the Board's largest dam, measuring 2385ft [727.1m] long by 160ft [48.8m] high above itseepest foundations. Its construction required 286,000 cu ft of concrete to impound no less than 7.5 million cu ft of water. An even larger volume of materials would have been required, had it not been possible to build the dam in the form of two wings inclining towards each other and abutting onto an island.

The dam is of mass gravity type, and in late 1949, when the N wing was already well advanced, it was necessary to economise. The option of completing the S wing to a buttress gravity design was rejected on account of the inevitable delays in revising the shuttering and plant layout, with resulting increases in labour and logistic counts. In the event, it was decided in March 1950 to reduce the height of the S wing by 20ft [6.1m]. This was countermanded in February 1951, but the wing was completed to a revised design based on that used for the Mundaring Weir (Australia), which did not require the insertion of steel bonds. The dam was completed in summer 1952, some time after partialimpounding had begun.

P L Payne 1988.

Affric-Cannich scheme, 1952. Mass gravity dam on Loch Mullardoch and tunnel to Loch Benevean. Tunnel from Loch Benevean to to Fasnakyle Power Station (John Cochrane and Sons Ltd). Average annual output: Mullardoch 8 million units, Fasnakyle 223 million units.

J Miller 2002.

This dam spans the upper reaches of the River Cannich, at the E end of Loch Mullardoch (NH13SW 6).

The location assigned to this record defines the approximate midpoint of the structure. The available map evidence indicates that it extends from NH c. 21945 31589 to NH 22239 31362 (bend) to NH c. 22312 31017. The compensation water outflow is at NH 22200 31426.

Information from RCAHMS (RJCM), 12 May 2006.