Crannog 20 Loch Awe [click on graphics for larger view in new window]

Location: Ederline Boathouse

Map reference: NM 883 039

Date of Survey: 22 September 1972

Loch level OD: 35.509 m

Highest point of crannog OD: 36.409 m

Usable area: 25 m x 18 m

Description (1972): Flat sandy bottom with bedrock ridge NE-SW which continued into crannog and protruded out of the top on the NE side. Grass and shrubs on the highest part, to SW end.

Several heaps of head-sized stones and a general scatter lay around and against the south side of the bedrock ridge underwater, as if stone facings had been started but not finished. Further heaps of stones lay to the ESE, S and to the N of the crannog, 6-10 m from the base of the slope.

The crannog itself was steep-sided, built of random-shaped stones which a man could comfortably lift.

Timber was visible in the bottom around the crannog:
• mortised plank 1.75 m x 0.15 m with two square mortise holes ca 0.10 m x 0.05 m, on sandy bottom facing the shore
• several beams visible in the bottom, protruding from underneath the crannog stones on the south side
• at least six timbers lying side by side embedded in sand on north side of crannog
• at least 50 pieces of timber visible in east side of the top of the crannog, out of water, among the surface stones. They ranged from large oak baulks to ends of beams and branches. The largest oak trunk had an approx 2 cm deep slot cut in it. The timbers at the SE side appeared to have a radial layout.

To NE side of crannog a hollowed-out area among the stones which suggested a slipway or 'harbour' for a boat, with a scatter of smaller stones on the bottom. At its inner end three stones were set on edge and another long stone lying outside them.

Three metres further toward centre of crannog a flat stone was set on edge among the surface stones.

Finds:
• underwater at the outer end of the 'harbour' lying halfway down the slope of the crannog was a broken saddle quern of hard blue stone.
• on top of the crannog at the inner end of the 'harbour' by the bedrock ridge, out of the water among surface stones, lay a broken rotary quern of reddish schist.

Dating: The two quernstones would suggest a later prehistoric date, probably pre-Roman Iron Age

Post-1972: Later sampling of two of the upper timbers gave C¹⁴ dates, which show this part of the crannog in use in the Iron Age:
• 370 bc ± 45 (UB 2415), taken from about 100 years of tree rings into the timber, so tree cut down ca 270 bc
• a provisional 'Iron Age' C¹⁴ date which agrees with the former date: see Taylor & Holley

CLICK TO ENLARGE

Difference in loch levels: normal (above) and in September 1972 (below)

Crannog 20 from the east

Much of top of crannog 20 was out of water due to the unusually low loch levels Summer 1972

Large oak log among other timbers; note slot far end. Scale 10 cm

Broken saddle quern (above). Below: edge of saddle quern, above broken rotary quern