The Carpow Log Boat

by Grace Woolmer-White and David Strachan

The Carpow logboat following its excavation and recovery in 2006 © Perth and Kinross Heritage Trust

In 2001, a remarkable discovery was made on mudflats near Abernethy, on the Tay Estuary: a prehistoric logboat, dating to around 1000 BC, the second oldest known from Scotland, and one of the best preserved in Britain (MPK12214). Eroding from Carpow bank, it was at risk of further erosion, and eventual loss, and the decision was made to remove it. Excavation and recovery of the logboat proved extremely challenging, as located within the inter-tidal zone of the estuary, it was only accessible for only a few hours over 4-5 days during spring tides between June and August. Once successfully moved to the National Museums of Scotland, it underwent detailed study, revealing fixtures and fittings, damage, wear, and tool-marks. Conservation has ensured that it will be remain preserved for generations to come.

Timeline

The story of the logboat’s discovery, excavation, recovery, and conservation extended over a ten-year period:

August 2001- A partially exposed timber on Carpow bank was recognised as a logboat by metal detectorist Scott McGuckin and reported. A team from Perth and Kinross Heritage Trust, Historic Scotland, National Museums Scotland and Perth Museum and Art Gallery confirmed this and planned further evaluation.

The Carpow logboat when it was discovered in 2001 © Perth and Kinross Heritage Trust

November 2001- A radiocarbon date of 1260-910 BC, confirmed a Late Bronze Age date, making it one of the earliest boats discovered in Scotland.

October 2002- Evaluation excavation of the logboat assessed the exposed bow section of the boat; much of this had been lost through erosion but this had not occurred as badly to the buried section.

July 2003- A second excavation revealed the full length of the boat (surviving to 9 m) and revealing the buried stern, which was in an excellent state of preservation.

2004 to 2005- The logboat was reburied and covered in sandbags to protect it from erosion. Its condition was monitored but by 2004 it was clear that its long-term preserved in situ was at threat. Plans for excavation, recovery, conservation, and display were made to ensure its long-term protection.

Dive term insert the vessel into the lifting frame © Perth and Kinross Heritage Trust

July to August 2006- Part funded by HS, PKHT fully excavated the logboat over two tidal windows totalling seven days. The interior, exterior and surroundings were excavated; the boat was then rigged with part filled barrels and floated to nearby reed beds. Fully revealed for the first time, it was de-rigged and photographed, before being re-rigged and towed 3km to Newburgh quay. It was guided into a steel box frame which was lifted by crane onto a flatbed lorry and transported to the National Museum of Scotland for conservation.

2006 to 2012- Detailed study and conservation work of the logboat was undertaken by the National Museum of Scotland.

2012- The log boat was displayed in Perth Museum and Art Gallery.

The Carpow logboat on display with Perth Museum and Art Gallery © Perth and Kinross Heritage Trust

Conservation and Study

Prior to conservation, the logboat was recorded in detail. This included ahigh-resolution digital photography and early 3D scanning. As it is unknown how much of the bow had been lost, though extrapolation of its tapering sides suggest that it would be no longer than 11m. The oak tree trunk it was formed from is probably have suffered from ‘brittle heart’ rot, which starts at the base of the tree. As a result, a separate transom was fitted at the stern, and this had been preserved in situ. A thick D-shaped plank of oak (on which tool marks were preserved on one side) was shaped to fit into a groove cut into the stern end of the vessel. The join had been sealed, or caulked, with mosses and carpentry waste.

Just forward of the transom were two protruding footrests for the helmsman of the boat. Three holes, known as sheerline holes, were also visible on the sides of the boat, two on one side and one on the other. These are likely to have formed two pair of holes, opposite one another on each side of the boat, with the missing hole eroded away. If the pattern was maintained, up to eight holes may have been present. It is not known precisely what function these would have had, but they may have related to fittings for the construction of the boat, or been for operational purposes, such as securing a spray deck. Several features indicating repair works to the boat were also discovered.

Diagram of the main elements of the Carpow logboat © Perth and Kinross Heritage Trust

The boat had only survived due to its waterlogged location, in which a lack of oxygen prevented it from decaying. During the recording work, the log boat was kept wet to ensure this continued, but this would not have possible for long term display and storage. Therefore, it was submerged in three pieces in a specially made tank containing a waxy polymer called polyethylene glycol (PEG) which would replace the water in the wood. Afterwards, it was freeze-dried, with the water turning into ice and removed as a vapour within a vacuum.

Use and Deposition

Logboats were not sea-going and were more suited to shallow and sheltered waters, such as rivers and the edges of the estuary. The Carpow vessel could have carried up to 14 people, or with a crew of two, around one tonne of cargo. It could have been used as a barge or ferry for transporting people or cargo, or as a working boat for fishing or wild fowling. It would have been paddled or punted around the Tay Estuary and inland along the rivers Tay and Earn, and would have made use of the tides in doing so. Repairs indicate that it was used for some time and demonstrated the value of the boat to those using it; the tool marks on the transom suggest that this itself may have been a replacement, but as the tool marks had not been weathered and worn by use, was perhaps not in use for very long before the boat went out of use.

An artist’s reconstruction of the logboat in use transporting people across the Tay © Perth and Kinross Heritage Trust

The findspot of the Carpow logboat, where the rivers Tay and Earn meet to open into the estuary, may be significant. It is not possible to say for sure whether this was the boat’s original resting place, however, and so we don’t know if it was accidentally or deliberately sunk. Its condition might suggest the latter, and there are examples of ritually deposited logboats. This, and the many Bronze Age metal-work finds, also probable votive offerings, indicate the areas was a focus for ritual activity, perhaps supporting a deliberate and ritualistic sinking of the vessel.

The Replica Log boat

To bring the Carpow logboat to life and discover more about how it was made, an experimental archaeology project was undertaken by Perth and Kinross Heritage Trust, in partnership with the Scottish Crannog Centre. In August 2009, a logboat, inspired by the Carpow vessel, was made using a Douglas fir (as oak trees of the size and shape required are no longer available in Britain). Replica late Bronze Age tools were used, including axes, adzes, chisels and gouges, along with modern tools for comparison.  Once completed the ‘Dalerb’ logboat paddled across Loch Tay to the Scottish Crannog Centre where it is still in use.

The replica logboat launched into the Tay © Perth and Kinross Heritage Trust

More can be read about the Carpow logboat and the replica in the short publication booklet and the full monograph. Videos of the recovery, conservation and replica project are also available on PKHT’s website and YouTube channel.

Bibliography

Strachan, D 2010a Carpow in context: A Late Bronze Age Logboat from the Tay. Edinburgh: Society of Antiquaries Scotland.

Strachan, D 2010b The Carpow Logboat: A Bronze Age vessel brought to life. Perth: Perth and Kinross Heritage Trust.

Online Resources:

PKHT Carpow Logboat project

PKHT Loch Tay Logboat project