The house in the loch: a Time Team Special

Diving into the Iron Age
In the summer of 2003, a small crew from Time Team spent eight weeks in the beautiful setting of Loch Tay, Perthshire, in Scotland. They were filming the ongoing underwater excavation of Oakbank crannog, an Iron-Age lake dwelling, which was first surveyed in 1979 and is the subject of a full-scale crannog reconstruction at the Scottish Crannog Centre on Loch Tay.

The husband-and-wife team of Dr Nick Dixon and Barrie Andrian had invited Time Team to follow their summer's excavations, and to recap on two decades of work on a site that is causing archaeologists to re-write what we know about life in the Iron Age. Tony Robinson made a flying visit to the site and fronts the film, but for the main part Nick, Barrie and the students who were participating in a summer field school there take centre stage.

Perfect preservation
Oakbank crannog is completely submerged in the clear waters of Loch Tay. Underwater, the peaty loch bed provides almost perfect preservation conditions, and thus supplies more finds and information than equivalent land archaeology. Previous discoveries at the sites had included a wooden butter dish with butter still in it, bronze pins, floor timbers, small insects, a swan-neck pin, beads, a canoe paddle, woven cloth and cooking utensils. Altogether, the excavations on the site have found the remains of some 200 different plant species, including opium seeds and spelt wheat which previously the Romans were believed to have introduced to Britain.

Time Team was particularly excited to be there in the summer of 2003 because not only was this the first time a field school had been organised on the site, but it was also the first time the excavations had delved below the loch bed. Previously, the excavators had just looked at what was lying on top.

Excavating underwater
Excavating underwater is a slow, laborious and often frustrating process. The heavy equipment has to be set up and cleared away each day; the water is extremely cold (less than 5°C); and weather conditions can often lead to silt being washed back over cleared areas. The diggers work in teams of two or three underwater, with a surface air supply. They generally stay underwater for up to three hours before having a break. At all times, there are people doing 'platform duty' which is tedious but an absolute necessity. These are the people who ensure that the divers have a clean supply of air, and stop lines getting tangled.

Underwater, the archaeologists lie on specially constructed metal grids. As well as providing balance, these map out the trenches on the site. The excavators work along their trench, clearing away silt and putting waste material up the suction dredge.

Twigs, leaves and sheep droppings
The disposal of material in this way is one of the hardest things for experienced archaeologists to get used to. The preservation conditions are so good on the loch bed that material that would be regarded as an exceptional find on a land site has to be treated as waste here. Underwater there is simply so much material that it is not possible to raise and preserve it all so miscellaneous Iron-Age twigs, leaves, sheep droppings and other discoveries all go up the spout.

Even so, the dredge pile was thoroughly checked at the end of each day and anything interesting was bagged and brought to the surface, where it could be processed at the on-land storage facility. It made for very long days when dive logs had to be completed, finds analysed and recorded, and dive suits dried ready for an early start again the following morning.

Bringing the Iron Age to life
Excavation has been going on at the Oakbank site since 1980 largely due to the passion and dedication of Nick Dixon, who runs the Scottish Trust for Underwater Archaeology at Edinburgh University. His wife, Barrie Andrian, shares his enthusiasm for the site, and over the years it has turned into something of a life's work for the pair of them.

A few years ago, they used their discoveries and understanding from Oakbank to reconstruct a complete crannog at what is now the Scottish Crannog Centre about four miles away. Based entirely on the archaeological deposits found at Oakbank, the reconstruction not only provides the perfect context to the archaeology, but really brings Iron-Age society to life.

As well as featuring the excavation itself, the Time Team Special at Loch Tay also focused on the experimental archaeology carried out at the crannog centre. Finds made on the loch bed were brought to life through the work of the centre, with Iron-Age fencing and flooring techniques, cooking, fire-lighting and tool-making all featuring. For Nick and Barrie the crannog centre is an integral part of their work and all the visitor fees and other income is ploughed back into research and work at Oakbank.

In the course of the eight weeks, Time Team and the excavation crew experienced teething problems, tension and triumph. By the end of the summer, those present had made significant headway – and some dramatic new discoveries – during their dive into the Iron Age.

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