Crannogs were Celtic vernacular buildings which formed the ordinary living house for a family unit and also, in some instances, livestock. Irish examples are more commonly referred to as "defended homesteads" From the point of view of PARABOW, the importance of crannogs is that, apart for a few stone examples in Wales, Portugal, the Hebrides, etc, the superstructure was entirely built of wood. The name "crannog" comes from the Irish "crann" meaning "tree". Archaeological excavations have shown that crannog buildings were constructed as early as the Neolithic period (4000-2000 B.C.) and continued into the 17^th century in remoter parts of Ireland and Scotland. It is even reported that English Hanoverian soldiers, in punitive action after the Jacobite Rising of 1745, destroyed some crannogs to subjugate the Highlanders and reduce their defensive and aggressive capabilities.

The size of the crannog was an indication of the status of the person living there, much as is the case in native African settlements today. As with African and North American Indian buildings, crannogs were round because, as people all over the world discovered independently, a circle is a physically strong structure for a building, with no part of the building bearing more load than another, i.e., it is the perfect shape for even distribution of load. The adoption of this shape meant that the builder could select small diameter timbers and dispense with the need for exhaustive cutting, shaping and jointing of wood. The timbers were supplied on a cyclical basis from "coppice" woodland and the need to select straight poles with minimal taper, suggests that the woodlands were actually managed to get that type of wood. The coppicing also gave the "withies" for weaving the wattle walls. We could say that the crannog builders were also capable foresters and "silviculturalists".

The more status the owner of the crannog had, the larger the building and also the more difficult it was to build. Beyond a critical diameter, the roof needed a central supporting pole and/or stronger walls; the larger the roof area, the greater its weight and load. The load is shared between the apex point where the poles join and the walls, which bare the downward thrust. Beyond a certain roof load, it is necessary to share the load with struts between the rafters. It seems unlikely that every Celtic village had its own mathematician and engineer, it is more likely that trial and error and a great deal of common sense went into the decision about when and on what size of building, to introduce structures to share roof load. The diagram below shows the principle.

Another crannog feature is that they were very often built on piles over water, with a bridge or walkway connecting them to the shore or were built on natural or man-made islands, in both cases harbours and jetties are a common feature as are middens for the disposal of domestic waste. We cannot really say why such sites were chosen, perhaps it was a status symbol or for defence or for ease of transport by boat on the lake, or for access to fish, shellfish and wildfowl or for some religious reason (the Celts believed that god figures dwelt in lakes), we just do not know for sure. There are some definite examples where the defensive attributes of lakes and marshes were considered important, Julius Caesar, speaking of the Morini, a Belgic (Celtic) tribe in Gaul, wrote…"They had no place to which they might retreat, on account of the drying up of their marshes (which they had availed themselves of as a place of refuge the preceding year), and almost all fell into the power of Labienus" (Com. iv c.38). In her book The Archaeology of Early Medieval Ireland, Nancy Edwards states that nearly all of the 1,200 catalogued crannog sites in Ireland, were constructed for defence, she suggests that the need for water-based crannogs was by the wealthier people with more to protect. Some Irish crannogs were royal sites, the example at Lagore was recorded in the annals as Loch Gabair and was the seat of the kings of Southern Brega. Attacks by other Irish tribes and Vikings are mentioned and many weapons plus over 200 human bones were found, some were headless skeletons and a violent death is suggested; slave"s leg irons were also found leading to the notion that crannogs may have been used as prisons. Palisades were a common feature of crannogs and also strengthen the argument that they were constructed for defence. At Lagore, the archaeologist, Hencken, identified three successive palisades representing different construction techniques; other Irish evidence suggests sunken and pointed posts as a defence for fouling attacking boats and Edwards likens these to the French chevaux de frise. We do know that crannogs were built away from the water as well but they have not survived to the same extent for us to examine.

The water-based crannogs are what provides the main archaeology; the anaerobic nature of wet soils or totally submerged sites, means that timbers are available to study. In Scotland particularly the lochs are so cold, dark (because of surrounding topography) and bacteria free, that organic materials such as wood, plant fibres, leather, etc., are generally well preserved. In Ireland, the PARABOW team looked at crannog "legs" submerged in loughans (i.e., at Turlough in Co. Mayo) and were able to measure distances between them, visualise the shapes of the buildings, etc. The state of preservation in Ireland is due in part to high acidity, which preserves (pickles) the wood, even though water temperature and light levels are generally higher than in Scotland. In Scotland the Scottish Crannog Centre on Loch Tay, lead the field (through Glasgow University Archaeology Dept.) in underwater archaeology and have used their findings to re-create an accurate 2,500 year old crannog using not only the right dimensions and design but also the right timber species. This is "Oakbank" crannog and a visit to see the construction and talk to those responsible is a must for anyone entertaining the idea of reconstructing a crannog. Visits over a two-year period, to the Scottish Crannog Centre were certainly the catalyst for attempting the PARABOW reconstruction in Ireland.

In Scottish loch based crannogs the evidence is of alder (Alnus glutinosa) legs, birch (Betula pendula) and ash (Fraxinus excelsior) roof timbers, incidental rowan (Sorbus aucuparia) timbers and willow (Salix caprea & cinerea), hazel (Corylus avellana) and bird cherry (Prunus padus) "withies" in the woven walls. The Irish crannogs had oak legs (Quercus petraea) but evidence of all the same species plus aspen (populus tremula) have been found. The legs (piles) of the Oakbank crannog were recreated from excavated examples, which had been pointed with a iron axe, blade width and the length and quality of the scours showed this. The PARABOW team were privileged to see at the Archaeological Superintendancy for Tuscany in Florence an Italian pile that was pointed with a bronze axe (an older Po Valley example) but no examples of Irish pile pointing was examined in the project period (time just did not allow).

The selection of timbers was of course, partly due to availability but also (we guess) an appreciation that alder is a good timber for wet situations and oak (especially the heartwood) is the most durable of native timbers.

The weaving of wattle walls for buildings was certainly a Celtic trait, which is not to say that Vikings, Slavs and Saxons did not do the same, perhaps they learned the process from the Celts they came into contact with. I personally find these concepts fascinating, I well remember first showing Finnish forestry students how to weave wattle and none of them had ever heard of the concept, whereas in France, Belgium, Netherlands, the United Kingdom and Ireland, it is well known and still commonly practised. During the PARABOW visit to the UNESCO heritage town of Levoca in Slovakia, we were intrigued by a clear picture of wattle work on a 14^th century church fresco (I dearly wanted to photograph it but the Priest would not allow it) and wondered if the Germanic people that settled their had learned the technique back in their home country or from locals who were descendants of the Celts moving westwards between the High Tatras mountains and the Danube.

In Loch Tay, the underwater archaeology has also revealed much about the above ground structure of crannogs, which Irish investigations have not (yet). The team behind the Scottish Crannog Centre have been able to examine semi-complete collapsed crannogs on the loch bed and determine something about roof and wall structure as well as main structural "leg" timbers.

Other archaeological evidence comes from Celtic lake villages in Switzerland, France, Italy and Slovenia and from the well-known site at Glastonbury in England. The most dramatic example is Venice which Quennell writing in 1921 described thus,… "the Queen of the Adriatic, is a glorified crannog which started as a place of refuge". The city of Amsterdam is built on timber piles and excavations have revealed that the earliest timbers were pre-Roman, did Holland"s capital city begin life as a Celtic crannog ? With regard to Glastonbury, Arthur Bulleid was investigating field mounds in fenland in 1884, which turned out to be crannogs left exposed as the water table dropped due to agricultural land drainage. Comprehensive excavations began in 1892 and revealed a village "occupying 10,530 square yards and containing 90 buildings varying in diameter from 18 to 28 feet". It is likely that not all the buildings were houses because, although many had a central hearth, others did not and the quantity of preserved cereal material in some (smaller) buildings, suggests they were for food storage. The residential buildings all had wattle walls daubed with clay, this is known for sure because dried clay with the marks of the wattle withies was discovered in the excavations. Interestingly, each building had a central pole or rooftree. It is known that the village was burnt, it would seem deliberately, because numerous fired clay pellets were found and Roman literature describes the use of such as a common Celtic war practice; as when Julius Caesar described how "the Nervii, when attacking Cicero"s camp, set fire to the thatch of the huts, by discharging red-hot clay sling bullets" (Com. v, c 43). The degree of "baking" of the daub with its wattle marks, also indicates great heat.

The book by Routledge "With a Prehistoric People" (1905) contained a sketch (reproduced below) in which a typical Glastonbury crannog type building was illustrated, complete with wattle walls and thatch.

It is very interesting that Routledge compared the building with a Kikuyu hut (left side) in Kenya; this was not an attempt to show any anthropomorphic link between races living over 5000 kilometres apart but rather to illustrate parallel evolution of technique. It is also possible to observe Kikuyu buildings today and the examinations of the techniques they adopt (as a primitive people) are a form of experimental archaeology. Observation of the Kikuyu today is valuable for any crannog reconstructor; they first erect 20 poles with a fork at the top of each one and in a 4 to 5 metre diameter circle and then withies are woven around the tops of the uprights to form a wall plate which carries the thrust of the roof; a centre pole is erected and poles are lashed into the woven withies and pass across the diameter of the circle being tied to the centre pole each time as well as joining the wall on the other side of the circle. The wall uprights with the forked tops are then used to carry the roof poles. Throughout the whole Kikuyu building process no timbers are greater than 6cm is diameter. At Glastonbury, evidence of timbers with forks left intact were found and at the Loch Tay underwater excavations, two such forked timbers were found but cannot be definitely described as wall uprights with top forks to carry roof poles.

In the standard carpenters work "Conservation of Timber Buildings" by F W & M Charles, the diagrammatic representation of a post built peasants house shows the use of forked "Y" shaped, upright wall posts. In another section of the "PARABOW Workers Manual", I will refer to the Dublin Hiberno-Norse buildings at some length, suffice to say here that "Y" shaped poles were also found in the Fishamble Street excavations.

As well as through observation of African tribal people today, interesting comparisons of parallel evolution can also be made with the summer lodges of Canadian Micmaq Indians and this is another example of parallel evolution of technique.

With regard to the fixing of timbers in crannog construction, no evidence was gleaned from Glastonbury but the Scottish investigations have revealed the use of mortice and tenon and simple check joints.

Although the Scottish, Swiss, Irish and English archaeology all reveal the diameter of crannogs, it is also interesting to compare wooden Celtic buildings with stone ones. During the PARABOW project, there was some opportunity to do this and comparative measurements were taken of Portuguese Celtic round houses in the Braga region of northern Portugal and Welsh Romano-Celtic buildings at Din Llygwy on Anglesey (Wales). The dimensions of the two stone examples were almost identical , 7.3 metres in Portugal and 7.4 metres In Wales and they also fell into the same diameter range as the wooden crannogs. PARABOW is not really about stone but it is an interesting observation that even with stonewalls, which can take a larger diameter roof, the Celts did not exceed a certain maximum for their round buildings. The use of stone as opposed to wood seems to have been a matter of availability, in Wales and Portugal, both wood and stone were available and it may be that the sites were more settled, permanent and free from the strife of warfare, it is also possible that the use of stone required more effort and reflected higher status. In the Scottish Hebrides, wood was not readily available and stone was used for crannogs as a matter of necessity.

Evidence from Loch Tay has shown that the Scottish Celts used reed, heather, broom and bracken as a roofing thatch. The reconstruction on Loch Tay has used reed to good effect so we decided to utilise the same for our Irish reconstruction but this was not until we had looked into the use of heather and broom at the "Highlands Vernacular Buildings Trust" (HVBT) at Newtonmore in Scotland.

When it came to deciding on construction technique and sourcing the material for our Irish crannog, we needed to be inventive without losing cultural integrity and heritage accuracy. We determined from the outset that our PARABOW crannog was going to be land based. The site we were offered by Newport Town Council in Co.Mayo was a children"s play area on the banks of the river flowing between Beltra Lough and Clew Bay, we did look at one or two lough sites but health and safety considerations and the time allowed were deciding factors. The Oakbank crannog took over 1 year to complete and involved driving the alder piles into the loch bed. The experience of having to do this in reality was a classic case of experimental archaeology. The Scottish team looked at and rejected various modern (oil rigg derived) techniques and finally, through experimentation, used cross members to "screw the heavy timbers into the mud by manpower alone and proved that the original Celtic builders (who could only have used a similar technique) were not just inventive and technically skilled but also a tough bunch ! We had the willing participation of German, English and Irish students, trainees and staff but decided that screwing 8-10 metre piles into a lough bed was beyond us. For similar reasons of finite resources we decided on a smaller crannog but still took some reassurance that Glastonbury crannog buildings were typically only 3 to 4 metres in diameter (the size we chose). The approach adopted also allowed us to proceed without the need for planning approval and building regulations.

We experienced some difficulty in the sourcing of suitable material. Although the Irish Celts lived on an Ireland which was covered in native hardwood forests, the Ireland of today with 7-8% forest cover is one of Europe"s most denuded countries in terms of woodland. Through the work of Jerry Hawe of Clark Mactavish and his network of colleagues in the Millennium Woodland Trust and Irish Coppice Society, we were able to access the ash roof poles and hazel withies but the oak was more problematic. Atlantic oak forest is a rare and threatened biotype in Ireland and although Clark Mactavish work extensively in the ancient woodlands of Brackloon (Westport) and Treanlaur (Newport), the small diameter and straight oak poles needed are not available in sufficient quantity to allow even limited removal. Our solution was to bring structural sessile oak poles from Celtic Cumbria in the north west of England, with the "Y" shaped tops, that we felt sure were used by crannog builders. When it came to sourcing reeds (Phragmites spp.), we were also challenged. Although Ireland has an abundance of this species on account of the wet climate, generally high water table and large areas of wetland, the reeds had not been harvested for many years and therefore contained too much dead and fragmented old growth. We ended up bringing our reeds from Scotland and used a source recommended by the Scottish crannog builders.

We then had to consider technique and the skills of our young worker resource. The Celts would have shaped their timbers with bronze or iron axes, also iron "billhooks", depending on the historical period; we decided to use iron edged tools (axes and billhooks). The Celts had saws which were toothed in such a way as to cut on the upstroke only and iron slashers which are rather similar to 20^th century farmers" "straw knives"; we used only hand tools but were advantaged by the use of handsaws which cut on both the up and down stroke.

The thatching also gave us pause for thought. The thatching method of today is thought to date from the Medieval period which uses a lot of reed bundles, "tarred marlin" (twine/rope) for tying the thatch to the roof poles, hazel thatching pegs, hand shears for reed cutting and a "leggit" for tapping the cut ends into an evenly curving roof shape. Nobody really knows what the Celtic method entailed but it was probably closer to the African, which uses far less material and requires more regular replacement. We did some research and met with Patrick Wallace of the National Museum of Ireland in Dublin. Although the major works of Mr Wallace relate to the Hiberno-Norse buildings of Viking Dublin, he has made interesting observations about 10^th century thatching…"the houses were thatched with straw, probably on a sod underlayer to which the thatch appears to have been fixed by pointed wooden pins or scallops (from the Irish word "scoilb"). Examples of scallops were found in association with sods and straw on the floors of the Fishamble Street buildings. The thatch probably oversailed the eaves as generously as the narrow space between buildings would have allowed" (p.7 The Viking Age Buildings of Dublin, vol. 1). Despite the lack of oversailed thatch representation on the Glastonbury sketches (which are not necessarily archaeologically accurate), we decided to oversail as Patrick Wallace suggested. With regard to the thatching method, we opted for the Medieval but did utilise the services of a Saxon age reconstructor from Bedes World in England. Our progress illustrated a reality of experimental archaeology, we could only use the skills and technique of "best fit" craft workers within the timescale – as long as this is recognised at the time, some integrity is maintained.

We did consider bark peeling the timber but Scottish evidence showed that this did not generally happen, so we used the greenwood in its raw form. Here is another example of a reconstructors quandary, we know today that peeled timber lasts longer because bark contains a lot of plant sugar so is more susceptible to rot but to undertake bark peeling would be doing something that we know the Celts did not do.

Before beginning work, we produced a sketch (see Fig. LIBBY PLEASE INSERT), which could not be described as an architects plan but did act as a guide to our willing young builders. The whole question of using architects work in ancient wooden building reconstruction, requires some discussion. PARABOW was pleased to avail itself of the services of Graeme Wylie, a skilled architect / archaeological illustrator, but we did this for ease of dissemination and guidance only rather than any admission that pre-Medieval builders bothered with plans. The work of A. Rappaport in House Form and Culture (1969) puts forward some valuable ideas…(ancient houses) …"are the result of the collaboration of many people over many generations as well as the collaboration between the makers and users of buildings, which have no need for drawings and architects".

We began our crannog in March 2000 and made decisions along the way – this seems to always be the case in reconstructing ancient buildings because no amount of pre-planning can prepare for the actuality. The soil on site was a stognogley brown earth and winter waterlogging would be a common occurrence followed by summer drying out; such soils are aerobic and have an active carbon and nitrogen cycle. There was little doubt amongst the team that the oak structural timbers and hazel/ alder "sails" on the wattle walls would rot quite quickly in this soil and we discussed how preservation might be assured. There has been some evidence that "charring" of wooden posts reduces rot because it produces dead and carbonated material which bacteria and fungi cannot colonise; charring was carried out in certain archaeological examples but it is uncertain if this was not an attempt at wood hardening rather than deliberate preservation. The Celts certainly do not seem to have applied anything to wood to prolong its life. In the end, we peeled the poles where they were to go into the ground but did no more; we accepted the fact that ancient wooden buildings rotted, in fact they were expected to rot and be repaired / replaced – they did not have the permanence of stone. This view was taken from Oakbank crannog in Scotland, where a regular repair programme is ongoing but is concentrated particularly in the early Spring after the ravages of winter; very probably, as the Celts repaired their crannogs each spring.

Our crannog site was in the town of Newport and close to the main road. As the pile of rough wood and reed was transformed into a replica ancient building, the excitement of the builders, Irish residents and tourists, increased. The general feeling was one of…."how can so much grow out of so little". Because we predicted that the weight of the thatch would be greater than the Celts would have experienced (the Medieval method we adopted uses much more reed because it was designed for a 40 year + lifespan), we had inserted a centre pole / roof tree and as the skeleton of the building took shape, it was a constant battle to retain a perfectly conical roof structure. We inserted the wall-plate poles into the "Y" shaped oak structural timbers but did not mortice the wattle into these but rather wove the structurals in as additional "sails"; this gave a very strong, continuous wall rather than one made of individual wattle panels. Evidence for the continuous rather than sectional wattle wall again came from the 10^th century Dublin Hiberno-Norse examples. We used leather bindings (there is much archaeological evidence for this) to lash roof poles to the wall plate and purlin/spars concentrically up the roof. We had not anticipated just how much leather was needed so soon had to start using spare tarred marlin from the Thatcher"s stores.

Once the wattle walls were completed, we had to make a decision about whether to daub them ? Remember that the Glastonbury examples were daubed but also there was no real evidence from Scotland where wool and moss pushed into cracks seemed to be the norm. At Glastonbury and later Saxon sites, there was evidence that storage buildings were never daubed – presumably to allow air to circulate and dry grain, etc. In the end we decided not to daub because…….

0. The wattle walls were attractive.

0. We wanted people to see the wattle and appreciate the use of wood in the overall structure.

0. Archaeologically speaking, there is no evidence that all wattle walls were daubed.

0. The Irish west coast climate is such that daub would require constant work to maintain it – we could not give such a commitment to ongoing maintenance given the finite funding for PARABOW.

Completion of the crannog took 2½ quite extensive weeks with the wooden structure only taking a week and then the complex thatching taking the remainder of the time. A very positive aspect of our reconstruction was that, apart from a small skilled core of PARABOW workers, all the other participants, 30 young German, English and Irish people, were doing this type of thing for the first time. To say it captured their collective imagination was an understatement; they were stimulated to enquire about the Celts and wanted to visit crannog sites in the neighbourhood. We took them to two ancient Atlantic oak woodlands in between building shifts and we could tell that they were looking at these woodlands in a very different way.