The technology and economics of water-borne transportation systems in Roman Britain

The thesis examines a number of questions concerning the design, construction, costs and use of Romano-British seagoing and inland waters shipping. In the first part the reasons for the methods of construction for seagoing and coastal vessels, such as the Blackfriars Ship 1, the St. Peter Port Ship and the Barland's Farm Boat, have been investigated. The constructional characteristics of the two ships are massive floors and frames, with the planking fastened only to the floors and frames with heavy clenched iron nails. There is no edge to edge fastening of the planks, with tenons inserted into mortises cut into the edges of the planks, as is normal in the Mediterranean tradition of ship construction in the Roman period. The Romano-British ships also differ from the Scandinavian tradition of clinker building with overlapping planks nailed to each other along their length. It has been concluded that a natural phenomenon, the large tidal range around the British Isles and the northern coasts of Gaul and Germany, had a dominant effect on the design of seagoing vessels. Deep water harbours, such as Portus, Caesar ea Maritima and Alexandria in the Mediterranean, where ships could lie afloat at all times, were neither practicable nor economic with the technology available. At the British ports, such as Dover, London and Chichester, ships had to come in with the high tide, moor to simple wharves at the high tide level, and then settle on the ground as the tide dropped. At the numerous small havens, inlets and estuaries around the British coasts, ships would come in with the tide, settle on a natural or man-made 'hard' as the tide fell, and discharge cargo over the side to carts, pack animals or people. This mode of operation required sturdy ships that could take the ground without damage, and also withstand a certain amount of 'bumping' on the bottom in the transition period from fully afloat to fully aground. The second part of the thesis investigates the cost of building, maintaining and operating various types of vessels. To do this, a new mode for measuring cost, the Basic Economic Unit, or BEU, has been developed. The probable volume of the various types of cargoes carried has been examined. It appears that grain was the dominant cargo in both coastal and overseas traffic. The total cost of building, maintaining and operating the seagoing and inland water shipping was less than one percent of the gross product of Britain, a small cost for an essential service.Arts, Faculty ofClassical, Near Eastern and Religious Studies, Department ofGraduat