Wherries were large sturdy barge-like crafts built by the shell-clinker method (nail-fastened overlapping planks). The technique was similar to that used by the Vikings for their ships. Wherries had heavy hulls and pointed stems and sterns. During the C19 there was a decline of keels due to changing transport and coal shipping methods. Tyne Wherries were thus designed as more versatile, general purpose vessels for carrying raw materials and finished goods. They also acted as 'lighters' to ferry materials to and from visiting ships which had increased in size after 1850. At first they were propelled with long oars (sweeps) or punting poles and simple sailing rigs. Strings of wherries could be towed by paddle-tugs. In the later C19 many became self-propelled using small boilers and steam engines. Steam wherries were called 'puffers'. Typically wherries were some 50 feet in length and 25 feet beam and weighed 35-40 tons. Later they were even larger. Steam wherries usually had a small hand-operated deck crane. All wherries had a great open hold with short decks at either end, with accomodation for the crew beneath one of them. By the turn of the C20 over two dozen companies or individuals were operating wherries on the River Tyne (e.g. The Tyne Wherry Co. and Allen Brown Ltd (Lightermen)). Some major riverside industries ran their own wherry fleets (e.g. United Alkali chemical works and Cookson's lead refining works). After the First World War the number of wherries declined with the decrease in numbers of ships visiting the Tyne and the improvements in road-freight. After the Second World War many were abandoned at the riverside or cleared upriver by the Port Authority to a 'graveyard' above the head of navigation. By the 1970s only one Tyne wherry was left afloat - the Elswick No. 2, which had been launched in 1939. This was donated to the Maritime Trust and is now owned by Tyne and Wear Museums {'The Last Tyne Wherry - Elswick No. 2', factsheet by Tyne and Wear Museums}.