German S-Boat ...  High speed German motor torpedo boat, at a length of 33mtrs and powered by 3 Daimler Benz marine diesel engines, she was capable of speeds up to 44 knots. Her armament consisted of 2 x 21 inch torpedo tubes with 4 torpedoes carried, 3 x 20mm cannons, 1 x twin and 1 x single along with a single 37mm flak cannon. The S in S boat stands for schnell, this meaning fast in German, the name given to these craft was Schnellboot (Fast boat).

J.P. Rennoldson, Builder of the Hull Trader. In 1850 after the death of his father, George Rennoldson, James Purdy Rennoldson took control of his fathers business which was founded in 1826, this being G. Rennoldson of South Shields. By 1837 G. Rennoldson were building locomotive engines along with marine engines, though in time marine engines were to become the foremost part of the firms business. By 1857 and under the control and new name of J. P. Rennoldson the firm had expanded into ship building and repairs at their North Shields yard. In 1863 an additional yard was aquired in South Shields, this being the former  Wallis yard at Lawe. The initial intention for the new yard was to construct and repair wooden vessels, however by 1874 the firm were constructing iron vessels. After the death of J.P. Rennoldson in 1878 the business was taken over by his to sons Charles and Joseph and renamed J.P. Rennoldson & Sons. In 1913 the two brothers parted ways with Joseph keeping control of the shipyard and engineering department and Charles opening a new shipyard (Charles Rennoldson & Co). After the death of Joseph  both the shipyard and engineering department was managed by his son-in-law Charles Ross. Due to the recession and lack of business the firm closed its gates for the final time in 1929.

Triple expansion engine (three phase) as fitted in the Hull Trader ...  Steam enters the high pressure cylinder (red) from the boiler and is expanded, this being phase one of the triple expansion process. Having lost pressure and heat the steam is then exhausted and expanded directly into the larger volume Intermediate pressure cylinder (yellow, phase 2). From here and once again having reduced in heat and pressure the steam is exhausted and expanded directly into the higher volume low pressure cylinder (blue, phase 3). From here it enters the condensor from the low pressure cylinder where it passes over cold water pipes within the condensor and is in turn taken back to its formative state, ie water and is then returned to the boiler for reuse. In using an engine of multipal expansion design, ie multiple cylinders of an increasing size it allowed for greater extraction of energy from a given amount of steam as it was utilised three times, this in turn reducing fuel consumption for a given vessel. Note, as can be seen to the left of each cylinder a valve can be seen opening and closing as it allows the steam in and out of each respectice cylinder. The valves in the model are driven by the crank via eccentrics, this particular design of valve workings being known as Stephensons valve gear.

Boilers ... The Hull Trader was fitted with two Scotch type single ended boilers . Each boiler was fitted with two plain furnaces. Note .. The boiler pictured is fitted with corrugated furnaces.