Tom Pudding - Development

Development

On 20 May 1861, Bartholomew met with Mr. Wilson and Mr. Warde-Aldam, the company chairman, and they discussed the possibility of using iron compartments, which would be filled with coal, and emptied by a hoist at Goole. Bartholomew thought that a compartment holding 30 tons would be ideal, although Warde-Aldam recommended 25 tons. The plan was to use six compartments, sandwiched between a bow and a stern compartment, which would be towed like a conventional boat. The hoist would be hydraulic, and they were already considering the introduction of hydraulic power at Goole to operate the locks. On 20 December 1861, a board meeting authorised the expenditure of £13,382, which would include three 'train boats' costing £1,100 each, a hoist at £2,500, and the hydraulic equipment to operate both the lock and the hoist.

By the time Bartholomew had obtained a patent on 7 February 1862, the plans had developed somewhat, as the design now included a steam-powered pusher tug instead of the stern compartment, and included chains which ran the length of the train to enable it to be steered. He had no idea how the boat would behave when afloat, and so the detailed design work was give to Hudswell and Clarke of Leeds, while the design of the hoist was the responsibility of William Armstrong and Co. Ltd. The original plan was to use doors in the side of the compartment to unload the coal, which would require it to be hoisted some 35 feet (11 m) upwards to allow the coal to discharge into a coaster. Although Hudswell and Clarke may have built one compartment with side doors, and several designs were contemplated, the engineer at Armstrong's suggested that a better solution would be to raise the compartments in a cage, which could then be tipped right over, so that the coal was emptied out of the top of the boat. This they thought would only require the compartment to be raised by 25 feet (7.6 m), and so the hoist would be cheaper to build. By September 1863, the Aire and Calder had taken delivery of six compartments and a stern tug, but the bow section was missing, and construction of the hoist had not begun. Warde-Aldam expressed some concern, as the handling of such a boat was still unknown.

Warde-Aldam's fears were unfounded, as by the end of the year trials with the complete boat were sufficiently successful that an order was placed for more units. Each tug and bow section would have three sets of six compartments, so that one could be loading, one unloading, and the third could be in transit. Steering of the boat was controlled by the chains running down both sides of the assembly, which were connected to two steam-operated pistons on the tug. In order to keep the compartments in line, each had a projecting stem post, which fitted into a recess in the back of the next compartment. The hoist was eventually tested on 4 February 1864, and full trials began in August of that year. Operation of the hoist was deficient, and the two small hydraulic cylinders which powered it were replaced by one much larger one. Subsequent hoists had two large cylinders, and the hydraulic pressure was increased from 750 pounds per square inch (52 bar) to 825 pounds per square inch (56.9 bar) and finally 900 pounds per square inch (62 bar). Having handled 1,198 tons of coal during the trials, the system was operational by the beginning of 1865.