Model of a Chain Pump

Model of the cross-section of a ship at the level of the mainmast, with four decks and a chain pump. The pump consists of a chain of buckets that are led down along a pump pipe to the keel and come up again along another pipe; on the upper deck they pass over a pentagonal wheel, which is driven by a crank and flywheel. The four decks are partially planked and are supported by deck beams, which are provided with eight different hollow metal knees: some are nailed to the wooden knee they cover, others to the waling, some in the deck beam, others in the deck planks. Scale 1:20 (according to Obreen).