English: Profile (top) and longitudinal vertical section (bottom) of SS Great Britain, showing her interior layout and deck plan. Key to symbols in bottom image as follows (from Claxton, p. 6): A–B: Surface line of upper deck. C: Aft or promenade deck. D (looks like an "O" on the diagram): First class or dining saloon. E: Cargo deck. F: Iron fresh water tank. G: Coal store. H: Elevation of engines. I: Ditto of boiler. J–J: Iron deck over boiler, for cooking apparatus. K: Fore or second class saloon. L: Lower fore saloon. M and N: Iron-floored cargo decks. O: Air chamber from boiler to bulkhead, of the shape of the ship. P: Officers' berths. Q: Sailors' mess room. R: Sailors' berths; r: Small water tank. S: Water closets. T: Ship's stern post, through which the screw passes. U: Drive shaft, from engine to screw. V: Diagonal stay from the ship's side to the stern post. W: Side view of screw stern post, in which the end of the screw spindle revolves. X: Keel under the screw, uniting the stern post to the vessel. Y: Hollow rudder foot, and of such a thickness to receive the stern post, which forms its pivot.