Messrs. Winans’ first cigar ship, though not fulfilling all the hopes formed of her, was, on the whole, sufficiently successful to encourage the continuance of the experiments, for in the two following years she was severely tested both for speed and seaworthiness in all sorts of weather. Another vessel was built at St. Petersburg in 1861 with a submerged screw propeller at the stern, which gave so much more satisfactory results than the revolving belt apparatus that Messrs. Winans were encouraged to order a third spindle ship. This was built by Mr. John Hepworth of the Isle of Dogs, and was named after her inventor, Mr. Ross Winans. This boat was 256 feet in length with a diameter and depth of 16 feet, and was circular in form throughout. The top of the vessel was strengthened for 130 feet amidships by four longitudinal ribs of steel which supported the deck, and also rendered the top as strong to resist tension and other strains as the bottom. Internally there were iron ribs running round the vessel 4 inches deep and 3 feet apart in the engine and boiler room, and 7 inches deep and spaced 6 feet elsewhere. The bottom and side plates were of iron, were thicker amidships than at the end, while the bottom was further strengthened and protected outside the skin plates by a plate of iron 1 inch thick and 33 inches across at its widest and diminishing to a point at the ends. The skin plates of the top were of toughened steel ³⁄₈ inch thick amidships. The two screw propellers, one at either end, were 22 feet in diameter and were only half immersed in the water, though it is difficult to imagine what advantages were supposed to be gained by incomplete immersion, seeing that the exposed part represented so much dead weight to be carried, to say nothing of the other drawbacks. A space 48 feet 6 inches long amidships was devoted to the engines and boilers. Each of the four boilers had a fire-box, and was surmounted by two vertical cylinders containing vertical tubes; while the centre portions of the boilers were tubeless to allow of more ready cleaning and a better circulation. A fan increased the draught and also the ventilation of the ship. The engines were surface-condensing. The problem of allowing the longest possible stroke was ingeniously solved. Above each of the three jacketed steam cylinders was a shaft, carrying two cranks and working by the sides of the cylinder, the piston-rods passing the shaft and connecting with a cross-head above, which was connected with the cranks by two rods. The three engines were joined by a system of return cranks and a peculiar coupling, which prevented cross-strains from the transmission of power from engine to engine, and from the shafts of the different engines getting out of line. The ship could carry coal for twelve days at normal consumption. On deck it carried two masts and two funnels, all having a considerable rake aft.