Figure 4.—Marestier's drawings of the Savannah's engine (from plate 7 in Withington's translation of the Marestier report). The graphic dimensions do not precisely correspond to the scale of dimensions in Marestier's text, nor with other recorded measurements.
Marestier's drawings of the engine and paddle wheels[8] are reproduced in [figure 4]. The nonoscillating engine is inclined toward the paddle-wheel shaft. The connecting rod operates a crosshead to which is pivoted a pitman, or oscillating rod, that operates the paddle-wheel crankshaft. Alongside the steam cylinder is an air pump cylinder, also connected to the crosshead. The steam inlet and outlet pipes enter a valve chest on top of the steam cylinder, which is described as being 1.035 meters (3.4 feet) in diameter, and of 1.5 meters (4.9 feet) in stroke.
The paddle wheels are shown as being of iron, with two fixed arms opposite one another on the hub. The other arms (four above and four below the fixed arms) are pivoted to the hub and held spread by chain stays. These eight blades fold, in pairs, to each of the fixed arms. The wheels are shown in elevation, with the upper pivoted arms folded on top of the fixed arms, and in cross section; the latter shows the shape of the buckets, hub, and outboard bearing of the shaft. The wheels are described as being 4.9 meters (16 feet) in diameter, while the buckets are 1.42 meters (4.65 feet) wide and 0.83 meters (2.72 feet) deep. The two outer corners of each bucket are snyed off at nearly 45°. The wheels are shown folded in the sketch; according to the description, they could be unshipped from the shaft and stowed on deck when desired. The method of removing the wheels from the shaft is not described, but from the drawings it seems probable that they were detached from the shaft by removing a lock bolt outboard and sliding the wheels off the square shaft. The hub seems adequate for this. Marestier states that this removal could be accomplished in 15 to 20 minutes; the logbook shows that it took 20 to 30 minutes to perform this operation at sea.
Marestier states that the ship had spencer masts and trysails on fore and main, and a spencer mast on the mizzen for a spanker; he illustrates these as having royal poles, but with no royal yards crossed.[9] The smokestack is described as pivoted. The mainstay is double, setting up at deck, near rail, and forward of the foremost shrouds of the foremast to clear the stack and foremast.
The boilers were in the hold, but Marestier gives no dimensions. However, he comments that, in American steamers, the space for steam in the boilers varied from 6 to 12 times the capacity of the cylinder. He gives the Savannah's boiler pressure as 2 to 5 pounds per square inch and the maximum revolution of the wheels as 16 revolutions per minute. The boilers could burn coal or wood. Judging by Marestier's sketch of the ship, the stack was at the firebox end; the boiler or boilers were underneath the engine.
The log of the Savannah gives little useful technical information other than that the ship readily made 9 to 10 knots under sail in fresh winds, showing she could sail well. Under steam alone the log credits the ship with a speed of 6 knots; Marestier estimated her speed at 51/4 knots in smooth water. The log shows that she usually furled her sails when steaming, though on a few occasions she used both steam and sail. In her crossing from Savannah to Liverpool she appears to have been under steam for a little less than 90 hours in a period of about 18 days (out of the total of 29 days and 11 hours required to cross). There is no evidence of any intent to make the whole passage under steam alone, for the vessel was intended to be an auxiliary, with sails the chief propulsion.
Captain Collins states in his notes that the ship was built by Francis Fickett as a Havre packet, that she stowed 75 tons of coal and 25 cords of wood, and cost $50,000. Apparently quoting Preble[10] to a great extent, he also states that the engine developed 90 horsepower and had a 40-inch diameter cylinder with a stroke of 5 feet.
Preble states that the ship was purchased for conversion to a steamer after launching and gives statements by Stevens Rogers, sailing master of the Savannah, to the effect that the ship was built as a Havre packet and that the project ruined financially one of the investors, William Scarborough. Rogers, who made these statements in 1856, also said the ship was built by "Crocker and Fickett." Contemporary newspapers, quoted by Preble, state that the ship had 32 berths in staterooms for passengers.
Morrison[11] credits the building of the Savannah to Francis Fickett and says she was intended for the Havre packet run. He states that the vessel cost $50,000; that her paddle wheels, each with eight buckets, were 16 feet in diameter; and that she had canvas wheel boxes supported by an iron frame. Morrison also relates the history of the ship after her return from Russia—the removal and the sale of her machinery to James P. Allaire, the operation of the ship as a sailing packet between New York and Savannah under the ownership and command of Captain Holdridge, and her stranding and loss during an east-northeast gale on November 5, 1821, at Great South Beach, off Bellport, on the south shore of Long Island. He also states that the steam cylinder of her engine was exhibited at the Crystal Palace Fair in New York during 1853, and that the ship proved uneconomical due to the large amount of space occupied by the engine, boilers, and fuel, leaving little space for cargo. Morrison apparently used some of the statements made in 1836 and 1856 by Stevens Rogers, who was the sailing master on the famous voyage.