Figure 11.—Model lines redrawn to outside of plank to show hydrodynamic form of the Steam Battery.
Though the double canoes of the Pacific Islands were probably known to some in Europe in 1662, there is no evidence that Petty based his designs on such craft. He appears to have produced his designs spontaneously from independent observations and resulting theories. Before Petty concluded his experiments, a number of double-hull craft had been produced by others; however, some “double” craft, such as “double shallops” may have been “double-enders,” as shown by a “double-moses boat” of the 18th century and later. [16]
The use of two canoes, joined by a platform or by poles was common in colonial times; in Maryland and Virginia, dugouts so joined were used to transport tobacco down the tidal creeks to vessels’ loading. Such craft were also used as ferries. M. V. Brewington’s Chesapeake Bay Log Canoes [17] and Paul Wilstack’s Potomac Landings [18] illustrate canoes used in this manner. A catamaran galley, two round-bottom hulls, flat on the inboard side (a hull split along the centerline and the inboard faces planked up), 113 feet long and each hull a 7-foot moulded beam, 6-foot 6 inches moulded depth, and placed 13 feet apart, was proposed by Sir Sidney Smith, R.N., in the 1790’s, and built by the British Admiralty. Named Taurus, she is shown by the Admiralty draught to have been a double-ender, with cabins amidships on the platform, an iron rudder at each end (between the hulls) steered with tillers (to unship), and with a ramp at one end. The plans are undated, signed by Captain Sir Sidney Smith, and a field-carriage gun is shown at the ramp end of the boat. This, and the heavy rocker in the keels, suggests the Taurus was intended for a landing boat. No sailing rig is indicated, but tholes for 12 oars or sweeps on each side are shown. The oarsmen apparently sat on deck, or on low seats, with stretchers in hatches between each pair of tholes (Admiralty Collection of Draughts, The National Maritime Museum, Greenwich, England).
Figure 12.—General plan of the Taurus, a catamaran galley gunboat proposed by Sir Sidney Smith, R.N., to the British Admiralty in the early years of the French Revolution. From the Admiralty Collection of Draughts, National Maritime Museum, Greenwich.
Another experimenter with the double-hull type of vessel was a wealthy Scot named Patrick Miller who was particularly interested in manual propulsion of vessels, employing geared capstans to operate paddle wheels. In a letter dated June 9, 1790, Miller offered Gustav III of Sweden a design for a double-hulled 144-gun ship-of-the-line (rating as a 130-gun ship) propelled by manually operated capstans connected to a paddle wheel between the hulls. She was rigged to sail, with five masts and was to be 246 feet long, 63 feet beam, and 17 feet draft; the hulls were 16 feet apart.
This project was submitted by the King to Fredrik Henrik af Chapman, the great Swedish naval architect, who made an adverse report. Chapman pointed out in great detail that the weight of the armament, the necessary hull structure, the stores, crew, ammunition, spars, sails, rigging and gear, would greatly exceed Miller’s designed displacement. He also pointed out the prime fault of catamarans under sail—slow turning in stays. He suggested that the speed under sail would be disappointing. He doubted that a double-hull ship of such size could be built strong enough to stand a heavy sea. He remarked that English records showed that a small vessel of the catamaran type had been built between 1680 and 1700 which had sailed well (this may have been one of Petty’s boats), and that “36 years ago” he had seen 8 miles from London, a similar boat that had been newly built by Lord Baltimore and was about 50 feet long; this was a failure and was discarded after one trial. Therefore, said Chapman, the Miller project was not new but rather an old idea. Chapman’s final remark is perhaps the best illustration of his opinion of the catamaran, “Despite all this, two-hull vessels are completely sound when the theory can be properly applied; that is in vessels of very light weight, and of small size, with crews of one or two men.”
A “model” of such a double-hull ship—the Experiment, built at Leith, Scotland, in 1786 by J. Laurie—was sent to Sweden by Miller. She was 105 feet long, 31 feet beam, and cost £3000. This vessel arrived in the summer of 1790 and King Gustav in a letter dated July 26 ordered Col. Michael Anckerswärd to welcome the vessel at Stockholm. The King presented Miller with a gold snuffbox and a painting was made of the vessel. The Experiment had five paddle wheels in tandem between her hulls, operated by geared capstans on deck. These gave her a speed of 5 knots but caused the crew to suffer from exhaustion in a short time. The vessel was badly strained in a storm and was finally abandoned at St. Petersburg, Russia.[19]