Robert Fulton and the Submarine

by William Barclay Parsons

The Nautilus, defective as she was in many particulars which Fulton admitted, clearly demonstrated certain facts: firstly, that a boat could be made to plunge and rise at will; secondly, that it could remain under water with a crew of three men for several hours; thirdly, that it could be manoeuvered and steered by the compass under water as well as on the surface. These features are the essence of the principle of successful submarine practice, and so much Fulton accomplished.

It is a far cry from a little vessel like the Nautilus, no bigger than a ship’s boat that is carried at the davits, to a modern submarine capable of keeping the seas for many weeks, of crossing and recrossing the ocean without replenishing either stores or fuel, and of carrying not only torpedoes and apparatus for their discharge but also a 12–inch long-range gun firing a projectile weighing nearly one-half ton. Except as to size, which is not really a basic feature of principle, the modern submarine differs from Fulton’s proposals in that it possesses an engine actuated when on the surface by a fuel (oil) whose activity can be instantly stopped preparatory to plunging, and by a power (electric storage battery) that neither generates heat nor vitiates the air while submerged. For that combination of motive power the world had to wait another hundred years.

The Nautilus, as a matter of fact, was something vastly more than a toy or experimental model. It possessed real offensive powers, and a fleet of them, as Fulton proposed and as the British navy officials feared, would have been able to do real havoc. In estimating the offensive power of Fulton’s design, the picture of the modern submarine must be kept out of sight. The latter is called on to meet conditions of mechanical development and types of hostile vessels that are as much in advance of those existing when Fulton lived, as is the complicated mechanism of a present-day submarine over the hand-driven propeller proposed by him.

At the beginning of the last century, a ship-of-the-line was a very unwieldly affair. She was bluff bowed and high sided and consequently could be handled satisfactorily only when “off the wind.” Even under these favorable conditions, speed was comparatively slow. With a light wind, especially with a light adverse wind, she could make but little headway. Such a wind rendered capital ships practically helpless. That they were not destroyed by the opposing force was because at such times the opposing force was helpless too. A boat that had offensive power of attack and had means of locomotion enough to overcome tidal currents would have been an effective menace. As Fulton pointed out, the only measure of defense by a large vessel at anchor would lie in a cordon of small boats. But a boat fully, or even partially, submerged would have had an excellent chance to get through a cordon and destroy her prey. In spite of the limitation of speed and cruising range that today would condemn any such boat as absolutely worthless, these limitations were sufficiently generous when compared with the status of naval architecture that prevailed in 1800–1806 to make Fulton’s submarine, when he proposed it, a factor of actual and positive value.

If that can be said of the Nautilus, all the more it is true of the design that he submitted to the British Government. Between the Brest experiments in 1801 and his proposals in 1804, as evidenced by his “Drawings and Descriptions,” it is clear that he had given the matter considerable thought and to some purpose. The specifications as submitted to the British agent called for a boat 35 feet long and 10 feet beam as compared with the similar dimensions of the Nautilus of 21 ft. 3 in. and 6 ft. 4 in., respectively, giving at least three times the tonnage. It was to carry a crew of six instead of three men with provisions sufficient to enable her to be kept at sea for 20 days. The offensive capacity was 30 submarine bombs (or mines) as against a single trailing one with the Nautilus. The vessel designed for the British Government was a real sea-going boat that could independently navigate the Channel while the little Nautilus could not venture far from land or from some large vessel acting as a base.

An examination of the details, particularly those on Plates First and Second will disclose many improvements over the French prototype, shown facing page 26. In the first place the hull is that of a seagoing boat, equipped with a well-developed sail plan for propulsion when on the surface and not the queer contraption that the French marine architects condemned. On the surface this boat could have been handled as easily and she would have sailed as fast as any sloop of the same size. The mast could have been laid back on the deck and the sails disposed of in a few minutes preparatory to plunging.

To plunge and again come to the surface of the water, ballast tanks, sea valves and hand pumps provided ample facilities readily to overcome or restore excess of buoyancy. The brass cylinder with the hemispherical ends would suffice to withstand the exterior hydrostatic pressure. The required thickness of shell was a matter of computation, one readily made with certainty even in those days.

The difficulty with all early submarines was motion beneath the surface. In the British plan, Fulton proposed to obtain motion by a manually operated crank turning a propeller. The boat was larger than the Nautilus, but so also would have been the crew. For short distances he could undoubtedly have driven the boat at his estimated speed. The propeller was a two-bladed affair of modern type. Fulton had now definitely abandoned the full helical or Archimedes screw that Bushnell used and which he had himself tried in his first experiments.

Reference to Plate First and its description will show, however, an exceedingly interesting addition that Fulton had made in the British boat. He reasoned correctly that a propeller when not turning would cause a considerable drag to the boat when sailing, and thus reduce her speed. He, therefore, arranged that his propeller could be folded so as to lie horizontally. This he proposed to do by a hand crank and gearing operated from within the boat. On Plate Seventh it will be seen that the propeller when folded lay well above the water surface and so would not have been an impediment to the motion of the boat. When it is recalled that the propeller was not generally adopted as a means of vessel propulsion until after 1845, when the steamship Great Britain crossed the ocean between England and New York, the first vessel driven by a screw propeller to accomplish the feat, and that a propeller that could be folded or hoisted above water was not introduced until about 1850, because at that period steam was merely an auxiliary to sails, it will be seen how far ahead of his time Fulton was in the design that he made in 1804.

Another radical innovation was a horizontal propeller, Marked B in Plate First, attached near the bow of the boat. This propeller, also actuated by a crank from within the boat, was to give the boat vertical motion when submerged and so enable it to be kept at any depth that might be desired. This principle of the horizontal propeller is that of the helicopter, the device now being experimented with by airplane designers in order to give planes a vertical motion or permit them to hover stationary in the air. It was precisely those same results in the water that Fulton undertook to accomplish with his submarine.